Study On Emergy Evaluation Method Of The Value Of Ecological Water Use Based On Material Cycle

With the rapid development of society and economy, the shortage of water resources and the deterioration of water environment have become the bottleneck restriction to the development of society and the protection of ecology and environment. In 2013, Ministry of Water Resources of China issued Opinions of Ministry of Water Resources on Accelerating the Construction of Water Ecological Civilization which stressed “We should accelerate the construction of water ecological civilization and reverse the deterioration of water ecological environment from the source”, and pointed out that water ecological protection is the key to the construction of ecological civilization.Assessment of the value of ecological water use can help us know the structure,function and health status of water ecosystem, analyze the advantages and disadvantages of the system, and provide guidance for water ecological protection and ecological restoration. This study is financially supported by the National Natural Science Foundation of China(NO. 51379191) and the National Water Pollution Control and Treatment Science and Technology Major Project(NO.2015ZX07204-002-04). A study on emergy evaluation method of the value of ecological water use was conducted based on the theory of Ecological Economics in this paper, and the main research contents were as follows:(1) The existing research results of analysis of the value of ecological water use in both domestic and overseas were summarized, and the deficiencies of evaluation method of ecological water-use value at present were pointed out, then the necessity and research content of this paper were confirmed.(2) The concept and classification of ecological water use were defined from the idea of Ecological Economics, then the connotation of ecological water-use value based on the material cycle were expounded. The process of ecological water use was seen as a process of circulation and energy flow of water cycle and other material cycle. According to the different paths of water cycle, the ecological water was divided into two parts, which were instream ecological water use and off-streamecological water use. Then the connotation of ecological water-use value based on the material cycle were expounded.(3) From the point of view of material cycle, the composition and expression forms of the ecological water-use value were discussed. The composition and expression forms of the instream ecological water-use value were discussed from the cycle of water, carbon and nitrogen. The composition and expression forms of the off-stream ecological water-use value were discussed from the cycle of natural factors and social economic factors.(4) Based on the theory and method of emergy analysis, the emergy evaluation method of ecological water-use value was put forward. According to the composition and expression forms of the ecological water-use value, based on the analysis of material and energy flow of water ecosystem, the theory system emergy evaluation of ecological water-use value was established, and the index calculation method was put forward.(5) Zhengzhou city was selected as the research object. With the emergy evaluation method, the value of ecological water use of Zhengzhou city was calculated from 2011 to 2015. The evaluation results can provide decision reference for the sustainable utilization of water resources, ecological environment protection and optimal allocation of water resources in Zhengzhou city.(6) The conclusion of this study was presented, and further questions needed to be studied deeply were put forward.