DEPTH TO GROUNDWATER: INTERPOLATION TECHNIQUES USING LARGE DATASETS FROM GROUNDWATER WELLS IN LOUISIANA

The purpose of this study is to interpolate average depth to groundwater in all major Louisiana aquifers. Increasing usage of groundwater and decreasing recharge has become a growing concern in Louisiana. Through a National Science Foundation Water Sustainability and Climate grant, we are collecting water level data to interpolate the depth to groundwater. This information will be used to quantify the energy required for pumping groundwater among various users and to ultimately encourage users of depleted aquifers to utilize surface water in an effort to reduce groundwater over pumping.

Raw groundwater well data was collected through the USGS National Water Information System for all years from 1960 to present for each aquifer system in Louisiana. Grand average, decadal average, and seasonal averages were calculated by station. Each station was then assigned to an aquifer system. Once the averages were determined per local aquifer per station, kriging techniques were performed using the spatial analyst extension in ESRI’s Arc-Map. The interpolated functional surfaces for each aquifer were then clipped to their corresponding boundary and all local aquifers were merged into one single mosaic dataset. The interpolated dataset shows spatial heterogeneity in average depth to groundwater and qualitative analyses are presented here to demonstrate spatial correlations between groundwater levels and differing water well user types.