The Banqiao Reservoir Dam Failure Essay Example | Topics and Well Written Essays - 2750 words

The Banqiao Reservoir Dam Failure - Essay Example This essay discusses that the collapse of the Banqiao and Shimantan Dams together with a several dozen much smaller dams in the Zhumadian Prefecture of Henan Province in China in August 1975 is among the world’s most devastating dam failures. Initially, it was reported that the dam failure was attributed to a natural disaster. However many years later and after considerable research, researchers have come to the conclusion that the Banqiao Reservoir Dam’s design and the design of the other reservoirs, together with the standards associated with containing the river are partly responsible for the dam failure.   In essence, it is now generally accepted that the Banqiao Reservoir Dam failure was due to both man-made error/engineering failure and a natural disaster. Zhumadian is situated in the Southern region of Henan Province with Hong and Ru Rivers running east through Zhumadian converging upon the Huai River.   The Banqiao Dam was constructed on the Ru River in 1952 as part of the flood control programme for the Huai River.   In 1956, the Banqiao Dam was reconstructed elevating the dam height and improving the capabilities of the reservoir.   The Banqiao Dam was constructed so that it could withstand â€Å"1-1in-1,000 year flood (306mm rainfall per day)†. The Banqiao Dam was described as a â€Å"clay-core earth fill dam† measuring 24.5 meters in height with the ability to store up to 492 million meters and with a further 375 million cubic meters â€Å"reserved for flood control†.... The parapet walls elevation was 117.64 meters. The discharge capacity was built for 3,092 cubic meters with 1,800 cubic meters accounting for the main spillway, 1,160 cubic meters were designed for the supplementary spillway and 123 cubic meters designed for the conduit (Xu, et. al., 2008). The Disaster The collapse of the Banqiao Dam began on the evening of August 7, 1975 when a large storm became stationery over the Henan Province. As a result the deluge sustained over a foot of rain daily for a period of three days (Chiles, 2001). The rainfall dumped by the storm amounted to 1005 mm of rain in a day’s time and 1605 mm of rain over a three day period. In one hour, flooding overtopped the Banqiao and Shimantan dams leading to their collapse (Eliasson & Lee, 2003). In all, over 60 smaller dams collapsed because â€Å"dikes and flood diversion projects further downstream could not resist such a deluge† (Eliasson & Lee, 2003, p. 620). Land measuring over one million hecta res also sustained flooding, more than 100 km of the railway line connecting Guangzhou to Beijing sustained damages, many villages and towns were either entirely or partly submerged in water and several million residents became homeless. Conservative estimates report that some 26,000 persons drowned in the flood directly linked to the failed dams and an additional 145, 000 eventually died as a result of causal famines and epidemics in the weeks that followed (Eliassin & Lee, 2003). Evaluating the Engineering Failures of the Banqiao Dam Collapse Becker (1998) puts the construction of the Banqiao Dam and the associated dams in its proper perspective. According to Becker (1998) the Banqiao Dam was constructed around a time where irrigation was a prime agricultural policy. At the