Caracterização física e socioambiental da microbacia hidrográfica do Riacho Namorado no município de São João do Cariri-PB.

Abstract

This study aimed characterize the physical and socio environmental of the Namorado Watershed, located in the municipality of São João do Cariri-PB by morphometric analysis, preparation of thematic maps, estimating the erosivity index, socio-environmental diagnosis of the population, identification of water use and climate suitability of crops for the region. The morphmetric parameters and production of thematic maps were obtained with the ArcGIS 9.3 Software in a GIS environment. The estimation of rainfall erosivity index was to support the universal equation of loss and socio-environmental diagnosis the methodology of Rocha (1997). Were obtained through technical visits and photographic record information that identified the use of water resources in the catchment. Based on the climatic water balance (BHC) and evapopluviograph of the study region, the classification of the climatic skills of crops preestablished ande characterized was obtained. The results showed that the watershed is mall (13.85 km²) and less extensive (5.6 km from the main course) with low drainage density (about 1.66 km/km²) and hydrographic (0.722 channels/km²). The river hierarchy is of 2° order with low hypsometric 1 amplitude (130m) and reliefmostly flat and smooth rolling. The erosivity is higher in the months of February, March and April, coinciding with the highest monthly precipitation data. The socio-environmental diagnosis showed that the population has low levels of education and income, are land owners and residents for over ten years in the region. Families use firewood as anergy source, associated with GLP. The main sources of water are tanks and ponds and the solid waste is burned or disposed freely in the environment. Agriculture and livestock are the main economic activities of the properties, with the production used primarily for family subsistence. The multiple uses of water in the reservoirs of the watershed are: irrigation, agriculture and low water supply for humans. The agroclimatic zoning showed only full fitness for the cultivation of sorghum, limited ability for beans, cassava and upland cotton; unsuitable for pineapple, banana, cashews, sugar cane, castor bean, maize, sisal; and no ability to moderate for any kind of cultivation.