Hydrogeological characterization of Gold Valley: an investigation of precipitation recharge in an intermountain basin in the Death Valley region, California, USA

摘要

Gold Valley is typical of intermountain basins in Death Valley National Park (DVNP), California (USA). Using water-balance calculations, a GIS-based analytical model has been developed to estimate precipitational infiltration rates from catchment-scale topographic data (elevation and slope). The calculations indicate that groundwater recharge mainly takes place at high elevations (>1,100m) during winter (average 1.78mm/yr). A resistivity survey suggests that groundwater accumulates in upstream compartmentalized reservoirs and that the groundwater flows through basin fill and fractured bedrock. This explains the relationship between the upstream precipitational infiltration in Gold Valley and the downstream spring flow in Willow Creek. To verify the ability of local recharge to support high-flux springs in DVNP, a GIS-based model was also applied to the Furnace Creek catchment. The results produced insufficient total volume of precipitational infiltration to support flow from the main high-flux springs in DVNP under current climatic conditions. This study introduces a GISbased infiltration model that can be integrated into the Death Valley regional groundwater flow model to estimate precipitational infiltration recharge. In addition, the GISbased model can efficiently estimate local precipitational infiltration in similar intermountain basins in arid regions provided that the validity of the model is verified.