Application of interactive multiple goal programming for red soil watershed development: a case study of Qingshishan watershed

Abstract

Red soils cover 21% of China's surface: some 2.10 6 km 2. Much of the area is hilly. Rice grows mainly in the lowlands. Only a fraction of the uplands in the red soil area is cropped, but yields are low due to inadequate topsoil as a result of erosion and nutrient mining. The remainder is wasteland that is not used for cropping and a little for grazing. But these areas have a high agricultural production potential if some constraints are removed. The World Bank has set up a major project named “China Red Soil II”. It comprises a total area of over 9.10 4 ha for development or rehabilitation, with 215 small watersheds including one named Qingshishan. Techniques of system analysis and optimization are applied to this watershed, and a watershed development planning model (QINGS) has been created. QINGS includes seven objectives, 32 activities and some constraints, two scenarios; three land use forms and two irrigation systems are available to the model for selection. This complexity provides a web of possibilities and there can be many solutions for suitable development. By running QINGS a number of times for successively more specific goals, a window of opportunities is established where land use practice is the key factor to development and where all goals are met to a certain degree. Feasible solutions can then be identified in which reduction of soil erosion, increased income and sustainability in land use are combined. Local farmers and technical officers can identify and accept the best compromise. QINGS is a tool for watershed developers that allows them to quantify opportunities and constraints, and set specific targets for developments with the local population. Results of QINGS can empower local farmers in negotiations with watershed developers. After 5 years of red soil development supported by the World Bank Project, various activities were initiated, including new crops (e.g. bamboo), trees (e.g. mulberry), livestock, fish and pearl production, and an ecological and social benefit forest. Infrastructure was improved (such as irrigation system, traffic conduction, biogas ponds and so on). The year 2000 total net income is 870,000 yuan, compared with 265,000 in 1994 before the project. Before the project, the forest cover rate was 9%, now it is up to 50%; soil erosion is at low level, and water supply has increased the length of the secure growing season by more than 50 days. The social employment conduction is also improved, especially the employment of rural women. The whole structure of agro-ecology system is optimized.