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 Sustanibilability and Climate grant, we are collecting water level data to interpolate the depth to groundwater in an effort to quantify the energy required for pumping groundwater among various users. This information will be used to encourage users of depleted aquifers to utilize surface water order to reduce groundwater over pumping.

Raw groundwater well data by well was collected through the USGS National Water Information System. For all years from 1960 to present for each aquifer system in Louisiana were calculated by station. Grand average, decade average, and seasonal analysis were calculated by station. Each station was then assigned to an aquifer system. Once the averages were found per local aquifer per station, kringing 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 in order to merge all local aquifers into one single mosaic dataset.

The interpolated dataset showed spatial heterogeneity in average depth to groundwater. Furthermore, the larger research team will use the singular mosaic dataset, to calculate the energy needed to pump water from each aquifer. Qualitative analyses are presented here to demonstrate spatial correlations between depth to groundwater and identifying differing water well users.