Groundwater-derived land subsidence in the North China Plain

Abstract

Land subsidence usually bears strong relationship to abstraction of underground fluid. Land subsidence occurs commonly in the North China Plain (NCP) and has become a major environmental factor hindering regional sustainable development. This paper focuses on issues associated with mechanism of land subsidence in the NCP. The analysis shows that multi-layer aquifer systems with deep confined aquifers and the thick normally consolidated or unconsolidated compressible clay layers are the key of geological and hydrogeological conditions favorable for the development of land subsidence in the NCP. Groundwater withdrawal results in an increase in the distribution of effective stress within the strata and the compression of the aquifers and the confining layers, and then triggers land subsidence. In the middle-east plain of the NCP, the land subsidence volume approximately represents the amount of water released from compression of deep aquifers and aquitards in that land subsidence is primarily caused by excessive groundwater withdrawal in deep aquifer system. The percentage of water released from compression of aquifers and aquitards in deep groundwater abstraction is significant but distinct in Cangzhou City and in the whole middle-east plain. This is due to the difference in local lithological structure and recharge and discharge conditions of deep groundwater system. The hysteresis of land subsidence is also discussed in typical areas and the results reveal that the time for completing the primary consolidation ranges from less than one year to tens of years, and that the rate of secondary compression tends to increase with the moisture content.

Statistical Downscaling of GRACE‐Derived Groundwater Storage Using ET Data in the North China Plain

“…The climate of the region is continental arid climate with annual potential evaporation between 900 and 1,400 mm. Mean annual temperature is 8–15 °C, and the perennial mean precipitation ranges from 500 to 600 mm (Guo et al, ; S. Wang et al, ). The NCP has been an important base of grain production, supplying about 22% of the China's wheat production and about 15% of maize production in 2012 (Cao et al, ).…”

“…The climate of the region is continental arid climate with annual potential evaporation between 900 and 1,400 mm. Mean annual temperature is 8-15°C, and the perennial mean precipitation ranges from 500 to 600 mm (Guo et al, 2015;S. Wang et al, 2008).…”

Experimental study on the vertical deformation of aquifer soils under conditions of withdrawing and recharging of groundwater in Tongchuan region, China

“…Figure 9 shows that following each declining porefluid pressure stage (proxy for groundwater withdrawal), the vertical deformation continued to increase over time. The hysteresis phenomenon is a complex issue that can involve several factors such as leaking recharges from aquitards to aquifers, internal overpressure disequilibria in soils, and creep effects (Galloway and Burbey 2011;Guo et al 2015;Modoni et al 2013;Shi et al 2007;Xue 2003;Zhang et al 2013). For the experiment, the variation in the pore-water pressure in the samples was controlled artificially without a disequilibrium distribution, and there was no hysteresis effect caused by the recharge between an aquitard and aquifer, therefore, the hysteresis effect is embodied as a secondary consolidation following primary consolidation, which occurs under a load until excess pore-water pressure in the sample has dissipated (Guo et al 2015).…”

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“…If the imbalance continues and nothing is done to restore the aquifer, wells will eventually go dry and the land will sink (Chrisholm 2012). Land subsidence associated with groundwater pumping from aquifers, especially in high population areas, has been well documented (Guo et al 2015, Kearns et al 2015.…”