Landscape Spatial-temporal Evolution And Ecological Environment Response In Chongqing Yubei District

As the major area of Chongqing city and new industrial development, YubeiDistrict has contributed significantly to Chongqing's urbanization and suburbeconomic development; meanwhile, its landscape structure has gone through greatchanges under the high-intensity human disturbance, therefore the environmentprotection presents a great challenge and requires higher standards. Furthermore,being in the heart of "Liangjiang New Area", the only national development zone inmiddle-west of China ,Yubei will be face the challenging problems coming along withhigh intensity development during the next period. The conflict between humandevelopment and the environment will be inevitable, how to protect ecologicalenvironment and balance economic and environmental development need the supportof advanced technical means and scientific methods.In the process of extracting land cover data, firstly, the spectral signature andtexture feature of different land use type based on TM/ETM data are analyzed . thedifference of ground objects spectrum are classified using mean spectral curve andbox plot through sample analysing. then, proper TM spectral signatures for specificland cover type are identified. texture feature spectral curve also be confirmed forinformation extracting.By combining the image spectral signatures of geological,terrain, soil, DEM and land cover data, CART decision tree will be introduced toremote sensing image classification to formulate a decision-based, multisource-basedlandscape identification and extraction system.Based on accurate extraction of land cover of study area, different land coverdynamic change are analyzed through patch Class-level index(TA,PLAND,NP,PD,LPI,LSI),Landscape-level index(NP,PD,LSI,IJI,AI,CONTAG )to mine outthe trend of regional landscape development. Extensive analysis is also carried out onother man-made landscape, such as, city built-up area, road, mine, to providescientific evidence for regional planning. Using climate, environmental and social-economic data, the study of ecological response to landscape change in studyarea are carried out, putting an emphasis in the effect of urbanization oneco-enviornment. This study also proposed a feasible regional ecological environmentquality evaluation index system ,with compositive index method to classify theeco-enviornment quality of the study area into four categories: high quality area, goodarea, normal area and degraded area, and thus provided an alternative mean toeco-enviornment protection.Major conclusions as followed:Classification accuracy of land cover information extraction at the hilly area withmulti-source data has been proven to be effective in the research. Based on TMimages texture features and spectral analysis, combined with DEM, topography,geology and other data, CART decision tree are introduced to remote sensing imageclassification, finished the 1988, 2000, 2007, 2010, four periods of land-use(construction land, water, grassland, woodland, arable land) information extraction.Using the error matrix to assess accuracy, the classification accuracy obtained is asfollows: 71.89%, 85.87%, 78.8% and 86.96%, indicating that the classification iseffective.By applying landscape ecology theory and methodology to analyze the change ofbuilt-up area, arable land, water, grassland, woodland landscape between 1988 and2010 year, the results showed that: the decrease and fragmentation of water landscapearea is serious from 1988 to 2010; area of construction land has been increasing,showing a trend of concentration; forest landscape is subject to greater damage beforethe year 2000, but a substantial increase and plaque area decreased; grassland andwoodland change follows the contrary law, it can be to determine that the changes inforest landscapes are caused by turf or at least an important factor in landscape change;farmland is the main type of landscape, it has not changed significantly. Built-up areasof Yubei extended as sheet style and axial spread mode during 1988-2007, but theleapfrog extension and axial spread mode is the main type of growth from 2007 to2010; roads of YuBei has been greatly extended between 2000 and 2010, road densitysignificantly increased, which has the same pattern with the overall expansion ofurban built-up areas; mine development have a major impact on the local ecologicalsystem, the number of mine and development strength increased significantly from2000 to 2010.Combined urbanization process to analyze the ecological effects of landscapechange, we can see that the regional climate, air quality, water quality, the value of ecosystem services are changing to different extent, which are closely related withartificial landscapes increasing, the expanded scale of urban construction projects, asubstantial increase in population and increased greenhouse gas emissions. Throughthe comprehensive evaluation of local ecological environment quality, high qualityarea, good area, normal area and degraded area were classified, and a reasonableenvironmental recovery and protection measure was proposed. And finally, this paperalso provided reasonable countermeasures of ecological construction and protectionaccording to natural conditions, natural resources, industrial base and development ofthe present situation.