Spatially-Distributed Cost-Effectiveness Analysis Framework to Control Phosphorus from Agricultural Diffuse Pollution

• Published in: PloS one Vol. 10; no. 8; p. e0130607
• Main Authors: Geng, Runzhe, Wang, Xiaoyan, Sharpley, Andrew N, Meng, Fande
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 27.08.2015; Public Library of Science (PLoS)
• Subjects: Agricultural economics; Agricultural management; Agricultural pollution; Agricultural practices; Agricultural watersheds; Agriculture; China; Computer simulation; Cost analysis; Cost benefit analysis; Creeks & streams; Economic aspects; Environmental Pollutants - analysis; Environmental Pollutants - chemistry; Environmental Pollution - prevention & control; Environmental protection; Eutrophication; FORTRAN; Hydrologic models; Hydrology; Integrated approach; Load; Methods; Models, Theoretical; Nonpoint source pollution; Optimization; Phosphorus; Phosphorus - analysis; Phosphorus - chemistry; Placement; Pollutants; Pollution; Pollution control; Pollution effects; Receiving waters; Risk Assessment; Rivers; Sensitivity analysis; Simulation; Software; Soil erosion; Statistical analysis; Tourism; Water pollution; Water Quality; Water shortages; Water Supply; Watershed management; Watersheds; China; United States; Beijing China; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0130607

Best management practices (BMPs) for agricultural diffuse pollution control are implemented at the field or small-watershed scale. However, the benefits of BMP implementation on receiving water quality at multiple spatial is an ongoing challenge. In this paper, we introduce an integrated approach that combines risk assessment (i.e., Phosphorus (P) index), model simulation techniques (Hydrological Simulation Program-FORTRAN), and a BMP placement tool at various scales to identify the optimal location for implementing multiple BMPs and estimate BMP effectiveness after implementation. A statistically significant decrease in nutrient discharge from watersheds is proposed to evaluate the effectiveness of BMPs, strategically targeted within watersheds. Specifically, we estimate two types of cost-effectiveness curves (total pollution reduction and proportion of watersheds improved) for four allocation approaches. Selection of a ''best approach" depends on the relative importance of the two types of effectiveness, which involves a value judgment based on the random/aggregated degree of BMP distribution among and within sub-watersheds. A statistical optimization framework is developed and evaluated in Chaohe River Watershed located in the northern mountain area of Beijing. Results show that BMP implementation significantly (p >0.001) decrease P loss from the watershed. Remedial strategies where BMPs were targeted to areas of high risk of P loss, deceased P loads compared with strategies where BMPs were randomly located across watersheds. Sensitivity analysis indicated that aggregated BMP placement in particular watershed is the most cost-effective scenario to decrease P loss. The optimization approach outlined in this paper is a spatially hierarchical method for targeting nonpoint source controls across a range of scales from field to farm, to watersheds, to regions. Further, model estimates showed targeting at multiple scales is necessary to optimize program efficiency. The integrated model approach described that selects and places BMPs at varying levels of implementation, provides a new theoretical basis and technical guidance for diffuse pollution management in agricultural watersheds.