Application of geostatistical methods in analyzing piezometric heads of dams (case study: Shahghasem Dam)

Stability and safety of the dam is one of the most important challenges during construction and performances. The aim of this study is to make accurate water table and piezometric heads through embankment and its foundation of the shahghasem dam which is located near Yasouj city. Applying geostatistical, Simple Kriging, Ordinary Kriging and Weighted Moving Average, interpolation was done using Gaussian, exponential and spherical models. For comprising the results, we use the statistical index including MAE, MBE, RMSE and GSD. Results indicated that Simple Kriging with Gaussian model is the best one, while Ordinary Kriging with Gaussian model and Ordinary Kriging with spherical model are in the next order. The Weighted Moving Average method with different exponents indicated a significant error comparing to other methods. As a result, the depicted maps show a hole through foundation near right abutment of the dam. Finally, being a hole in foundation could strength piping and internal erosion.