Assessment On The Ecological Vulnerability In Eastern Qilian Mountainous

In this paper, a case study on the regional ecological environment vulnerability inEastern Qilian Mountains is carried out. The remote sensing images in1994,1995and2009are used as the basic information sources. Based on the seven indicators oflandscape pattern that is the patch density, boundary density, isolation, reciprocal offractal dimension, etc, the model of landscape vulnerability index was established and theregional eco-environmental vulnerability was studied from the perspective of landscapepattern. This study will provide important scientific bases for the regional ecologicalsecurity research and ecosystem restoration and reconstruction. The results showed that:(1)During1994to2009years, Landscape pattern dynamic changes in EasternQilian Mountains expressed as the shrub, bare land and grassland are increased, of whichthe maximum increased area of shrub, the minimum increased area of grassland; and theforestland, ice and water are decreased, of which the maximum reduced area of forestland,the minimum reduced area of water.(2) In1994, the vulnerability of various landscape elements in the study area wasin the following decreasing order: shrub>water>bare land>grassland>forestland>ice; In1995, water>shrub>bare land>grassland>forestland>ice; In2009,water> shrub>grassland>ice>bare land>forestland. Comprehensive analysis of the landscape elements ofvulnerability of the study area in1994,1995and2009years that: As human activities onnatural resources of high strength development, lead to landscape disturbance drastic inthe study area，The higher ecological vulnerability of the water, shrub, grasslandillustrated that the three landscape elements have the lower stability, the more sensitive tooutside interference and the larger impact of human activities.(3)Significantly positive relationships were found between the vulnerability oflandscape elements and fragmentation, isolation, and they can reflect the eco-environment issues well; however, reciprocal of fractal dimension, connectivity and thevulnerability of landscape elements were negative correlation. The landscapefragmentation and isolation degree caused by human activities were the decisive factor oflandscape fragility in Eastern Qilian Mountains.