基于地质灾害的陇南山区生态风险评价——以陇南市武都区为例

Ecological Risk Assessment of Longnan Mountainous Area Based on Geological Disasters——A Case Study of Wudu

陇南山区地质构造活动强烈,频繁的地质灾害对生态环境和生态安全构成严重威胁。分别以陇南市武都区的主要地质灾害(滑坡、泥石流和地震)和景观类型为风险源和受体,以景观结构指数和易损性指数作为评价指标,构建生态风险评价模型,进行生态风险特征评估。结果表明:武都区生态风险特征的分布主要受地质灾害风险分布和景观格局的影响,人类活动、植被覆盖度和海拔梯度也是重要的影响因素。极高风险区和高风险区主要集中分布在东江镇以东的白龙江沿岸及整个白龙江南岸、安化、马街、汉王和两水镇北部等地;低风险区和较低风险区主要分布在武都区东部和南部以及西部和西北部区域。基于景观结构的多风险源生态风险评价对于区域生态风险管理具有重要的现实和指导意义。

Longnan mountainous area was famous for its intensive geologic structure activity and frequent geo-disas- ters which caused loss and threatening the local fragile ecological environment and security. In this paper, typical geological disasters （debris flow,landslide and earthquake） in Wudu and 6 landscape types （forestland, farmland, grassland, water area, constructed and residential land, unused land） were selected as risk sources and receptors separately, landscape pattern index and vulnerability index were considered as indicator for an ecological risk as- sessment model to evaluate the ecological risk of Wudu. The results showed that ： 1 ） the distribution of ecological risk levels was mainly caused by the risk distribution of geological disasters and landscape patterns. 2） human ac- tivities, vegetation coverage and elevation also affect risk distribution. 3 ） the extreme high and high risk areas dis- tributed mainly in the south coast area of Bailongjiang river and east part of Dongjiang town along Bailongjiang riv- er, and partly in Anhua, Majie, Hanwang and north of Liangshui;while the lower and low risk areas scattered prima- rily in the east and south of Wudu and partly in the west and northwest of Wudu. Ecological risk assessment with multi-risk source and landscape pattern can be very useful for regional ecological risk management and environmen- tal protection.