IHE Delft 💧 Alumni Online Seminar on Groundwater - Sida Liu on Yongding River Catchment, China

IHE Delft 💧 Alumni Online Seminar on Groundwater - Sida Liu on Yongding River Catchment, China - Assessing the impact of Managed Aquifer Recharge on the groundwater system by numerical modelling.

This is the second part of the IHE Delft Alumni Online Seminar entitled 'Groundwater: seeing the invisible in its key role for a sustainable world' that was held on 10 March 2022.

Background

As the largest liquid reservoir on earth, groundwater is inevitably a major role player in global development and adaptation to climate change. Given its invisible nature, this resource is still frequently undervalued, insufficiently understood and consequently poorly managed. This is why the UN-Water theme of 2022, ‘Groundwater, making the invisible visible’, is so relevant. If we want to maximize the potential of groundwater use in a sustainable and equitable way, we need to make this resource visible. We need to see how it moves and how it interacts with hydrological cycle components. We must recognize its enormous ecological value for the many surface water bodies and wetlands that depend on it. Not only that, but we have to acknowledge and mitigate pressures from exploitation, contamination and climate change on groundwater.

About the speaker and her case study

Sida Liu is a PhD candidate at IHE Delft Institute for Water Education. She received her bachelor’s degree in Groundwater Science and Engineering in 2014 from China University of Geosciences and her IHE Delft MSc on Hydrology and Water Resources, with Distinction, in April of 2016. For her PhD, she is researching the use of a multi-scale groundwater model to assess the design and operation of the Managed Aquifer Recharge (MAR) in the Beijing Plain, China.

Case study: Yongding River Catchment, Beijing, China - Assessing the impact of Managed Aquifer Recharge on the groundwater system by numerical modelling.

The surface runoff downstream of Yongding river has been cut off for decades due to the continuous drought from 2000 to 2010 and the huge water demand of Beijing city. To maintain the environmental flow and enhance groundwater recharge through the river leakage, water release from the upstream reservoir in Yongding river has been implemented since 2019. To evaluate the impact of the water release on the groundwater system, a 3D transient groundwater flow model has been constructed. Results show that enhancing the groundwater recharge efficiency requires longer water release period and a lower release rate. In addition, the high-water levels during water releases events need to be controlled to prevent groundwater pollution. To improve the groundwater recharge efficiency and avoid the potential hazard related to high groundwater levels, a lower water release rate and longer release period are recommended in future water release