Spatial Variability Analysis of the Piezometric Levels the Groundwater: Case Study in the Sub-Basin of the Coxim River, Mato Grosso do Sul

Abstract

The information about the piezometric surface of groundwater is necessary for an optimized and sustainable exploitation. This study aims to analyze the spatial variability of the piezometry in a system of free aquifers. The study area is comprehends the sub-basin of the Coxim River, located at the central portion of São Gabriel do Oeste Municipality, Mato Grosso do Sul, characterized by the intense agricultural use. Piezometric data from 22 wells were analyzed and the theoretic semivariogram was adjusted by the spherical model. The cross validation was used to measure the exactness of the spherical model proposed. It was checked the existence of a strong spatial dependence, a reach of 16,5 Km and an overestimation of the groundwater surface of 10% on the kriging, an error considered acceptable for the interpolation of the data.