Influence of land use and land cover's change on the hydrological regime at a Brazilian southeast urbanized watershed

Land use and land cover have a direct influence on the hydrological regime. Urbanization and deforestation are accountable for reducing the water infiltration and consequent runoff's increase. These modifications lead to high peak flows responsible for catastrophic events. Thus, this work analyzed the impact of land use and land cover's change on the hydrological regime in a Brazilian southeastern urbanized watershed; considering current and future scenarios. The hydrological model HEC-HMS was used to estimate stream flow and aided in the search for suitable solutions. Using the Land Change Modeler tool made possible to design 2030's land use and land cover in Grande river watershed. Hydrological simulations were carried out for 2030 using HEC-HMS. Some of the forested areas were replaced by agriculture and pasture. The agricultural areas were the ones that showed greater expansion. Such changes contributed to a mean increase of 52% in the stream flow hydrograph when compared to the watershed's current scenario. After the use of best management practices, the stream flow hydrograph had a mean reduction of 44%. The structures considered were bio-retention cells, rain gardens, infiltration trenches, and permeable pavements for urban areas. For rural areas, the practices suggested were level terraces, no-till farming, and contour farming. All structures were applied in a distributed manner throughout the watershed. Therefore, it is concluded that land use and land cover's change in Grande river watershed significantly influence the stream flow regime, and the use of best management practices proved efficient in reducing floods.