Hydrological trends during the past 50 years in the Yangtze River basin

摘要

The hydrological cycle has been highly influenced by climate changes and human activities, and it is significant to analyse the hydrological trends that occurred in past decades in order to understand past changes and predict future trends. Water resources in the Yangtze River basin have been paid more attention, especially for the Three Gorges Dam and the South-to-North water diversion project. Based on the climate data from 180 stations in the Yangtze River basin, it was found that pan evaporation showed a decreasing trend as a whole during the past 50 years with the increasing in air temperature, indicating that the evaporation paradox existed in this basin. At the same time, actual evaporation estimated by water balance decreased with increasing precipitation. Based on the Budyko curve, it can be concluded that the decrease in actual evaporation was caused by the decrease in energy.