Study And Development Of GIS-Based Water Environment Information Management System In Wuhan East Lake

Water pollution and eutrophication are the most serious environmental problems to lakes. To strengthen management is an important task for lake protection and pollution prevention. For the sake of the complex spatial characteristics of water environment information, it has a great meaning to integrate the techniques of computer display technique, database and water environmental models together.Taking East Lake as a research sample, this paper established the basic database of water environment for the lake. Through using the secondary development technique of GIS, the program language of VB.NET and comGIS of MapObjects, applying the SQL Server background database management system, as well as environmental models, a GIS-based water environment information management system is carried out. The system consists of six function modules: system control, database management, digital map display and control, water environment information management, information query, and picture output. Every module is independent and has a style of its own in its function. But for the whole system, they are mutually dependent and become an organic whole body.This research analyzed and calculated the water quantity input and output, as well as the total phosphorus and total nitrogen flowing in and out during a balance year in East Lake. According to the calculation and balance equation, the proper environmental capacity models for TN, TP and CODCr are selected, that are Dillon model, OECD model and zero-dimension capacity model for CODCr. And the proper water quality evaluation model and eutrophication assessment model are also selected. Through the program language of VB.NET and database technique, the functions of water quality and eutrophication assessment, environmental capacity calculation, and query are carried out.The system has an easy-operated interface, and carries out most of the map functions of GIS software. By the means of the water system digital map, the data can be displayed visually with graphs. This system also adapts to other lakes similar to East Lake, which are of middle or small size.