Analysis Of Eco-environmental Vulnerabiltiy In The State-level Economic And Technological Development Zone Of Changxing Island

In recent years, with the rise of the island's development in our country regions the human developments make a serious negative impact on the island's ecological environment under the shallow recognition, only the immediate economic benefits and the predatory development strategy. Changxing Island is the largest island in the north of Yangtze river in China. It was listed the coastal industrial zone in 2005,and was upgraded to the state-level economic and technical development zone in 2010.The interferences of the large-scale economic development activities and the freshwater resources utilization in the beginning, will give the island's fragile ecosystem great pressure. Thus, according to the natural geographical characteristics and the present economic development intensity, based on the technical support of GIS, used the USLE equation of the soil erosion and the mathematics model of the seawater intrusion hazard in the km grid, this study evaluates the soil erosion intensity and the potential dangers of the seawater intrusion respectively. Based on them, the study uses the comprehensive model of the ecological environment to analyze the eco-environment vulnerability and the space differentiation of Changxing Island. The main research results are that:(1)The soil erosion modulus of the study area is 869.87t/km~2. a. The soil erosion exists micro degrees erosion, mild erosion, moderate erosion. The area proportions of three types are 35.89%, 49.94%, 3.29% respectively, and the total area proportion is 89.12%.The results show that the study area covers a wider range of the soil erosion. The bigger mountain, the unused land of the poor vegetation cover and a part of farmland are the main areas of the soil erosion, and the soil erosion is lighter in residential, the coastal lowlands, the low mound of the good vegetation cover generally.(2) The risk area of the seawater intrusion is 114.84 km~2 in the study area, accounting for 32.68% of the total area. The dangerous kinds of the seawater intrusion contain mild risk, moderate risk, high risk. The area proportions of three types are 12.15%, 19.76%, 0.95% respectively. Among them, the high risk zone of the seawater intrusion is mainly distributed in the central region of Changxing Island, and the average risk index is 0.70. The moderate risk zone of the seawater intrusion is mainly distributed in south coast of the centre of Changxing Island, and the average risk index is 0.59. The mild risk zone of the seawater intrusion is mainly distributed in the southeast of Changxing Island, around the high risk zone and on the west coast of Jiaoliu Island, and the average risk index is 0.46.(3) The ecological environmental vulnerability status represent to micro degrees vulnerability, mild vulnerability, moderate vulnerability, strength vulnerability, extreme intensity vulnerability in the study area. The corresponding vulnerable area proportions are 50.75%, 24.04%, 6.41%, 18.51%, 0.29% respectively. Among them, the area of the extreme intensity vulnerability is distributed in Changxing Island, only one km grid area, and the average vulnerability index is 1.6. The strength vulnerable area is mainly distributed in the northeast, central of Changxing Island, and the average vulnerability index is 1.32. The moderate vulnerable area is mainly distributed around the high risk zone, and the average vulnerability index is 0.85. The mild vulnerable area is mainly distributed in the west of Changxing Island and the west corner of Xizhong Island, and the average vulnerability index is 0.46. The micro degrees vulnerable area is centralized Jiaoliu Island, Fengming Island, Camel Island, Xizhong Island, and the average vulnerability index is 0.2.