崩滑堰塞坝(湖)的地貌环境效应  

Geomorphology and Environment Effects of Landslide Dams (Dammed Lakes)

作　　者：余国安[1,2] 王兆印[2] 黄河清[1] 刘怀湘[3] 

机构地区：[1]中国科学院地理科学与资源研究所,北京100101 [2]清华大学水沙科学与水利水电工程国家重点实验室,北京100084 [3]南京水利科学研究院,江苏南京210029

出　　处：《地球科学进展》2010年第9期934-940,共7页Advances in Earth Science

基　　金：国家重点基础研究发展计划项目"次生灾害链生效应;潜在次生灾害判识及风险控制"(编号:2008CB425803);国家杰出青年基金项目"河流过程与流域管理的复杂性研究"(编号:40788001)资助

摘　　要：崩滑堰塞坝(湖)具有显著的地貌环境效应,这种效应在时间尺度上分为短期和长期2种,主要表现在河流水文过程、地貌演变、环境生态、景观等方面。堰塞坝形成初期河流原有生境受到干扰,河流生态和景观出现退化。堰塞体溃决强烈改变下游水文过程及河流地貌,严重冲击河流生境和生态,并可能对下游基础设施和群众生命财产造成灾难性破坏。长期稳定维持的堰塞坝深刻影响河流地貌过程,并显著改善河流生境、生态,提升景观水平。堰塞坝(湖)是河床持续下切、岸坡失稳而自然反馈形成的裂点,能增加河流阻力,控制河床下切,如能长期维持是河流健康稳定的促进因素。Landslide dams （dammed lakes） posses distinct geomorphologic and environmental effects, which can be grouped to short-term and long-term on time-scale, and mainly embody on hydrologic process, fluvial mor- phology, environment and ecology, and landscape. During the initial stage of landslide dams, the aquatic ecology and landscape often undergo some kinds of degradation since the pre-existing habitats were violently disturbed or e- ven destroyed. Burst of landslide dams intensively change the hydrological process and fluvial morphology within a short time, and have strong negative impacts, even devastation, on downstream aquatic habitats, ecology and land- scape. The landslide dams （dammed lakes） may be preserved for long term, and they will develop into knickpoints by long-term action of the flow, and act as a primary control of river bed incision, thus, reducing the potential of new landslide. Landslide dams （dammed lakes） which stably maintain in long-term scale greatly affect the fluvial morphology. Large knickpoints can totally change the fluvial processes and river morphology. Uplift of the Qinghai- Tibetan Plateau has caused extensive channel bed incision along almost all rivers. For many rivers （ such as the up- stream Yangtze） the incision has been partly controlled by knickpoints. Upstream reaches of a knickpoint have a new and unchanging base level. If hundreds of landslide dams occulted simultaneously on a reach of a mountain river, the potential energy of bank failure and the slope erosion would be greatly reduced and sediment yield from the watershed might be reduced significantly. The long-term maintained dammed lakes can greatly enhance stream habitats, aquatic ecology, surrounding landscape, and sometimes cause a change in local micro-climate. Many dammed lakes have become favorable touring destination, and have potentiality for hydropower generation. Land- slide dams （dammed lakes） are knickpoints formed by natural feedback to continually incision of stream bed and in

关 键 词：堰塞坝(湖) 裂点 地貌过程 环境生态 效应 

分 类 号：P642.2[天文地球—工程地质学] X14[天文地球—地质矿产勘探]