Ecological Security Evaluation And Pattern Construction Research Of Guangxi Beibu Gulf Coastal Zone

The study area is located in the southern coast of Guangxi,with large shallow sea,beach,and is located in the northern tropical zone,with appropriate water temperature.In this area,many rivers pour into the sea perennially,such as Nanliujiang,Dafengjiang,Mao Lingjiang,and Beilun River and there is abundant food.And this area has a famous fishing ground in China,which provides a good development foundation for the aquaculture,especially for the shallow and beach.Recently,although Guangxi Beibu Gulf in the national marine functional areas has obvious advantages in the ecological environment,and it is known as the last piece of clean ocean,the urbanization's process of coastal areas continues to accelerate,with the continuous development of the Economic Zone in Guangxi Beibu Gulf.And with the occurrence of the natural disasters,the rapid growth of population,the increase of environmental pressure,the increase of man-made damage and the increase of ecological environment in coastal zone,the author studies and discusses deep on the ecological security in coastal area.Through the remote sensing interpretation and the literature collection,the author analyzes and processes the original data and materials as well as dissects preliminarily three aspects between the natural environment,socio-economic development,the ecological environment in Guangxi Beibu Gulf coastal and the ecological security status in Guangxi Beibu Gulf Coast.Based on the PSR(pressure-state-response)model and the catastrophe theory,the author builds the ecological security evaluation index system of Guangxi Beibu Gulf Coast,including system pressure,system status and system response.On this foundation,this paper builds evaluation model of ecological security in Guangxi Beibu Gulf Coast and evaluates the ecological security of Beibu Gulf Coast in Guangxi from three time points: 2005,2010 and 2015 and with12 districts and county administrative units as the evaluation unit.Based on the basis of remote sensing interpretation,the paper extracts ecological patches such as water bodies,forest land and farmland as wellas combining with the evaluation results the paper constructs the ecological pattern of coastal zone in Beibu Gulf of Guangxi.And the paper Concludes as follows:(1)During the study period,the overall trend of ecological security shows a slow decline trend,and the most remarkable downward trend is the Gangkou District,following by the Qinbei District,a slight increasing in Hepu County,Dongxing City and Lingshan County,basically flating Yinhai District,Fangcheng District,Shangsi County,Qinnan District and Pubei County.(2)In 2005,there were two levels of ecological security grade.From? and ?,the ecological security level mainly distributed in the east,and the land area of grade ? was higher than that of grade ?.In 2010,the ecological security level has four grades,from the ? to ? level,and the ecological security level is mainly distributed in the west as well as the ecological security level for the ? level occupied a high proportion;in 2015,the ecological security level has four grades,from? to ? level,the safety level distribution was more uniform,and ecological security grade ? and ? level of the proportion of was relatively high.(3)The change of ecological security index is influenced by the pressure of the system,which indicates that the ecological load is caused by human activities to the natural environment and it is greater than the measures taken by human beings to improve the ecological environment.Through the interpretation of remote sensing images of the Beibu Gulf Coast in 2005,2010 and 2015,the author analyzes recent ten years' dynamic law of land use and extrates the ecological plots of forest land,inland water and cultivated land,based on the evaluation results.Combining with the nature reserve,the protection of important water source,and the coordination of urban construction and development needs,the author also builds“3 +12 + X” Guangxi Beibu Gulf Coastal ecological security pattern.“3” is the high level of the main area of forest ecological patches,the level of ecological zoning of land ecological patches and the mainlow-level zoning of urban construction land;“12” is seven water ecology corridor of along the river and along the protection of the formation,along four traffic ecological corridor of main traffic trunk green belt and a coastal ecological protection zone;“X” is the ecological node of a number of nature reserves,key water-based ecological source and ecological corridor intersection.