Estimation of Groundwater Flow Balance Components and Its Error Improvement Using Taguchi Method (Case Study: Mahvelat Aquifer)

Preparation of the conceptual model of groundwater flow, as an essential step in groundwater flow modeling, is one of the primary measures in properly managing groundwater resources, especially in arid areas where most consumption is directed to groundwater resources. Preparation of groundwater balance as an essential component of the conceptual model of groundwater flow is associated with problems such as lack and heterogeneity of information due to lack of proper spatial-temporal monitoring network. In the present study, we tried to provide methods for estimating the groundwater balance equation's components as accurately as possible by using auxiliary data, mathematical-statistical tools, and new capabilities of GIS, such as a geostatistical analyst. These methods were implemented in the Mahvelat aquifer, one of Iran's critical aquifers, for 2001-2012 (12 Years). The balance equation's mean error was calculated to be 26.9% of the total components of the balanced input using the proposed methods of the present study. Then, due to the significant amount of error in the available information, by considering the correction coefficients for the balance equation's components on an annual scale, the absolute value of the errors was minimized using the Taguchi method. The output of these calculations was the optimal values of the corrective coefficients. The result showed that the error was reduced by 97%; from 227 to 115 million cubic meters.