New Mexico Geological Society Annual Spring Meeting — Abstracts

In arid and semiarid regions, mountains provide most of the freshwater to the surrounding basins. Mountain-block recharge (MBR) is an important component of basin groundwater replenishment. Previous studies show that MBR in the volcanic San Juan Mountains can be as much as 38% of annual precipitation. With highly permeable volcanic non-welded tuff, and fractured welded tuff, the Jemez Mountains should have similar or even larger rate of MBR. MBR starts with water partitioning on the mountain hillslopes. In this presentation, both specific and generic high-resolution hydrologic simulations were conducted to understand hillslope water partitioning. With a given bedrock hydraulic property, soil type, and vegetation coverage, the water partitioning is primarily controlled by topography-modified evapotranspiration (PET) to precipitation (P). Based on the results, potential distributed MBR (or the maximum possible MBR) was estimated as the function of PET/P. Similarly, the total water yield, defined as P-ET, was estimated as a function of PET and P.

Finally, maps of potential distributed MBR and total water yield were constructed for the Jemez Mountains based on the PET and P maps. PET was estimated from the maximum and minimum daily geostatistic model (ASOADeK) was applied to produce the precipitation map.