| Wetlands provide many crucial ecological and environmental functions, such as flood control, ground-water recharge, and fish/wildlife habitat support. Characterized by a shallow water table, wetlands are prone to be filled in, drained or ponded by a variety of human activities. Thus, wetland protection has become an issue of national emphasis for the environmental policies in the United States. Identifying vulnerable wetlands, whose functions are more likely than others to be degraded by human activities, is critically needed to facilitate the wetland regulation processes.; The main objective of this study was to develop a geospatial methodology for rapidly assessing and prioritizing wetland vulnerability under anthropogenic pressures at a watershed scale. Wetland vulnerability index (WVI), in this study, was calculated by compositing a wetland's biological, hydrological, chemical, physical and socioeconomic vulnerability index; vulnerability index, for each of the five categories, was conceptualized as a three-dimension variable interactively determined by the wetland's hydrogeomorphic/landscape characteristics, functions and values, and adverse anthropogenic pressures in the particular category. Suitable indicators were designed and measured accordingly using geospatial methods, aiming to alleviate the needs for time-consuming field surveys. Fuzzy ranking algorithms were applied to address the uncertainties arising from data collection, indicator measurement, and the incomplete knowledge of the interrelationships among various indicators. A GIS-based decision support system (DSS) was developed to provide user-friendly interfaces to facilitate the processes of wetland vulnerability assessment, making itself a useful tool for wetland managers and public stakeholders with little geospatial technology background.; Applied in the Little Blue River Watershed, Jackson County, Missouri, the geospatial methodology for assessing wetland vulnerability was demonstrated to be both efficient and effective in providing baseline and pre-warning information on wetland vulnerability at a watershed scale. The wetland vulnerability assessment results were demonstrated to have a high correlation coefficient of 0.87 with the field reconnaissance results. Based on the spatial patterns revealed by the wetland vulnerability assessment results, non-spatial and spatial decision rules were derived and analyzed in details, which could provide valuable guidelines for wetland protection and restoration. |
