| The developing countries face the very serious challenges of natural resource constraints and environmental degradation as they try to enter the mainstream of socio-economic development. But the fact remains that a very formidable natural resource/environmental challenge is faced by the developing countries. Therefore, to avoid increasing damage to the eco-environment, they would need to boost water resource use efficiency by the same factor, and have to protect the needs of water dependent ecosystems where the eco-environment has been identified as a key factor in water allocation. But no policy statement has previously existed to describe the principles and approaches for appropriate provision of water for the eco-environment in china. With development of industry and agriculture, and increase in population, the water consumption in rural areas and cities will increase constantly, the water resources crisis turns worse. Especially, in arid and semi-arid area of the northwest china, water resources is serious lack, the eco-environment is very friability, human being activity may cause the land degeneration to turn with desert, and the biology diversity will reduce continuously. Therefore, the research of the district water requirement of eco-environment and ecosystem water resources reasonable allocation, not only benefit to society economic keep on the development, but also benefit to the eco-environmental protection and recover. But, the current research concerning this aspect still stays around a qualitative analysis and the macroscopic research. Aim at the problem existed in the research, several problems have been solved in this paper. The concept system of the district eco-environmental water requirement, including the concept and the meaning, is defined. Based on characteristic of eco-environmental water requirement (EEWRs), EEWRs concept frame and the certain step are established, according to principle that certain EEWRs, the mathematics model of the district EEWRs are set up. That model not only includes the land EEWRs, river EEWRs, but also includes the estuary, wetland EEWRs. The mathematics model of the estuary, self-purify and dilution of the river contamination, and drainage sand during the no-flood season EEWRs are set up. The theories system and the quantificational method of the district eco-environmental water requirements are enriched and perfected in this paper. The district model of the worth a correction in ecosystem service function is established. The ecosystem service function unit price calculated by Costanza is revised making use of biology quality, then the development coefficient is reckon making use of the Engel coefficient to revise the ecosystem value, and getting the district ecosystem value finally. The textual research provided a new path for the reasonable certain district ecosystem value. The theories frame system for water reasonable allocation that is dynamic feedback type is put forward, water allocation is put into this big system for eco-environment to study in this allocation mode, not only EEWRs is considered, but also feedback information to come into being by water allocation for ecosystem and hydrology system, then water allocation will be revised to attain the person and natural coordination. The waters resources allocation mode, not only benefit to the water resources to make use of efficiently, but also benefit to the environmental protection in ecosystem and prevent the water pollution. Based on the definition of the benefit coefficient, the concept of the benefit coefficient to use water for eco-environment is defined, and the mathematics model is too created. The same time, the benefit coefficient to use water for life, agriculture, and industry are analyzed and investigated. Water resources reasonable allocation model is created, the target function is the synthesize benefit maximum for the economy, society and eco-environment, and this model is calculated by accelerated genetic arithmetic. Result enunciation: The model stabilizes, practical and reasonable, the maneuverability is strong. The model is systematization, rationalization, more integrality, also enriched the theories system for water resources reasonable allocation. The application study for EEWRs and water resources reasonable allocation in downstream of ShiYang River—MinQin County to make use of research conclusion in this paper is implemented. As a result: (1) EEWRs is calculated in MinQin county, consisting of the terrestrial vegetation (forest, grass etc.), evaporation and leakage in reservoir etc., its amount range from 0.537×108m3 to 2.289×108m3. (2) The value of the ecosystem services iscalculated in MinQin during 2000 year. Thereinto, 0.78×108 yuan/a for forest, 0.081×108 yuan/a for grass, 0.2598×108 yuan/a for marsh and wetland, 0.055×108 yuan/a for lake and river, 0.0923×108 yuan/a for cropland. (3) The net benefit coefficient is calculated to use water for eco-environment, life, industry, and agriculture etc. 0.2734 yuan/m3 for eco-environment, 0.32 yuan/m3 for life, 0.3159 yuan/m3 for industry, 0.2769 yuan/m3 for agriculture. The same time, water requirement is calculated for life, industry, and agriculture. The agriculture water requirement is range from 2.2226×108m3 to 4.8497×108m3, The life water requirement is range from 0.0492×108m3 to 0.0820×108m3, The industry water requirement is range from 0.0486×108m3 to 0.0616×108m3. (4) According to the supply water amount in MinQin County, the six concrete models for waters resources reasonable allocation have been established, each model includes three kinds of projects again. The model calculated solution: The ecosystem moderate with economy water resources allocation mode will be to maintains MinQin County economy keeping on the sustainable development and validly protecting eco-environment. The people life EEWRs are first satisfied, and there are a coordination allocation among eco-environment, industry, and agriculture in this mode. It benefited to protect the ecosystem environment, also maintain the certain economy increases speed.
|
PDF Full Text Request