Research On Estimating Ecological Frangibility Of Zhalong Wetlands

Wetland is an ecosystem with particular structure and function, it can not only supplypeople with lots of producers's goods and consumer goods, but also has ecological functions,such as storing floodwater and fighting a drought, depurating contamination, regulatingclimate and so on. But the human exploration with little reasoning and planning directlyimpacts the natural material cycle and energy flowage of the wetland, makes the wetland notfully exert its ecological functions, and causes wetland ecosystem health injured andecosystem frangibility aggravated. So I take Zhalong wetland as my research area, carryingthrough the study on the ecosystem frangibility of Zhalong wetland.Zhalong nature dependency locates the lower reaches of WuYu-er river in the westwardof Heilongjiang Province and marcher with FuYu,LinDian,DuMeng,Tailai countries. It isan inland wetland and water area ecosystem which reed swamp dominates it and is listed inthe important wetland records of the world in 1992. But the human exploration has made thewetland face tremendous pressure. The water level of the wetland goes on descending, thewater polluted badly, the biology resource reduced rapidly, the wetland degenerated seriously.The thesis analyses the composition and function of Zhalong wetland by open researchand extensive data gathering and evaluates the ecosystem frangibility. The main content is asbelow:1,Data disposal and analysis. Revising the remote sensing image,toning the image andmatching the image by using ERDAS IMAGE 8.6, then obtaining the vector map of Zhalongwetland.2,Extracting the estimate indexes. The indexes are of five sorts: pressure,livingness,organization,function and state.3,Estimating the ecosystem frangibility through pressure-state-respond (PSR) model.During the estimate, I take 100m×100m GRID as my estimate cell and define the estimateresults as EVI(Eco-environmental Vulnerability Index). The frangibility is more badly whenthe EVI is more small.4,Exporting the distributing picture of the frangibility grades and analyzing therepresentative areas. The estimate result displays that almost the whole potential fragility areas and the slightfragility areas are in the interior reed swamp, while the middle fragility areas and the seriousfragility areas are dominated by the paddy fields;the center of the wetland is superior to theedge. In a word, the middle fragility areas and the serious fragility areas accounts for 19% andthe potential fragility areas and the slight fragility areas accounts for 64%. The result can beused for reference on the protect and renovating of Zhalong wetland.