Abstract:

The urbanization watershed of Songhua River in Harbin section was as example, using RS and GIS technology, the ecological risk index (ERI) was constructed based on the analysis of land use change and structural characteristics. The spatial distribution and change characteristics of ERI distribution map that obtained using block Kriging from the samplings were analyzed, which to reveal the spatial temporal evolution characteristics, change rules and formation mechanisms of ecological risk based on land use on the background of urbanization, to reduce the land use risk in greatest extent during urbanization process. The results showed that: the moderate ecological risk level was major and the proportion of high ecological risk was lowest, the change volumes of high and low ecological risk were greatest, the high and extremely high ecological risk was focused on the urban region and Peri-urban transition zone, the region of low and extremely ecological risk was mainly located in forest land with higher vegetation, water bodies, grassland ,shrub land and so on, meanwhile, the transition zone from high to low ecological risk was very obvious, cropland→cultivated land and cropland →forestland were the major transform trajectory for the region of slightly worth and slightly better, the gravity shift volume of extremely low ecological was greatest, while, the high ecological was least, which accounted for 12.31 km and 0.57 km, respectively.