Dead in the water

 作者:毕壕     |      日期:2019-03-07 05:18:11
By Fred Pearce DAMS on the River Rhône in Switzerland are threatening to turn the crystal waters of Lake Geneva into a deoxygenated, weed-covered dead zone, say researchers at the University of Geneva. Over the past forty years, engineers have built nine large hydroelectric dams on the tributaries of the Upper Rhône, the main source of water for the lake—the shoreline of which is known as the Swiss Riviera. One result has been to disrupt the seasonal flow of the river. The dams capture the peak summer flows from melting snow and glaciers,