Ecosystem Structure And Pattern Remote Sensing Survey And Change Analysis In Urban Area

In this study, using remote sensing information technology and GIS spatial analysis methods, combined with ground surveys, we made the decade (2000-2010) Remote Sensing Survey and analyzed the Dynamic Change of Hangzhou urban ecosystem structure and pattern. In the support of ENVI, the computer automatic classification of three Phases of Landsat remote sensing in2000,2005and2010was made and information was extracted. In that case, Hangzhou urban area ecosystem was divided into four types:forest, farmland, water, artificial surface, and with the application of GIS spatial analysis and landscape pattern index, the decade ecosystem structure and pattern and variation in Hangzhou urban area were deeply analyzed. The conclusions are mainly the following aspects:First, the distribution and proportion of Hangzhou urban area ecosystem. The total area of Hangzhou urban area is329,748.65hectares. In2000, the area of arable land is171,986.30hectares, which is52%of the total area;64,383.69hectares of artificial surface is20%of the total area; the area of forest is62,224.59hectares, which accounts for19%;311,154.07hectares of water body takes up9%of the total area. In2005, the arable land of Hangzhou urban area is145,666.02hectares, accounting for44%of total area;98,167.81hectares of artificial surface is about27%of the total area;57,095.16hectares of forest makes up17%of the total area; while311,154.07hectares of water occupies11%. The arable land of Hangzhou urban area, in2010, is about130,337.56hectares,40%of the total area;108,824.44hectares of artificial surface,33%of the total area;56,724.53hectares of forest,17%of the total area;311,154.07hectares of water,10%of the total area. From the overall analysis, by2010, the arable land and forest area decreased more seriously while artificial surface area increased rapidly; water area has a larger increase from2000to2005. But, from2005to2010, the total area has increased more or less.Second, the changes of Hangzhou urban area ecosystem composition. Based on the number of patch, the changes are:the plaque number of Hangzhou urban area farmland has been in the state of sustained growth in the past ten years; the plaque number of artificial surface decreased and then increased while the number of patches of forest and water experienced a decreasing trend after its first increase. Based on the area, the changes of the Hangzhou urban ecosystem composition are:the arable land and forest area of Hangzhou urban area experienced sustained decline; arable land area decreased by a big margin, relatively small for forest area; oppositely, artificial surface area has been in the state of continued growth during this decade and the water area declined after the first increase in the change process, but in increasing trend in general.Third, Hangzhou urban area ecosystem landscape pattern characteristics. By making a comprehensive analysis of Patch number, mean plaque area, average classes plaque area, boundary density and aggregate indices, the overall fragmentation of the Hangzhou urban area has been increased from2000to2010. Especially farmland fragmentation largely increased, which showed that the proportion of large areas of contiguous blocks of arable land decreased to a certain extent. Water and forest fragmentation reduced, accounting for that the overall contiguous nature of water and forest has improved. The artificial surface fragmentation decreased first and then increased. The fragmentation of the end of the study increased substantially compared to the beginning of the study. From the overall, fragmentation of artificial surface still continues an increasing trendFourth, the inter-conversion characteristics of Hangzhou urban area ecosystem types. According to the Ecosystem types transfer matrix, from2000to2010, the loss of ecosystem types:farmland> water> forest> artificial surface. By2010, the flow of ecosystem types:artificial surface>water> farmland> forest. Each type ecosystem structure changes of Hangzhou urban area from2000to2010:farmland> water> forest> artificial surface. From2000to2010, the consolidated rate of change of ecosystem:artificial surface> water> land> forest. From2000to2010, the cover types of every ecosystem type get worse, but deterioration degree of forest cover is most serious.