2011 International SWAT Conference & Workshops The use and results of the Soil and Water Assessment Tool in Brazil: A review from 1999 until 2010 Luis H. P. Garbossa, PhD in hydraulics and sanitation Santa Catarina Agricultural Research and Extension Corporation – Epagri/Ciram – Florianópolis, SC, Brazil. E-mail: [email protected] Luiz R. C. de Vasconcelos, undergraduate student of Sanitary and Environmental Engineering Santa Catarina Federal University – UFSC – Florianópolis, SC, Brazil. E-mail: [email protected] Katt R. Lapa, PhD in hydraulics and sanitation Santa Catarina Federal University – UFSC – Florianópolis, SC, Brazil. E-mail: [email protected] Éverton Blainski, PhD in agronomy Santa Catarina Agricultural Research and Extension Corporation – Epagri/Ciram – Florianópolis, SC, Brazil. E-mail: [email protected] Adilson Pinheiro, PhD in Water Resources Blumenau University – Furb – Blumenau, SC, Brazil. E-mail: [email protected] Abstract The Soil and Water Assessment Tool (SWAT) is becoming a familiar tool for some Brazilian students, professors and professionals. The model has been applied for several hydrological studies and evaluations under Brazilian conditions. This research was carried out with the objective of identifying the SWAT model applications in Brazilian watersheds, its strengths, and its weaknesses. Over 70 publications such as theses, dissertations and articles about the use of the model in Brazilian watersheds were analyzed. From these, 60 are referred to in this paper. Despite the significant variability of climates and hydrological behaviors of the modeled watersheds, the results provided by the papers demonstrate that the model had good performance in several Brazilian regions. Based on the papers’ results, it is also possible to identify that the SWAT performance in Brazilian watersheds permits its use as a support decision tool for municipalities, state companies, federal institutions, basin committees, and environmental organizations. However, there are very few reports about using the SWAT as a practical assessment tool in Brazil. Furthermore, there is some evidence that the hindrance to use SWAT in Brazil is not whether the model can be used here or not, but how to obtain enough quantity and quality data to simulate a basin. Keywords: SWAT, Brazil, review, application. 2011 International SWAT Conference & Workshops Introduction The approval of the Brazilian National Water Resources Policy in the year of 1997 demands tools to support decision making. The researchers, engineers and professionals involved with the water resources management were facing the need for the development and improvement of these tools. The hydrological and quality water models are these tools, and one of these models is the SWAT. This model allows the simulation of hydrological processes, sediments production and transport, and nutrients and pesticides cycling. Moreover, it is possible to simulate different scenarios of water availability for climate changes, which is one of the objectives of the CLIMASUL project (Study of the climatic changes in southern Brazil), supported by MCT/Finep-CNPq. The project involves universities and research institutions from three southern Brazil States: Paraná, Santa Catarina and Rio Grande do Sul. The CLIMASUL project aims to evaluate the effects of climate changes in experimental watersheds using the SWAT model with input data from HadRM3P regional climate model. The SWAT is becoming a familiar tool for some Brazilian students, professors and professionals. The model has been applied in several hydrological studies and evaluations in Brazilian watersheds. One of the first registers found of the use of the Soil and Water Assessment Tool (SWAT) in Brazil dates from 1999. Since then, the model has been used in several academic studies in various Brazilian regions. It is possible to find articles published in scientific journals, meetings and conferences. Over 70 publications were found as theses, dissertations and articles about studies applying SWAT in Brazilian watersheds. Despite the growing use of deterministic hydrological models in Brazil, the use of the SWAT was restricted mainly to researches in academic studies. These studies focused mainly on the capacity of the model to represent Brazilian watersheds adequately. There are few reports on the use of the model for practical applications by environmental companies, private and governmental institutions. Therefore, this situation is beginning to change with studies that will use SWAT for environmental assessments. There is, for instance, a study of the influence of the water contribution from watersheds in the Florianópolis Bay and its influence on shellfish production. The SWAT will be used to simulate the contributing watersheds streamflow. This paper aims to present the uses of the SWAT model in Brazil in the past twelve years, the results obtained using the model, the regions where the model has been applied, the main results obtained, and the viability of using the model in Brazil. SWAT published papers in Brazil from 1999 until 2010 This survey has identified several papers from master theses and doctoral dissertations, to congress and seminars publications to scientific papers about the use of SWAT in Brazil. The year of 1999 was defined as the starting survey date due to the information availability. Furthermore, it was identified that one of the first reports on the SWAT use in Brazil was made by Oliveira (1999). The theses and dissertations presented as bibliographical reference were used just when no article was found. For this study 74 publications about the use of SWAT in Brazil were found. From these, 60 are presented in this paper and 52 publications are reported in Table 1. The publications that are found but not presented here correspond to 14 theses and dissertations that are already reported in papers. The studies applied SWAT for several watershed sizes, topographic conditions and different climate regions in Brazil. The smallest watershed modeled has approximately 1.2 km2 and is located in Rio Grande do Sul, and the largest one has 29,000 km2, and is located in the State of Mato Grosso. 2011 International SWAT Conference & Workshops The focus of most studies was to verify the viability of using SWAT in Brazil. Most of the papers presented the data source used as input data, the calibration and validation results and the main conclusions about its applicability. For this study an indicator was created in order to separate the studies in three indicators. These indicators correspond to studies focused on streamflow, sediments, and nutrients. Figure 1 presents a summary of the proportion of studies in each class and the quantity of studies developed in the past twelve years. Indicator Years 2% Streamflow 16% Nutrients 1999 2003 2004 2005 2006 2007 2008 2009 2010 8% Sediment 4% 25% 17% 41% 15% 43% 13% 10% (a) 6% (b) Figure 1. Percentage of each indicator (a); distribution of the SWAT publications for the period (b). It is assumed that studies that have used the model to simulate sediments have already simulated streamflow, even if not presented. Moreover, it is assumed that studies that presented nutrients results have already simulated streamflow and sediments, even if not presented. It is possible to identify in Figure 1(a) the percentage of studies for the three indicators. Almost half of the studies have modeled streamflow and sediment. In Figure 1(b) it is possible to identify that, besides the year of 2005, the years of 2009 and 2010 are the ones with the largest number of publication about SWAT in Brazilian watersheds. This is a strong indication of the growing use of the SWAT model in Brazil. Based on the information gathered in the consulted bibliographical reference it was possible to identify the Brazilian territory where SWAT applications were made. Figure 2 is a map of Brazil with the location of the studies developed. The States of São Paulo, Santa Catarina, and Paraná are responsible for 51% of the SWAT papers, distributed as 19%, 16% and 16%, respectively. The South region of Brazil, which is composed of Paraná (PR), Santa Catarina (SC) and Rio Grande do Sul (RS), is responsible for 42% of the published studies. The second region that publishes the most studies is the Southeast (São Paulo (SP), Rio de Janeiro (RJ), Minas Gerais (MG) and Espírito Santo (ES)), with 32%. The state with the most studies of water quality is Paraná, which is the same state where practical applications of the model were found. 2011 International SWAT Conference & Workshops Figure 2. Map of Brazil with states, number and indicator of SWAT modeled watersheds. Table 1 summarizes some information about SWAT use in Brazil. The tabulation was based on the model presented by Gassman et al. (2007). This table model was chosen because it makes it possible to compare the results obtained in Brazil with other world basins. This table was organized by year of paper publication and by alphabetical order. Several studies presented statistical calibration and some others presented graphical statistics. The two statistical parameters chosen to be present in Table 1 are NSE (Nash-Sutcliffe Efficiency Index) and R2 (Coefficient of Determination). Some of the other statistical parameters presented in the papers are detailed in this text. Table 1. Published papers using SWAT in Brazilian watersheds from 1999 until 2010. Reference Year 1 Oliveira and Medeiros 1999 2 Barsanti et al. 2003 3 Garrido 2003 4 Machado and Vettorazzi 2003 5 Machado et al. 2003 6 Minoti et al. 2004 7 Silva et al. 2004 8 Baldissera 2005 9 Coelho et al. 2005 10 Neves et al. 2005 11 Oliveira et al. 2005a 12 Oliveira et al. 2005b 13 Pereira et al. 2005a 14 Pereira et al. 2005b 15 Prado et al. 2005 16 Silva et al. 2005 17 Armas 2006 Watershed (location) Joanes River (Bahia) Taquarizinho river Aquidauana river Jiquiriçá river (Bahia) Marins river (São Paulo) Marins river (São Paulo) Guabirobas river (São Paulo) Canchim river (São Paulo) Cuiabá river (Mato Grosso) Piraquara river (Paraná) Bonito river (São Paulo) Salitre river (Bahia) Salitre river (Bahia) Jiquiriçá river (Bahia) Jiquiriçá river (Bahia) Jundiaí-Mirim river (São Paulo) Bonito river (São Paulo) Corumbataí river (São Paulo) Drainage Area (km²) Indicator Time Period C = calib. V = valid. 