New Mexico Geological Society Annual Spring Meeting — Abstracts

Karst represents about 25 percent of the New Mexico landscape with hundreds of caves and numerous karst springs throughout the state. While many of the major systems have been studied to varying degrees, many questions remain to better understand and protect these unique groundwater systems. The National Cave and Karst Research Institute is continuing to grow research on these systems in the state and beyond to better understand how to ensure groundwater resource security.

Expanding on work from other parts of the country, we have begun focusing our efforts on the Government Spring – Fort Stanton Cave system. Utilizing existing geologic, geospatial, and hydrologic data, we modeled the intrinsic vulnerability of the groundwater system to human activities in the drainage basin using a modified version of the COP method (Vais et al. 2006; Jones et al. 2018).

The resulting spatial vulnerability modelof the greater Rio Bonito and upper Rio Hondo watersheds, showed generally lower vulnerability with some areas of higher vulnerability. Surface areas with the highest potential to impact groundwater resources and Government Spring are areas proximal to the known sinking streams, areas close to faults along these same streams, and where the aquifer units, San Andreas Formation and Artesia Group, are exposed at the surface. To validate these results and improve our ability to mitigate impacts, next steps in the project include qualitative and quantitative dye tracing efforts in the basin.

References:

1. Jones, N.A., Hansen, J., Springer, A.E. et al. 2018. Modeling intrinsic vulnerability of complex karst aquifers: modifying the COP method to account for sinkhole density and fault location. Hydrogeology Journal27: 2857–2868. https://doi.org/10.1007/s10040-019-02056-2
2. Vías, J.M., Andreo, B., Perles, M.J. et al. 2006. Proposed method for groundwater vulnerability mapping in carbonate (karstic) aquifers: the COP method. Hydrogeology Journal14: 912–925. https://doi.org/10.1007/s10040-006-0023-6