Impact of impoundment on groundwater seepage in the Three Gorges Dam in China based on CFCs and stable isotopes

It is a common concern that the groundwater flow field caused by the Three Gorges Dam changes the regional seismic activity and environment. The changes in the seepage region could be effectively reflected through the analysis of the groundwater age using chlorofluorocarbons (CFC)-based techniques. In this study, the influences of the reservoir water on groundwater and the seepage region boundary of the reservoir were investigated using CFCs, stable isotopes, and water level in groundwater, reservoir water, and spring water during the water storage process of the Three Gorges Reservoir. The results show that the water supplied by the groundwater is older, whereas the water supplied by the reservoir and the springs is younger. With an increase in the water level of the reservoir, the water in well W3, which is located at the vice dam of the head region, becomes older due to the reservoir loading effect, whereas the water in well W4 become younger due to the lateral seepage of reservoir water. This finding indicates that the groundwater seepage regions in wells W3 and W4, which are located at upstream of the reservoir, are all influenced by the Three Gorges Reservoir. In contrast, the sampling points in the northern section of the Xiannvshan fault zone, which is farther from the dam, did not exhibit any direct hydraulic connection between the groundwater and the reservoir water; thus, the reservoir seepage effects may not affect the northern part of the Xiannvshan fault zone. These research results provide important reference data that can be used to analyze the effects of the Three Gorges reservoir storage on the regional environment.     

沥青铀矿中氧同位素测定方法

本文介绍了一种直接测定沥青铀矿中氧同位素的分析方法－－五氟化溴法，实验分析和数据首次表明，铀氧化物中的氧同位素主要是富轻氧的。     

Effects of key components of <Emphasis Type="Italic">S. triqueter</Emphasis> root exudates on fractions and bioavailability of pyrene–lead co-contaminated soils

The key components of S. triqueter root exudates involved 4-oxo-pentanoic acid, succinic acid, glutaric acid, phthalate acid, citric acid, vanillic acid, myristic acid, pentadecanoic acid, decanoic acid, 14-methyl-pentadecanoic acid, hexadecanoic acid, octadecanoic acid and oleic acid, and the content of the water-soluble organic acids (citric acid, succinic acid and glutaric acid) significantly increased in pyrene and lead co-contaminated rhizosphere soil. These three water-soluble organic acids including citric acid, succinic acid and glutaric acid were detected as the specific root exudates of S. triqueter under stress of pollutants for pyrene and lead, so they were chosen as the research objects, and they were added into the bioremediation systems of pyrene and lead co-contaminated wetland soils. Compared with the control, the treatments added the three organic acids always improved the quantity of the bioavailable fraction of pyrene and lead in wetland soils and greatly influenced other chemical states of pyrene and lead fractions in the test concentration range. Under the 50 g kg^?1 of organic acids concentration, the amount of the bioavailable fraction of pyrene and lead increased 41.0 and 872.7 % by citric acid, respectively. The enhancement of bioavailability of pyrene and lead in the wetland soil by adding organic acids generally decreased in the following order: citric acid > succinic acid > glutaric acid. Enhancing effects of organic acids on the bioavailability improvement of pyrene and lead is remarkable.     

An approach to mass movements in the Jiuzhaigou catchment

This paper presents a preliminary study of the main types, features, genesis, and countermeasures of mass movements in the Jiuzhaigou catchment, which is one of the most scenic regions in China. The main features are debris flows, rock-segment flows, landslides, and avalanches. Rough relief, fractured rocks, drifts, steep slopes, intensive rainstorms, and earthquakes produced their geneses. Countermeasures should include the integration of engineering and biological projects.     