1993-1995 1997-2002 Best NSE and R² C = Calibration V = Validation Daily Monthly Annual C: 0.61 and 0.79 C: 0.58 and 0.82 C:-1.03 and 0.23 V: -65.9 and 0.37 - 755.40 Streamflow sediment 1,500.00 15,200.00 Streamflow 6,900.00 Streamflow 59.73 Sediment C: 1999-2000 - C: 0.83 and 0.92 - 59.73 Streamflow C: 1999-2000 - C: 0.92 and 0.94 - 54.12 Sediment 1999-2003 - - - 15.00 Sediment 1999-2003 - - - 29,000.00 Streamflow C: 1994-1998 - C: 0.77 and 0.81 - 100.00 Stream flow Water Quality C: 1984-1998 - - C: - and 0.83 - - 223.00 ---- 1992-2004 - - - 13,470.00 Streamflow C: 1969-1972 - C: - and 0.80 - 13,470.00 Streamflow C: 1977-1979 V: 1969-1973 - C: - and 0.88 C: - and 0.70 - 6,900.00 Streamflow C: 1993-1995 - - - 6,900.00 Streamflow C: 1993-1995 V: 1997-2002 C: -2 and 0.37 V: -49 and 0.51 - - 120.15 Sediment - - - - 47.17 Sediment 1992-2004 - - - 1,710.00 Streamflow C: 1973-1984 V:1985-2003 - C: 0.94 and 0.94 V: 0.84 and 0.92 C: 0.89 and 0.93 V: 0.27 and 0.67 2011 International SWAT Conference & Workshops N Reference Year 18 Bittencourt and Gobbi 2006 19 Moro et al. 2006 20 Neves et al. 2006 21 Paiva and Paiva 2006 22 Silva et al. 2006a 23 Silva et al. 2006b 24 Machado et al. 2007 25 Rodrigues and Reis 2007 26 Roloff et al. 2007 27 Adriolo et al. 2008 28 29 Lopes and Kobiyama Lopes and Kobiyama 2008a 2008b 30 Lopes et al. 2008 31 Marchioro 2008 32 Blainski and Garbossa 2009 33 Gibertoni et al. 2009 Watershed (location) Piraquara river (Paraná) Marins river (São Paulo) Bonito river (São Paulo) Menino Deus I (Rio Grande do Sul) Canchim river (São Paulo) Beija-Flor/Jataí river (São Paulo) Marins river (São Paulo) Coruripe river (Alagoas) Toledo river Ajuricaba river (Paraná) Apucaraninha river (Paraná) M2 Experimental (Santa Catarina) M2 Experimental (Santa Catarina) M2 Experimental (Santa Catarina) Santa Maria river (Rio de Janeiro) Araranguá river (Santa Catarina) Antonina Bay (Paraná) Drainage Area (km²) Indicator Time Period C = calib. V = valid. 58.00 Streamflow Phosphorus 1998-2002 59.73 Sediment 1999-2000 - - - 223.00 Nitrogen Phosphorus 12 years period - - C: 0.76 and C: 0.74 and - 18.00 Streamflow 1996-1998 C: - and 0.54 C: 0.88 and 0.88 - 15.00 Nitrogen Phosphorus 1993-2004 1993-2004 - - C: 0.79 and C: 0.80 and - 110.00 Sediment - - - - 59.73 Sediment 1999-2000 - C: 0.78 and - - 1,562.00 Sediment 2004-2006 - - - 65.00 16.50 Streamflow, sediment and quality 1998-2004 - - - 504.00 Sediment C: 2000-2005 V: 1988-1999 C: 0.20 and V: -2.36 and - C: 0.42 and V: 0.62 and - - 8.56 Streamflow C: 2007 C: 0.23 and 0.51 - - 8.56 Streamflow C: 2007 C: 0.23 and 0.51 - - Streamflow Sediment Streamflow Sediment C: 2006-2007 - C: - and 0.59 - - C: 2006-2007 - C: 0.72 and C: -6.11 and - 3,000.00 Streamflow C: 2005-2007 - C: 0.72 and - - C: 1975-1991 V: 1992-2007 C: 0.42 and 0.47 V: 0.53 and 0.54 ------------------C: 0.41 and 0.42 V: 0.52 and 0.49 C: 0.81 and 0.65 V: 0.74 and 0.72 ------------------C: 0.94 and 0.63 V: 0.92 and 0.70 - 1,597.00 Streamflow ----------------Sediment 8.56 13.50 Best NSE and R² C = Calibration V = Validation Daily Monthly Annual C: - and 0.82 - - - 2011 International SWAT Conference & Workshops N Reference Year Watershed (location) Drainage Area (km²) Indicator Time Period C = calib. V = valid. 34 Lino et al. 2009 Preto river (Santa Catarina) 1,000.00 Streamflow C: 1993-1997 - C: 0.51 and - - 35 Lubitz 2009 Concórdia river 30.74 Streamflow Sediment Nutrients 2006-2009 C: 0.32 and C: -0.03 and * C: 0.88 and C: 0.84 and * - 36 Paim and Menezes 2009 2,840.00 Streamflow 1991-2001 - C: 0.73 and 0.95 - 37 Souza et al. 2009 788.00 Streamflow C: 1994-1998 - C: 0.72 and - - 38 Uzeika 2009 C: 2002-2006 C: 0.79 and C: -5.58 and - C: 0.84 and C: -6.53 and - - 39 Xavier 2009 1994 - - - 40 Baltokoski et al. 2010 - C: 0.70 and C: 1.00 and - - 41 Blainski et al. 2010 C: 0.85 and 0.85 - 42 Blainski et al. 2010 43 Bonumá et al. 2010 44 Fontes et al. 2010 45 Garbossa et al. 2010 46 Guimarães et al. 2010 47 Lelis and Calijuri 2010 48 Pereira et al. 2010 Tijucas river (Santa Catarina) A. Negro river (Santa Catarina) Arvorezinha (Rio Grande do Sul) Manso river (Mato Grosso) Conrado and Pinheiro rivers (Paraná) Araranguá river (Santa Catarina) Lajeado dos Fragosos river (Santa Catarina) Arroio Lino (Rio Grande do Sul) Jacuípe river (Bahia) Lajeado dos Fragosos river (Santa Catarina) Riacho dos Namorados (Paraíba) São Bartolomeu river (Minas Gerais) Cachoeirinha (Minas Gerais) 1.19 10,553.00 Stramflow Sediment Streamflow Sediment 52.97 Streamflow Phosphorus 2003-2005 3,000.00 Streamflow C: 2005-2007 59.00 Streamflow Sediment C: 1999-2009 - 3.20 Streamflow Sediment 2004-2005 1,895.00 Streamflow C: 1966-1974 V: 1975-1982 59.00 Streamflow 13.00 Best NSE and R² C = Calibration V = Validation Daily Monthly Annual - - C: 0.73 and - V: 0.55 and 0.74 V: 0.57 and -0.33 - V: 0.87 and 0.90 V: 0.70 and 0.77 C: 0.84 and 0.71 V: 0.63 and 0.39 - C: 1999-2009 - C: 0.73 and - - Streamflow 1993-2006 - - - 54.22 S. Runoff Sediment 2006-2008 - - - - Sediment 1979-2008 - - - * Due to table organization, the nutrients statistical parameters are presented in the text. 2011 International SWAT Conference & Workshops N N Reference Year Watershed (location) Drainage Area (km²) Indicator Time Period C = calib. V = valid. 49 Santos et al. 2010 Apucaraninha river 504.00 Streamflow ----------------Sediment 1988-2005 50 Schultz et al. 2010 788.00 Streamflow Sediment 1994-2004 51 Souza et al. 2010 - Streamflow 2003-2006 C: 0.84 and - - - 52 Trindade et al. 2010 85.00 Nitrogen Phosphorus 1999-2007 - - - A. Negro river (Santa Catarina) Tocantins-Araguaia sub-watershed (Tocantins) Experimental (Espírito Santo) Best NSE and R² C = Calibration V = Validation Daily Monthly Annual C: 0.73 and V: 0.78 and ----------------------------------C: 0.20 and C: 0.42 and V: -2.36 and V: 0.62 and C: 0.71 and C: 0.38 and C: 0.86 and - 2011 International SWAT Conference & Workshops 2011 International SWAT Conference & Workshops Observing the statistical results presented in Table 1 it is possible to identify in the studies that the model runs for monthly average outputs is normally adequate to represent the watersheds. It is possible to identify that these results were obtained for different watershed sizes and locations. However, there is great variation in the model performance when evaluating the model output statistics on a daily basis. Most of the studies have a poor representation of the watershed when evaluating the statistical parameters on a daily basis. This can be identified for both small and large watersheds. There is little statistical evaluation to validate the presented modeled watersheds. Probably this is because of the lack of information and sufficiently long datasets. Brazilian data sources used for SWAT modeling In this chapter the focus is to verify the data sources used in order to obtain the necessary information to run the model. In Brazil there are some national institutions that have some of the information needed. The main national institutions are ANA (National Water Agency), ANEEL (National Agency for Electrical Energy), Embrapa (Brazilian Agricultural Research Corporation), (IBGE) Brazilian Institute of Geography and Statistics, INMET (National Institute of Meteorology), and INPE (National Institute for Space Research). ANA owns the daily basis national network database for precipitation, streamflow, sediment, and water quality. Besides that, the papers report several state institutions, universities and private companies monitoring databases. These databases are from watersheds of interest and experimental watersheds, generally with sub-daily data. These databases have provided important information to be used as input data for the model. The data used to run SWAT in the Joanes River watershed and Jacuípe river basin were obtained mainly from the Bahia state company of urban development in scales of 1:100,000 (soil use and vegetation) and data from exploratory soil surveys obtained during the RADAMBRASIL (Radar in the Amazon) project during the decades of 1970 and 1980 (Oliveira and Medeiros, 1999; Fontes et al., 2010). Other data sources for the Jacuípe river basin were the GETOPO 30, SRTM in the EROS DATA CENTER – USGS for DEM (Digital Elevation Model). The weather data was obtained from Morro do Chapéu weather station. Finally the precipitation data was gathered from ANA (Fontes et al., 2010). For the studies developed in the Marins river watershed (Machado et al., 2003; Machado and Vettorazzi, 2003; Moro et al., 2006; Machado et al., 2007) the soil use data was obtained from an image of the SPOT satellite, taken in 1998. The information about the soil was obtained from a scientific bulletin by the agronomic institute of Campinas and from a project called Piracena project. The Brazilian soil classification system from Embrapa was also used as a data source. The weather, precipitation and sediment data were obtained from the University of São Paulo and from the Department of Water and Electrical energy. The data used for Taquarizinho and Aquidauana basins was obtained from several sources. The DEM was obtained by digitalizing topographic maps with a scale of 1:100,000 from the year 1966. The land cover databases were created from Landsat 5 TM images for three different periods, 1966, 1985 and 1996. The soil map was obtained from a study developed for the Alto Paraguay Basin Conservation Plan. The agricultural management data was obtained through interviews with local agricultural organizations. The hydrological data was obtained from ANEEL’s reports. The sediment data was obtained from other studies developed in similar basins (Barsanti et al., 2003). 2011 International SWAT Conference & Workshops Minoti et al. (2004) constructed the DEM from topographic maps from IBGE. The soil use information was obtained from LANDSTAT-7 satellite images. The weather data was obtained from a weather station, property of Embrapa. For the study developed in the Piraquara river watershed the soil use data was obtained from the PARANASAN project, which was an environmental sanitation project for the state of Paraná. The soil characteristics were obtained from studies developed by Paraná Federal University. The DEM was built from information obtained from COMEC (Coordination of the Metropolitan Curitiba Region), which is a governmental institution. The streamflow data was obtained from ANA. Finally, the weather data was obtained from Simepar (Paraná Technology Institute) and SUDERSHA (Paraná Water Institute), both of them state companies (Coelho et al., 2005; Bittencourt & Gobbi, 2006) The soil use data for Cuiabá river basin and Manso river sub-basin were obtained from the RADAMBRASIL project. The DEM was obtained from previous studies developed in the area. The soil data was obtained from a study organized by FEMA (Mato Grosso Environmental State Foundation). The precipitation data and streamflow data were obtained from gauges operated by ANA. The weather data was acquired from two meteorological stations, one from UFMT (Mato Grosso Federal University) and the other one from INMET (Baldissera, 2005; Xavier, 2009). The data to simulate the Salitre river basin was obtained from several sources. The soil use map has a scale of 1:250,000. The map was obtained from the integrated management project for São Francisco Basin supported by ANA. The DEM was