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Wang Z.Q.,Hebei University of Technology | Wang L.H.,Tianjin Institute of Geological Survey
Advanced Materials Research | Year: 2014

Regional groundwater exploitation is the foundation and basis for the groundwater resources administrative department to plan the rational utilization and protection of local groundwater resources. The dynamics characteristics and regularity of the local groundwater exploitation are studied in Tianjin from 1998 to 2009 by the methods of time-series analysis. The results show that it provides scientific basis for better understanding the present situation of groundwater exploitation objectively and planning the exploitation and utilization of groundwater resources reasonably. © (2014) Trans Tech Publications, Switzerland. Source

Cui Y.,Water Resources University | Su C.,Water Resources University | Su C.,Chinese Academy of Geological Sciences | Shao J.,Water Resources University | And 2 more authors.
Journal of Earth Science | Year: 2014

In this paper, a coupled numerical groundwater and land subsidence model was developed for the Tianjin Plain. The model was employed to investigate the groundwater resources and their changes over the last decade, and to further predict the changing patterns of the groundwater level and associated land subsidence in future. First, according to the regional hydrogeology, the simulation area was defined with an area of 10.6×103 km2, which was divided into six aquifer units. A coupled groundwater and land subsidence numerical model was built by using Modflow2005 and the land subsidence simulation module SUB (subsidence and aquifer-system compaction), in which the groundwater flow was modeled as three-dimensional unsteady flow and the land subsidence simulation was based on one-dimensional consolidation theory. The model was then calibrated by using the groundwater level contour lines, hydrographs, and land subsidence hydrographs over the period of 1998–2008. In addition, groundwater balance analysis of the simulation period indicated that under multi-year groundwater withdrawal condition the cross-flow recharge, compression release, and lateral boundary inflow contributed 44.43%, 32.14%, and 21.88% to the deep aquifer recharge, respectively. Finally, the model was applied to predict the changing patterns of the groundwater levels and the associated variations in land subsidence under the control of groundwater exploitation after implementation of the south-to-north water diversion project. The simulation results demonstrated that the groundwater level may gradually increase year by year with an decrease in the groundwater withdrawal; and the land in dominated land subsidence regions including the urban area, Dagang, Hangu, Jinghai, Wuqing, and Jinnan, may rebound at an average rate of 2–3 mm/a, and the land subsidence rate in the other regions may decrease. © China University of Geosciences and Springer-Verlag Berlin Heidelberg 2014. Source

Cao F.,China Institute for Geo environmental Monitoring | Li R.-M.,China Institute for Geo environmental Monitoring | Wang Y.,China Institute for Geo environmental Monitoring | Ma Z.-S.,Hebei Institute of Geological Survey | And 4 more authors.
Geological Bulletin of China | Year: 2010

Based on the data obtained from the multipurpose regional geochemical survey (1:250000) in the Beijing, Tianjin and Heibei Province, and the basic conception of geochemical baseline and environmental background values, the study area (Northern Haihe plain) was divided into three statistical units in light of the different depositional conditions. By using the method of standardization, that is, after repeatedly crossing out the surface soil anomalous data, geochemical baselines of various indicators were obtained through the correlation between other elements and inert element Ti, and after repeatedly crossing out the deep soil anomalous data, mean values, standard deviations and variation coefficients of 34 indicators were obtained, and thus characterized the background values. The above study may be cited as major scientific basis for regional soil environmental quality evaluation and monitoring. Source

Cheng T.,China University of Geosciences | Cheng T.,Tianjin Institute of Geological Survey | Yang W.,Tianjin Institute of Geological Survey | Wang D.,Chinese Academy of Geological Sciences
Geotectonica et Metallogenia | Year: 2014

The Alubaoge granite in Xiwuqi of inner-Mongolia, which is located in the middle segment of the northern margin of North China Craton geologically, consists mainly of porphyritic monzogranite. The Alubaoge granites are characterized by high SiO2 (71.29%~72.12%), high potassium (K2O=4.93%~5.27%, Na2O+K2O=8.70%~8.98%) content, and enriched in LREE, depleted in HREE(LREE/HREE=7.69~12.18), with obviously negative Eu anomaly (δEu=0.08~0.14). While the trace elements are characterized by Rb, Th, K, La, Nd, Hf, Zr, Pb enriched, and Ba, Ta, P, Ti depleted, as well as with high Ga/Al ratio (2.96×10-4~4.00×10-4), high Zr+Nb+Ce+Y value (548×10-6~739×10-6). The chemical signatures belong to A-type granite. In discrimination diagrams, all the samples show geochemical characteristics of A2-type granitoid, which means that the Alubaoge granite may be formed in post-orogenic stage. The zircon LA-ICP-MS U-Pb dating gives a weighted average age of 132.19±0.77 Ma (MSWD=4.6). The age suggests that the granite was emplaced in the Early Cretaceous. Considering the wide distribution of the Late Mesozoic basic and intermediate-acid volcanic rocks in depression basins, the authors suggest that this area was in post-orogenic regime in the Early Cretaceous. Source

Li G.-K.,Tianjin Institute of Geological Survey | Wang W.-X.,Tianjin Institute of Geological Survey | Li H.,Tianjin Institute of Geological Survey | Yang F.-T.,Jilin University | And 2 more authors.
Geology in China | Year: 2014

Located in the northwest of Zunhua City of Hebei Province, Tangquan is characterized by hilly landscape and rich geothermal resources. In this paper, the authors studied the borehole data of many bedrock thermal wells (water wells) in the study area, and investigated the distribution characteristics and controlling factors of the geothermal field. The results show that borehole temperature is significantly affected by groundwater flow, and the vast majority of temperature wells are characterized by convective heat transfer, with a few temperature wells characterized dominantly by heat transfer conduction. The geothermal anomaly center of the study area is located in the area from Tangquan Fuquan Palace to the sanatorium, and the anomaly center exhibits bipolar distribution; the temperature of water at the depth of 50m in the geothermal anomaly center is about 51∼54°C, and that at the depth of 100m is up to 60∼67°C. The geothermal water of the geothermal system is caused by gradual heating action of surrounding rocks under the normal heat flow background in the process of deep circulation of groundwater. The water storage structure from Fuquan Palace to the sanitarium is formed by a buried basin with granite confining floor. Because faults cut through monolithic granite body, and cause the upward migration of the heat flux of the deep rock along the fault, whereas the heat flux is mixed with fissure water of the gneisses and is concentrated in the area from Fuquan Palace to the sanatorium. Because the gneiss fractures the aquifer in Fuquan Palace area and sanitarium area, the deep heat can quickly reach the shallow strata and give rise to local abnormal high temperature in the shallow part. The geothermal fluid belongs to continental sedimentary water that is formed in the strata with dissolved salt brine, and is mainly derived from meteoric water. Source

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