Hydrological Impacts of Groundwater Depth on Lakes in Northern China: Exploring the Mechanisms through Climate Change and Human Activities
- 1State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing , China (yingjiecui@tsinghua.edu.cn)
- 2Key Laboratory of Hydrosphere Sciences of the Ministry of Water Resources, Tsinghua University, Beijing, China
Abstract: The depth of groundwater is a critical factor that significantly influences the development and conservation of both surface water and groundwater in lakes located in Northern China, exemplified by Baiyangdian (BYL), the largest lake situated in the North China Plain. It forms a critical foundation for the ecological integrity of BYL by quantifying hydrological fluxes and investigating variations in surface water and groundwater across distinct groundwater depths. To address this inquiry, we established a distributed hydrological model for the basin, enabling the simulation of surface runoff (horizontally) and vertical processes such as evapotranspiration and infiltration. Findings for the period 1966-1980 reveal an overall shallow groundwater condition in the Baiyangdian plain area, with a multi-year average depth of approximately 4 meters. Precipitation recharge, lake evaporation, surface water inflow, surface water outflow, groundwater inflow, and groundwater outflow during this phase were quantified at 187 million m3, 288 million m3, 960 million m3, 683 million m3, 160 million m3, and 40 million m3, respectively. The predominance of horizontal flux (62%) signifies rapid lake water replenishment. Conversely, during the later period of 1981‒2018, groundwater depth in the plain area substantially increased, averaging 23.48 meters. Precipitation recharge, lake evaporation, surface water inflow, surface water outflow, and groundwater outflow were computed at 179 million m3, 227 million m3, 294 million m3, 118 million m3, and 127 million m3, respectively. The horizontal flux contribution diminished to 22%, while the vertical flux surged to 78%, indicating slower lake water renewal and heightened risks of water quality degradation. Climate change and human activities emerged as drivers of rising groundwater depth, subsequently weakening water cycle dynamics over BYL. In the future, the comprehensive recovery of groundwater facilitated by the South-to-North Water Diversion for lake and river replenishment will play a pivotal role in reinstating water cycle dynamics and enhancing ecological integrity. This study establishes a foundation for understanding the intricate interactions between lakes, rivers, and aquifers as groundwater depth evolves over time. It holds significance for water conservation and the preservation of BYL's water quantity and quality in the future.
Key words: Baiyangdian Lake; distributed hydrological model; hydrological flux; Groundwater depth
How to cite: Cui, Y., Long, D., and Cui, Y.: Hydrological Impacts of Groundwater Depth on Lakes in Northern China: Exploring the Mechanisms through Climate Change and Human Activities, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8680, https://doi.org/10.5194/egusphere-egu24-8680, 2024.
