Use of geographical information system for determining the erosive potential of hydrographic basins: Case study in the Rio do Campo/PR Basin

Abstract

Soil erosion by water is one of the most important problems of environmental degradation and risk in modern times, worldwide, because it removes rich nutrients from the soil and increases the natural level of sedimentation in rivers and reservoirs, reducing their storage capacity, as well as causing degradation of water quality. The objective of the present study was to estimate soil loss in the Rio do Campo/PR basin, through the Universal Soil Loss Equation (USLE) with support from the Geographic Information System (GIS). The survey of USLE factors proved to be an excellent way of obtaining necessary data for the diagnosis of the basin conditions under study, observing that in 48.1% of the Rio do Campo/PR basin the soil loss was classified as 0 and 10 ton.ha-1.year-1. The loss of large amounts of soil occurs in small percentages in relation to the total area of the basin, covering only 2.57% of the area with values between 300 and 450 ton.ha-1.year-1 and 1.26% of the area with losses greater than 450 ton.ha-1.year-1. Although the largest losses occur in the smallest areas analyzed, it is important to identify them, as they demonstrate the respective susceptibilities to the damages caused by soil losses in the basin. Thus, quantifying soil loss becomes extremely important for the environmental planning of a river basin, being an excellent subsidy tool for land use management and environmental resource management.