地震诱发的堰塞湖初步研究

由于地震引发山体滑坡并堵塞河道形成的湖泊称为地震堰塞湖。据统计,我国自1856年以来,共计产生141个地震堰塞湖,按照其形成和造成的灾害来看,堰塞湖可以分为3类:高危型堰塞湖、稳态型堰塞湖和即生即消型堰塞湖。高危型堰塞湖由于蓄水量大、落差大,往往在形成后几天至几年后会被冲垮,形成严重的地震滞后次生水灾。稳态型堰塞湖(亦称“死湖”),可以存在很长时间且湖积水量很大。即生即消型堰塞湖为震时形成的短时堰塞湖,很快会被后来累积的水体冲毁,一般危害不大。如果简单的用时间来区分堰塞湖的类型,那么在一天或者几天内溃决的是即生即消型堰塞湖;几天至100年溃决的是高危型堰塞湖;溃决时间超过100年者,是稳态型堰塞湖。

PRELIMINARY STUDY ON EARTHQUAKE-INDUCED DAMMED LAKE

Earthquake-induced dammed lake is the lake caused by an earthquake-induced landslide blocking a river channel. Based on the statistics, there are altogether 141 earthquake-induced dammed lakes in China since 1856. According to the formative process and the degree of potential danger, three types can be divided: high-danger dammed lake, steady-state dammed lake and transient dammed lake. High-danger dammed lake, with great storage capability and high drop height, is often burst in several days to several years after its formation, and causes severe secondary flood disaster. Steady-state dammed lake (also called “dead lake”) can exist for a long period with very huge water storage. Transient dammed lake, formed while an earthquake occurring. It is a short-period one, which can quickly burst by the accumulating water. The damage is therefore generally not very large. The dammed lakes can also be classified simply with time. The one that may be broken in several days is called as transient dammed lake. That may be broken in several days to one hundred years is called as high dangerous dammed lake. Those may be stable more than one hundred years is called as steady-state dammed lake.