汶川地震引发的山地灾害以及堰塞湖的管理方略
|
摘要
汶川地震触发了大规模的崩塌与滑坡等山地灾害,形成众多堰塞湖。为分析其风险与应对措施,本文通过野外考察、卫星影像与数据分析等方法,研究了灾后堆积体与堰塞湖的稳定性,以及它们与下切性河流之间的关系。结果显示,山地灾害在不同程度上释放了潜在势能,其中滑坡释放能量最大,因此滑坡堆积体的稳定性较好,而崩塌堆积体稳定性较差。从长期治理角度看,若能控制河床下切则可避免部分灾害的产生。堰塞湖管理方略包括两种:对于风险高的堰塞湖应以拆除为主,而对于风险很小的堰塞湖则应予以保留。震区大部分河流处于不稳定的下切拓宽阶段。保留堰塞湖可以加大河床阻力,使河流提前达到平衡,降低未来地震中山地灾害发生的风险。
The Wenchuan earthquake triggered numerous avalanches and landslides and created many quake lakes. The stability of mass movement deposits and quake lakes and its relationship with riverbed incision are studied by field investigations together with satellite images and data analysis. The mass movements released different degrees of potential energy. The landslides have released the most of its energy and have high stability. The avalanche deposits have lower stability and are dangerous. From the viewpoint of river training, some landslides might be prevented if the riverbed incision were controlled. Two strategies are applied to manage the quake lakes: to remove the high risk lakes and to preserve the low risk lakes. Most rivers in the earthquake-hit area are in unstable geomorphology stage. Lakes preservation may change the rivers into equilibrium, thus, reduce the mass movements in a future earthquake event.
The Wenchuan earthquake triggered numerous avalanches and landslides and created many quake lakes. The stability of mass movement deposits and quake lakes and its relationship with riverbed incision are studied by field investigations together with satellite images and data analysis. The mass movements released different degrees of potential energy. The landslides have released the most of its energy and have high stability. The avalanche deposits have lower stability and are dangerous. From the viewpoint of river training, some landslides might be prevented if the riverbed incision were controlled. Two strategies are applied to manage the quake lakes: to remove the high risk lakes and to preserve the low risk lakes. Most rivers in the earthquake-hit area are in unstable geomorphology stage. Lakes preservation may change the rivers into equilibrium, thus, reduce the mass movements in a future earthquake event.
引文
[1]Wikipedia.2008Sichuan earthquake[DB/OL].http://en.wikipedia.org/wiki/Wenchuan_earthquake,2008.
[2]Lin J C,Jen C H,Petley D N,et al.On the response of the fluvial system to extensive earthquake-triggered landslides[J].Geophysical Research Abstracts,2005,7:72-81.
[3]Malamud B D,Turcotte D L,Guzetti F,et al.Landslides,earthquakes and erosion[J].Earth and Planetary Science Letters,2004,229:45-59.
[4]Gaziev E.Study of the Usoi landslide in Pamir[C]//Proc.of the4th Int.Symp.on Landslides.Toronto:1984:511-514.
[5]Di B F.Investigation of sediment erosion induced by the May12Wenchuan earthquake[C]//Symposium on earthquake induced mountainous hazards and disaster reduction.Chengdu Research Institute of Mountain HazardReduction and Environment,2008.
[6]Huang R Q.Analysis on the distribution of secondary geological hazards induced by the Wenchuan earthquake and its impacts on reconstruction[C]//Symposium on earthquake induced mountainous hazards and disaster reduction.Chengdu Research Institute of Mountain Hazard Reduction and Environment,2008.
[7]Wang Z Y,Xu J,Li C Z.Development of step-pool sequence and its effects in resistance and stream bed stability[J].International Journal of Sediment Research,2004,19(3):161-171.
