GEOGRAPHICAL RESEARCH ›› 2002, Vol. 21 ›› Issue (1): 25-33.doi: 10.11821/yj2002010004

• Earth Surface Processes • Previous Articles     Next Articles

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

LIU Gao-huan1, ZHU Hui-yi1, CAI Qiang-guo1, Gan Guo-hui1, Ferko Csillag2, Virginia Maclaren2   

  1. 1. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China;
    2. University of Toronto,Toronto,Canada
  • Received:2001-06-14 Revised:2001-11-20 Online:2002-02-15 Published:2002-02-15


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.

Key words: user model, GIS, integration, land-unit