Coupled processes of groundwater dynamics and land subsidence in Tianjin, China after the South-to-North Water Transfer Project

• DOI: 10.5194/egusphere-egu24-4831
• Publication Date: 2024-03-08T14:37:51Z
• Authors: Guangli Su; Chunbao Xiong
• Keywords: Water transfer

Over the past six decades, groundwater became main source of water following a serious shortage in surface North China Plain (NCP). This resulted large area level (GWL) depression and land subsidence cones. To address this crisis, Chinese government implemented largest transfer project human history—the South-to-North Water Transfer Project (SNWTP), middle route which was completed put into operation 2014. In context, Tianjin, one beneficiaries project, has been relieved from shortages begun to implement Groundwater Management Plans (GMP) such as conversion ecological replenishment for rivers lakes since 2018, undoubtedly have significant effect on recovery. Meanwhile, provides good case studying coupled process ground settlement dynamics, especially soil deformation pattern driven by rebound. analyze these issues detail, field well data collected depict flow field. Moreover, geodetic also collated, including leveling, GPS, InSAR, so that vertical with high spatiotemporal resolution could be generated. The results reveal GWL third confined aquifer is exploitation layer Tianjin recovered significantly 2018 rate 2.1 m/yr. cones depth greater than 70 m decreased 85%. dynamic patterns indicate reduced significantly, accompanied sharply declining (decreased -32.2 mm/yr -4.5 mm/yr). Particularly, poroelastic rebound occurred Wuqing Beichen districts 2020, uplift rates some areas exceeding 10 mm/yr. Furthermore, due delayed pore pressure dissipation aquitard, we find time delay 0.3–5.5 years between series, far less estimated hydrogeological parameters, latter ignored recharge recovery capacity system. Finally, evolution model presented illustrate interactive among deformation, pressure, hydraulic head. general, SNWDP GMP restored aquifer, subsidence, alleviated storage depletion China.