[8]Becker J S,Johnston D M,Paton D,et al.Response to Landslide Dam Failure Emergencies:Issues Resulting from the October1999Mount Adams Landslide and Dam-Break Flood in the Poerua River,Westland,New Zealand[J].Natural Hazards Review,2007,8(2):35-42.
[9]Korup O.Geomorphometric characteristics of New Zealand landslide dams[J].Engineering Geology,2004,73:13-35.
[10]Costa J E,Schuster R L.The formation and failure of natural dams[J].Geol.Soc.Amer.Bull.,1988,100:1054-1068.
[11]Ouimet W B,Whipple K X,Royden L H,et al.The influence of large landslides on river incision in a transient landscape:Eastern margin of the Tibetan Plateau(Sichuan,China)[J].Geological Society of America Bulletin,2007,119(11):1462-1476.
[12]Korup O,Schlunegger F.Bedrock landsliding,river incision,and transience of geomorphic hill slope-channel coupling:Evidence from inner gorges in the Swiss Alps[J].Journal of Geophysical Research,2007,112:37-45.
[13]Wang Z Y,Tian S M,Yi Y J,et al.Principles of river training and management[J].International Journal of Sediment Research,2007,22(4):247-262.
[14]余国安,王兆印,张康,等.人工阶梯-深潭改善下切河流水生栖息地及生态的作用[J].水利学报,2008,39(2):162-167.
[2]Lin J C,Jen C H,Petley D N,et al.On the response of the fluvial system to extensive earthquake-triggered landslides[J].Geophysical Research Abstracts,2005,7:72-81.
[3]Malamud B D,Turcotte D L,Guzetti F,et al.Landslides,earthquakes and erosion[J].Earth and Planetary Science Letters,2004,229:45-59.
[4]Gaziev E.Study of the Usoi landslide in Pamir[C]//Proc.of the4th Int.Symp.on Landslides.Toronto:1984:511-514.
[5]Di B F.Investigation of sediment erosion induced by the May12Wenchuan earthquake[C]//Symposium on earthquake induced mountainous hazards and disaster reduction.Chengdu Research Institute of Mountain HazardReduction and Environment,2008.
[6]Huang R Q.Analysis on the distribution of secondary geological hazards induced by the Wenchuan earthquake and its impacts on reconstruction[C]//Symposium on earthquake induced mountainous hazards and disaster reduction.Chengdu Research Institute of Mountain Hazard Reduction and Environment,2008.
[7]Wang Z Y,Xu J,Li C Z.Development of step-pool sequence and its effects in resistance and stream bed stability[J].International Journal of Sediment Research,2004,19(3):161-171.
[8]Becker J S,Johnston D M,Paton D,et al.Response to Landslide Dam Failure Emergencies:Issues Resulting from the October1999Mount Adams Landslide and Dam-Break Flood in the Poerua River,Westland,New Zealand[J].Natural Hazards Review,2007,8(2):35-42.
[9]Korup O.Geomorphometric characteristics of New Zealand landslide dams[J].Engineering Geology,2004,73:13-35.
[10]Costa J E,Schuster R L.The formation and failure of natural dams[J].Geol.Soc.Amer.Bull.,1988,100:1054-1068.
[11]Ouimet W B,Whipple K X,Royden L H,et al.The influence of large landslides on river incision in a transient landscape:Eastern margin of the Tibetan Plateau(Sichuan,China)[J].Geological Society of America Bulletin,2007,119(11):1462-1476.
[12]Korup O,Schlunegger F.Bedrock landsliding,river incision,and transience of geomorphic hill slope-channel coupling:Evidence from inner gorges in the Swiss Alps[J].Journal of Geophysical Research,2007,112:37-45.
[13]Wang Z Y,Tian S M,Yi Y J,et al.Principles of river training and management[J].International Journal of Sediment Research,2007,22(4):247-262.
[14]余国安,王兆印,张康,等.人工阶梯-深潭改善下切河流水生栖息地及生态的作用[J].水利学报,2008,39(2):162-167.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心