constructed from topographic maps with a scale of 1:100,000. The weather data was obtained from INMET for 3 stations and the precipitation data was obtained from ANA from 14 gauges. The soil data was obtained from the results of the RADAMBRASIL project (Oliveira et al., 2005a, 2005b). The Jiquiriçá river basin soil characteristics data was obtained from a study developed for the PDRH (Water Resources Master Plan for Bahia State) (Garrido, 2003; Pereira et al., 2005a, 2005b). The DEM was created based on maps with the scale of 1:100,000. The soil information was obtained from documents developed by SRHSH (Water Resources, Sanitation and Housing Secretary) during the execution of the Environmental Recovery Program for Jiquiriça river watershed and information from Embrapa. The soil use data was based on images from the LANDSAT-7 satellite, documents from IBGE and field surveys. The weather data was obtained from one weather station from INMET. Finally the precipitation and streamflow data were obtained from INMET and ANA gauges, respectively. The topographic, land use and soil characteristics data were obtained from the Campinas Agronomic Institute. That information was acquired during the development of the Environmental diagnosis for land use management of the Jundiaí-Mirim river watershed in 2002 (Prado et al., 2005). The Bonito river watershed input data was obtained from previous studies in the watershed as presented for several papers. (Silva et al., 2005; Silva et al., 2006a; Neves et al., 2005; Neves et al., 2006; Crestana et al., 2010). The previous studies obtained weather data from Embrapa weather station. The DEM was built from an IBGE topographic map from 1971 with a scale of 1:50,000. Studies developed in the years of 2000 and 2003 created the soil use and soil maps used in the studies. The soil use and soil data used to model Corumbataí river basin was obtained from the Master Plan for conservation of the water resources developed by the Institute for Forest Studies and Researches with a grid of 25 m x 25 m extracted from a map with a scale of 1:100,000. The DEM was obtained from PIRACENA project (Project developed by the Center for Nuclear Energy in Agriculture, Piracicaba Campus). The weather data was obtained from the Meteorological station of ESALQ/USP (Luiz de Queiroz Superior 2011 International SWAT Conference & Workshops Agriculture School) and from the Meteorology and Climatology Analysis Laboratory from UNESP. The precipitation and streamflow data were obtained from DAEE database (Department of Water and Electric Energy of São Paulo state). The sediment and water quality data was obtained from field surveys. Armas (2006) reported that the refinement of the model could be done with more detailed information about soil characteristics. The Beija-Flor and Jataí rivers sub-watersheds are located inside the Mogi-Guaçu river watershed. The database used as input to the model was obtained from previous studies. The data quantity and quality was available due to the projects developed in the Jataí ecological station (Silva et al., 2006b). The Apucaraninha river watershed sediment data was obtained from previous studies in the area and an intensive monitoring of sediment transport during the years 2004 and 2005 (Santos et al., 2006; Santos et al., 2010). The DEM, land use, weather and soil information source was not detailed in the text. Paiva and Paiva (2006) used weather data from an INMET weather station. The soil map was obtained from previous studies in the area. The soil use was obtained from maps built from 1998 LANDSAT satellite images. The DEM was built from topographic maps with a scale of 1:50,000. The study developed in the Coruripe river basin used a DEM developed from the SRTM (Shuttle Radar Topography Mission). The soil use was obtained from the river Coruripe Water Resources Master Plan published in the year 2000. The soil classification and characteristics were obtained from Embrapa and studies developed by a private company named Coruripe Plant. The weather data was obtained from Coruripe Plant. The precipitation data was obtained from 10 precipitation gauges owned by ANA (Rodrigues and Reis, 2007). The paper states that SWAT is an excellent tool to be used as a scientific support decision tool. However, the model calibration was not possible due to the lack of detailed information. The input weather data to be used in Toledo and Ajuricaba river watersheds was obtained from a weather station owned by Simepar. The soil characteristics were based on Embrapa’s database. The other data sources were studies developed in these watersheds during the execution of the Good Water Farming Program supported by Itaipu Binacional. The soil characteristics in M2 - experimental watershed were obtained from the Embrapa’s database (Lopes and Kobiyama, 2008a). The weather database was supplied by Battistella Florestas Company and part of the precipitation data from Epagri/Ciram (Santa Catarina Agricultural Research and Extension Corporation). The soil use data was generated from Rio Negrinho’s municipality orthophotographs. The soil use map for Santa Maria river was obtained from previous studies and is composed mainly by meadows (67%) and forests (20%). The soil use map was made from photos with scales varying from 1:10,000 up to 1: 30,000. The soil information was also obtained from previous academic studies and technical reports developed in the area. The classification was based on Embrapa’s recommendations. The weather data was obtained from previous studies and from INMET meteorological station. The streamflow data and the information on sediment production were acquired during the research development. There was a hydro-sedimentologic gauge monitoring turbidity and water level in the watershed (Marchioro, 2008). The data source used for the Tijucas river basin was obtained from several sources. The DEM was obtained from the SRTM. The soil map was gathered from Embrapa with the scale of 1:250,000. The soil use information obtained from the Landsat_5_TM satellite image. The precipitation and streamflow data was acquired from ANA. The weather data was gathered from two weather stations, in Florianópolis and in São José (Paim and Menezes, 2009). 2011 International SWAT Conference & Workshops Gibertoni et al. (2009) obtained the soil use data from the LANDSAT ETM satellite for the year 1999. The hydrologic and meteorological data were obtained from the Aneel and Suderhsa. Lubitz (2009) applied the model to the Concórdia river watershed located in city of Lontras region. This watershed has a monitoring history because it is one of the seven monitored watersheds of the Prapem and Matasul projects. The Prapen is a project of environmental recovery and support for small farms and Epagri is one of the companies that give support to the watershed hydrology and precipitation monitoring. Besides, there are several scientific studies developed in the watershed. These studies have contributed to the hydrological and meteorological data acquisition. The soil characteristics and management were obtained from Embrapa’s and Epagri’s studies. The DEM was developed from IBGE topographic maps with the scale of 1:50,000 from 1980, and aero-photos with the scale of 1:25,000 from 1978. The soil use information was obtained from SPOT5 satellite images. The sediment data was obtained through field surveys. The database used in the Araranguá river basin model was obtained from several sources. The DEM was constructed from a topographic map by IBGE in the scale of 1:50,000. The soil map was gathered from Embrapa and the soil use information was obtained from Fatma (Santa Catarina State Environmental Company). The meteorological data was available on Epagri’s and Casan’s database. Finally, the hydrological information was acquired from ANA (Blainski and Garbossa, 2009; Blainski et al., 2010). The Preto river basin soil characteristics database was obtained from Embrapa. The DEM was constructed by Epagri from a topographic map by IBGE with the scale of 1:50,000. The soil use was obtained based on three LANDSAT-TM5 satellite images. The weather data was gathered from Epagri’s and Inmet’s meteorological station. The streamflow data was obtained from a limnimetric gauge owned by ANA (Lino et al., 2009). The database to the Altíssimo rio Negro watershed was obtained mainly from the same sources as the Negro river basin (Souza et al., 2009; Schultz et al., 2010). Uzeika (2009) obtained soil use data from field surveys during the research project development. The Arvorezinha watershed soil characteristics were obtained from previous studies in the area and from EmaterRS (Agricultural Technical Assistance and Extension Corporation – Rio Grande do Sul). The DEM was created from IBGE topographic maps with a scale of 1:50,000. The management practices input data was organized during the development of the study. The precipitation, streamflow and sediment data started to be collected during a governmental program named RS-Rural in 2004. After the end of the program, a partnership among Sindifumo (Rio Grande do Sul Tobacco Trade Union), Emater-RS and UFRGS-IPH (Hydraulics Research Institute) is monitoring the watershed. The Lajeado dos Fragosos river watershed soil characteristics map was generated based on soil samples analyses and classified as recommended by Embrapa. The soil use was obtained from Fatma. The hydrologic information was obtained from Embrapa and Epagri. (Blainski et al., 2010; Garbossa et al., 2010). Complementary information was obtained from PNMA II (National Program for the Environment II) reports. Bonumá et al. (2010) obtained the input data from previous studies developed in the Arroio Lino watershed. The weather and precipitation data for Riacho dos Namorados watershed were obtained from gauges previously installed for researches. The DEM was obtained from the SRTM images (Guimarães et al., 2010). Ribeirão Cachoeirinha soil use database was constructed during the study development. The DEM was built from IBGE topographic maps on a 1:50,000 scale. Emater provided the information about soil characteristics with the scale of 1: 1,000,000. The weather and hydrologic data were obtained from INPE and ANA (Pereira et al., 2010). 