Predicting Long-Term Wetland Hydrology from Hydric Soil Field Indicators

摘要

Current regulations governing wetland identification make it virtually impossible to identify freshwater wetland routinely using current technology. Jurisdictional wetlands include areas that are saturated within 30 cm of the surface for 5% of the growing season in 5 or more years out of 10. Such information on wetland hydrology can be obtained by long-term monitoring studies that span both wet and dry years. These require long periods of time (5 to 10 years) to complete, and are too expensive to do at most sites where the information is needed. An alternative approach is to use hydrologic models to estimate water table data over long periods at a few bench-mark sites. These data can be obtained quickly (in less than 6 months). The hydrologic information can be extrapolated to other soils by calibrating soil indicators of saturation for the specific frequencies and durations of saturation estimated by the model. These indicators (basically seen as gray and red colors) occur in most wetland soils that are chemically reduced and can be easily identified during on-site inspections. By using hydrologic models in combination with hydric soil indicators, we should be able to estimate quickly and economically how long the major soils are saturated in the Coastal Plain region of North Carolina.