The Health Evaluation Of Urban Green Land Of Wuhan Main City Zone

This paper aims at the main urban areas of Wuhan and gives the health evaluation of its Green-land System.From the ideological of forest ecosystem health evaluation and from the three aspects of dynamic,organizational structure and the stability,we have constructed a set of multistage syntheses evaluation system.Use method of scoring by specialist and Analytic Hierarchy Process(AHP) to confirm indexes and ensure the weight of them.Use integrated evaluation and restricting factors evaluation on modeling. And class the health indexes.So we can give a health evaluation of green-land in the main urban areas of Wuhan.The results show that:(1)According to the area of the green patch,the article divides the urban green land into four styles on the basis of GIS establishment of urban green land of Wuhan.They are Pint-size green land(area from 0 to 1hm~2),Moderate green land(area from 1 to 15hm~2),Large-scale green land(area from 15 to 30hm~2) and Oversize green land(area more than 30hm~2).(2)According to the ecological environment situation of main city zone of Wuhan, the article establishes health evaluation index system of urban green land in this area. The system begin with activity,organization structure and functional stability on a goal of stability and sustainability of green land system of main city zone of Wuhan,and uses growth potential,the degree of pests and diseases,the value of synusia,the cover degree of every layer,species diversity,regulation of micro-climate,the stablity of landscape effect and niche overlapping as health evaluation indexes,and then it applies expert evaluation method and analytic hierarchy process to determine the weight of every index.(3)Inputting the datas of all the quadrats into the urban green land evaluation model which based on the method of exponential sum,it can get the healthy comprehensive index.The conclusion is as follows:the healthy comprehensive index of exceptionally Oversize green land is between 0.472 to 0.867;the healthy comprehensive index of Large-scale green land is between 0.535 to 0.777;the healthy comprehensive index of Moderate green land is between 0.326 to 0.801 and the healthy comprehensive index of Pint-size green land is between 0.296 to 0.723.The avrage of the healthy comprehensive index of Oversize,Large-scale,Moderate and Pint-size green land is 0.726,0.691,0.613 and 0.499.The change trend of the avrage of the healthy comprehensive index is Oversize green land＞Large-scale green land＞Moderate green land＞Pint-size green land.(4)According to the classification of healthy comprehensive index,it can divide the urban green land of Wuhan into morbid green land,unhealthy green land,sub-healthy green land,healthy green land and ultra-healthy green land five parts.Through calculation the conclusion is as follows:Among 386 quadrats,there is no morbid green land,and it occupies 0%;there is 37 unhealthy green lands,and it occupies 9.59%;there is 147 sub-healthy green lands,and it occupies 38.08%;there is 191 healthy green lands, it occupies 49.48%and there is 11 ultra-healthy green lands,and it occupies 2.85%.(5)The investigation results indicate that the situation of small green land in main city zone of Wuhan is between unhealth and sub-health.According to unhealthy green land,it can find that the synusia,species diversity and the stablity of landscape effect are key factors which can affect the health of green land.Based on the conclusions,we can apply some methods to solve the problems:the area that the value of synusia is lower need reseed shrubs and hedgerow;the area that species diversity is lower should be reseeding and green supplement and the area which the landscape effect is poor is should be trimming,watering,fertilizing and increasing investment on management.