This paper is the case study of land subsidence mitigation.
Objective The Beijing Plain, as a typical region with the most prominent water resource in northern China, has suffered from severe environmental and geological issues caused by prolonged groundwater over−extraction. Years of excessive exploitation have not only led to systematic depletion of deep aquifers but also triggered large−scale land subsidence. Since 2010, Beijing has implemented stringent groundwater restriction policies coupled with inter−basin water transfer projects such as the South−to−North Water Diversion Project, effectively curbing the declining trend of regional groundwater levels. However, the impact of these comprehensive management measures on land subsidence and their regulatory effectiveness remain to be systematically elucidated.
Methods This paper reveals the evolutionary characteristics of land subsidence during 2010—2020 based on geodetic data and groundwater level data, and quantifies the contribution of factors in the development of land subsidence by combining machine learning.
Results The results indicate that the subsidence rate in the Beijing Plain underwent four distinct phases: rapid increase (2010—2012), decelerated growth (2013—2014), fluctuating variation (2015—2017), and rapid deceleration (2018—2020). Standard deviation ellipse analysis revealed that the centroid of the ellipse shifted eastward during the first three phases but moved southward in the fourth phase, indicating continued rapid subsidence in the southern region. Quantification results showed that the second confined aquifer (Aquifer Ⅲ) and the third confined aquifer (Aquifer Ⅳ) were the primary controlling layers for subsidence, jointly contributing over 65% of the total subsidence. From the first to the third phase, Aquifer Ⅲ had the highest contribution, though its influence gradually decreased. By the fourth phase, the contribution of Aquifer Ⅳ surpassed that of Aquifer Ⅲ. The implementation of water resource management policies was identified as the main reason for the declining contribution of Aquifer Ⅲ.
Conclusions Given the emerging coexistence of land subsidence and uplift in the Beijing Plain, it is recommended to optimize groundwater resource allocation by adopting strategies such as “compensating deep aquifers with shallow ones and supplementing groundwater with surface water,” while expanding water supply networks to reduce deep groundwater extraction. Additionally, special attention should be paid to monitoring differential subsidence risks in transition zones between subsiding and uplifting areas, investigating their disaster mechanisms and compound hazard patterns. A land subsidence prevention and control system adaptable to the coupling effects of subsidence and uplift should be established to ensure regional geological safety.
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