随着西部水电建设事业的深入开展，环境边坡危险源问题也日益突出，这是由于人类工程活动对坝区开口线内的开挖边坡稳定性给予了足够重视和治理，而对于开口线以外保持其自然稳定的环境边坡，不可能也没必要对其自然状态开展整体性分析与大规模治理，也不可能强求达到与工程开挖边坡一样的安全控制标准，加之目前尚无规范明确指导，亦无研究资料公开出版以供参考，导致其评价标准和防护体系不系统、不统一，成为了水电站施工和运行期的安全隐患。通过对环境边坡危险源的定义、类型、边坡安全等级、防治标准等一系列问题进行阐述和讨论，建立了系统的边坡危险性评价体系，为进一步研究提供基础。

The construction of hydropower station in west China gave rise to an increasingly obvious problem of environmental slope hazard. The stability of slope within the opening line received sufficient attention and regulation by human engineering activities ； whereas the environmental slope outside the opening line still keeps its natural stability. It is neither necessary nor possible to make comprehensive analysis or extensive regulation on its natural state and to impose the same safety control standard as with excavated slopes. In addition, the lack of standard guidance or research documents published for reference brings about neither systematic nor unified evaluation criteria and protective measures, which has become a potential safety hazard for the construction and operation of hydropower stations. In this paper, issues regarding the defining, classification, slope safety level, prevention and control criterion of environmental slope hazard are expounded, and a risk assessment system is proposed to provide basis for further research.