Assess On Environmental Vulnerability In Mu Us Desert Agroecosystem And Study On The Optimization Mode

The Mu Us Desert was located in farming-pastoral zone of northern china, a very typical ecological fragile region, which was effected by human activity greatly. It was represented to a great extent many typical problems about the relationship between human activity in semi-arid, aid desert area and natural environment. Research on change of natural environment and effect of human was very meaningful to prevention of land desertification in farming-pastoral zone of northern china, our national ecological environment and regional development trans-province (zone).This research was adopted the analysis hierarchy process in assessment of environmental vulnerability in Mu Us Desert agroecosystem, a comprehensive analysis on variation characteristics of environmental vulnerability in Mu Us Desert agroecosystem was analyzed, a vulnerable degree assessment model was estabilished. And optimized models of improving fragile agroecosystem in Mu Us Desert were proposed, there were an optimized model on planting subsystem—a structure model of water-saving planting; an optimized model on animal husbandry husbandry system—a structure model of grain-saving animal husbandry and an optimized model on forestry subsystem—an ecological structure model of restoration and reconstruction. The main conclusions were as follows.1. The eleven counties(banners) of Mu Us Desert are chosen as appraisal units. A set of indexed system was set up for appraising environmental vulnerable degree, 11 indexes value including precipitation, evaporation, annual mean temperature, desertification degree, population, average agricultural output value, average industrial output value and so on. The weight of environmental vulnerable degree of each model was set up, the result of assessment was that the order of vulnerable degree of 11 counties(banners) from large to small was Etuoke banner>Dingbian>Wushen town>Yijinhuoluo town>Etuokeqian banner>Yanchi> Jinbian>Yuyang>Shenmu>Hengshan>Fugu. Vulnerable degree of northwest was high and that of southeast was low basically.2. Desertification was serious in this area and there was existed apparent regional difference. The total area of Mu Us Desert was increased, the growth rate of shifting sandy and fixed sandy land was quicker, shifting sandy land was dominated absolutely and the extending trend of desertation was very obvious; desertification of Etuoke town, Dingbian county, Wushen banner, Yijinhuoluo town, Etuokeqian banner, Yanchi county, Jinbian county and Yuyang region was serious and that of Fugu and Jia County was slighter relatively.3. The proportion of farmer population was large, the cultivated area of that region was incessantly decreased and the grazing capacity of unit land area was increased. Economic development was depended on farming to a great degree and vulnerability of economy was large. Cultivated land area totally and per capital was reduced in large range, estate structure was monotonous and agricultural development was depended on farming excessively.4. Optimized models of improving fragile agroecosystem in Mu Us Desert were proposed: supporting mechanism of policies and regulations, engineering technological guide and supporting mechanism, guarantee mechanism of fund, improving mechanism of population control and population quality.5. Optimized models on restoration and reconstruction of fragile agroecosystem in Mu Us Desert was proposed:(1) an optimized model on planting subsystem—a structure model of water-saving planting(2) an optimized model on animal husbandry husbandry system—a structure model of grain-saving animal husbandry.(3) an optimized model on forestry subsystem—an ecological structure model of restoration and reconstruction.