Environmental and deteriorating state analyses of the watershed Riacho do Tronco, Boa Vista, PB, Brazil

Abstract

This study proposes, from the subdivision of the watershed of Riacho do Tronco in eight sub-watersheds, to diagnose their potential for land use and occupation, determine the areas of conflicts in land use and the level of environmental deterioration of the watershed as a whole, to support planning and the consequent reduction of the expansion of desertification. Based on GIS analysis and field work, the environmental parameters that allowed the establishment of the roughness coefficient of each sub-watershed were calculated, following the methodology proposed by Rocha (1997) for the classification of the natural potential use of each watershed. The results showed that four sub-watersheds are suitable for agriculture, three for livestock and reforestation and one for reforestation only. It was also possible to diagnose land use and occupation of each one and to determine land use conflicts. This represented by inappropriate use of soil considering the natural vocation of some sub-watershed, as well as the occurrence of bare soil and mining activities that occur in some sub-watersheds. Thus, from the analysis of conflict in land use, areas to be afforested, availability for or intense use of agricultural lands and the estimate of areas where correct management practices have to be implemented, it was observed that the watershed of Riacho do Tronco has 42.7% of its area in deteriorated stage. Therefore, the high level of environmental deterioration is evident, with consequent risk of desertification. In addition, considering that this area is located in the Brazilian semi-arid region with economic activities practiced without conservation concerns, it is necessary that the government and organized society foster sustainable principles in the economic activities in this watershed.

Keywords

• Watershed
• environmental deterioration
• desertification