1. Use of the chloride ion in determining hydrologic-basin water budgets — A 3-year case study in the San Juan Mountains, Colorado, U.S.A
- Author
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Hans C. Claassen, Michael M. Reddy, and Douglas R. Halm
- Subjects
Hydrology ,Moisture ,Lithology ,medicine ,Precipitation ,Groundwater recharge ,Surface runoff ,Surface water ,Chloride ,Geology ,Groundwater ,Water Science and Technology ,medicine.drug - Abstract
Measurement of chloride concentration and water equivalent in precipitation and recharge at a site can be extrapolated to determine available moisture in a nearby basin. This method also may be extrapolated to a basin with similar climatic characteristics if precipitation, vegetation, and topographic data are available. The average accuracy of the total of evaporation, recharge, and runoff (assuming no storage) was about 10% of total precipitation. Soil-moisture measurements indicate the entire 10% error in moisture balance can be attributed to annual changes in storage. Data requirements for the method are considerably less than data requirements for energy-budget methods to determine available moisture. Potential applications of the method to hydrologic problem-solving are: 1. (1) Estimating total available moisture from chloride concentrations in groundwater or surface water or both. 2. (2) Modeling paleoclimate scenarios and evaluating their correctness by comparison with paleo-groundwater chloride concentrations. 3. (3) Providing an independent comparison for water budgets obtained by energy-budget methods. Obviously the method cannot be applied readily to systems with a lithologic source of chloride. Most systems primarily consisting of tuff, intrusive volcanic rock, nonmarine sediments, quartzite, and other metamorphic rocks will be suitable for application of the model.
- Published
- 1986