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Guo G.-X.,Hydrogeology and Engineering Geology Team of Beijing
Wutan Huatan Jisuan Jishu | Year: 2011

As an important geophysical detection mediod, electric sounding have been used widely in hydrogeological, engineering geological, environmental and mineral resources work. However, the traditional data processing mediod, such as cross-section mediod, transaction mediod and section lining mediod belong to two-dimension manner. In this paper, the main three method and their merits and drawbacks are presented by using the electric sounding data within Pinggu basin. Secondly, the introduction of software Voxler, which is used in this paper, is presented simply, In the end, a sample of 3D model based on all the data of Pinggu region is given. The application results show this interpretation mediod can characterize the underground geologic body very well. The outcome of the Voxler, which are excellent complement to traditional 2D-data processing methods, can help geologists enhance the studying resolution of subsurface within the working area gready.

Yu C.,Beijing Normal University | Yu C.,Inner Mongolia Institute of Environmental Science | Liu J.,Hydrogeology and Engineering Geology Team of Beijing | Liu J.,CAS Institute of Geology and Geophysics | And 3 more authors.
Advanced Materials Research | Year: 2012

The paper sets the definition of ecological water table in reclaimed water irrigation area, on which reclaimed water would not make the pollutants infiltrate into groundwater and not deteriorate groundwater environment. Case study from a soil profile in Daxing, Beijing shows that the ecological water table is changing due to the pollutants down movement in the unsaturated zone. Results show that the critical ecological groundwater depth is about 19.45 m in 2050 while the current is 8.25 m. The current water table depth of 18 m is within the ecological groundwater depth. The time lag between the human activities and water quality due to the relatively thick unsaturated zone should be paid attention to for sustainable water quality management. © (2012) Trans Tech Publications, Switzerland.

Pang Z.,CAS Institute of Geology and Geophysics | Yuan L.,CAS Institute of Geology and Geophysics | Yuan L.,University of Chinese Academy of Sciences | Huang T.,CAS Institute of Geology and Geophysics | And 5 more authors.
Journal of Earth Science | Year: 2013

Nitrate pollution is a severe problem in areas with intensive agricultural activities. This study focuses on nitrate occurrence and its constraints in a selected alluvial fan using chemical data combined with environmental isotopic tracers (18O, 3H, and 15N). Results show that groundwater nitrate in the study area is as high as 258. 0 mg/L (hereafter NO3 -) with an average of 86. 8 mg/L against national drinking water limit of 45 mg/L and a regional baseline value of 14. 4 mg/L. Outside of the riparian zone, nitrate occurrence is closely related to groundwater circulation and application of chemical fertilizer. High groundwater nitrate is found in the recharge area, where nitrate enters into groundwater through vertical infiltration, corresponding to high 3H and enriched 18O in the water. In the riparian zone, on the contrary, the fate of groundwater nitrate is strongly affected by groundwater level. Based on two sampling transects perpendicular to the riverbank, we found that the high level of nitrate corresponds to the deeper water table (25 m) near the urban center, where groundwater is heavily extracted. Groundwater nitrate is much lower (<12. 4 mg/L) at localities with a shallow water table (5 m), which is likely caused by denitrification in the aquifer. © 2013 China University of Geosciences and Springer-Verlag Berlin Heidelberg.

Wang S.,CAS Institute of Geology and Geophysics | Wang S.,China Institute of Geotechnical Investigation and Surveying Ltd. | Li L.,CAS Institute of Geology and Geophysics | Liu K.,Hydrogeology and Engineering Geology Team of Beijing | And 2 more authors.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2011

To study the mechanism of dynamic consolidation with drainage on dredged clayey soil, the model test is conducted by self-developed large-scale indoor model equipment and the dredged clayey soil from Tianjin is selected as research object. It is focused on monitoring and analyzing the dynamic variation in pore water pressure in tamping process. The model test results indicate that the water content of soil descends, density and shear strength of soil appear significant growth after consolidation. To make up the defect of model tests, numerical simulation is conducted by FLAC3D to discuss the dynamic response characteristics of dredged soil under impact loads. The instantaneous hammer-soil contact stress, displacement of soil skeleton and dynamic variation in pore water pressure are mainly studied. The results of model test and calculation both indicate that the pore water pressure appears sharp increase at the hammer-soil touching moment, and it can be divided by three phases of increasing-stable-descending. The calculation results also show that the contact force doesn't reach the maximum value at the hammer-soil touching moment. The contact force varies with ramming times and appears several bounces in tamping process. It is also found that the peak pore water pressure and peak displacement are delayed with the increasing depth and radial distance from center of the hammer bottom.

Liu J.,Hydrogeology and Engineering Geology Team of Beijing | Huang T.,CAS Institute of Geology and Geophysics
ISWREP 2011 - Proceedings of 2011 International Symposium on Water Resource and Environmental Protection | Year: 2011

Since deuterium excess would decrease during evaporation and has little effects by isotopic composition of initial water, rather than the relationship between δ18O (or δ2H) and salinity, it is a potential tool for determining contribution of evapoconcentration and dissolution of mineral for a given water body. The relationship between residual water fraction and deuterium excess was deduced from the Rayleigh distillation equation in the paper. The contribution of evapoconcentration and dissolution of mineral for a given water body then can be determined by comparing deuterium excess and salinity between initial water and the evapoconcentrated water. The study is important for sustainable water-salt movement and management. © 2011 IEEE.

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