Quantitative Analysis Of Landscape Pattern And Assessment Of Ecological Security Of Hefei City

The changes of landscape pattern and ecological security were closely related with living and producing of human, the study of these fields had become one of important fields of global change. With the development of the economic and industrialization and urbanization, the changes of land use and landscape pattern were greater. As a case study of Hefei city, it had had huge achievement in socio-economy development in recent years. At the same time, ecological security was not optimistic because people had less consciousness for the protection of the ecological environment. Therefore it was typical and representative to analyze and study on the changes of landscape pattern and ecological security of Hefei city. It is helpful for providing methods and basis of the quantitative study on the landscape pattern and ecological security of the Anhui province and other economic developed areas in China. Full study were divided into four parts:Firstly, based on the charts of land use types of Hefei city between 1985 and 1995, using GIS software Arcview, and adopting grain of 5m, the transfer matrix of area and the transition probability of Hefei city between 1985 and 1995 were determined. Based on Markov model, and Matlab software, taking 10 years as a length of stride, the dynamic simulation and the prediction of the landscape pattern of Hefei city were carried on. The results showed that 97.313% land area of Hefei city had not changed on land types and 2.687% had changed from 1985 to 1995. Among of them, the greatest change in the conversion was from arable land to the land of urban, rural and resident. It was 1187.468 hm2 that accounting for 91.046% in the total land change, followed by the conversion from the land of urban, rural and resident to arable land, and then from arable land to waters, which accounted for 8.687% and 0.267% in the total land change, respectively. The main land types were arable land, land of urban, rural and residents and waters in the mutual conversion of land use change. According to the forecast results of markov model, the change trend of the landscape pattern of Hefei city was that the ratio of arable land occupied in the total area will gradually declined, while the ratio of the land of urban, rural and resident occupied in the totla area will rise sharply.Secondly, based on the chart of land use types of Hefei city in 2002, using GIS software ArcView, and Fragstats3.3, the software for analyzing landscape pattern, selecting 22 landscape indices, the change characteristics of landscape pattern indices of Hefei city along with the increased grain size was explored. Meanwhile, using SPSS, the software for statistical analysis, and Excel, fitting function of partial landscape indices were obtained and the coefficients of variation were calculated. The results showed that: (1) along with the grain size increasing gradually from 10m to 100m, various landscape indices display different tendency of change, which showed that the change of spatial grain has the obvious influence on the change of landscape index, the effect of grain can be concluded as 4 kinds of situation, rise or drop overall, change a little, no regulation of change; (2) partial landscape indices were fitted using quadratic function, cubic function, power function, linear function respectively, and response curve of indices of landscape pattern to grain size were set up; (3) first scale domain is the better value scope of selecting the suiTablele grain, based on the 1:50000 chart of land use types of Hefei city, the suiTablele range of grain for computing and analyzing landscape indices was 20~30m.Thirdly, Using Statistical Yearbook of Hefei city, the ecological footprint of Hefei city from 2000 to 2006, ecological carrying capacity in 2002, and three indices of ecological security were calculated and analyzed comparatively. The results showed that: (1)The per capita ecological footprint of Hefei city increased from 1.372452hm2 in 2000 to 2.184914hm2 in 2006 and expressed the increasing trend, the ecological deficit was 1.499251hm2 in 2002, which showed that the intension of production and daily life of Hefei city exceed the ecological carrying capacity of the system. Regional ecosystem structure and function were needed to be adjusted; (2)Among the ecological footprints of various types of land, the ecological footprint of arable land was the largest, followed by fossil energy land, which reflected the economic development of Hefei city largely depended on the consumption of biological resource and natural resource. Although they showed increasing trend overall, the average ecological footprint of woodland and building land accounted for a relatively smaller proportion of total ecological footprint and had a smaller contribution rate for increase of ecological footprint per capita. (3)The level of ecological security of Hefei city was low, the percent of per capita ecological footprint of Hefei city in per capita ecological footprint of global was relative large, but the coordination between the socio-economic development and ecological environment needed to be further improved. Finally, the reasons of the ecological deficit was analyzed and countermeasures or measures during the sustainable development of Hefei city were proposed.Finally, According to the changing trend of landscape pattern and the situation of ecological security, the proposed strategy study of the construction of Hefei city was carried on, which contained several aspects: the esTablelishment of the ecological security pattern, comprehensive ecological management,the development of"low carbon"mode, the creation of ecological landscape.