|Sauer, Thomas - Tom|
Submitted to: Karst Water Environment Symposium
Publication Type: Proceedings
Publication Acceptance Date: 2/27/1999
Publication Date: N/A
Interpretive Summary: Karst is the term used to describe regions where the bedrock has large openings including caves and springs that formed when the carbonate rock dissolved and washed away. It is common, in areas with more uniform geology, for computer models of water and contaminant flow processes to predict these processes reasonably well. It is very difficult to develop accurate computer models for karst systems due to the random nature of the bedrock. This paper describes research conducted at the Savoy Experimental Watershed where the focus is to improve understanding of water flow in karst environments. Numerous studies are underway to measure the existing water quality and the geologic, hydrologic, and soil resources of this area. The emphasis of the modeling work is on testing theories and developing ideas on how water flows in the bedrock of this watershed. These models are seen as very valuable because they can be used to not only describe processes in this watershed but allow for comparisons with other watersheds. Models that predict behavior are much more difficult to develop and test because it is not possible to accurately describe all of the underground flow paths.
Technical Abstract: Karst hydrogeology does not lend itself to easy interpretation, and many well-respected researchers hold little hope of developing numerical tools and models that will be able to accurately predict ground-water flow and transport in karst aquifers at less than regional scales (from kilometers to tens of kilometers). Unfortunately, most of the ground- water problems faced today are at much smaller, site-specific scales - typically on the order of meters to tens of meters. This paper describes the results of a multidisciplinary, long-term effort to fully characterize the Savoy Experimental Watershed, a 1250-hectare University of Arkansas research property typical of the shallow karst basins in the southern Ozarks of Northwest Arkansas and the midcontinent of North America. Important objectives of the preliminary collaboration were to establish baseline water quality, to fully characterize the hydrology, the geology, and the soils, and to quantify each identifiable component of the hydrologic cycle at site-specific field scales for the complete range of hydrologic conditions encountered. Emphasis is on process assessment and hypothesis testing models. Models of this sort can be valuable tools in extending our understanding of observed hydrologic behavior elsewhere. Predictive models are still viewed with utmost caution, however, because most flow boundaries and flow paths in karst aquifers are not accessible, and one single undefined boundary or flow path can render model calculations meaningless at site-specific scales.