2011 International SWAT Conference & Workshops The São Bartolomeu river watershed soil use data was obtained from the IKONOS satellite image, associated with field surveys. The soil characteristics were defined by using the Embrapa soil database associated with soil analyses, satellite images and aero-photos. The DEM was created from maps with a scale of 1:50,000 (Lelis and Calijuri, 2010). The precipitation and streamflow data source used to model the Conrado and Pinheiro rivers watershed was obtained from monitoring gauges installed during the PNMA II. The DEM was created from topographic maps with a scale 1:50,000. The land use data was obtained from Landsat TM5 satellite images. The weather information was obtained from Iapar (Paraná Agricultural Institute) and Simepar (Batlokoski et al., 2010). Souza et al. (2010) have obtained the hydrological information from ANA. Besides that the authors have estimated the heat flow from orbital images with the model SEBAL (Surface Energy Balance Algorithms for Land). The SWAT model concept is to have a model in which you can readily use available data, such as SCS database and climatological radar data (Pereira et al., 2005a). However, the model input data to be used in Brazilian watershed modeling is not organized to be readily used by the model. The information has to be gathered from various sources, with a great variety of formats and levels of detail. This diversity of data sources and difficulties can be identified in the reported researches. Paiva and Paiva (2006) also report that there is a great need for more detailed information to be used in mathematical models. There is an effort in order to organize a Brazilian general use database. This can be seen in the available soil database from Embrapa and the available water resources database from ANA. But there is a great need for more detailed information. The soil data used from Embrapa is adapted and some theoretical parameterization is made because not all the input soil data is available. The use of SWAT in Brazilian watersheds should be preceded by an evaluation of the available data for the region. The official governmental institutions database should be consulted. Besides that, other regional, state and private companies should be consulted. Based on available dataset the modeler can decide when it is possible to apply the model for the region. The researched papers confirm the statement of Adriolo et al. (2008). The challenge to use SWAT in Brazil is not whether the model can be used here or not, but how to obtain enough data to simulate a basin. Climate characteristics of the modeled watersheds The variation of the climate in the presented watersheds is significant. The climate varies from tropical in Brazil’s Northeast Region to temperate in the extreme southern state. The mean annual precipitation varies from less than 500 mm up to more than 2,000 mm. The climate variation is presented here for each one of the four Brazilian Regions that presented studies with SWAT, except for one study developed in the southern part of the North region. Brazil’s Northeast Climate The Jiquiriçá river basin (Garrido, 2003; Pereira et al., 2005b) is located in a region where several weather classifications are found. Based on the Köppen climatic system it is possible to find the following types: Af, Am, Cwb and BSh. The basin region has climates varying from hot summer with average hottest month near 22 °C. The average annual precipitation varies from less than 800 mm in some region up to 1,200 mm for other areas. 2011 International SWAT Conference & Workshops The annual mean precipitation for the Jacuípe river basin varies from 500 mm up to 1,300 mm depending on the location. The average temperature is about 23 °C (Fontes et al., 2010). The annual precipitation in the Riacho dos Namorados watershed is 400 mm and occurs from March until June (Guimarães et al., 2010). The Coruripe river watershed is influenced by the tropical humid climate. In the far East there is a tropical climate and in the far West a semi-arid climate. The annual mean precipitation is approximately 1,100 mm. The annual mean temperature is above 18°C (Rodrigues and Reis, 2007). The region of Ribeirão Cachoeirinha watershed is located in the south portion of the Brazilian Northeast Region. The summer and winter are well defined and the annual average precipitation varies from 1,300 mm up to 1,700 mm (Pereira et al., 2010). Brazil’s Central-West Climate The Cuiabá river basin and the Manso river sub-basin are located in a region with Aw climate type by the Köppen classification system. The average precipitation is 1,500 mm distributed in two periods: a rainy period from December until March, and a dry one from June until August. The average temperature varies from 12 °C up to 28 °C (Baldissera, 2005; Xavier, 2009). Brazil’s Southeast Climate The Bonito river watershed and sub-watersheds modeling efforts are presented in several papers (Neves et al., 2005; Silva, et al., 2005; Neves et al., 2006; Crestana et al., 2010). The climate in the region is considered as Cwa in the köppen international system. This corresponds to mesothermal dry winter with temperatures varying from 18 °C up to 22 °C. The Jundiaí-mirim watershed has an Aw climate type by the Köppen classification system, with a very wet mesothermal climate without a well defined dry season (Prado, 2005). The regions of the São Paulo State where Corumbataí river and Marins river watersheds are located have a climate characterized as Cwa by the Köppen classification system. The region has a sub-tropical mesothermal climate. It has dry winters and rainy summers. The average annual precipitation is approximately 1,280 mm. The temperature varies from 22 °C in the summer and 17 °C in the winter. (Armas, 2006; Moro et al., 2006). Brazil’s South Climate Coelho et al. (2005) states that the climate for Piraquara river watershed is sub-tropical humid and mesothermal with fresh summers (under 22 °C) and winters with average temperatures close to 18°C. The annual mean precipitation is 1,400 mm. The Conrado river and the Pinheiro river watershed are located in a region with a climate labeled as Cfb in the Köppen classification system. The annual mean precipitation (1979-2006) is 2,094 mm (Baltokoski et al., 2010). The climate is labeled as Cfb for Köppen classification in the M2 - experimental watershed region. This climate is characterized for being temperate, continually wet, for having no dry seasons and for having a fresh summer. The annual average temperature varies from 15.5 °C up to 17 °C. The annual precipitation varies from 1,360 mm up to 1,670 mm (Lopes and Kobiyama, 2008a, 2008b; Lopes et al., 2008; Souza et al., 2009). Lino et al. (2009) modeled the Preto river basin. The basin is located in the same region as the M2 – experimental watershed and consequently has the same climatological classification. The Concórdia river watershed is close to the Preto river basin and has a humid subtropical climate, without a dry season and with 2011 International SWAT Conference & Workshops a hot summer. The hottest month has a mean temperature of 22 °C. The annual average temperature varies from 17 up to 19 °C. The annual precipitation varies from 1,320 mm up to 1,640 mm (Lubitz, 2009). The Tijucas river basin is located in two climatic regions. The East side presents warm and wet mesothermal summer and is labeled as Cfa in the Köppen classification. The West basin region has a mesothermal wet climate with dry summers and is labeled as Cfb in the Köppen classification (Paim and Menezes, 2009). The Araranguá river basin region has a climate labeled as Cfa in the Köppen classification system. The annual average temperature is 18 °C and the annual precipitation vary from 1,220 mm up to 1,660 mm (Blainski and Garbossa, 2009; Blainski et al., 2010). The Santa Maria river basin is located in a region with Aw climate type by the Köppen classification system. The tropical climate has well defined seasons. The region temperature varied from mean temperature of 19.9 °C in the coldest month and 26.5 °C in the hottest month Marchioro (2008). The climate is defined as Cfb for Köppen classification in the Arvorezinha watershed. This climate is characterized for being temperate, continually wet and with a fresh summer. The daily average temperature for the hottest month is approximately 22 °C and the daily average temperature for the coldest month is 3 °C (Uzeika, 2009). The Lajeado dos Fragosos river watershed region has a climate labeled as Cfa in the Köppen classification system. The annual average temperature is 18 °C and the annual precipitations vary from 1,700 mm up to 1,900 mm (Blainski et al., 2010; Garbossa et al., 2010). The climate in the Arroio Lino region is labeled as Cfb in the Köppen classification system. There are hot and wet summers, morning frost in the winter and well distributed precipitation along the year (Bonumá et al., 2010). Despite the fact of a significant variability of climates for the modeled watersheds, the results presented in the papers demonstrate that the model had a good performance for all the climate regions. This is a strong evidence that the climate is not a limiting factor to the model use in Brazil. Studies developed in Brazilian watersheds Oliveira and Medeiros (1999) wrote one of the first papers found for the 12 year period of researches using the SWAT model in Brazil. The studied watershed is located in the Northeast Region. The main objective was to evaluate the potential of using SWAT for watershed assessment. The authors concluded that the model can be used for planning and management of a Brazilian watershed. The studies in the Marins river basin tested different percentages of discretization, varying the area for discretization from 0.1 km2 up to 2 km2. The best results were obtained using 39 sub-watersheds for the upstream limnimetric gauge (Machado et al., 2003). This represents an average discretization area of 0.4 km2 and a NSE of 0.92 for the calibration. The authors concluded that, despite some events of super- or underestimations of sediment production, in general the model had a good performance representing the production and transport of sediments (Machado and Vettorazzi, 2003). A study of soil erosion in two basins of the Pantanal area was developed: a highly populated basin denominated Taquarizinho river and one little populated, the Aquidauana river basin. The calibrated model has shown the importance of management practices. High specific soil loss was identified comparing single crop (45 ton/ha) versus crop rotations (5 ton/ha). The correct pasture management resulted in a decrease of 2011 International SWAT Conference & Workshops specific soil loss from 12 ton/ha to 0.6 ton/ha. Barsanti et al. (2003) concluded that the model had a good estimation of the effects of soil use and management practices. Garrido (2003) modeled the Jiquiriçá river basin aiming to evaluate the SWAT applicability in order to support the water resources management for the region. The poorly gauged basin has shown to cause uncertainty in model calibration and validation. The obtained results may be considered inconsistent due to the lack of available data. Garrido (2003) states that these results should be a stimulus in order to improve the hydrologic monitoring system for the region. The discretization level for the Marins river watershed was