Ecological safety assessment in Hulunbeier steppe based on the landscape pattern

摘要

Based on TM remote sensing image and topographic map, the spatial information of landscape pattern was extracted in Hulunbeier steppe in 1995, 2000, 2005 and 2010. With the principles and methods of landscape ecology, landscape fragmentation index, division index, dominance index and fragility index were selected to construct the ecological safety index which was used to quantitatively analyze the dynamic changes of landscape pattern and elucidated ecological safety status in study area. Result showed that the overall landscape tended to become fragmentized and complicated with the total number of patches increasing in the study area from 1995 to 2010. The ecological safety index of landscape types can be classified into four grades, grassland > unused land, wood land > water body, crop land > construction land. Overall, the regional ecological safety status got worse with the ecological safety index of natural landscapes decreasing and the ecological safety index of artificial landscapes increasing. In particular, the area of construction land had a continuous increase with a higher growth rate (7.41% per year during 2005~2010), which will be unfavorable to regional ecological safety as the biggest potential risk.