分层取水:以获取更优质原水水质为目标的水库取水创新方式

SWS:An Innovation Way to Intake Raw Water of Better Quality from a Reservoir

如何在现有条件下尽可能取得更好的原水?除了上游流域的环境保护、水源水库的合理选址和设计外,通过创新的取水方式,也能达到更优的原水水质。经本刊约稿,来自日本的Hiroshi Yajima教授通过介绍日本已开展研究并应用的分层取水系统,为我国的水库取水方式提供了全新的思路和途径。

Main water quality issues related with dam reservoirs are prolonged-turbid water,water temperature problems and eutrophication with algal blooms in Japan.Selective withdrawal systems(SWSs)have been widely used as a management technique for the control of water quality from reservoirs,which was initially equipped with a scour valve at the bottom of a dam to flush poor quality water as early as1900[1].Since the late1970s,most dams in Japan have been installed with SWS[2].The type of SWS is divided into two categories:multi-level intake tower and others.The former type is classified into straight-line,semi-circular and circular shapes.This type is usually adopted when the intake discharge is large enough.Recently in Japan,a rack of vertically stacked siphon-type SWS,considered as a special type in the category of multi-level intake has been installed(Figure1,2).The benefit of this SWS is the low construction cost because it is not necessary to install heavy steel gates or winch system.A siphon functions as a gate by inflating or deflating air at the top of the inverted U-shaped pipe(Figure1).A rack of vertically stacked siphons was first installed at Shizumi Dam in2011where it has13gates.Then17stacked-siphon SWS was constructed at Tono dam.