HIGH RESOLUTION STATEWIDE GROUNDWATER RECHARGE MODELING IN NEW MEXICO

The rate and distribution of groundwater recharge to New Mexico’s aquifers is the least understood aspect of the state’s water budget. Despite a history of precise and distributed measurements quantifying surface water flow, water table elevations, precipitation amounts, as well as current models that describe evapotranspiration, a statewide assessment of recharge has not been completed. While recharge estimates and studies of recharge processes have been conducted, the effort to date has been on the basin scale, or by county and water planning region. With a long-term goal of estimating groundwater recharge on a statewide scale, this study seeks to compile existing recharge estimates throughout the state and to construct a recharge area map. We have compiled several recharge estimates made in New Mexico, many of which are from academic and government studies. Data are displayed in a format that contains the study citation, location (individual basins, counties, and water planning regions), recharge estimate, methodology, and other important information. A geographic information system (GIS) layer was created to display locations of recharge estimate research and water resource planning studies. A GIS-based distributed parameter soil water balance model, the Evapotranspiration and Recharge Model (ETRM) was developed to simulate recharge using gridded precipitation, reference evapotranspiration, geology, vegetation cover, and soils data. Results show high recharge in the mountainous areas of the state, which typically have thinner soils, lower temperatures, and higher rates of precipitation than the lowlands.