Aplicação do curve number como forma de avaliar os impactos nas mudanças no uso e ocupação do solo e na resposta hidrológica de uma pequena bacia semiárida

Abstract

Information on human land use occupation are important tools for the establishment of urban expansion policies as well as for the management of water resources, since the lack of control in the management of vegetation and soil can cause changes in infiltration characteristics and changes in the hydrological response of watersheds. Thus, this study evaluated the efficiency and feasibility of using the Soil Conservation Service (SCS) parameter CN, curve number, todetermine the temporal evolution of the change in the land use, in the infiltration capacity and in the concentration time of the Batateiras river basin of the region of Juazeiro do Norte (CE), from 1985 to 2018, through data on land use and occupation available through the MapBiomas platform. The results showed that there was a strong change in land use and occupation in the region, presenting a 25% loss in the forest area and an increase of 323% in the urban area from 1985 to 2018. The soil's infiltration capacity, consequently, suffered a reduction in areas with high infiltration potential, from 70% in 1985 to 50% in 2018. The municipality's average curve number increased from 79.4 to 82.1 in the 33 years of the evaluated period and the concentration time of the Batateiras river basin, located in the interior of the county, reduced from 13.1 hours to 11.9 hours, accumulating a reduction of 1.2 hours as a consequence of the county’s land use changes.