岩溶裂隙水动态系统的门限自回归模型分析

以淄河北部岩溶裂隙水系统为例,运用门限自回归模型分析方法,在模拟分析岩溶裂隙水动态系统特征的基础上,探讨北方岩溶区不同类型含水岩溶裂隙介质系统的岩溶发育规律和含水特征。      

An approach to studying heavy metal pollution caused by modern city development in Nanjing, China

 Nanjing is currently one of the fastest developing regions in terms of construction and economy in China. Heavy metal pollution is becoming more serious with the expansion of production and life scales. Four environmental units (highway, refinery, rubbish dumps associated with human daily life, and shoal of the Yangtse River) were selected from the region according to the geneses of the pollution to study and evaluate the distribution and mechanism of the contamination, the speciations of the polluting elements, and the geneses of the pollution in the soils and sediments. The purposes of the study are to understand generally the current situation and the cause of the pollution, and to provide a scientific basis to prevent and solve the pollution problem. At the same time, it would be helpful to probe the effective way of studying heavy metal pollution resulting from the development of modern cities and to accumulate data. It is indicated by the study that the heavy metals contained in the soil of the environmental unit of the highway are Pb, Co and Cr; in the soil of the refinery Cr, V, Pb, Ni, and Co; in the soil of the rubbish plot Co, Cu, and Sb; in the sediments of the shoal Pb, Co, Cu, and Ni. Fe-Mn oxide is given the first place to the speciations in polluting heavy metals transmitted by air. Carbonate is more in speciations of polluting heavy metals transmitted by water than in speciations of the metals transmitted by air. In the ten elements studied, Pb is most directly poisonous to the plants in the region; Co and Cu are the next, and Ni is the least. Heavy metal pollution has been occurring in the soils and sediments of the region and the situation will worsen if some effective measures are not taken. Received: 18 October 1997 · Accepted: 3 February 1998     

云南祖母绿的矿床地质及宝石学特征

云南祖母绿矿床产于寒武系变质岩中,矿体分别产于片麻岩的伟晶岩及云英岩脉中。属于典型的伟晶岩型或气成高温热液矿床。祖母绿的铬、钒来源于变质岩,而铍来源于伟晶岩。     

全国水文站网管理信息系统研究

全国水文站网管理信息系统是应用ＧＩＳ技术开发的信息管理系统,它为优化水文站网,提高站网管理水平,提供了迅速、全面的信息支持系统建成后,可实现水上网图、文、声、像信息的查询、漫游和图形报表的输出。介绍了系统的设计与研究成果。     

华东部分铀矿区内大气和饮用水体放射性水平调查研究

通过对华东地区２１ 个铀矿区内居民居住环境大气中氡及其子体α潜能浓度的调查,结果表明：居民居室外氡浓度均值范围为６．７３—１３２．９ Ｂｑ／ｍ ３,氡子体α潜能浓度均值范围为１１．０—７８．８ｎＪ／ｍ ３。居室内的平均氡浓度均值范围为１４．５—１８５．８ Ｂｑ／ｍ ３,氡子体α潜能浓度均值范围为１３．８—１０４．２ ｎＪ／ｍ ３;对居民饮用水源的取样分析表明,铀浓度均值范围为０．１２—１．６８ μｇ／Ｌ,钍浓度均值范围为０．０２—０．４２ μｇ／Ｌ,镭－２２６ 浓度均值范围为０．９０—１２．１ ｍ Ｂｑ／Ｌ,与全国和当地的放射性天然本底水平比较接近,均属正常本底水平。     

http://www.sciencedirect.com/science/article/pii/S1674987111000508

This paper presents the results of a set of numerical models focussing on structural controls on hydrothermal mineralization.We first give an overview of natural phenomena of structurally-controlled ore formation and the background theory and mechanisms for such controls. We then provide the results of a group of simple 2D numerical models validated through comparison with Cu-vein structure observed near the Shilu Copper deposit(Yangchun,Guangdong Province, China) and finally a case study of 3D numerical modelling applied to the Hodgkinson Province in North Queensland(Australia).Two modelling approaches,discrete deformation modelling and continuum coupled deformation and fluid flow modelling,are involved.The 2D model-derived patterns are remarkably consistent with the Cu-vein structure from the Shilu Copper deposit,and show that both modelling approaches can realistically simulate the mechanical behaviours of shear and dilatant fractures.The continuum coupled deformation and fluid flow model indicates that pattern of the Cuveins near the Shilu deposit is the result of shear strain localization,development of dilation and fluid focussing into the dilatant fracture segments.The 3D case-study models(with deformation and fluid flow coupling) on the Hodgkinson Province generated a number of potential gold mineralization targets.