Author(s): Cao Shuyou; Liu Xingnian; Huang Er; Yang Kejun
Linked Author(s): Kejun Yang
Keywords: Review; Historic flood; Dam break; Earthquake barrier Lakes; Sichuan
Abstract: Earthquakes frequently occurred in Sichuan Province, Southwestern China. Historical records show that rivers in the earthquake district had been damaged seriously after earthquakes since 181BC. Floods caused by dam break of earthquake barrier lakes might happen under certain conditions. To understand conditions and mechanics of historical floods caused by dam break of earthquake barrier lakes, a series of field studies, historical documents collection and analysis, physical modeling and mathematical modeling studies are conducted since 1934. Based on those research results, 155 earthquake barrier lakes since 181BC are collected and divided into two catalogues. The first catalogue covers 10 earthquake barrier lakes (181BC-1713) with limit information. The second catalogue includes 145 earthquake barrier lakes with more information (1786-2008) to divide into two periods in this paper. High flood risks were found in the first period including 32 earthquake lakes during 1786-1989. Those data show that 72% of cases caused floods by dam break, and 28% are stable. The second period is marked by the Wenchuan earthquake in 2008 with 113 earthquake barrier lakes. Among those cases in second period, 57% of quake lakes are not dangerous by artificial disposal or no longer present by natural scouring, and other 43% of cases were safe by river training. No serious flood diaster was happened due to earthquake barrier break in second period. Finally a typical comparison on earthquake-induced flooding at the Dujiangyan Water Intake System in the Minjiang River is analyzed.