Evaluating evaporation changes before and after the China Three Gorges Reservoir built

Abstract

The on-going Three Gorges Project in China is the largest water conservancy project up to the present human's known history, part of a comprehensive scheme to develop the Yangtze Valley region and being designed mainly to alleviate flooding in the areas downstream of the dam. The Three Gorges reservoir has different water surface areas for different water levels during the reservoir operation in different seasons. It would therefore be very useful to evaluate the evaporated water from different water surface areas for understanding water loss and potential regional climate change. This study may benefit the optimization of the water resources management of the Yangtze Valley region and facilitate more understanding of the hydrologic processes over large area of water surface. In the study, four different methods are applied to investigate the evaporation from the reservoir water surface. It is found that the evaporation will be increased about 10% after the reservoir is normally operated.