Three-Dimensional Green Measure And Calculate Of Wuhan City Green Community Based On RS

Urban green space is an important part of the city, it is closely related to the balanced development of the city and the quality of life.With a high degree of urbanization, resulting in the problems such as environmental degradation and ecological conditionsproblem, which may hinder sustainable urban development. Urban green space play an important role in Maintaining urban environment,it is not only the ecological regulator of city, but also beautify the urban landscape, shaping the urban characteristics.The rational layout of urban green space, can adjustment the overall arrangement of city.Urban green space played an important role in urban ecosystems, with the increasingly prominent and long-term ecological benefits it appear,more and more people pay attention to it.The criteria for judging the level of urban greening, form the early two-dimensional index such as"Green space ratio","Green coverage"develop to three-dimensional index-"Tridimensional green biomass."For Tridimensional green biomass,number of previous studies have done, look at the past research of determination of Tridimensional green biomass, easy to see that most of the research is based on the method " two-dimensional simulation Tridimensional ",which is said,most of the research is based on species of plants to measurement tridimensional green biomass.This article is based on communities of urban green space as the unit to measure tridimensional green biomass. Select the Wuhan East Lake Scenic Area and the surrounding area which has intensive vegetation as study area, in accordance the situation of communities in the city of Wuhan,we divided communities into 10 types, select the typical sample of each community type in study area, using HemiView measure the leaf area index (LAI) data of experimental plots.LAI as the aggregate indicator to polymerize communities together as several types of groups.extracted the vegetation index By August 25,2007 was a Landsat-5 TM image data, set up regression model of the LAI and VI,respectively research a linear and nonlinear regression models, nonlinear regression model including power, exponential, logarithmic, polynomial regression model.In previous studies,HemiView instrument is mainly used for investigations in the field of forestry, less involved the application of urban green space, this study investigated the types of urban green space for the use of HemiView Canopy Analyzer and correct the problem should be noted that the use of method; and respectively inversion trdimensional green biomass of the green community in the whole and classification, the results are as follows:(1)Using HemiView canopy analyzer to determination relevant ecological indicators of urban green space, needs cover white color on non-vegetation categories of landmarks, so the color of the spectrum of vegetation classes can be obviously judged, thus stop the software mistaken them non-vegetation for plants.The wrong justice caused by the sky background and sun’s rays need to be adjusted, so as to distinguish realistic.(2) Ues LAI as a single factor on the community of cluster analysis, the inversion result of classification of different types of groups significantly better than the inversion with the whole community. The overall inversion,DVI has the worst sensitivity, the best inversion model is the power, R2 is only 0.1626;MSAVI has the highest sensitivity for inversion, the best regression model is power, R2 up to 0.4766. The inversion by Community classification, the best regression model between DVI-LAI is the quadratic regression model,R2 up to 0.4391;The best regression model between MSAVI-LAI is the power model, R2 up to 0.7098.(3) In the selected vegetation index, NDVI, SAVI, MSAVI has high sensitivity in the inversion of LAI.power equation is good. Whether whole communities inversion or community classification inversion,power equation is the best regression model between the three vegetation indices and LAI.In overall inversion, the highest R2 respectively 0.4141,0.3307,0.4766;In classification inversion, the highest R2 respectively 0.4976,0.5219,0.7098.(4) Aggregation 10 community classification types of groups into four types of classification,the result of inversion is better.Four types of groups is:Type4-1:grass communities;Type4-2:bush communities,arbor communities,grass+bush communities, arbor+grass by human;Type4-3:arbor+bush communities, arbor+grass by nature;Type4-4:arbor+bush+grass communities by human, arbor+bush+grass communities by nature, communities stratified complex.The highest sensitivity model between MSAVI-LAI is power equation,within 3-3 types of group, power model, y=9.0083x1.1431,R2 is 0.4355;4-3 types of group, power model, y=6.9178x0.8452, R2 is 0.6536;4-4 types of group, power model, y=11.43x1.4534, R2 is0.5449.(5)This study measured the Tridimensional green biomass is based on built mathematical models through the vegetation indices and leaf area index.For different regions and different climatic zones, although the model and the fitting parameters need to re-adjust, and the vegetation index under different environmental sensitivity in the model may also vary with previous studies, but through this study we found that measurement of Tridimensional green biomass of urban green space based on community proved to be feasible.