This study had the main objective of evaluating the impacts of agricultural activities on water quality of Salitre watershed in the brazilian semi-arid region. For that, 92 water sources, located in areas with and without the influence of irrigation, were analyzed during rainy and dry seasons in 2001, evaluating the main parameters of water quality for human consumption and irrigation. From the results the influence of irrigation on water quality was observed, with the occurrences of significant increases of electrical conductivity of the waters and saturation extract of the soil; increases in the parameters indicate low efficiency of farming systems, 35 and 77% of the water sources were classified as C3 and C4, respectively. Also that 78% are located under calcareous formations and its influence on water quality can be observed from the high total dissolved solids (TDS = 7,940.0; 5,060.0 mg L-1), sodium adsorption ratio SAR = 25.27; 6.71 (mmol L-1)½, total hardness (TH = 2,999.6; 2,940.0 mg L-1), chloride percentage (ClP = 97.51; 94.59%), among other parameters, limiting their utilization; these results point out the need for strategies of preservation and conservation of the water resources and soils of the Salitre watershed in order to guarantee its sustainability.
environmental impacts; irrigation; water resources; semi-arid
