Response To Climate Changes On The Eco-systems Of Farming-Pastoral Region And Eco-economical Efficent Of Different Pattern In Northern China

Based on the climate data(l970-2000 year) in the dingxi county, using time series method, main factors analysis, periods extension, multi-aims line programming and analytical hierarchy process, the climate tendency and it's response to crop potential productivity, grass and forest potential productivity, stockbreeding productivity and the eco-economical efect of different pattern have been studied on the interlock of farming-pastoral region in Northern China. The main result have shown as follows:1. The trend of temperature will be upward, but the trend of precipitation may be downward in Dingxi county in the future, the trend of changing have a period trend of 7 years. The temperature will reach to 7.88 and precipitation will reduce to 377.7mm in the next cycle. According this trend Dingxi county will be defined as the pasturing area in 2024 year.2.The climate potential productivity will decrease because effect of temperature increasing is less than precipitation reduction. In this case crop potential productivity will decrease about 2.2%, potential productivity of grass and forest will decrease about 2.9% in next cycle. According theoretical potential of the natural grassland, artificial grassland and crop straw, result shows that practical animal carrying capacity do not reach the top of theoretic animal carrying capacity and developing potential is 39%. If the mode of utilization and quality structure are not changed, the author predicts that practical animal carrying capacity will reach the theoretical animal capacity in 2024.3. By the analysis of economy net income, the ratio of water and soil conservation and input standard, the author erects multi-aims line programming. By using AHP methods, the author calculates eight index value of different pattern, then calculates the value of multi-aims programming respectively, the limited conditions were 625Kg grain per people, average climate potential productivity and others limited conditions which were based on the condition of Dingxi now. By analyzing parameters of economy net income, the quantity of water and soil erosion and input standard and being carried on synthetical evaluation with unified to his measureless outilinezation, results were the most excellent structure proportion of farming, forest and grass in 2000 was adjusted from 79.2: 15.6: 5.0 to 30: 13: 57, in this model the average income of per person will double from 1258 yuan in 2000 year to 2699yuan, soil and water erosion will reduce to 1883t/hm2. Bbut the input standard is only 11669yuan/hm2. Soil and water erosion does not reduce to international UCL(1000t/km2.a). In the mode the main limited condition is grain. If the grain reduce to 300kg of average person, the soil and water erosion can be controlled at 1000t/km2-a, but can not realize self-sufficient of grain.