Geological interpretation of groundwater level lowering in the North China Plain

Abstract

Groundwater level lowering in the North China Plain (NCP) has been developing during past several decades by overuse in populated cities and industrial districts as well as by irrigation. To interpret groundwater level lowering in terms of aquifer-bearing beds having relatively high porosity, contour maps and cross sections of water level lowering based on monitoring data are compared with subsurface Quaternary geologic map. The comparison revealed that the extents of productive shallow and deep aquifers are generally restricted in specifi c regions where sand and gravel occur in lenticular form. The groundwater resources are regarded as fossil resource because groundwater of deep aquifer is dated as older than 10,000 years BP. Therefore, if overproduction of groundwater continues at the same rate as at present, it should result in depletion or severe lowering of water level and induce ground subsidence and water quality deterioration. To overcome the problems, effective use of irrigation and recycling of used water from industrial and domestic uses by water purifi cation are essential.

Evaluation of groundwater depletion in North China using the Gravity Recovery and Climate Experiment (GRACE) data and ground‐based measurements

“…One of the main reasons for this difference is that the GBCNP-based estimate includes only groundwater information in shallow aquifers of China northern plains, whereas the GRACE observes all GWS changes from all aquifers. Some studies have shown that the deep groundwater table is also decreased greatly in the piedmont region of the Taihang Mountains and the central plain region of the Hebei province [World Bank, 2001;Foster et al, 2004;Tamanyu et al, 2009]. The high-groundwater depletion rate estimated using GRACE data indicates the important contribution of groundwater depletion in deep aquifers of North China.…”

Estimating soil moisture storage change using quasi-terrestrial water balance method

“…This suggests that in the study area, storage gain in soil moisture is sustained by storage loss in groundwater (Yang et al, 2002(Yang et al, , 2003Moiwo et al, 2010;Hu et al, 2010). Saturated storage loss in the basin is estimated at 1.5-2.0 m/yr (Yang et al, 2002;Foster et al, 2004;Tamanyu et al, 2009;Hu et al, 2010). While a portion of the storage loss goes to augment soil moisture storage, another portion of it is lost to ET (Yang et al, 2006.…”

“…In the basin, Quaternary-aged aquifers of inter-fingering gravels, sands and silts extend to over 400 m beneath surface alluvial fans (Foster et al, 2004;Tamanyu et al, 2009). Although the groundwater is largely stored in bicarbonate (Fei, 1998) (Tamanyu et al, 2009), recharge is highest in the coarse deposits of the foothill corridor (Yang et al, 2002;Han et al, 2008, in press).…”

“…Although the groundwater is largely stored in bicarbonate (Fei, 1998) (Tamanyu et al, 2009), recharge is highest in the coarse deposits of the foothill corridor (Yang et al, 2002;Han et al, 2008, in press). …”

“…Land productivity in the region is further enhanced by extensive water development and soil conservation. Hence not only are surface waters almost always dried, but there also exists massive groundwater depression cones in the region (Foster et al, 2004;Tamanyu et al, 2009;Moiwo et al, 2010).…”