Relationship between deep groundwater resources composition and land subsidence under the condition of exploitation in Dezhou, Shandong, China

Aimed at continuous drawdown of ground water table resulted from over-exploitation, land subsidence and other geo-environmental problems, this paper selected deep groundwater and land subsidence monitoring and corresponding clay layers as main objects. Using hydrogeochemical, groundwater dynamic methods and isotopic technology, the paper made following research. Storage resources of deep groundwater in Dezhou were mainly from precipitation recharge in the last glacial period. Under the conditions of land subsidence, exploitation resources mainly included lateral runoff recharge and cross-flow recharge, which took 20.6% of the total recharge, and were from regional runoff systems, reflecting natural regeneration ability of deep groundwater. The percent of elastic releasing water is 17.5% and in which 61.9% come from compression releasing water of clay layers，which were the direct factors predicting land subsidence.