Assessment Of Ecological Vulnerability In Kashgar Prefecture Based On 3S Technology

The assessment of ecological vulnerability has greatly significant for comprehending,defending and transforming ecological environment,as well as the promotion of harmony between human and nature.Based on the exposure-sensitivity-resilience framework,this paper took Kashgar as an example,selected the relevant meteorological data,remote sensing and socio-economic development data,then using the methods of empirical mode decomposition,landscape pattern analysis and spatial statistical analysis researched the change of climate factors in the northern plain area of Kashgar,the temporal and spatial change characteristic of land landscape pattern,the degree of ecological vulnerability of each county and city in Kashgar and its spatial change driving force,which provided scientific theoretical support for the green and high-quality development of Kashgar.The conclusions were as follows:(1)In Kashgar and Yeerqiang River oases,the annual average temperature was almost the same.The precipitation was mainly from May to August,and the monthly average precipitation was about 10.76 mm.The abrupt test of annual average temperature showed that the annual average temperature in recent 30 years had experienced the fluctuation of first cooling and then warming.After 1997,the annual average temperature of Kashgar plain had changed from cold to warm,and the linear fitting warming rate was 0.47±0.15℃/10a.The precipitation was fluctuating and rising slowly,which was still in short of supply.The temperature increased obviously,which aggravated the ecological vulnerability of regions.(2)The spatial trend of Kashgar land had changed obviously,which had shifted from southwest to northeast,the fragmentation of each landscape type was increasing,the human disturbances were strong and the landscape heterogeneity of cultivated land with unused land were more obvious.There were mutual changes among the land types,the most of that was unused land,respectively converted into construction lands,farmlands,grasslands,forest lands.The increase areas of cultivated land and construction land were relatively the most,and the net change rate was more than 40%.The land use change density of various counties and cities showed a "centralized diffusion trend".Under the economic drive,a pattern of rapid development of surrounding counties and cities led by Kashi City had been formed.(3)The ecological vulnerability of Kashgar region showed a spatial pattern of high in the north and low in the South.The average value of the overall ecological vulnerability index had a relatively small increase,that was still at a mild vulnerability level.The increase in highly vulnerable areas mainly comed from moderately vulnerable areas.The lowest value of ecological vulnerability was in tashkurgantajik Autonomous County,followed by Kashgar City and Zepu County,all of them belonged to micro vulnerability;the highest were Shache County,Jiashi county and Bachu County,wich belonged to highly vulnerable areas.Besides,the Kashi City and Zepu County were more significant.(4)Desertification type land had a great impact on ecological vulnerability.The gobi,saline alkali land and desert area were mainly contained medium and high vulnerability.Among the four types of land in nondesert areas,cultivated land,construction land,water and grassland,medium and highly fragile areas account for a relatively small amount.When human activities were reasonably arranged,it could reduce the ecological vulnerability of the area and restore the quality of the ecological environment.The factors of the total amount of water resources,terrain and vegetation coverage caused the spatial differentiation of ecological vulnerability in the north and south of Kashgar region,the human activities in the northern plain region were intense,the landscape fragmentation caused by the increase in the cultivated land area and the number of livestock had increased,which coupling with the bad natural environment aggravated the ecological vulnerability of Kashgar region,which made the overall ecological environment vulnerability expand to the northeast.The ecological vulnerability and ecological pressure in the peripheral areas had increased.