# Analysis of a Landscape Intensely Modified by Agriculture in the Tiete-Jacare Watershed, Brazil
## 2 Materials and Methods  
### Study Area  
The water resources management in Sao Paulo state is carried out through the Water Resources Management Units (WRMU), instituted by State Laws No. 7.663 of 30/12/1991 and No. 9.934 of 27/12/1994 [27; 28]. The state currently has twenty-two WRMUs delimited by river basins, which encompass the water resources that converge into the mainstream, justifying the need for a link between research and management [29]. Figure 1 represents the Tiete-Jacare Watershed, located in Sao Paulo state, Brazil, between 49\({}^{\circ}\)14\({}^{\prime}\) and 47\({}^{\circ}\)70\({}^{\prime}\) West and 21\({}^{\circ}\)62\({}^{\prime}\) and 22\({}^{\circ}\)79\({}^{\prime}\) South. The region is divided into 37 municipalities, with 1,500,000 inhabitants and a total area of 1,181,090 hectares. The Tiete-Jacare Watershed has a drainage area of 8669.09 km and contains three main rivers: the Tiete River, the Jacare-Guacu River, and the Jacare-Pepira River. According to Koppen-Geiger classification, the climate of this region is between humid tropical (Aw--from October to March) and dry winter (Cfa--from April to September) [30; 31]. The Tiete-Jacare Watershed region is located in both the Atlantic Forest (23%) and Brazilian Savanna (_Cerrado_) (77%) biomes, considered biodiversity hotspots. These regions remain important fragments that preserve an endemic fauna and flora surrounded by an agricultural matrix, where the leading economy is related to agroindustry (sugar, alcohol, citrus, and cellulose) [30; 31]. The watershed territory and boundaries have had an industrial and agricultural outline since the 18 th century. During this period, coffee and sugar production and cattle were the three main economic activities in Sao Paulo state. However, in the 19 th century, coffee production increased and became the primary income source for the state and the country [32; 33]. In addition, the region experienced a development process in this period due to the construction and opening of railroads, which were the main factor of the urban network, attracting the growth of cities near the stations [33; 34]. The first three decades of the 20 th century experienced overproduction crises, primarily attributed to the decrease in external demand because of the economic crisis of 1929. In response to the coffee market crisis, there was an intensification in the production of food crops, livestock, cotton, and sugar cane in Brazil. Between 1931 and 1945, sugarcaneproduction increased by 570%, consolidating Sao Paulo state as the largest producer in Brazil [32; 33]. This remains the case into modern times, further potentialized by ethanol production from sugarcane since 1970. Between the 1960s and 1970s, a reasonable number of health and education infrastructures, including hospitals and higher education schools, were developed. Other agro-industrial segments expanded in this period, such as vegetable oils, soy, meat, milk products, and citrus juice [32; 33]. The modernization of agricultural activities and the regional road and water network influenced the growth of agro-industrial facilities and industries producing chemical inputs, farming implements, and equipment for plants and distilleries,  
Figure 1: Tiéé-Jacaré Watershed-SP study site. which contributed to the expansion process of this region, mainly between the 1980s and the 1990s [30; 33]. The drainage network was, and continues to be, vital for the occupation, management, and development of the region. Through the Tiete-Parana Waterway, various products, such as construction materials, limestone, bran, soybeans, sugar cane, grains, wood, and fertilizers, are transported over an expanse of 1000 km. Currently, the Tiete-Jacare Watershed region presents a diversified economy, with sectors focused on drinks, paper, mechanical metal, and tourism, while also emphasizing the alcohol and sugar complex and the planting and processing of citrus fruits [34; 35].