Comparison of the interpolation methods for estimation and interpretion of the piezometric heads through embankment dams (case study: Shahghasm dam)

Leakage of dams causes water losses and in some cases endangers the stability of the dam. Controlling stability and safety of the dam is one of the most important challenges during construction and exploitations of civil projects. By obtained interpolation from piezometers, the water stability level of the dam can be achieved. After interpolations in Shahghasem dam by using surfer Software 9, the minimum curvature method having with lower values (RMSE = 5.26) and (MAE = 3.67) and (R2 = 0.77) is the best method for finding the height of water stability along Shahghasem dam. Polynomial regression and Kriging methods are the next priority. Consideration of iso-line map of the Kriging method showed a hole in dam foundation. The results of the minimum curvature method confirm the results of Kriging method and both results indicated a subsurface cavity too. Existence of this hidden cavity can be a danger for water loss and stability of dam.