Determination of Groundwater Spring Potential Using Maximum Entropy, GIS and RS Emphasizing HAND Topographic-Hydrologic New Index (Case Study: Urmia Lake Basin)

The purpose of this research is to determine the groundwater potential of areas and to prioritize the factors affecting it using the maximum entropy method and the new height above the nearest drainage index. In the present study, 14 effective indicators have been used for groundwater potential including topographic, geological, climatic, hydrological and land use factors as well as a new height above the nearest drainage index (HAND). First, the factors were divided into two parts including of topographic and other factors such as geology, climate, hydrology and land use, and groundwater potential map was prepared based on them. Then, with the integration of the indices, the final groundwater potential map was prepared. Of the 2547 springs, using the Mahalanobis distance method, 60% of the data was classified as test data and 40% as validation data. The results showed that according to topographic indices, other factors and the combination of all indicators, 38.5, 27.4 and 34.7 percent of the area have groundwater potential, respectively. Also based on Jackknife Diagram, the altitude, land use, slope, relative slope, HAND index and lithology were the most important factors influencing groundwater potential. The area under curvature (AUC) based on ROC diagram indicates accuracy of 83, 83 and 85% (very good) at the training stage and 82, 81 and 84% (very good) in the validation step based on topographic indicators, other factors and the integration of all indicators. Given that the HAND index has been an effective factor of groundwater, it has a crucial role in identifying areas with groundwater potential.