基于景观结构的延河流域生态风险评价

Ecological risk assessment of Yanhe watershed based on landscape structure

本研究基于景观结构指数和生态脆弱度指数构建生态风险评价模型,综合评价了延河流域生态风险状况及空间分布特征,并提出了相应的风险管理对策。结果表明,流域中以裸地的景观结构指数最大,受人类活动干扰程度较大,水域次之,灌丛最小;流域生态风险空间分异明显,流域中部生态风险等级较高,并以此向外围呈递减趋势;生态风险分布与景观类型关系密切,建筑工矿用地、旱地和水域等景观生态风险等级较高,草地和灌丛生态风险等级较低;要因地制宜地实施生态风险管理,确保流域生态系统稳定,降低生态风险威胁。

An ecological risk assessment model incorporating the landscape structure index and landscape fragile degree index was put forward to comprehensively evaluate ecological risk status and its spatial distribution characteristics of Yanhe watershed. The results indicated that： the landscape structure index of bare land was the largest in the study area and it had a higher human activities disturbance degree. Water area came second,and shrub forest had the smallest value. There were some obvious spatial differences of ecological risk levels in the watershed,with the central part of watershed having the higher ecological risk level,and with a decresing trend from this area to the surrounnding areas. The distribution of ecological risk levels had a close relationship with landscape types. The building and industrial land,dry land and water area had a higher ecological risk levels,while grassland and shrub forest had a lower level. We should adjust measures to local conditions in implementing ecological risk management,to ensure a stable ecological system and to reduce the threat of ecological risk.