Design And Development Of The WebGIS-based Information System For The Nutrient Balances And Environmental Risk Evaluation In Chinese Crop Production System

With more synthetic nitrogen application for the agro-ecosystem, the rate of the production incresement by fertilizer dromaticly discreased. Redundant nutrient have been lossed to the atmosphere and ground or surface water, which caused serious environmental problems and lead to a serious non-point pollution in agriculture of china. So the researches on the process of nutrient cycle in farmland system and the study of its regional risk evaluation system have significant meaningful to the improvement of agriculture level and sustainable agriculturaldevelopment in our county .The technology and trend of WebGIS have being reviewed and the system framework and operation mechanism of ArcGIS Server have been studied. With surpport of ArcServer , ArcSDE , ArcMap , Visual Studio , Microsoft SQL Server and ASP.NET technology , the agriculture information and the nutrient balance database have been set up, and the WebGIS-based information system for the nutrient balances and environmental risk evaluation have been designed and developed for Chinese Crop Production system.The gapless joint of the spatial data and attributes data has been realized and the efficiency of data retrieval has been improved in this system. The geographical features such as Administration layer and soil layer and attributes such as related crop production parameters, soil nutrient and agricultural management factors have been integrated into the RMBS, it manages the data effectively and unified and makes the consistency and completeness of spatial data and attribute data. Meanwhile remote management and update of database have been realized.Based on ArcGIS server 9.0 , the system realized the WebGIS fuctions of Farmland nutrition mapping, nutrition balance analysis and environmental risk analysis. By utilizing the powerful spatial analysis capacity of GIS, inquiring map information from attribute information, inquiring attribute information from map, zooming in and out the electronic map fom the thematic map can be carried out. The system provides information and service with the words and pictures for users. It integrates nutrition balance calculation model and environmental risk estimation model, realizes real time building model analysis of WebGIS. On-line analysis of nutrition balance and Environmental risk analysis are finished, which can provide technical support for managers of agriculture, ecological, environment and so on.