Abstract: The West-East Gas Pipeline Project (WEPP）starts from Lunnan Town of Luntai County Xinjiang, and then crosses arid desert region from west to east part of China.The project disturb the ecosystems along the pipeline,and lead to many environmental calamities such as,soil quality decline,vegetation degradation,biodiversity decline and so on.It also imperils regional eco-safety and the safety of the pipeline.The ecosystems in different stable levels perform different responsibilities to the disturbance.Ecosystem stability assessment will be in favor of designing proper measures to promote the ecosystem resilience and help to protect the safety of pipeline.This paper focuses on ecosystems resilience,and values the ecosystems stability by Weight-degree model with the help of GIS.The stability is classified into four levels,namely,unstable,under stable,sub-stable and stable.Soil and vegetation are selected as the assessment factors.Stability levels are calculated out based on the evaluations that are given by experts according the resilience ability.
It is found that Saline desert and sandy desert both belong to unstable ecosystems; meadow and shrub desert belong to under stable ecosystems,these kinds of ecosystems occupy53％ of research region area; oasis are substable; and stone deserts are stable.In order to promote ecosystems restoration in those unstable areas,such as salinized soil area,sandy soil area and brown desert soil area,corresponding rehabilitation measures are designed.In saline desert area,it is important to create favorable condition for vegetation restoration and salt shells recovering at ground surface.The dug out soil should be stacked and filled back respectively according to primary soil layers order.Further more,man-made ridge due to pipeline can be use to collect runoff,which will promote surface vegetation recovering.For sandy desert area,it is necessary to protect the roots of plants.Grass lattice technology should be used to fix sands.Moreover,some human activities,such as grazing,that will destroy vegetation along the pipeline should be forbidden.In shrub desert area,the key point is to protect gravel layers at the ground surface.Gravel layers destroyed should be paved artificially,in order to conserve the soil.Manmade ridge due to pipeline can also be use to collect runoff,which will promote surface vegetation recovering.

Key words: stability assessment, ecosystems, WEPP, disturbance