evaluated (Machado et al., 2007). Six discretization levels were tested, resulting in 15, 17, 25, 33, 39 and 43 sub-watersheds. From 17 up to 33 subwatersheds no significant changes were identified in the NSE and R2 coefficients. Satisfactory results were obtained with 39 sub-watersheds together with a sediment production increase. When using 43 subwatersheds, besides the increase in the sediment production, a significant fall occurred for the NSE coefficient. These results are linked to the variation in the topographic characteristics of the sub-watersheds, markedly the channel slope and length. Minoti et al. (2004) and Silva et al. (2004) discuss the output results obtained by the model but there is no detailed information about the efficiency of the model in the calibration and validation steps. These authors focused on the discussion of the model capabilities based on the results presented. The conclusion is that the model has great potential do be used as an assessment tool, but further investigation should be conducted. A study was developed in the Curitiba region. The objective was to evaluate the possibility of using SWAT as a tool to quantify environmental impacts in a watershed and support decision makers (Coelho et al., 2005). The correlations between measured and modeled values were considered poor. Probably this problem is related to the fact that the precipitation and streamflow data were not hydrologically reliable. Another important piece of information is that the soil use data was from a different period of time from that of the streamflow data. Besides some problems, the authors considered SWAT a good tool to be used in Brazilian watersheds. Neves et al. (2005) evaluated three methods to calculate the evapotranspiration with SWAT. The highest evapotranspiration values were obtained by the Hargreaves method and the lowest values by the Penmanmonteith method. The authors concluded that in the study area the best method in representing the evapotranspiration was the Penman-Monteith. The Salitre river basin has some problems with water availability, mainly in dry months, from August to October. Several Salitre river contributory streamlets and the Salitre river itself have no flow during dry seasons. There was a lack of information to parameterize the model, but still the model was capable of representing the streamflow behavior. The obtained coefficient of determination was 0.8, despite the poor data available (Oliveira et al., 2005a). SWAT users should be aware that the available information about CN values, outside the U.S., is sometimes not representative (Oliveira et al., 2005b). Pereira et al., (2005a) focused on the study of sensibility analyses. They have identified that the model was sensible to the following parameters: FFCB, SOL_AWC, SOL_Z, SOL_BD, and SOL_K, and for the evapotranspiration processes are the CANMX and ESCO, and the superficial runoff the CN. Pereira et al., (2005b) chose the Hargreaves method to calculate evapotranspiration, based on the results of other studies developed in the region. To evaluate the results of the calibration and validation the authors used five different methods on a daily basis. 2011 International SWAT Conference & Workshops The objective of the study developed in the Jundiaí-Mirim river watershed was to evaluate the model capacity to represent different scenarios of land use. Prado et al., (2005) concluded that the SWAT has an adequate level of response to detect different soil uses, even for small changes. Garbossa et al. (2010) used the model and identified that the SWAT response can simulate the compliance with the Brazilian forest law watershed effects. The objective of Baldissera (2005) was to evaluate the applicability of the SWAT model for flow estimation in the Cuiabá river basin. The model was applied to simulate the present scenario and simulate the streamflow considering that 100% of the original vegetation was recovered. The model was adequate to represent the basin. The statistical evaluation of four streamflow gauges resulted in NSE above 0.7. The main problem was to represent the base flow values. Probably this issue was due to the limited availability of information on soil quality. A study was developed in the Manso river basin, which is a sub-basin of the Cuiabá river basin. The objective was to evaluate five different scenarios, testing the soil use of the basin for agriculture, meadow, forest and others. The model was considered a promising model to be used as an assessment tool. For this study the results were used as a qualitative approximation for flow values. The scenarios indicate the most vulnerable area, but it was not possible to quantify the sediment loss (Xavier, 2009). Silva et al. (2005) used the SWAT model to simulate the soil loss in the Bonito river watershed. Although the statistical analysis was not presented, the authors identified that the model had adequately represented the watershed soil loss. Moreover, the model identified the areas in the watershed that were more susceptible to soil erosion. The study developed in the Corumbataí river basin aimed at the evaluation of the biogeodynamic of the pesticides employed in sugarcane production. The study first identified that the most used pesticides in the basin are the herbicides for sugarcane production. The herbicides were monitored for water and sediment samples. The SWAT was used to identify the critical areas in the basin for pesticides contribution. Three different scenarios were simulated for sugar-cane tillage with different herbicides application. Armas (2006) stated that the model was capable of simulatimg the herbicides behavior in the basin when it is adequately calibrated and validated. The Canchim river watershed is a sub-watershed of the Bonito river watershed. Phosphorus and nitrogen were simulated in the sub-watershed. The model presented promising results. The deviation of the measured and simulated data resulted in a value of -2.25%. This indicates that the simulation overestimated the measured values. The results of the NSE were 0.79 and 0.80 for nitrogen and phosphorus, respectively (Silva et al., 2006). Another study in the Bonito river watershed in an area of 223 km2 evaluated the nutrients entry due to poultry activity. The deviation resulted in -2.8% and -2.4% for nitrogen and phosphorus, respectively (Neves et al., 2006). The SWAT was able to adequately simulate the influence of the nitrogen and phosphorus behavior on the watershed. Silva et al. (2006b) identified the adequate model response to the soil use in the watershed. The paper authors stated that the results are just indicative and the simulation should be improved. Still, the authors detailed neither information about the period of time used nor the statistical coefficients results. Seven scenarios were simulated to evaluate the sediment production in the Marins river watershed (Moro et al., 2006). The scenerios were composed by area variations for sugar-cane production, meadow and native cover. Despite the fact that the calibration and validation results were not presented, some conclusions were made. The authors presented the results comparing each scenario with each other. The model output data resulted in equal values to different scenarios. The repetition of output data was attributed to the level of the 2011 International SWAT Conference & Workshops discretization and tolerance for land use. The results indicate that the native vegetal soil cover was a better protection for the soil than other uses. The contribution to sediment production was strongly related to the terrain slope and the sugar-cane culture. The Apucaraninha river watershed was evaluated for seven different scenarios, including the present condition. The scenarios tested different soil use conditions. The discharge NSE values for calibration and validation were both above 0.7. The total mean observed and simulated flow values had a difference of less than 1%. The study has shown the model ability to represent adequately the Apucaraninha river watershed. (Santos et al., 2006; Santos et al., 2010). A study was developed in Menino Deus I watershed to evaluate the viability of using SWAT in the region. The watershed was adequately represented on a daily basis, with a determination coefficient value of 0.53 and correlation coefficient value of 0.73. The model results were used to build the duration curve and compare with the duration curve built from measured data. It was possible to identify a good match between the two curves (Paiva and Paiva, 2006). The research developed in the Coruripe river basin established an erosion rate. This rate represents the sediment volume produced for a constant area and soil type. It was identified that areas with sugar-cane have a low impact on the soil erosion, with an erosion rate of 0.52. The urban areas and the meadow areas are more susceptible to erosion, with rates of 1.65 and 1.17, respectively. The meadow occupies a significant area in the watershed; consequently, it was responsible for 75% of the erosion (Rodrigues and Reis, 2007). The main objective of modeling the Piraquara watershed was to test the viability of using data generated by SWAT together with the TMDL (total maximum daily load) process. The TMDL is a process developed by EPA (Environmental Protection Agency) to evaluate processes that cause or contribute to the loss of water quality. The calibration of the SWAT model for Piraquara watershed was made to the streamflow data. The calibration to the phosphorus simulation was not possible because of lack of data. There were phosphorus data samples collected to the watershed, but the sampling interval was not adequate to calibrate the model. The SWAT run simulated a 10 year period, from 1998 until 2008, for phosphorus discharge in the Piraquara II reservoir. The results of the simulation were used to test the TMDL process (Bittencourt and Gobbi, 2006). The simulations developed in the Toledo river and in the Ajuricaba river watersheds aimed to evaluate the model applicability to the area. The presented scenarios were modeled and the results were discussed just comparing the different scenarios with one another. Regardless of the fact that there was not model calibration, it was identified that the model presented coherent responses. The paper states that it is an important tool that can be used for watershed management (Roloff et al., 2007). The monthly correlation coefficient for the Apucaraninha river watershed resulted in a value of 0.83 and 0.84 for calibration and validation, respectively. The monthly determination coefficient to the entire period is 0.65. The daily NSE results were not satisfactory. Nevertheless, the monthly and annual results were promising. The modeled data graphical evaluation does not have a perfect adherence to the observed data but demonstrated a similar behavior. The results for sediment are promising since the difference between the observed and the simulated data was only 2.6%. Adriolo et al., (2008) concluded that the SWAT model can be used in the Brazilian conditions. The M2 Experimental watershed was modeled for streamflow data. A good adjustment was obtained but the model over-estimated the streamflow values for dry periods. Besides, the model significantly underestimated a peak flow event of 15.5m3.s-1. The authors attribute this to an intense upstream precipitation event that was not measured. An analysis of the sediment production was made evaluating the hydrologic and sediment equilibrium of the watershed. Fifteen anomalous events were identified by the analyses. 