The Study On Sustainable Bearing Capacity And Optimal Allocation Of Water-land Resources In Guanzhong Region

With the increasing of population as well as acceleration of industrialization and urbanization, the scarcity of water-land resources and eco-environmental degradation resulted from unsustainable use of water and land resources more and more obvious especially in Guanzhong region. It is important to Guanzhong region that study water-land resources bearing capacity and their optimal allocation in order to realize regional sustainable development.With the guide of sustainable development theory and the means of system science principle, based on the analysis of water-land resource in using present condition and problems, in this paper, the utilization and use of water - land resources are concluded in the sustainable development of water-land and eco-economics complex system, through overall anglicizing the ecology, resources and environment function of the water-land factor, the conception and evaluation model concerning water and land resources sustainable bearing capacity are established in order to evaluate the ability of sustainable bearing capacity in water - land resources, and then an operating mode of the degree of sustainable development is established to evaluate the sustainable situation in Guanzhong region, in the last, the author try to explore the sustainable development pattern based on the water-land resources sustainable bearing capacity in Guanzhong region. Some conclusions are as follows:(1) the conception of water-land resources sustainable bearing capacity is put forward, it is defined that under the specified region, meted period and fixed technology term, after overall anglicizing the ecology, resources and environment function of the water-land factor, the region's development dimension that can be borne and population in the special living standard are posed so as to realize the water-land and eco-economics complex system's sustainable development.(2) Guanzhong region itself can be considered as a unfold and complex huge system in this region, the research of water-land resources sustainable bearing capacity with water-land resource's high efficiency utilization is the sensitive index to this huge system.(3) Qualitative analysis and quantization analysis are joined to discern the factor affecting the water-land resources utilization and use in Guanzhong region. Cultivated land as a example, twenty index in the last llyears (1993-2003) are decided, through the analysis of gray connected degree model, the result showed that industrialization and the increase of population are the key index ,for the more , people is the source.(4) through analyzing the water-land resources system's supporting capacity and pressure, CSI and CPI index are pointed, CSI can be divided into water-land eco-environment supporting index and water-land resources supporting index. CPSI is aFunction of CSI and CPI. This index can evaluate the institution of water and land resource sustainable bearing capacity, so the evaluation model is established in order to evaluate the institution and change of water -land resources sustainable bearing capacity during the last 11 years (1993-2003) in Guanzhong region and five cities that included in it. Through this evaluation, eco-environment supporting index isn't change apparently and its bearing capacity is poor, the eco-environment system is not steady. Water-land resources supporting index is medium supporting capacity and improved every year, but water resources and land resources are not matched each other, the bearing capacity of water resources is poorer than land resources, because of this, and the bearing capacity of water and land resources is dropped. CSI display that in the same time that the increase in water and land resources supply ability, the stability in eco-environment in this period is dropped. CPI in this period are increased steadily, it also changed from low pressure situation in 1994 to medium pressure situation, in 2002 and 2003, it come to the high pressure situation. The CPSI of Guanzhong region are all larger than 1 from 1994, this conclusion show that on the basis of the unsteady eco-environment and the medium bearing capacity's water-land resources, because of the medium pressure of society, economics and population, the demand ability is larger than supply ability. So regarding to water-land resources, it is not sustainable bearing capacity for the development of society and economics.(5) the model of sustainable development degree is pointed out. It is started from the subsystem of water-land resource, water-land environment, economy, people, and society in order to evaluate the region's sustainable situation in the last 11 years (1993-2003) on the basis of the water-land resources sustainable bearing capacity .the conclusion showed that the sustainable development degree of economics, society and population subsystem are more large than the one of water-land eco-environment and resources subsystem. The sustainable development degree of the total system is situated in between them. The conclusion indicates that in the same time that the improvement of economics, society and population subsystem, the water-land eco-environment and resources subsystem are destroyed. This conclusion is the same as the evaluation of water-land resources sustainable bearing capacity. These show that a water-land resource bearing capacity is not sustainable .in the last, the region sustainable pattern on the basis of water-land sustainable bearing capacity is supplied.(6) the key that realize the sustainable bearing capacity of water-land is the optimal allocation between water and land.