GROUNDWATER RECHARGE POTENTIAL ZONE MAPPING USING A GEOSPATIAL APPROACH- A CASE STUDY IN THE HIGH PLAINS AQUIFER

Groundwater is an invaluable commodity for human population especially in arid and semiarid areas. For sustainable development and efficient resource management, it is important to determine groundwater recharge potential zones and fluxes. Finding recharge potential zones are also important for risk and aquifer vulnerability assessment. There are several methods including geological, hydrogeological, geophysical and geospatial techniques that are available for recharge potential zone mapping. The High Plains Aquifer is a very important resource which serves as the primary drinking water source for an eight-state region. With continued decline of water levels due to withdrawals for agricultural irrigation and drinking water supply, proper assessment of water availability is required for local water managers and planners to make informed decisions about future water use and water management practices. This study will support sustainable management of groundwater resources and contribute towards enhanced and robust estimates of groundwater recharge by producing a groundwater recharge potential map of the High Plains Aquifer.

For estimating recharge efficiently, it is important to identify and assess large-scale groundwater recharge potential zones first. This study uses geospatial techniques integrating remote sensing and a geographic information system for exploring potential recharge zones instead of conventional ground surveys (on-site exploration). This approach saves time, effort, and cost as well as provides a wider scale of the spatio-temporal distribution of observations. The factors considered in this study are lithology, land use/land cover, lineaments, drainage density, and slope. The influence of the factors for groundwater recharge and the interaction between them are also being examined as the factors have different degrees of influence during the recharge process.

The results will show the most effective recharge potential zones and classification (excellent, good, moderate, and poor) of potential recharge areas and their coverage along the surficial expression of the High Plains aquifer. The results will also aid in identifying areas of interests for conducting further detailed hydrogeological ground surveys.