2011 International SWAT Conference & Workshops Comparing the results to SWAT output, six events are coincident with higher sediment production (Lopes and Kobiyama, 2008a). Another study developed in the M2 Experimental watershed tested three different precipitation inputs and infiltration methods. The simulation with the best results used the daily precipitation data instead of the sub-daily data and, consequently, the CN method. This result was attributed to the daily precipitation data series length, which has the double quantity of the sub-daily data. The model had adherence to the measured streamflow data but almost all simulations over estimated the peak flow and the mean flow (Lopes et al., 2008; Lopes and Kobiyama, 2008b). Gibertoni (2009) evaluated the use of SWAT to simulate the Santa Maria river watershed. Moreover, a scenario considering the compliance with the Brazilian Forest law was simulated. He concluded that the model is an important tool to identify sensible areas to sediment loss and to evaluate alternative land use scenarios. Different from streamflow values, the sediment production was poorly represented by the model. Gibertoni (2009) stated that these results are associated to constant soil use modifications in the watershed and to the database low data quality and quantity. The Tijucas river simulation output data was compared to the data of three hydrologic gauges to verify the model performance. The model had an adequate performance in the outlet 24 with the NSE of 0.73. The measured data in the outlets 9 and 10 had a poor correlation with the simulated data. The lack of sediment data became a limitation to advance in the basin modeling. Paim and Menezes (2009) concluded that their simulation can be used to evaluate the basin in a qualitative manner, but not the quantitative output values. The Araranguá river basin simulation obtained satisfactory results, with an NSE of 0.72 on a monthly basis. It was simulated for three different scenarios in order to test the model response. The model presented coherent responses. The Araranguá river basin has an area of intense irrigated rice farming. From August until December a water deficit may arise depending on the precipitation intensity (Blainski and Garbossa, 2009). The hydrological modeling with SWAT can be used as a tool to evaluate the water availability and establish a water use protocol for the region (Blainski et al., 2010). Lino et al. (2009) modeled the Preto river watershed including two reservoirs, one 200 km2 and the other 300 km2. The existence or not of the reservoirs made no difference with an effect in the superficial runoff of 0.93 mm. This corresponds to a flow variation of 0.75%. The streamflow mean deviation resulted in - 4.96. The model underestimated the peak flow events. The conclusion was that the model adequately represented the watershed. However, in order to obtain better results, more detailed information about the soil and land use is necessary. Souza et al. (2009) considered that the streamflow was adequately represented for Altíssimo rio Negro watershed. However, there were limitations simulating peak and recession streamflow values. The water use permit in Brazil is issued based on the low-flow indices obtained from the flow duration curve. The maximum use permitted in the state of Santa Catarina corresponds to 50% of the Q98. For the state of Paraná the maximum use permitted corresponds to 50% of the Q95 (Souza et al., 2009). The Altíssimo rio Negro watershed output was used to estimate the Q95 and Q98 low-flow values for each sub-watershed and compared the Q95 and Q98 low-flow to measured streamflow. The model has shown that if the water use permit was based only on the Altíssimo rio Negro watershed low-flow values, some problems could occur. Sub-watersheds could not supply the Q95 based forecast and attend the water demand. Schultz et al. (2010) simulated the same watershed and found satisfactory results for monthly sediment production. The daily simulated sediment production presented certain limitations. Probably this limitation is related to the overestimated peak flows and under-estimated recession flow also observed by Souza et al. (2009). 2011 International SWAT Conference & Workshops The Arvorezinha watershed modeling objective was to evaluate the model applicability and to simulate three different soil use scenarios. The NSE was calculated for each year with the mean results for flow values. The model poorly represented the watershed on a daily basis, except for one year, in which the NSE reached 0.79. The model had a better performance for monthly average. Uzeika (2009) concluded that the model was adequate to represent small watersheds for streamflow on a monthly basis. But the model was not adequate to simulate sediment production for small watershed. Lubitz (2009) developed a study in the Concórdia stream watershed. The objective was to evaluate the use of the model in the watershed and the results for streamflow, sediment and nutrients. The nutrients modeling results presented an NSE of 0.20 and -0.35 for nitrite and nitrate, respectively. These results are attributed to two major issues. There was a need for more detailed information about effluents discharges and residues management and there were just a few punctual water quality results, which did not represent the watershed behavior. The difficulties were similar to modeling total phosphorus and orthophosphate. The NSE resulted in -4.76 and -0.04 for total phosphorus and orthophosphate, respectively. The model represented adequately the watershed for streamflow and sediment on a monthly basis. SWAT users should be careful when the data parameterization is made beyond certain limits. It can cause too much distrust about the model results. Blainski et al. (2010) simulated different scenarios to test the model response. Three hypothetical scenarios were created substituting meadow and pasture for reforestation, annual crop with conventional soil preparation and annual crop with no tillage. There was no sediment calibration. It was possible to identify that the reforestation scenario significantly reduced the soil loss in comparison to the other scenarios. The Lajeado dos Fragosos river watershed was simulated to evaluate the effects of the Brazilian Forest law compliance in the streamflow. Besides the NSE of 0.73, a mean error of 46 L.s-1 and a value of -0.04 for residual mass coefficient were obtained. It was possible to identify an increase of approximately 3.5% in the water availability if the Forest law was complied. This represents an increase of 4.000 m3.day-1. The daily output data had a poor NSE coefficient, probably because of the low water residence time in the watershed. (Garbossa et al., 2010). Fontes et al. (2010) studied the use of the isotopic hydrology associated with SWAT to calibrate the model and solve problems of hydrological data deficiency. The model over-estimated values of discharge for peak flows and long-term dry weather. The simulation adequately represented the mean streamflow values for the Jacuípe river basin. Bonumá et al. (2010) applied a sensibility analysis to evaluate the effect of certain parameters on the water balance and sediment production values and their relations. The parameters CN2 and ESCO influenced significantly both water and sediment production. The results indicate that the CN2, ESCO and Alpha_Bf were the most important parameters for flow calibration. The parameters Usle_P and Slope significantly influenced the sediment production. The results obtained in the Arroio Lino watershed demonstrated the potential of using SWAT to simulate Brazilian watersheds. These results are attributed to the quality of the input data available for this research. The study developed in Riacho dos Namorados aimed to evaluate the effect of DEM interpolation in SWAT results. The DEM used was from SRTM project with 90 m. Different interpolation techniques were used, such as Nearest Neighbors, Simple Average, Weighed Average, and Quadrant Weighed Average. Significant differences were identified in the morph metric model parameters for each interpolation. Apparently the interpolation with simple average was inadequate. The DEM generated from the SRTM with a resolution of 30 m has shown stability and consistence to the model results (Guimarães et al., 2010). 2011 International SWAT Conference & Workshops Pereira et al. (2010) studied the sediment production in the Ribeirão Cachoeirinha watershed. They compared the results obtained with the model and concluded that the sediment yield results are similar to values found in previous studies in the same region. Lelis and Calijuri (2010) monitored the superficial runoff and sediment production in ten representative locations of the São Bartolomeu watershed. The results of the monitoring were used to calibrate the model. They identified and quantified the effects of previous precipitation and precipitation intensity in the sediment production. A comparison of simulated runoff was compared with the measured runoff. The SWAT was efficient in representing the sediment production and scenarios simulation. The Conrado river and the Pinheiro river watersheds were simulated to streamflow and phosphorus and the results were acceptable. The authors concluded that a regular sampling frequency is important to be able to calibrate the model (Baltokoski et al., 2010). Souza et al. (2010) estimated the heat flow from orbital images with the model SEBAL. The integration of SEBAL output with SWAT input data allowed an improvement of 0.27 in the NSE for the simulated daily streamflow when compared to the results without the use of SEBAL heat flow estimation. Trindade et al. (2010) developed a study in an experimental watershed located in the state of Espírito Santo. The objective was to evaluate the model sensitiveness for seven fertilization scenarios. The conclusion was that the model adequately simulates the nutrients behavior related to the precipitation events. There were no evidences of the need to change the model