HYDROGEOLOGIC CHARACTERIZATION OF EPIKARST IN HIGH ELEVATION, SEMI-ARID SOUTHWESTERN UNITED STATES

The Mogollon Rim, the south-central escarpment of the Colorado Plateau, in central Arizona is largely comprised of surface karst topography that rapidly drains meteoric water into the groundwater system. Although this region has some recently well mapped cave and karst terrain, the hydrogeology of the karst aquifers is still poorly understood. In a semi-arid, mountainous area where total precipitation and recharge rates are predicted to decline, it is critical to develop models for local and regional aquifers to plan for future hydrologic responses. The network of subsurface conduits and subsequent groundwater flow was characterized by utilizing several cost-effective and non-intrusive techniques including spring monitoring and data analysis. Clover Springs offers a window into the shallow epikarst groundwater flow system on the Mogollon Rim, and has been instrumented with modern technologies to offer quantitative understandings of groundwater flow mechanisms. This research includes the delineation of Clover Springs catchment area, an examination of structural and topographic controls that govern groundwater flow, discharge hydrograph and chemograph analyses, and an assessment of historical hydrogeochemical data from Clover Springs. These coupled studies provide valuable insight to diurnal, seasonal, and annual processes in a complex karst network without the need for costly well drilling or aquifer pumping tests. The results provide important clarification on karst groundwater flow processes on the Mogollon Rim and may be an effective analog to describe recharge mechanisms of similar karst aquifers in semi-arid, mountainous regions around the world.