Dynamic Analysis Of Urban Landscape And Ecological Environment Assessment Based On Remote Sensing Technology

This paper aims to ecological changes in Chengdu, focusing on urban ecological environment evaluation, land use/cover change and landscape pattern analysis. The results may provide a scientific basis for decision-makers, good for the overall co-ordination between urban development and the environment, and ensure sustainable development.This paper combines with remote sensing technology, improving Ecological Environment Evaluation Index recommended by the "ecological environment evaluation of technical specifications (Trial)" (HJ/T192-2006), building the Urban Environment Evaluation Index System based on remote sensing technology, and evaluated the Ecological Environment of Chengdu Center City District (within the first high-speed beltway region).This paper, the central city of Chengdu (first beltway less region), for example, used of remote sensing data of 2000,2004,2008 and 2012 four years, by classificating with remote sensing classification of supervised classification and visual interpretation, and amended extract land use/cover change information, and analyzed the feature of the study area land use/cover change of different periods, and select reasonable landscape indices, quantitative analyed characteristics change features by using landscape index each time the land use/ cover and landscape pattern, to further explore the causes of the driving factors of this change and its ecological significance.The results showed that:(1) urban development within the study area land use/cover change of the main driving forces. Urban land area by the year 2012 to 2000 165.96km2 342.46m2, the rate of increase of 106.35%.2000 urban construction land mainly in the Third Ring Road, in 2012 to expand into urban construction land outside the Third Ring Road, inside of the first beltway area. In contrast, other types of regions are reduced. In addition to unused land, the largest decline for water and arable land, had a respectively decrease of 57.66% and 52.59%, and plenty of water and arable land changed into the urban construction land. Vegetation is also reduced by 20.70% in 12 years, comparing to a smaller reduction of arable land and waters. (2) characteristics of different landscape structure in different periods. In 2000, study area mained in agriculture, which land, water and vegetation accounted for 65.08% of the total area and urban land accounted for 31.52%; although it is not absolutely dominanting arable land, but it still holds 48.68%. In 2004. the urban land accounted for 44.16% and became the dominant type. In 2004 urban land began to expanse to regions outside of tricyclic. In 2008, construction area continues to grow of the entire study area, become the dominant type of land, accounting for more than half of the total area; arable land continued to decline, and the rate of reduceing remains around 10%; the reducing rate of water area slows, while green vegetation increase. Construction land plaque became concentrated in Third Ring Road outside region, the vegetation distribution is more discrete, patches spacing becomes larger with low connectivity, and urban land plaque area was significantly increased with obviously integration. In 2012 landscape pattern of the study area was completely dominated by the urban development. (3)A slight deterioration of ecological environment. In the 2000 to 2012, the ecological environment was general in central city of Chengdu. From 2000 to 2004, El has the biggest change,which mainly due to the reduction of biological abundance index and soil degradation index, human disturbance to the environment increaseing; but last eight years, due to urban planning became more and more reasonable, so that the biological abundance index slow its space of decreaing, although the density of vegetation cover and water were reduceing, but there have been cases in the central city of increasing vegetation cover, soil degradation slowing, making no significant change of ecological environment in the last eight years. (4) rational urban planning is an effective way to alleviate the deterioration of the ecological environment.