sub-routines related to phosphorus. However, Trindade et al. (2010) identified a strong evidence that the model over-predicts the nitrogen kinetic behavior. The study concluded that SWAT must be used carefully when simulating nutrients in tropical watersheds. Changes in the sub-routine responsible for nitrogen transformation may be needed. Based on the papers’ results, it is possible to identify that the SWAT performance for Brazilian watersheds permits its use. Furthermore, there is evidence that the limiting factor is the database quality and availability. The minimum requirements to use the model in Brazil should be defined. Based on those requirements it will be easier to choose when one should invest time to model a watershed using SWAT. Practical application in Brazilian watersheds Some of the presented papers report the use or the attempt to use SWAT for real assessments. Coelho et al. (2005) stated that the present-day law instruments for water and watershed management in Brazil demand tools for environmental assessment of the watersheds. Hydrological models are a great support decisions tool for municipalities, state companies, federal institutions, basin committee and environmental organizations. Documents about the use of SWAT for practical application in Brazil were not easily found. There are very few reports about using the SWAT as an assessment tool in Brazil, although, some governmental and private institutions have used the model as a tool to make decisions about soil erosion and sediment transport. The companies that have used the model are hydroelectric energy power plants (Santos et al., 2005 apud Souza et al., 2009). A final report (LACTEC, 2007) of a hydroelectric energy power plant project evaluated the viability of using SWAT. The report states that studies results recommend the use of the SWAT to evaluate the sediment transport and water quality in the watershed. 2011 International SWAT Conference & Workshops Junqueira and Silva (2008) have evaluated three different tools to plan and manage watersheds. The Amorim & Cordeiro and PESMU (Strategic and sustainable planning of the urban environment) tools are methods that use a matrix, and in some aspects qualitative data rather than quantitative. The third method evaluated was SWAT. They have concluded that the three methods are valid to support decisions about the watersheds. However, the user should evaluate his objectives, database information, watershed size, and software and hardware availability. A technical plan developed by UFBA (Federal University of Bahia) has proposed the use of SWAT as a part of the methodology to use it as a tool for the implementation of the water resources management instrument in the state of Bahia (UFBA, 2004). It was identified that despite the fact of poor available data the model had an acceptable adjustment level. However, non reported documents have been found about the use of the model as a management tool in the watershed. A study named “Influence of the Governor Parigot de Souza Power Plant in the Antonina bay siltation” was developed with the use of SWAT. The sediment production and transport was simulated as solid discharge in the Antonina Bay. Distinct scenarios of soils use on the upstream basin were developed. The scenarios were the present situation, a pessimistic scenario and a most probable scenario. The values of the statistical efficiency for flow and sediment simulation were considered satisfactory and the results could be used to assess the different land use scenarios and support future decisions about the Antonina bay basin (Gibertoni et al., 2009). Conclusions The results from the existing papers show that SWAT has a great potential to be used in Brazil as a decision support tool by watersheds committees and, by environmental and hydrological governmental institutions. The use of SWAT in Brazil occurred mainly for academic purposes. Several studies have identified the potential of using SWAT in different Brazilian regions, for different climates conditions, watershed sizes, soil and environmental conditions. Most of the papers identify that the model presented adequate performance modeling the watersheds. A total of 60 studies were presented in this paper. From these, 27 papers present information about statistical coefficients for monthly basis. A total of 23 papers present a monthly NSE above 0.7 for at least one of the evaluated indicators. Few papers have identified the need for model adaptations in order to use it in Brazil. These results are an indication of the model robustness. It is important to continually test the model to different conditions, but also to use it as a support decision tool in practical applications. The researched papers confirm the statement of Adriolo et al. (2008). The challenge to use SWAT in Brazil is not whether the model can be used here or not, but how to obtain enough data to simulate a watershed. The use of models such as SWAT should be addressed to the effective data availability (Garrido et al., 2003). This will prevent that SWAT output results in generic conclusions Probably the greatest hindrance in spreading its use in Brazil is the database availability. Besides that issue, the model needs specialized professionals that sometimes are not available in environmental and regulating governmental agencies and watershed committees. 2011 International SWAT Conference & Workshops Acknowledgements The authors would like to thank the institutions that have supported, in some way, the development of this study. They are CNPq (National Council for Scientific and Technological Development), Epagri (Santa Catarina Agricultural Research and Extension Corporation), Furb (Blumenau University) and MCT/Finep/Ação Transversal - Previsão de Clima e Tempo - Edital 04/2008, convênio 01.08.0568.00FINEP. References Adriolo, M. V., Santos, I., Gibertoni, R. C., Camargo, A. S. G. 2008. Calibração do modelo SWAT para a produção e transporte de sedimentos. In VI Simpósio Brasileiro sobre Pequenas e Médias Centrais Hidrelétricas. Belo Horizonte – Minas Gerais. Brasil. Armas, E. D. 2006. Biogeodinâmica de herbicidas utilizados em cana-de-açúcar (Saccharum spp.) na subbacia do rio Corumbataí. PhD diss. Piracicaba, São Paulo: Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz. Baldissera, G. C. 2005. Aplicabilidade do modelo de simulação hidrológica SWAT (Soil and Water Assessment Tool), para a bacia hidrográfica do rio Cuiabá/MT. MS theses. Cuiabá, Mato Grosso: Universidade Federal de Mato Grosso, Instituto de Ciências Exatas e da Terra. Baltokoski, V., Tavares, M. H. F., Machado, R. E., Oliveira, M. P. 2010. Calibração de modelo para a simulação de vazão e de fósforo total nas sub-bacias dos rios Conrado e Pinheiro – Pato Branco (PR). Revista Brasileira de Ciência do Solo. 34: 253-261. Barsanti, P., Disperati, L., Marri, P., Mione, A. 2003. Soil erosion evaluation and multitemporal analysis in two Brazilian basins. In 2nd International SWAT Conference. Bari. Italy. Bittencourt, S. and Gobbi, E. F. 2006. Carga máxima de fósforo admissível ao reservatório Piraquara II, uma aplicação do processo TMDL. Nota. Revista Brasileira de Ciências do Solo. 30: 595-603. Blainski, E. and Garbossa, L. H. P. 2009. Estimativa do regime hidrológico em uma bacia hidrográfica com base na modelagem hidrológica dinâmica e distribuída. In XVIII Simpósio Brasileiro de Recursos Hídricos. Campo Grande – Mato Grosso do Sul. Brasil. Blainski, E., Garbossa, L. H. P., Maluta, S. 2010. Aplicação do modelo hidrológico SWAT (Soil Water Assessment Tool) para a simulação da perda de solo e da disponibilidade hídrica em uma bacia hidrográfica não instrumentada. In X Simpósio de Recursos Hídricos do Nordeste. Fortaleza – Ceará. Brasil. Blainski, E., Silveira, F. A., Conceição, G., Garbossa, L. H. P. 2010. Utilização do modelo SWAT (Soil and Water Assessment Tool) para estudos na microbacia hidrográfica do rio Araranguá / SC. In Tecnologias para o Uso Sustentável da Água em Regadio, 617-626. 1 st ed. Torrecillas, A., Palácios, E., Victória, F. B., Pereira, L. S., Garcia, M., Paredes, P. Lisboa, Portugal. Colibri. Bonumá, N. B., Reichert, J. M., Minella, J. P., Barros, C. A. P., Rodrigues, M. F., Buarque, D. C. 2010. Balanço hídrico e sua relação com a modelagem da produção de sedimentos em uma pequena bacia hidrográfica rural. In IX Encontro Nacional de Engenharia de Sedimentos. Brasília – Distrito Federal. Brasil. 2011 International SWAT Conference & Workshops Coelho, A. C. P., Hardt, L. P. A., Fernandes, C. V. S. 2005. Agregação de novas variáveis ao processo de planejamento urbano e regional sob a perspectiva de gestão dos recursos hídricos. In XVI Simpósio Brasileiro de Recursos Hídricos. ABRH. João Pessoa – Paraíba. Brasil. Crestana, S., Minoti, R. T., Neves, F. F. 2010. Modelagem e simulação aplicadas à avaliação dos impactos da perda de solo e dos dejetos de suínos na qualidade da água de microbacias. In Planejamento ambiental do espaço rural com ênfase para microbacias hidrográficas: Manejo de recursos hídricos, ferramentas computacionais e educação ambiental. 167-199. 1st ed. Gomes, M. A. F. and Pessoa, M. C. P. Brasília, DF: Embrapa Informação Tecnológica. Fontes, A. S., Oliveira, M. Q. C., Medeiros, Y. D. P. 2010. Calibração do modelo SWAT em bacias do semiárido com auxílio da hidrologia isotópica. In X Simpósio de Recursos Hídricos do Nordeste. Fortaleza – Ceará. Brasil. Garbossa, L. H. P., Blainski, E., Justen, J. G K., Vasconcelos, L. R. 2010. Potencial de uso de modelo hidrológico de base física na avaliação da legislação florestal e seus impactos nos cenários hidrológicos. In X Simpósio de Recursos Hídricos do Nordeste. Fortaleza – Ceará. Brasil. Garrido, J. M. 2003. Aplicação de modelo matemático de simulação com utilização de SIG à bacia do rio Jiquiriçá – Bahia. MS theses. Brasília, Distrito Federal: Universidade de Brasília, Departamento de Engenharia Civil e Ambiental. Gassman, P. W., Reyes, M. R., Green, C. H., Arnold, J. G. 2007. The soil and water assessment tool: historical development, applications and future research directions. Transactions of the American Society of Agricultural and Biological Engineers. 50(4): 1211-1250. Gibertoni, R. F. C., Santos, I., Müller, I. I., Pereira, P. S. 2009. Modelagem da produção e transporte de sedimentos em bacias hidrográficas do litoral paranaense: o caso da bacia do rio Nhundiaquara. In XVIII Simpósio Brasileiro de Recursos Hídricos. Campo Grande – Mato Grosso do Sul. Brasil. Guimarães, J. C. N., Lunguinho, R. L., Srinivasan, V. S., Rufino, I. A. A., Taveira, I. M. L. M. 2010. A influência dos métodos da interpolação na geração dos modelos numéricos de terreno e os resultados da simulação pelo modelo SWAT. In IX Encontro Nacional de Engenharia de Sedimentos. Brasília – Distrito Federal. Brasil. Junqueira, C. A. R. and Silva, R. S. 2008. Avaliação ambiental aplicável a bacias hidrográficas no meio urbano: Análise dos métodos Amorim & Cordeiro, PESMU e SWAT. Revista de Estudos Ambientais. 