Study On Ecological Risk Assessment Based On 3S

With the development of socioeconomic, the land resources as an important carrier for human production and life, and its ecological risk related to the speed and quality of socioeconomic development for human. Wetland, which as the kidney of the earth, its ecological risk related to the cycle of water, air and other systems. But the traditional land resource monitoring system was very difficult to obtain the information for land resources structure and the change of land use ecological risk, as the development of 3S technology which provides the dynamic monitoring for the study of the land use ecological risk. This article taken national nature reserve in Anhui Shengjin Lake as the research object, and used 1986、1995、2000、2004 and 2011 TM remote sensing image as the basic data sources, combined with the 1:1 million topographic map for the national nature reserve in Anhui Shengjin Lake, the function plan for the nation nature reserve、remote image for SPOT5、 statistical yearbook data and other datum. With the support of the 3S technology, we used ERDAS 9.2 to combined the band, corrected geometric, cut and set the classification template for land use, and then got the landscape map for land use classification by supervised classification, after that we used Fragstats software to analyze the landscape index for land use of study regional, and established the comprehensive model for land use ecological risk by AHP, which we can use it to calculated the comprehensive index for land use ecological risk and drawn the interpolation map for land use comprehensive ecological risk that we can obtain the causes for the formation of land use ecological risk, so that we can provide the theoretical basis for dynamic monitoring for land use ecological risk.(1) From the landscape map of 5 periods, we knew that the status basement for land use on study area was cultivated land and waters, which including cultivated land accounts for about 43.86% of total area on the study regional, while water accounts for about 40% on the study area, the second was the forest land, construction land, traffic land, unused land, garden land and grassland. From 1986 to 2011,the changes of land use on study regional showed a gradual decrease of the area for cultivated land、while the traffic land and construction land showed increased trend, which it suggested that the structure of land "use on study regional influenced by human became more and more activity. Because of the vulnerability and difficulty recover for wetland, the fast growth of construction and traffic land will damage the overall balance of ecological system for land use, so it was necessary to pay attention to protect the cultivated land、woodland and other original land on the development and utilization for land resource.(2) We established the comprehensive model for land use ecological risk according to the socioeconomic data of land use、the change data of land use area and the landscape index of land use for 5periods,which we knew that the land use ecological risk was decrease in the study area, and the main risk regional was distribution in southwest and northeast corners in study area.(3) This article used Markoff chain to predict the condition of land use ecological risk for several years. We use land use transfer matrix from2004 to 2011 years to predicted the condition of land use change for 2018 years, and calculate the index for land use comprehensive ecological risk. According to the result of 2018, we knew that the cultivated land and water will decrease, and the reduction rate was low which was about 4.85%, while the reduction rate of water was high which about 41.94%,and the increased rate of garden area was greatly which was about 10 times compared with 2011.In addition, the land use ecological risk index,which showed downward slowly trend that was about 0.86 compared with 2011.