Spatiotemporal Groundwater-Level Change for the Evaluation of Groundwater Use and Dynamics

Abstract:

Sustainability of water resources is a particular concern in arid and semiarid regions including the southwestern USA. With increasing water needs and diminishing supplies due to drought, surface water shortfalls are leading to increased groundwater extraction. Groundwater extraction may provide short-term resiliency of the hydrologic system at the cost of long-term resource sustainability. Proactive conjunctive use of surface and subsurface water requires research-based information. The inaccessibility and variability in groundwater data can make it challenging to examine impacts of drought, changes in agriculture, and population variability. The purpose of this study was to advance our understanding of changes in groundwater levels and how they relate to water use dynamics. We utilized both spatial and temporal methods for evaluation of changes in groundwater level data. We compiled monitoring data provided by several government agencies in New Mexico, simulated, with loess regression, the temporal trends between data collection periods, and used geographic information system software to spatially represent changes in groundwater levels for various time intervals. Wells located closer to major rivers typically had lower rates of decrease in groundwater elevation. Areas without surface water had higher rates of groundwater elevation decrease. Several regions had reversals in groundwater-change trends from increasing groundwater elevation to decreasing and vice versa. There were some anomalously increasing groundwater elevations even when overall groundwater elevations decreased in certain areas. The rate of water-level change as a function of time shows promise for evaluation of groundwater use and dynamics, thus providing the basis for improved groundwater sustainability.