10(2): 6-23. LACTEC. 2007. Relatório Final – Atendimento aos requisitos da LP 9589 – UHE Mauá. Consórcio energético Cruzeiro do Sul. Available at: http://www.usinamaua.com.br/. Accessed 08 February 2011. Lelis, T. A., Calijuri, M. L. 2010. Modelagem hidrossedimentológica de bacia hidrográfica na região sudeste do Brasil, utilizando o SWAT. Revista Ambiente & Água – An Interdisciplinary Journal of Applied Science. 5(2): 158-174. Lino, J. F. L., Corseuil, C. W., Kobiyama, M., Malutta, S., Uda, K., Bortolotto, N. L., Santos, I. 2009. Análise da vazão da bacia hidrográfica do rio Preto com o modelo SWAT. In XVIII Simpósio Brasileiro de Recursos Hídricos. Campo Grande – Mato Grosso do Sul. Brasil. 2011 International SWAT Conference & Workshops Lopes, N. H. Y. and Kobiyama, M. 2008a. Análise do equilíbrio hidrossedimentológico em uma microbacia experimental com o modelo SWAT e as características geomorfológicas. In VII Simpósio Nacional de Geomorfologia e II Encontro Latino-Americano de Geomorfologia. Belo Horizonte – Minas Gerais. Brasil. Lopes, N. H. Y. and Kobiyama, M. 2008b. Análise da produção de sedimentos e da qualidade da água em uma microbacia experimental com SWAT. In: VIII Encontro Nacional de Engenharia de Sedimentos. Campo Grande – Mato Grosso do Sul. Brasil. Lopes, N. H. Y., Godoy, F. B., Kobiyama, M. 2008. Análise da produção de água e de sedimento em uma microbacia experimental com a aplicação do modelo SWAT. In VI Simpósio de Engenharia Ambiental. Serra Negra – São Paulo. Brasil. Lubitz, E. 2009. Avaliação da aplicação do modelo hidrológico SWAT à bacia do ribeirão Concórdia – Lontras, SC. MS theses. Blumenau, Santa Catarina: Universidade Regional de Blumenau, Programa de Pósgraduação em Engenharia Ambiental. Machado, R. E. and Vettorazzi, C. A. 2003. Simulação da produção de sedimento para a microbacia hidrográfica do ribeirão Marins (SP). Revista Brasileira de Ciências do Solo. 27: 735-741. Machado, R. E., Vettorazzi, C. A. and Cruciani, D. E. 2003. Simulação de escoamento em uma Microbacia Hidrográfica Utilizando Técnicas de Modelagem e Geoprocessamento. Revista Brasileira de Recursos Hídricos. 8(1): 147-155. Machado, R. E., Xavier, A. C., Cruciani, D. E., Vettorazzi, C. A., 2007. Efeito do nível de subdivisão em uma bacia hidrográfica na simulação da produção de sedimentos. Revista Brasileira de Recursos Hídricos. 12(4): 49-58. Marchioro, E. 2008. Modelagem hidrossedimentológica na bacia do córrego Santa Maria: Subsídios à aplicação de práticas de conservação de água e solo no noroeste fluminense. PhD diss. Rio de Janeiro, Rio de Janeiro: Universidade Federal do Rio de Janeiro, Programa de pós-graduação em geografia. Mercuri, E. G. F., Deppe, F., Lohmann, M., Simões, K. 2009. Metodologia da geração de dados de entrada e aplicação do modelo SWAT para bacias hidrográficas brasileiras. In XIV Simpósio Brasileiro de Sensoriamento Remoto. Natal – Rio Grande do Norte. Brasil. Minoti, R. T., Silva, F. G. B., Angelotti Netto, A., Machado, R. E., Tsuhako, E. M., Cestana, S. 2004. Determinação preliminar do aporte de sedimentos na microbacia do ribeirão Guabirobas (Estado de SP). In VI Encontro Nacional de Engenharia de Sedimentos. ABRH. Vitória – Espírito Santo. Brasil. Moro, M., Cruciani, D. E., Vettorazzi, C. A., Machado, R. E. 2006. Aplicação do modelo SWAT para simulação da produção de sedimentos em uma microbacia hidrográfica em cenários alternativos de uso do solo. In VII Encontro Nacional de Engenharia de Sedimentos. ABRH. Porto Alegre – Rio Grande do Sul. Brasil. Neves, F. F., Silva, F. G. B., Crestana, S. 2005. Comparação entre três métodos de evapotranspiração potencial aplicados a duas sub-bacias hidrográficas de Descalvado – SP. In XVI Simpósio Brasileiro de Recursos Hídricos. ABRH. João Pessoa – Paraíba. Brasil. Neves, F. F., Silva F. G. B., Crestana, S. 2006. Uso do modelo AVSWAT na avaliação do aporte de nitrogênio (N) e fósforo (P) aos mananciais de uma microbacia hidrográfica contendo atividade avícola. Engenharia Sanitária e Ambiental. 11(4): 311-317. 2011 International SWAT Conference & Workshops Oliveira, M. Q. C. and Medeiros, Y. D. P. 1999. Aplicação do modelo SWAT na avaliação de impactos decorrentes da modificação no uso do solo em bacias hidrográficas. In XIII Simpósio Brasileiro de Recursos Hídricos. ABRH. Belo Horizonte – Minas Gerais. Brasil. Oliveira, R. C., Oliveira, M. Q. C., Medeiros, Y. D. P. 2005a. Aplicação do modelo SWAT em região semiárida. In XVI Simpósio Brasileiro de Recursos Hídricos. ABRH. João Pessoa – Paraíba. Brasil. Oliveira, M. Q. C., Oliveira, R. C., Medeiros, Y. D. P. 2005b. Hydrologic Modeling of a Semi-Arid Region in Brazil. In 3nd International SWAT Conference. Duebendorf. Switzerland. Paim, J. B. and Menezes, J. T. 2009. Estimativa do balanço sedimentar da bacia do rio Tijucas (SC-Brasil) a partir da aplicação do modelo hidrológico SWAT. Revista Geográfica Acadêmica. 3(2): 5-14. Paiva, R. C. D. and Paiva, E. M. C. D. 2006. Simulação hidrológica com modelo SWAT na Bacia Menino Deus I, representativa da Mata Atlântica. In I Simpósio de Recursos Hídricos do Sul-Sudeste. Curitiba – Paraná. Brasil. Pereira, J. C. D., Silva, F. G. B., Dupas, F. A., Paes, F. S. 2010. Estudo de perda de solo na bacia hidrográfica do ribeirão da Cachoeirinha-MG, com a finalidade de obter estimativas aproximadas para o município de Santa Rita do Sapucaí-MG. In IX Encontro Nacional de Engenharia de Sedimentos. Brasília – Distrito Federal. Brasil. Pereira, J. M. G., Eid, N. J., Campana, N. A. 2005a. Aplicação de modelo matemático complexo de simulação com base em dados disponíveis. In XVI Simpósio Brasileiro de Recursos Hídricos. ABRH. João Pessoa – Paraíba. Brasil. Pereira, J. M. G., Campana, N. A., Eid, N. J. 2005b. Processamento de dados para utilização de modelo matemático de simulação à bacia do rio Jiquiriçá - Bahia. In XVI Simpósio Brasileiro de Recursos Hídricos. ABRH. João Pessoa – Paraíba. Brasil. Prado, T. B. G., Moraes, J. F. L., Adami, S. F. 2005. Evolução do uso das terras e produção de sedimentos na bacia hidrográfica do rio Jundiaí-Mirim. In XVI Simpósio Brasileiro de Recursos Hídricos. ABRH. João Pessoa – Paraíba. Brasil. Rodrigues, D. F. and Reis, R. S. 2007. Aplicação do modelo SWAT na estimativa da produção de sedimentos na bacia hidrográfica do rio Coruripe / AL. In XVII Simpósio Brasileiro de Recursos Hídricos. ABRH. São Paulo – São Paulo. Brasil. Roloff, G., Bley Jr, C., Souza, M. L. P. 2007. Modelo SWAT: Potencial de uso como auxiliar na gestão de pequenas bacias hidrográficas sem dados históricos. In XVII Simpósio Brasileiro de Recursos Hídricos. ABRH. São Paulo – São Paulo. Brasil. Santos, I., Andriolo, M. V., Gibertoni, R. C., Kobiyama, M. 2010. Use of the SWAT model to evaluate the impact of different land use scenarios on discharge and sediment transport in the Apucaraninha River watershed, southern Brazil. In Symposium of the International Commission on Continental Erosion – Sediment Dynamics for a Changing Future. Warsaw. Poland. Santos, I., Andriolo, M. V., Gibertoni, R. C., Pereira filho, D. L. B. 2005. Projeto CGER 036 Desenvolvimento de modelo de avaliação da qualidade de água e transporte de sedimentos para pequenas e médias centrais hidrelétricas: Modelagem da erosão e transporte de sedimentos. 91. LACTEC – Instituto de tecnologia para o desenvolvimento. Curitiba-PR. Brasil. 2011 International SWAT Conference & Workshops Santos, I., Andriolo, M. V., Gibertoni, R. C., Pereira Filho, D. L., Nishida, E., Silva, R. C. 2006. Simulação com modelo SWAT das condições hidrológicas e de produção e transporte de sedimentos na bacia do rio Apucaraninha – PR. In VI Simpósio Nacional de Geomorfologia – Geomorfologia Tropical e Subtropical: processos, métodos e técnicas. Goiânia – Goiás. Brasil. Schultz, G. B., Souza, R. M., Santos, I. 2010. Simulação da produção e transporte de sedimentos na bacia do Altíssimo rio Negro com o modelo SWAT. In IX Encontro Nacional de Engenharia de Sedimentos. Brasília – Distrito Federal. Brasil. Silva, F. G. B., Minoti, R. T., Reis, J. A. T., Tsuhako, E. M., Angelotti Netto, A.Cestana, S. 2004. Simulação da produção de sedimentos em uma sub-bacia hidrográfica experimental com o modelo SWAT. In VI Encontro Nacional de Engenharia de Sedimentos. ABRH. Vitória – Espírito Santo. Brasil. Silva, F. G. B., Neves, F. F., Crestana, S. 2005. Avaliação da perda de solo em sub-bacias hidrográficas da região de Descalvado-SP a partir do modelo AVSWAT. In XVI Simpósio Brasileiro de Recursos Hídricos. ABRH. João Pessoa – Paraíba. Brasil. Silva, F. G. B., Neves, F. F., Crestana, S. 2006a. Simulação de parâmetros de qualidade de água em bacias hidrográficas com o uso do modelo AVSWAT. In VIII Simpósio Ítalo-Brasileiro de Engenharia Sanitária e Ambiental. ABES. Fortaleza – Ceará. Brasil. Silva, F. G. B., Pioltine, V., Minotti, R. T., Crestana, S., Dupas, F. A. 2006b. Estimativa preliminar de perda de solo com o uso do modelo AVSWAT para bacias da região de Luís Antônio – S.P. In VII Encontro Nacional de Engenharia de Sedimentos. ABRH. Porto Alegre – Rio Grande do Sul. Brasil. Souza, A. M. L., Castro, N. M. R., Kaufmann, V., Vitorino, M. I. 2010. Estimativa dos fluxos de calor a partir de imagens orbitais para aplicação na modelização hidrológica. In XVI Congresso Brasileiro de Meteorologia. Belém – Pará. Brasil. Souza, R. M., Santos, I., Kobiyama, M. 2009. O modelo SWAT como ferramenta para a gestão de recursos hídricos: avaliação de vazões de outorga na bacia hidrográfica do altíssimo rio Negro. In XVIII Simpósio Brasileiro de Recursos Hídricos. Campo Grande – Mato Grosso do Sul. Brasil. Trindade, P. B. C. B., Coutinho, L. F. N., Caiado, M. A. C., Heatwole, C. D. 2010. Evaluation of nutrient modeling by SWAT under tropical conditions. In 21st Century Watershed Technology: Improving Water Quality and Environment Conference Proceedings. Universidad EARTH, Costa Rica. UFBA. 2004. Gerenciamento dos recursos hídricos do semi-árido do estado da Bahia: Volume II – Subprojeto enquadramento de rio intermitente – estudo de caso do rio Salitre. Departamento de Engenharia Ambiental. Salvador-BA. Uzeika, T. 2009. Aplicabilidade do modelo SWAT (Soil and Water Assessment Tool) na simulação da produção de sedimentos em uma pequena bacia hidrográfica rural. MS theses. Porto Alegre, Rio Grande do Sul: Universidade Federal do Rio Grande do Sul, Programa de Pós-graduação em Recursos Hídricos e Saneamento Ambiental. Xavier, F. V. 2009. Contribuições metodológicas ao estudo da produção e distribuição espacial de sedimentos na bacia hidrográfica do rio Manso utilizando o modelo AVSWAT. MS theses. Cuiabá, Mato Grosso: Universidade Federal de Mato Grosso, Instituto de Ciências Exatas e da Terra.