Impact of land use/land cover changes on water quality and hydrological behavior of an agricultural subwatershed

Knowing the influence of land use/land cover changes on the hydrological behavior of a subwatershed is essential to land use planning. The Alto Paraguaçu Watershed is a major producer of fruits and vegetables, and currently the largest producer of English potato in the north/northeast of Brazil. The water availability in the region can be considered the limiting factor to the expansion of agricultural frontiers. Therefore, in order to assess the influence of land use/land cover on the quality and quantity of the water resources in the subwatershed, three sampling campaigns were carried out (two in the rainy season and one in the dry season) at ten points throughout the watershed, as well as the hydrological analysis and land use/land cover changes assessment for both seasons. The objective was to relate land use/land cover indicators with hydrological indicators in order to fit a model to predict water changes in the studied subwatershed. The results showed that the changes that occurred in land use/land cover for the development of the current agriculture have significantly impacted the hydrological behavior in the Alto Paraguaçu watershed. It was possible to observe that the quality and quantity of water were directly influenced by the anthropization process. This study highlights the importance of suitable land use/land cover for the conservation of water resources.