Intensifying drought of Poyang Lake and potential recovery approaches in the dammed middle Yangtze River catchment

Abstract

Study regionThe middle Yangtze River-Poyang Lake-catchment, China. Study focusThe natural hydrological regime (HR) of the study area was altered by extreme climate conditions and human activities, leading to frequent seasonal droughts. However, the ability of the existing reservoirs and proposed hydraulic projects to restore the HR is not yet clear. A hydrological model for the middle Yangtze River was used in combination with a lake water balance model to assess the recovery degree of the Poyang Lake HR under the regulation of the existing reservoirs and proposed hydraulic projects. New hydrological insights for the regionIn the past 20 years, the water level of Poyang Lake decreased by 5.9%, and the duration of the drought (lake level < 12 m) was prolonged by 39.5% compared to 1953–2002. The potential recovery capacity of the existing reservoirs (including the TGR and the lake catchment reservoirs) and the proposed hydraulic project (PLHP) at the discharging waterway at the north end of Poyang Lake was quantified for typical hydrological years. It was found that the HR in typical hydrological years can be entirely restored by joint regulation of the existing reservoirs, but that this method is not successful in extremely dry years. The PLHP can cope with extreme droughts, such as that in 2022, to restore the lake to a reasonable water level.