Study On Urban Land Use Change And Its Eco-environmental Effect Based On RS&GIS

The development of economy and society has not only led to sharp increase demand for natural resources, but also has to be faced with immense pressure resulted from the resources, environment and population, and then the sustainable development of economy and society and ecological security issues has been produced. In this paper, the study area is the core region, includes the districts and counties in Chenghua, such as Wuhou, Qingyang, Jinjiang, Jinniu, Gaoxin, Longquanyi, Qingbaijiang, Xindu, Wenjiang, Shuangliu and Pxian. The study area is in the period of economy fast development, pressure resulted from the population sharp increase and urbanization process is picked up, the trouble resulted from human is especially extruded. So, encircled the global change and its response, Chengdu city was chosen study area by its fast development in economy and society. The spatio-temporal change of urban land use about 16 years within the study area and its driving forces and eco-environmental effect was analyzed based on RS images, RS and GIS technique, synthesizing integration the data such as RS data, economy and society data, and environmental data,and so on. The understanding and results are as follows.(1) The synthesis integration of model and its calculation methods on multilayer RS thematic information extraction. The model and its calculation methods on multilayer RS thematic information extraction were brought forward in this paper. The separation methods between the thematic information and its background information within the whole region images were emphasis studied and application methods system of object-based RS information extraction was built. The knowledge about surface substance spectrum, space structure and its forms, the reciprocity relationships within the space, and so on was integrated into models step by step through delamination levels partition and logic distinguish based on delaminating classification resulted from different character parameters and different classification methods in the process of thematic information extraction. The RS thematic information extraction models and its calculation methods of object-based study area about the spatio-temporal change of urban land use were built based on RS data. The study results show that classification precision based on this methods is good with the Kappa is 0.871,0.857and 0.863. The application results about this thematic information extraction also show that this models and its calculation methods is agility and efficient.(2) The speed of spatio-temporal change of urban land use is quickened and its intensity is notable. The study results show intensity of urban land use change is notable and the speed of spatio-temporal change of urban land use is quickened. The area of cultivated land is continuance decrease, about 12.066×104hm2, built-land area and forest land area is in the increase process, about 6.225×104hm2, 3.195×104hm2 in the year of 1992~2008, respectively. The integration index of urban land use degree within the study period has an increase current in the whole. The integration index of urban land use degree in 1992~2000 has a little descend current, while has a strong increase current in 2000~2008.The value of urban land use change in the period of 1992~2000, 2000~2008 and 1992~2008 is adjust period, development period. The difference of spatio-temporal change of urban land use is obviously. There is a different characteristic in cultivated land, forest land, and built-land, that is the cultivated land keeps decrease current in the process of transform, and other land was translated into forest land, so, the forest land is increase, built-land area is in the increase process current. The area transformed from the cultivated land into built-land has led to increase speed of urban expansion. The spatio-temporal diversity of urban land use in translation and directions is notable. In the period of 1992~2000, the results of the transform quantum proportion show that the maximum value is forest land, about 29.9%, the nest place is cultivated land and built-land, about 15.8%, 5.17%, respectively. Forest land was transformed into cultivated land and country residence land, the much area transformed from paddy land to forest land is 3.309×104hm2. The much area of water body land was transformed into built-land and forest land, while the area transformed from forest land is 4 484.51hm2. The much area of cultivated land was translated to built-land and forest land, about 6.693×104hm2, thereinto the area of dry land is increase 4.386×104hm2. The area of cultivated land was main transformed into built-land and its increase area is 2.935×104hm2. In the period of 2000~2008, the results of the transform quantum proportion show that the maximum value is cultivated land, about 29.9%, the nest place is built-land, about 8.07%, respectively. In the period of 2000~2008, the results of the transform quantum proportion show that the maximum value is cultivated land, about 29.9%, the nest place is built-land, about 8.07%, respectively. Much forest land area was transformed into country residence land and paddy field, while the increase area transformed from cultivated land is 1 139.72hm2. The much area of water body land was transformed into dry land, while the area translated from forest land and cultivated land is 2.197×104hm2. The much area of cultivated land was transformed into built-land and forest land is about 5.372×104hm2, thereinto the decrease area of dry land and paddy field is 3.714×104hm2, 1.658×104hm2 and 4.386×104hm2, respectively. The area of built-land mainly transformed from cultivated land is 3.289×104hm2.(3) The economy development, urbanization level were the main caution for urban land use change. The factors on driving forces of urban land use change in study area was discussed, and its dynamical mechanism of urban land use change was open out applying for the quantitative method and qualitative method based on synthesis integration concerned data such as LUCC data, economy dada, society data ,and other natural data, and so on in study area. The results show that the economy development, urbanization level were the mostly caution. The development level of economy and society has led to enhance domino effect in built-land area at forth expanding in the course of urbanization process in study area.(4) The value of ecosystem service was main supported by the ecosystem from the woodland, water body and farm land in study area. Environment protection in Chengdu city is not only very important for development of the society, economy, and ecosystem security, but also important strategy status for the eco-environmental protection for the upper reaches of Yangtse River and three gorges reservoir. Land use is in dynamical change and a complexity system, the fast development of economy and society, especial the fast urbanization process in Chengdu city has led to frequently human activity, intensity impact, land use manner and structure become complexity, ecosystem is also become frailness, therefore issues resulted from human activity has apparent, and become main restrict factors impacting on sustainable development of local society and economy. Land use change in study area has caused environmental response such as water environmental effect, atmosphere environmental effect, and soil environment effect, a series of environment problems, and so on. the result of surface temperature retrieval information from TM/ETM+ within Chengdu city based on methods of single-window algorithm and spatial modeling shows that the surface temperature lower with increasing distance from the inner city and impervious getting lower at the same time; there is positive correlation between surface temperature surface impervious. The results from the value of ecosystem service show that the total value increased 5.2 754×108 RMB yuan in study period, and the value of ecosystem service was main supported by the ecosystem from the woodland, waterbody and farm land in study area. The results also show that the regional difference of value of ecosystem service is notable.(5) There is negative correlation relationship and positive correlation relationship between surface temperature information varying from the distance from the midtown to suburb and surface impervious ability. The study results on surface temperature information show the spatial distribution of the isotherms with the response of permeable surface is significant applying for two information obtain methods, such as single-window algorithm and a negative correlation between impervious surface and vegetation coverage in urban built-up area according to RS images in third ring road of Chengdu, to obtain surface temperature information and impervious surface area in the ERDAS spatial modeling module respectively. Through the random sample analysis, correlation analysis, as well as overlay analysis of isotherms and equal surface water lines, focusing on the urban surface temperature response to the effects of impervious surface on basis of former study. It is proved that the surface temperature lower with increasing distance from the inner city and impervious getting lower at the same time; there is positive correlation between surface temperature surface impervious in Chengdu that the correlation is 0.73. The spatial distribution of the isotherms with the response of permeable surface is significant.