Water Resources Research Act Program

Details for Project ID 2014LA94B

Groundwater Recharge Estimation under Climate Change Impact for the Southern Hills Aquifer System of Southeastern Louisiana and Southwestern Mississippi

Institute: Louisiana
Year Established: 2014 Start Date: 2014-03-01 End Date: 2016-02-28
Total Federal Funds: $15,000 Total Non-Federal Funds: $30,030

Principal Investigators: Frank Tsai

Abstract: The goal of the project is to develop a GIS-based water budget framework to estimate groundwater recharge under climate change for the area of Southern Hills aquifer system (SHAS). Increases of concentrations of CO2 and other greenhouse gases have a significant effect on global climate, precipitation and hydrology, which in turn influences recharge to aquifers. Groundwater recharge plays a vital role in replenishing aquifers, which impacts on groundwater availability. Groundwater recharge study is imperative to the SHAS because it is a sole source aquifer system to the citizens of southeastern Louisiana and southwestern Mississippi. To trace the climate impact and its consequent groundwater availability, this project proposes a GIS-based framework that connects climate models to a high-resolution hydrologic model to quantify long-term groundwater recharge. This project proposes the Hydrologic Evaluation of Landfill Performance (HELP3) model, a hydrologic model, to estimate spatial-temporal distribution of potential recharge for a regional scale. HELP3 model is especially suitable for the SHAS recharge study due to humid climate in this region and the use of a region-scale water budget approach. To develop the HELP3 model, the project will collect detailed surficial soil property and land cover from the NRCS and the USGS to derive a map of curve number. Wireline well logs and drillers logs will be analyzed to determine stratigraphic lithology up to the first major sand encountered beneath the soil layer. The project will utilize GIS to intersect various datasets and create hundreds of thousands of subdivisions, each of which requires a HELP3 model run. The framework will include parallel programming to distribute the massive HELP3 model runs to supercomputers to expedite computation time. Under the parallel computation, the HELP3 model will be calibrated by the USGS WaterWatch runoff dataset and will be verified by the MOD16 evapotranspiration dataset. The HELP3 model will be adopted to estimate historical recharge for 1950-2010. For climate change scenarios, the general circulation model (GCM) downscaled daily precipitation and temperature obtained from USGS CASCaDE Project Climate Data will be used as the forcing input to the HELP3 model. The emission scenarios considered in this study will be A2, B1 and A1FI from NCAR Parallel Climate Model 1 (PCM) and from the NOAA Geophysical Fluid Dynamics Lab's GFDL CM2.1 model. The HELP3 model will be used to estimate recharge for three future periods: 2020’s climate (2010-2039), 2050’s climate (2040-2069) and 2080’s climate (2070-2099) for the SHAS. The project will predict the range of possible future recharge changes between the most optimistic scenario and the most pessimistic scenario.