# Analysis of a Landscape Intensely Modified by Agriculture in the Tiete-Jacare Watershed, Brazil
## 4 Discussion  
The increase and predominance of agricultural activities driven by sugar cane coincide with the history of Sao Paulo, which is considered to be the largest sugar cane and alcohol producer in Brazil. As is also the case in the Tiete-Jacare Watershed, this is due to the favourable conditions for sugar cane cultivation, with a high number of areas with fertile soils and water resources, which causes the increase in average productivity in some regions to be higher than in other regions of the country [52; 53]. These characteristics, such as natural vegetation conversion in other land use and land cover and forest loss in general, were also found in other studies on different regions in the state and the country [54; 55; 56]. This vegetation loss value over time was similar to that reported by [PERSON] [57] and [PERSON] [58], who also evaluated the forest and vegetation covers in the _Cerrado_ and the seasonal semideciduous forest regions (vegetation types present in the study area) [57; 58]. The authors evidenced the progression of vegetation loss, isolation, and fragmentation in the landscape due to anthropic actions. Other regions in the country with different biomes and contexts also presented similar results, such as those found by [PERSON] et al. [6], who showed the loss of vegetation in the Sao Luis municipality, Maranhao state which is a highly urbanized region. It is essential to highlight that this study did not focus on the fragmentation processes and their spatial patterns. However, we noticed in our study area an increase in forest loss, and consequently in the fragmentation process, due to land use and land cover changes. Important initiatives to analyse the land use and land cover changes in Brazil are the Brazilian Annual Land Use and the Land Cover Mapping Project (MapBiomas). The project involves a collaborative network that relies on the Google Earth Engine platform and its cloud processing and automated classifiers' capabilities to generate Brazil's annual time series on a scale of 1: 250.000. The results encompass the years 1985-2019, when a significant loss of vegetation was noticed in all Brazilian biomes due to agricultural activities [59]. Figure 10: Number of pixels found for the years 2016, 2017, and 2018. A management plan is then necessary to develop actions and policy strategies to minimize the impacts of land use and land cover changes, and to avoid the landscape's fragmentation. This is an ongoing process due to the expansion of anthropogenic activities, not only for the watershed studied herein, but for the state and the country as a whole. These negative impacts can compromise the environmental structures and ecosystem services, affecting the biodiversity, water resources, climate regulation, and the quality of soils that support forest cover and are significant energy sources for life [60; 61]. The unplanned land use and land cover occupation and the inadequate soil management have caused several environmental problems, including soil compaction and desertification. On watersheds, these impacts decrease the infiltration of rainwater and increase runoff - factors that intensify the water erosion process and the loss of soil quantity and quality [62; 63]. In the case of water resources management, the issue of water quantity and quality is attributed to the pollution caused by different sources, such as industrial, household, urban, and agricultural effluents, as well as to deforestation (in a landscape perspective). The contamination by effluents involves the improper discharge of materials and industrial products used in many processes, which are a complex concern to the environment, considering the concentration and volume of the waste produced. The resulting scenario is the degradation of water sources, with a consequent increase in plants and algae due to the use of nitrogen and phosphorus by farms and confined animal production [64; 65].