基于数据库的农业非点源污染最佳管理措施效率评估工具构建

针对流域非点源污染的关键源区，配置最佳管理措施（BMPs，Best Management Practices）是非点源污染控制的有效途径.然而，受限于研究成本和不同地区自然地理条件的差异性，通过实地监测对BMPs削减效率进行评估的研究案例还不多见.多数相关研究仅关注单一类型BMPs的效率评估，使得研究成果仅仅适用于某些特定区域.对BMPs的潜在效益进行评估，可通过收集不同区域内BMPs的削减效率信息来实现.本文采用基于文献的BMPs效率评估方法，通过整理国内154篇关于BMPs研究的文献信息，建立适用于农业流域非点源污染控制的BMPs数据库.在此基础上，采用VBA（Visual Basic for Applications）和SQL（Structured Query Language）程序语言构建BMPs削减效率评估工具箱.该工具箱适用于非点源污染控制措施削减效率的评估，能够根据不同研究区特征，给出目标BMPs的污染负荷削减量，从而为BMPs的优选提供定量依据.以密云水库上游蛇鱼川小流域为案例研究区，根据该流域的非点源污染特征，对拟采用的BMPs进行评估，结果表明：草型植物篱、25 m河岸缓冲带、河岸带畜禽活动护栏以及集中放牧等措施控制效率最高.

A tool for estimating best management practices effectiveness for agricultural non-point source pollution control based on the MS ACCESS

Best management practices (BMPs) are used to control agricultural nonpoint source pollution in the watershed. It is critical to estimate BMP effectiveness prior to implementation. However, the actual effectiveness of these BMPs is not well known because of the cost of implementation and the site-specific status of watershed. Most previous studies on BMP have focused on determining the effectiveness of single BMP. The knowledge obtained from these specific studies is difficult to apply in other study area. Nevertheless, these data would be combined to provide estimates of BMP effectiveness through analyses based on the common available affecting factors. Collection and analysis of existing data from previous studies can be used more effectively in BMP decision-making process. This study establishes a means of estimating BMP effectiveness, based on data from over 154 references, and develops a tool that allows users to obtain BMP effectiveness based on on-site soil and slope conditions. The database includes 60 agricultural BMPs grouped into 6 classes, including Agricultural land use management, Soil erosion control, Nutrient management, Wastewater management, Livestock/manure management, and Nutrient management plan. There is quantitative information on reduction effectiveness of nutrients from non-point source pollution for 60 associated entries at the six classes of BMPs. Based on those references, the factors identified includes slopes, soils, location, and study scale. Data from the combined soil and slope analyses are used to design a BMP effectiveness estimator driven by user-specifìed hydrologic soil groups and slope classes, using the VBA (Visual Basic for Applications) and SQL (Structured Query Language) based upon MS Access 2010 built-in statistical functions. An example on how this tool can be applied in selecting BMPs at Sheyuchuan small watershed located within the upper watershed of the Miyun Reservoir, Beijing, is demonstrated. The estimated results indicate that this tool facilitates effectiveness-based BMP selection for non-point source pollution control by providing BMP effectiveness estimation based on study area characteristics, which is useful for watershed planners and local agencies. The tool can be used as a standalone application or can be linked with other applications. This tool can be easily expanded to include data available in the literature or used as a template for other BMP tools.