Community DECISIONS (Community Decision Support for Integrated, On-the-ground Nutrient Reduction Strategies)

摘要

Successful watershed management can be enhanced by effective stakeholder involvement. Community DECISIONS (Community Decision Support for Integrated, On-the-ground Nutrient Reduction Strategies) was designed to assist watershed stakeholders in evaluating and selecting strategies to reduce watershed nutrient imbalances. The decision process begins with stakeholders formulating objectives for the watershed. Through the Vector Analytic Hierarchy Process (AHP), stakeholders rank the objectives. Alternative nutrient management strategies are simulated using a nutrient accounting algorithm and nutrient treatment database. Based on nutrient loadings and implementation costs estimated for each strategy, stakeholders determine which strategies best achieve their objectives.The DECISIONS system was applied in the North Fork Shenandoah River watershed in Virginia, USA. Stakeholders came from the public and private sectors, including local government, state natural resource agencies, environmental organizations, and agriculture. The simulated strategies included point source (PS) upgrades and nonpoint source (NPS) management practices, implemented in different combinations across the watershed for each strategy. The cost per kg of nutrient reduction was an order of magnitude greater for NPS than for PS practices. The NPS control cost effectiveness can be improved by targeting practices rather than applying them across the watershed. Targeting riparian buffers to streamside cells delivering greater than 0.1 kg/ha/yr of N or P to the stream resulted in 2/3 the nutrient reduction at 1/3 the cost of implementing buffers along every stream. The stakeholders in the case watershed reported that the information provided by the DECISIONS system was useful in evaluating strategies to achieve objectives for their watershed.