Research On Ecological City Comprehensive Evaluation In Zhangye

City, as a symbol of human civilization and the carrier of social economic development, is a highly concentrated area of the population, industry, capital, productivity, science and technology and the core region of economic activity. With the advancement of urbanization and industrialization, social and economic develop rapidly. At the same time, a series of environmental problems occur including resource depletion, environmental pollution, ecological imbalance, population problem and so on. To make the urban natural, economic and social coordinated development, ecologists put forward the developing mode of "ecological city""Ecological city" is a development mode of urban human and the nature harmony, is the inevitable choice of sustainable development strategy. Because construction of "ecological city" has become the direction and goal of modern urban development, ecological city has become a focus in the current research at home and abroad.This article constructs ecological urban evaluation index system from city ecosystem structure, function and degree of harmony, uses entropy weight method and comprehensive index method to calculate ecological comprehensive index in the middle reaches of Heihe River Basin along Zhangye City from the year2002to2010, and forecasts ecological comprehensive index of the year2011to2015. The results showed that the ecological level is minimum in the year2007during the study period, with the comprehensive index of0.212; while in2010, the highest comprehensive index of ecological level is0.306. According to the level of ecological city grading standards, the ecological level of Zhangye City is lower because of its lower score of city ecological system structure and coordination degree. Coordination degree is relatively high but with decreasing trends. In view of its overall trends of urban ecological comprehensive index, the results show its slow ascending trends and indicate that the development of Zhangye City is toward eco-friendly direction. The author predicated that from the year2011to2015, ecological level continues to rise in Zhangye City, and in2015its ecological comprehensive index will be0.35, which is 1.7times that of the year2007; the ecological degree will reach average level. Basedon the study, the author put forward some policies and suggestions for Zhangye City’secological construction and development.