Establishment Of Urban Forest Comprehensive Evaluation System Of Hebei Province

Urban forest is an important component of urban ecosystems, compared with the general sense of urban greening, it is more prominent on the improving function of urban ecological environment. Give urban forest a scientific and reasonable evaluation is the foundation for the judgment if its structure is reasonable, whether the function is completely. It has great significance for guide the planning and management, and the health development of the construction of urban forest. Chinese scholars have done a lot of research on comprehensive evaluation of urban forest, but have not formed a mature evaluation system.The research takes the representational city of Hebei province as subject. Draw on the results and practice of urban forest assessment, reference to relative literatures, collect and arrange the high using frequency indexes, according the collection principles of index ,combine the city characteristics of Hebei province, after ask for expert opinions for times, established a set of preliminary system which is comprehensive evaluation system of urban forest about Hebei province. Then choose the representational cities to test and verify the scientific of this evaluation system, they are Qinhuangdao city, Baoding city, Shijiahzuang city and Handan city.1. This set of system covers seven level 2 indexes, they are the urban forest's total quantity, the quality, the structure, the function, the landscape culture, the social management and the social cognition, and it includes green space ratio, greenland coverage rate, park green per capita, three dimensional greening rate, road greening rate, incidence of diseases and insect, the proportion of native tree species etc. twenty-five level 3 indexes. Posed the rate of above-scale park green space, combined degrees of natural landscape and urban characteristic culture, let the content of urban forest evaluation system became enriched.2.This study use analytic hierarchy (AHP) to calculate the weight of each index, in order to ensure the objectivity and accuracy of the weights, ask for ten experts'opinions in this research, then on the basis of each pair of comparison value to establish multiple comparison judgment matrixes, calculate the weights of each index successively. The standards of"national forest city"and"national garden city"have priority to become the criterions of evaluate index in this system.3. In these seven level 2 indexes, the weights of total value is the highest which is 0.2347, this illustrate that the certain amount of urban forest area is the basis of a construction of urban forest; and the prerequisite to improve urban ecological environment. Next are the function, the quality and the structure, their weights are 0.2126, 0.2071, 0.1373. These are consistent with the significance of developing urban forest and the connotation of urban forest.4. The comprehensive evaluation index of the four cities successively is 0.8052, 0.7831, 0.7867, 0.7958, there is little difference between the four cities, their common problems are the function evaluation is lower and three dimensional greening rate should enhance. Every green index of Beidaihe harbor is the highest in Qinhuangdao city, its urban forest status is in the early stage development of level II, and the others are overall in the advance stage development of level III, there is certainly distance compared with"national forest city".The results indicate that: The verification result of the four cities with the specific reality of these cities is basically consistent, this set of evaluation system has certain scientific rationality, can provide reference for the development direction and general planning in the future urban forest.