Development And Application Of Agricultural Non-point Source Pollution Information System Based On WebGIS

The agricultural non-point-source pollution (ANPSP) refers to pollutants that cannot be identified as coming from one discrete location or point. Examples are nitrogen from fertilizers and pesticides, and animal wastes that wash into surface waters from agricultural lands. Natural and unknown causes of pollutants also can impact water quality and may be related to human activities. Agricultural non-point source pollution is a serious environmental problem nowadays. It directly restricts the sustainable development of society and economy in the world and has aroused more attention. Being instant, occasional and random, non-point source pollution is more complicated than point source pollution. Little is known about how to control ANPSP due to lack of the related theory and practical experience. Especially there is no satisfactory measure to reduce the runoff and leaching of N and P from agriculture into rivers and lakes. It's very significant in both theory and realism to reduce agricultural non-point source pollution and protect our ecological environment for realizing the harmonious development of resource, environment and agriculture in China.Hang-Jia-Hu water-net plain is the primary grain production base of Zhejiang Province. With a high population and intensive land utilization, agricultural non-point source pollution is extremely serious in this region. Animal wastes, household cleaning products, farmland runoff and leakage mainly contribute to the ANPSP. To control and solve ANPSP, it's necessary to apply information technology to obtain in-time, accurate and effective information on ANPSP and process it immediately. Based on GIS or WebGIS, the development of ANPSP management, planning, decision-making and consulting system has become the new trend in the establishment of environmental information system. However, so far most of research work in this field has focused on the formation, mechanism, modeling and control measure of ANPSP. An online human-computer interaction system needs to be urgently developed to realize visualizedissuance, management and analysis information of ANPSP.In the present paper, a complete attribute and spatial database on ANPSP is designed and created in three different levels of scale, Hang-Jia-Hu Plain (1:250000), Pinghu City( 1:50000), and field experiment (1:2000). Based on the GIS technique, especially WebGIS technique (ArcIMS, ArcSDE), an agricultural non-point source pollution information system (ANPSPIS) has been established in order to serve the management, planning and decision-making of ANPSP in Hang-Jia-Hu water-net plain. The ANPSPIS is composed of seven modules. They are overview of project, ANPSP status, ANPSP assessment, ANPSP maps, ANPSP control measures, ANPSP consulting and decision-making, and experimental demonstration. Each module includes several submodules. The major functions of ANPSPIS include querying and indexing information and maps, providing the pollution situation and dynamic change of ANPSP, and putting forward to control measures.