Impact assessment on ecosystem to climate change in Heihe river Basin in NW China

Based on the field investigation, documents and the concept of vulnerability, we developed a set of index system about vulnerability and adaptive capacity which influenced the ecosystem of Heihe River basin because of climate change. The index system mainly included two kinds of factors, climate factors and other factors. The climate indicators include humidity, annual rainfall, yearly temperature, etc; other factors include remote sensing data and socioeconomic materials, such as annual grassland area change, etc. We utilize the method of Analytic Hierarchy Plan (AHP) to distribute the weight of each indicator. We calculated quantitatively the vulnerability and adaptive capacity of the ecosystem to climate change of 9 counties in Heihe River Basin in 2000, this results represent the status quo. According to the GCMs project, the precipitation will rise by 27%, 19% and 30% when the concentration of CO₂ double. The future vulnerability and adaptive capacity to climate change of the ecosystem of 9 counties in Heihe River Basin when CO₂ double were calculated. The results show: (1)The ecological environment of the Heihe River Basin is incredibly vulnerable, on the whole, and in different places in the basin, its vulnerable degree is different to some extent. (2)In the whole basin, the comparatively low vulnerable ecosystem district is the upper reaches of the Heihe River. (3)In 2070, The most vulnerable district is still the lower reaches of the basin.