Spatial pattern of reference evapotranspiration and effective rainfall applied to ascertain irrigation requirements on the lower Jaguaribe Basin

Abstract

In order to more precisely quantify the water balance over one given area, it is necessary that all local data be geographically located and average values computed over that area being analyzed. In this paper, monthly average values of effective precipitation and reference evapotranspiration were estimated for the municipalities contained the irrigated areas of the Lower Jaguaribe Valley based on 5 weather stations and 12 raingage sites and using the squared inverse distance algorithm. The generated hydrologic balances made it possible to obtain more precise values of volume and flowrate to be allocated to each irrigated field on the watershed.