Groundwater use for agricultural purposes has been intensified in the State of Sergipe, mainly in the regions with more serious water shortage from surface sources. However, irrigation is still restricted to small areas like home gardens. In part, this problem is due to lack of studies on characterization of water resources, including availability and quality of groundwaters, detecting the spatial distribution of viable sources of groundwater for different uses. The potential hazards related to soil salinity and sodicity, toxicity of specific ions for crops, and clogging of components of microirrigation systems were evaluated. Physicochemical data of water from 278 deep wells located in Piauí River Basin, in the State of Sergipe, Brazil, were used considering the FAO restriction criteria for irrigation purposes. Maps of spatial distribution of groundwater quality indicators in the watershed were prepared by ordinary kriging procedures. Groundwaters showed good quality for irrigation use, mainly in the center-downstream portion of the river basin. There was a trend in increasing the salt concentration in water from the coast to inland in the Piauí River Basin area.
groundwater resources; water quality indicators; spatial analysis; kriging
