Assessment of eco-environment vulnerability in the Songhuaba watershed

The Analytic Hierarchy Process (AHP) has the special advantage in multi-indexes evaluation, and Geographical Information System (GIS) is good at spatial analysis. Combining AHP with GIS provides an effective means for studies of regional eco-environmental evaluation. In this paper, we analyze ecological vulnerability of the Songhuaba watershed using AHP. We extract the six ecological factors through remote sensing and GIS technology, including vegetation index, soil brightness and humidity index, elevation and slope information, and land use. Main conclusions are drawn as follows: Ecological and environmental conditions in the study area are in general light and medium level fragile areas, and heavy level fragile areas are small proportion. The results showed that the area with potential level was 12.17 km(2) and accounted for 2.1% of the total area, and the area with light level was 392.58 km(2) and accounted for 67% of the total area, and the area with medium level was 178.84 km(2) and accounted for 30.5% of the total area, and the area with heavy level was 2 km(2) and accounted for 0.3% of the total area.