Landscape Pattern Change Under The Effects Of Radiation Chengyu Dual-core Urban Region

Urbanization process has a direct effect on regional landscape pattern, which alsosignificantly threat to landscape ecological quality. Chengdu and Chongqing are twocore cities of Chengyu urban agglomeration. They are influenced by each other onspace and economy, which make up the largest dual-core urban agglomerationinfluencing the western economic development of China. In recent years, with therapid development of urbanization, as built-up areas are continuous expanding in theradiation region of dual-core urban, regional landscape pattern also changesdramatically, which results in air pollution, increasing of heat island effect,descending of biodiversity and other environmental problems. At present, numerousstudies have involved the eco-environmental effects of urbanization at home andabroad, but there is still lack of researches on the changes of the regional landscapepattern under the influence of radiation dual-core urban. Therefore, based on Chengyuurban agglomeration, through principles and methods of landscape ecology and3Stechnology, the thesis uses TM image data and socio-economic data in2000and2010for the underlying data source, analyzes the changing rules of landscape pattern in theprocesses of urbanization of the Chengyu dual-core city, reveals the influences ofurbanization on landscape pattern in the dual-core radiation regions. On the basis ofthese results, we evaluate the quality of landscape ecology in research area. Theresults are as follows:(1) There are significant spatial differences and imbalances in urbanization level,which play an important role in promoting the development of urbanization in the twocore areas. Especially affected by Chengdu and Chongqing, urban is continuousexpansion for ten years. The closer it gets to the downtown area, the greater theinfluence, which on the contrary results in development lag in the outer region.(2) The number of patches in Chengdu radiation zone reduced2476and thepatch density decreased from2000to2010. The degree of landscape fragmentation isgenerally low, the landscape pattern is scattered in distribution and the advantagestypes are not obvious any more. Woodland and farmland that have high degree oflandscape fragmentation are greatly influenced by urbanization. With the improvement of urbanization level, human pay more attention to the regional planning,many small residential areas are merged. The concept of urban development willchange from the disordered state to the direction of systaltic and rational distribution.(3) The number of patches in Chongqing radiation zone increased18040and thepatch density increased6.07%in the past10years. It was more serious than Chengduabout the degree of landscape fragmentation and there was a trend of intensification,so as to the forest land, arable land and place of residence.(4) The landscape fragmentation in dual-core co-radiation areas is serious and thedistribution of landscape type tends to be dispersed. The areas of forest land decreasedby833.13hm2in the past ten years, which was more serious than single–core radiationarea; the areas of arable land decreased by2.11%and there was a tendency ofintensification; the fragmentation degree of water and residence gradually reduced.(5) On the whole, the degree of landscape fragmentation in Chengdu radiationzone gradually reduced from2000to2010, the landscape shape and connectivity weregood and the patches in landscape showed a tendency of balanced distribution; thedegree of landscape fragmentation in Chongqing radiation zone was intensified andthe patch shape was complex; the degree of landscape fragmentation in Jianyang andLezhi reduced, which located in the dual-core co-radiation zone, while it was veryserious in Longchang and Suining.(6) The landscape structures in study area changed greatly over the past decade,the types of landscape were natural, semi-natural and semi-artificial at first, then itturned to be artificial later. Urbanization had greatly effect on arable land, whichresulted in the areas decreasing by4.35×105hm2; the areas of residence in contrastsignificantly increased, average annual growth rate was9.77%.(7) In2000, the area ratio of the study area, in which the degree of interferencewas regional level (weak) was67%. In2010, it dropped to17.94%. The proportion ofthe regional area, in which the degree of interference was in the level3(general), isincreased. The degree of interference which the landscape suffered had increased fordecades. Meanwhile, the landscape stability gradually decreased and the proportion ofthe regional area, in which the stability located in the level1(unstable), increasedfrom0.12%in2000to0.35%in2010. When up to level5(stable), the areaproportion reduced by7.32%in the past ten years.(8) From2000to2010, the area of proportion in study area in which had badecological quality of landscape increased significantly by38%. When reaching to level3(generally) or above, the proportion of the area in region had a significant reduce and decreased by50.86%. Although the landscape ecological quality in Chengdu andChongqing radiation zone turned to be better these10years, it was always bad. Thelandscape ecological quality changed greatly in study area for the decade, which hadchanged from level3of2000down to level1of2010and on the whole turned to beworse.