Analysis And Assessment Of Ecological Footprint And Ecological Vulnerability Of Yulin City

Take Yulin which is located between loess plateau in northern Shaanxi and maowusu desert as a case study, this paper analized its ecological footprint and assessed its ecological vulnerability. Using an improved model of ecological footprint-"provincial hectare", this paper calculated equivalence factor and yield factor suited for study area, and figured out the ecological footprint of Yulin city by provincial average productivity. On the basis of the regional ecological environment features, this study built a comprehensive evaluation index system of ecological vulnerability from local natural conditions and human interference, and determined these indexs'weights through the analysis of hierarchy process (AHP). Lastly, the method of comprehensive index was used to worked out ecological vulnerability. The results show that:(1) Per capita ecological footprint of Yulin appeared increasing trend from 1998 to 2008. The value increased from 0.60904 hm2 in 1998 to 1.42476 hm2 in 2008 and increased range was nearly 1.5 times. Per capita ecological capacity showed a trend of decline as a whole. The value declined from 0.79205 hm2 in 1998 to 0.74776 hm2 in 2008 and declined range was 5.6 percent. From 1998 to 2008, there were both ecological remainder and ecological deficit of Yulin and the trend was transforming from ecological remainder to ecological deficit. The transitional period was between 2000 and 2002. Ecological deficit increased gradually from 2002 to 2008.(2) Ecological footprint of Yulin showed space difference in 2008. Ecological stress of six counties in northern area was greater than other six counties in southern area. Yuyang, shenmu, fugu, hengshan, mizhi counties all appeared ecological deficit and ecological deficit of the top three counties were greater than the overall level of Yulin city in 2008.(3) The driving forces that influenced ecological vulnerability were natural cological background, environmental pressure, population capacity and economic and social development. Ecological vulnerability of Yulin was fluctuant widely and showed declined trend as a whole from 1998 to 2008. Because with the economic development, meanwhile, Yulin took great efforts to construct ecological environment in recent years.(4) Yulin possessed high degree of ecologic environment vulnerability in 2008, the area of extremely-vulnerable and highly-vulnerable regions have reached 26782.083 km2, accounting for 62.33% of study area, and was more than the half of total area. The regions mainly distributed in the northern aeolian sandy area along the great wall, and appeared great space difference.This paper maked accessment and analysis on the ecological footprint and vulnerability, which provided the data and basis for the Yulin city's action in reasonably developing resources, protecting and restoring ecological environment construction in the future. That helped to coordinate the various resources, enverionment and social economy to achieve sustainable development.