Studies On Vegetation Quantity And Ecological Network Of Six Green Wedges Of WuHan City

Both the urban and urban population have exploded since the acceleration of urbanization in China, which leads to the loot of ecological resources and the degeneration of urban ecological environments. Thus the construction of urban green space has been one of the best methods to improve the urban ecological environments and residential environments. However, the traditional green space index system has lagged behind the development of greenbelts. The living vegetation volume should be added to the green space index system, which is bound to guide the construction of green areas. Regretfully a unified research standard and methodology of vegetation quantity has not been founded yet.The thesis attempts to acquire the formula of three dimensional green quantity by regression analysis of vegetation indexes and LAI of plant communities. Presently, the plan of six green wedges in Wuhan is brewing, which could have a significant impact on Wuhan city. The dissertation figured out the total LAI of six green wedges with the equation produced by regression analysis and, approached the establishment of ecological network of vegetation quantity in the research areas. The conclusions are as follows:1 Formulas have been obtained by regression analysis of LAI and vegetation indexes, which are generated by Hemiview investigation and Landsat TM satellite image respectively. Among all the equations, the cubic formula y= 0.5621+4.9035 x-7.9810 x2+14.5540 x3, which was produce by regression analysis of the total data, was proved to be a best one, with the coefficient of determination (namely R2)0.733. The correlation coefficient of accuracy test is 0.841, and the data generated by the equation above has no significant difference with the data obtained from Hemiview.2 The arrangement order of regression analysis of all types is:the complex community is better than total regression, while the simple community is at worst.3 The area of lands which have LAI was figured out based on the classification of landscape types of six green wedges, combined with the regression equation. Also, high grade, middle grade and low grade LAI distribution in different landscape types were calculated out.4 The area of seasonal LAI change zone is much more than that of non seasonal LAI change zone. Moreover, the area of seasonal LAI change zone which relied on manual culture also exceeded that of the natural zone greatly. Specifically, total LAI of farmlands and pools surpasses that of woodlands and mountains, while the latter have more LAI than the lakes, wetlands and rivers.5 Ecological network of green quantity and the expansion network of the urban were established and then overlaid, based on the model of minimum cumulative resistance (MCR). Some measure of "source", corridor and strategic points are proposed aiming at protecting the ecological network structure of vegetation quantity and the ecological pattern.