Evaluation of potential water quality trading sites with network analysis

A precise trading ratio can help researchers to estimate an accurate water quality trading (WQT) result on both economic and environmental benefits. Most WQT studies focus on the market structure and price of credits, seldom address spatiotemporal variations of environmental uncertainties. Previous study showed the site-specific phenomena of the edge-of-field pollutant load is significant. Likewise stream delivery, lake detention may also have potential to affect the WQT results in space and time scale. This study attempts to analyze and evaluate the potential trading partners based on GIS network analysis techniques with site-specific trading ratios on pollutant load uncertainty and delivery effects. The delivery scenarios based on network connectivity, sources, and constraints coupled with land management scenarios were simulated at Lower Kansas subbasin in northeastern Kansas. The total nitrogen and phosphorus load reductions of between management scenarios as the trading targets had been simulated along stream network in the watershed. Several weighted factors such as flow length, travel time or flow rate were included in the network delivery analyses. The potential trading partners were then prioritized according to the final delivered load reductions under different scenarios within the watershed.