Study On Evolution And Optimization Of Man-land Areal System In Wei River Basin (Mainstream)

Man-land areal system is a nature-economy-society complex system, which is a multi-level, multivariable, time-space coordination coupling system formed by man and land in the basin. Taking the Wei river Basin (mainstream) as a case, based on field investigation and the combination of the theories in geography and system science, this thesis discussed the evolution process, situation pattern, analogue simulation, space management of man-land areal system in river basin by using a wide variety of technical means, such as the method of historical analysis, dynamic coupling model, factor analysis, space analysis method, system dynamics model, in order to providing scientific decision basis for the optimal regulation and sustainable development of river basin. Main results of this dissertation are as follows:(1)The author pointed out the weak side of this research field at present, and prospected the main research directions in the future. These studies showed that it is general for international scholars to pay close attention to the research of planning and management of basin development. The main contents involve the origin, type, management objective, problems of planning and management of river basin development, and which also caused Chinese scholars to the concern on watershed management. International scholars and domestic scholars also studied on the process simulation and scene analysis on the interaction of man-land areal system in river basin, including historical analysis and dynamic monitoring, situational analysis, sustainable development of man-land areal system in river basin. Meanwhile, the research on mechanism between human and land of man-land areal system in river basin was developed, including basic theory of man-land areal system in river basin, difference on different types of man-land interaction in river basin. The quantitative analytical methods, such as principal component analysis, gray relational analysis, coordination model, comprehensive evaluation index model, system dynamics model, were generally adopted to appraise man-land relationship areal system in river basin,. Geographic information system and decision support system have also been applied in the research on man-land areal system in river basin. Although a series of theories related to the research on the man-land areal system in river basin have emerged recently, there are a lot of weak points which should attract our attention. For example, theoretical studies and approach applications are still insufficient, and the research system is still not formed. Current research is generally lack of the comprehensive study of the structure evolution, the studies on the coupling mechanism and model of the factors between nature and human, summarized principle researches, quantitative analysis, dynamic analysis and the process of simulation and prediction in different scenarios of man-land relationship in river basin. The future research on man-land areal system in river basin should strengthen the multi-disciplinary integration, the mechanism of interaction of man and earth in river basin, the enrichment of research approaches and the application of new technical method and the dynamic simulation.(2) The analysis of man-land areal system historical evolution process in Wei river basin (mainstream) indicated that:man-land relationship in the period of primitive society was at the original and low-grade coordinate stage, human passively adapted to the environment. In the period of agricultural society, humanistic factors became more and more important in the evolution of man-land relationship, ecological environment was being at the stage of slow degradation, the succession of man-land relationship sped up.Time coupling research of man-land areal system shows that:the socio-economic level in mainstream basin of Wei river has increased volatility from 1996 to 2006 accompanied with the fluctuations of resource-environmental state. The resource-environmental sub-system shows repeated fluctuations status in the turn of the deteriorating and improvement. At present, man-land relationship areal system in Wei river basin is at over-exploitation phase. Also, the crisis of resource-environmental is in the incubation period. If we don't pay attention to environmental protection and go on to over exploit resources, the stage will be passed quickly. At that time, the growth in economic level and rising level of consumption of resources will overwhelm resource-environmental system and lead to environmental quality continuously decrease. Then the relations between the two systems will deteriorate, also the socio-economic system development will be constrained by resource-environmental system. The system will enter a phase of negative growth.The spatial pattern of man-land areal system based on the data in 2005 showed that:It can be divided into four types in Wei river basin, that is harmony, amelioration, confliction and low-level harmony. In 2005, the confliction is the dominant type, followed by amelioration in this area. The amelioration region is mainly distributed along the Longhai railway and GZ45 highway section of Tian(shui) Xi(an), where the economy is in large scale, the cities have complete structure and the quality and efficiency of development need to be improved. The confliction district with the strongest feedback effects of man-land relationship is distributed in the north and east of Wei river basin (mainstream). Some of these counties and districts have certain economic base and technical innovation ability, but the foundation of development is still weak; some other counties and districts focus on agricultural production, but long-term unreasonable development of water and soil resources has led to many ecological environment problems. The low-level harmony region located in Qinling and Huanglong mountains, where the social and economic development is in low level, feedback effects of man-land relationship is weak, and ecological function value is high in Wei river basin.(3)It is established dynamic model of man-land areal system in Wei river Basin (mainstream), by means of SD method and Vensim PLE software, and by taking utilization of water resources as the main clues. Through adjustment of water utilization and pollution index, the four scenarios of the simulation models during 2005-2025 have been established, which are the high-speed economic development mode, the water-lack feedback mode, the water-lack and environment-pollution feedback mode, and the water diversion coupling mode. The results show that:The water diversion coupling model introduces water resources outside into Wei river basin, by which the situation of water shortage can be improved clearly, also the economic development can keep increasing at a sustainable high speed, so it is an effective way to balance the man land relationship in Wei River basin, i.e, by 2025, the total water consumption should reserve 110×108 m3, GDP should increase by 10% at an annual average growth rate, and population urbanization level should control in the range of 52%. The measures such as environmental protection measures, water quota of the second and third industry and increased water resources utilization should be implemented.(4)The space management in the four kinds of spatial distributions in Wei river basin (mainstream) indicated that:For the amelioration region, the factors flow, industrial distribution, ecological environment protection and infrastructure construction should be coordinated to form the industry-urbanization dense zone and regional ecological network system. For developable confliction region, the influence of economic development on ecological environment should be minimized, and the attention should be paid to the admittance of population transfer from agricultural confliction region and low-level harmony region. For agricultural confliction region, the main task is to improve long-term and stable supplement of agriculture products, to strengthen land production potential and to develop characteristic agriculture according to local conditions. The spatial management in low-level harmony region is to enhance the ability of ecological service, such as water conservation and biological diversity, to develop suitable industries and to guide the ordered transfer of overload population, in order to construct the region for the harmony between man and nature.