Abstract

Technically sound water management practices in arid to semi-arid regions require effective quantification of model input parameters. Mountain-front recharge is one of the most uncertain parameters in groundwater flow models due to the complexity of estimation. This paper evaluated three mountain-front recharge estimation techniques using a numerical model developed for the Southern Jornada Del Muerto Basin, New Mexico. Digital elevation model (DEM) and distributed precipitation maps were used to delineate recharge zones in the study area on geographic information system (GIS) platform. Statistical and residual parameters were used to assess the reliability of the calibrated recharge. An estimated annual recharge of about 3,360 enters the basin through ephemeral streams. Simulated heads from the three estimation techniques had approximately equal mean, with different variance. Analysis of variance on the simulated piezometric heads revealed that all the three empirical methods were consistent with the observed data. Waltemeyer equation proved to be more efficient in estimating mountain-front recharge as it gave the closest match between the observed and simulated piezometric heads and other basin-specific climatic characteristics.

Key words: Mountain-front recharge, numerical model, Southern Jornada Del Muerto Basin, GIS.