小流域综合管理信息系统集成研究

本文介绍的小流域管理与决策支持信息系统 ,是以小流域综合治理与科学决策为目标 ,以地块为基本操作单元的土壤侵蚀模型、生产潜力模型、成本效益模型与GIS的集成系统。该系统具有数据管理、查询、更新、处理、模型分析和输出等多种功能。分析模型与GIS集成的基本单元是地块 (landunit) ,在地块上实现模型参数的提取与传递、模型计算及显示与分析。在分析各种集成方式的基础上 ,选取了动态连接库及其扩展方式 ,实现了土壤侵蚀模型、生产潜力模型、成本效益模型、规划模块与GIS的紧密集成 ,以统一的图形用户界面 ,服务于水土保持的现代化管理和小流域综合治理

A land-unit based integration method of geographic information system for small watershed management

The small watershed management information system is an integrated system of GIS and erosion model, land productivity model and cost-benefit analysis model. It can be applied in watershed planning and management in Loess Plateau.The system is developed for decision support in soil and water conservation with the functionalities of data management, data query, database updating, displaying, output and model analysis. The basic geographic unit for system integration is land-unit. The land-unit was defined as a piece of land with the homogeneous geographic characters such as elevation, soil type, land-cover, slope, aspect, etc. Based on the land-unit, three model groups were integrated with GIS. In order to realize those functions, basic integration methods were analyzed and the integration method of DLL and its extension was adopted. Then based on the method accompanied with Avenue programming language, the system was fully integrated in Arcview environment. A landunit based flow network model was developed for simulating the processes of drainage and sediment transportation among land-units, and it provides parameters for erosion model, economic model and yield model. The soil erosion model calculates soil loss for each land-unit in a watershed. Yield model and socio-economic model estimate crop productive and economic benefit in the watershed, such as river beach, check dam, agro-forest, terracing, etc. These three models are integrated with each other and fully linked to database system. Based on the result of model simulation, the soil and water loss, land productivity and economic benefits in a watershed can be estimated for different land planning and engineering strategies. The optimized management for watershed can be done through comparisons of varied planing. The arithmetic process and parameters of each model are also described in this article.