Quantifying changes in water use and groundwater availability in a megacity using novel integrated systems modeling

• Published in: Geophysical research letters Vol. 44; no. 16; pp. 8359 - 8368
• Main Authors: Hyndman, D. W., Xu, T., Deines, J. M., Cao, G., Nagelkirk, R., Viña, A., McConnell, W., Basso, B., Kendall, A. D., Li, S., Luo, L., Lupi, F., Ma, D., Winkler, J. A., Yang, W., Zheng, C., Liu, J.
• Format: Journal Article
• Language: English
• Published: Washington John Wiley & Sons, Inc 28.08.2017
• Subjects: Adaptation; Agricultural land; Climate; Climate and land use; Climate change; Climate models; Climate variability; Crop growth; Crop model; Economic factors; Evapotranspiration; Frameworks; Groundwater; Groundwater availability; Groundwater storage; Hydrology; Interactions; Land use; Megacities; Mitigation; Modelling; Population growth; Recharge; Social factors; Socioeconomic factors; Socioeconomics; Sustainability; Systems approach; Urban areas; Urbanization; Variability; Water; Water use; Beijing China; China
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/2017GL074429

Water sustainability in megacities is a growing challenge with far‐reaching effects. Addressing sustainability requires an integrated, multidisciplinary approach able to capture interactions among hydrology, population growth, and socioeconomic factors and to reflect changes due to climate variability and land use. We developed a new systems modeling framework to quantify the influence of changes in land use, crop growth, and urbanization on groundwater storage for Beijing, China. This framework was then used to understand and quantify causes of observed decreases in groundwater storage from 1993 to 2006, revealing that the expansion of Beijing's urban areas at the expense of croplands has enhanced recharge while reducing water lost to evapotranspiration, partially ameliorating groundwater declines. The results demonstrate the efficacy of such a systems approach to quantify the impacts of changes in climate and land use on water sustainability for megacities, while providing a quantitative framework to improve mitigation and adaptation strategies that can help address future water challenges. Key Points We quantify Beijing's water balance through time using newly coupled hydrology, biology, and land use models We use a crop growth model to simulate irrigation demand and recharge rate on agricultural land We demonstrate that land use change in Beijing enhances groundwater recharge, thus reducing the rate of groundwater level decline