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Inorganic pollution is widespread in groundwater, and sulfate pollution is one of the important types, which has an important impact on the ecological environment and human health. Elevated concentrations of sulfate ion pollutants often come from the sewage discharge of chemical plants. This study takes a sulfate-contaminated site in Dongying City, Shandong Province, China, as the research object. Nine boreholes were arranged along the sewage discharge ditches in the site to collect and analyze soil samples and groundwater samples in layers. The concentration of pollutants and the change with depths were determined; the maximum concentration of sulfate ion was 10,330 mg L−1 in groundwater, and the maximum pollution depth was no more than 8 m. A hydraulic barrier was carried out to cut off the pollution sources. Based on a comprehensive understanding of the hydrogeological conditions and pollution degree of the site, the hydraulic capture technique was used to control the water pumping and injection volume, so that the scope of the pollution plume was gradually reduced. The pumping wells were arranged in the polluted area, and the water injection wells were arranged at the outer edge of the pollution zone. According to the calculation of the single well water inflow and influence radius, 28 pumping wells and 66 water injection wells were needed to be arranged on the site. The treatment process was divided into four stages according to the following steps: water pumping, water injection, stoppage of water injection, stoppage of water pumping, collecting water samples after the water level recovered, and the completion stage of treatment. The above process was repeated twice. Chemical precipitation was employed in the last step. The results of the remediation showed that the sulfate concentrations in 54 percent of the samples decreased significantly to less than 100 mg L−1, and the rest were between 100 and 200 mg L−1 after the treatment process. Two pumping wells with serious pollution were selected as long-term monitoring wells, and two-year continuous monitoring results showed that sulfate concentrations in the monitoring wells ranged from 110 to 220 mg L−1, indicating that integrated groundwater remediation techniques are more effective and more reliable than one single technique.

Earth’s critical zone is defined as a plant–soil–water system, which covers a wide area and has a large vertical thickness, but the soil elemental stoichiometry characteristics of the critical zone at different depths are still unclear. In this study, the spatial distribution of soil carbon (C), nitrogen (N) and phosphorus (P) in the critical zone of a typical wetland in Dongting Lake, China, and their ecological chemometric characteristics were analyzed. The results indicated that: (1) the average C, N and P contents were 18.05, 0.86 and 0.52 g/kg, respectively, with a decreasing trend from the surface to the deeper layers. The soil is relatively rich in C and P, while N is the main element limiting plant growth and development. (2) The mean values of soil C/N, N/P and C/P were 21.1, 1.7 and 35.4 respectively, with the C/N ratio and C/P ratio showing a trend of increasing and then decreasing in the vertical direction and reaching a maximum at a depth of 2–5 m below ground. (3) According to the correlation results, C, N and P in soils are coupled and influenced by each other (p < 0.001), and pH, infiltration coefficient and human activities are closely related to the spatial distribution of C, N and P. (4) Stable Redfield ratios (1:1.6:35.4) may exist in lake wetland soils, and future studies should be conducted for complete systems of the same type of wetlands. The results of the study will provide a theoretical basis for the sustainable development and scientific management of lake wetlands.

Nitrogen pollution in wetland ecosystems has become a pressing global issue in recent years. The effects of redox potential on the environmental behavior of nitrogen remain elusive. In the present work, both field experiments and laboratory analyses have been carried out to characterize the spatial-temporal changes of dissolved inorganic nitrogen (NO3−, NO2−, NH4+) and redox potential in the riparian zones of West Dongting Lake Wetland, China. The stability field of groundwater for inorganic nitrogen was represented in an Eh-pH diagram. It is noted that NH4+ is the most abundant species in groundwater when −500 mV 400 mV), nitrogen is generally in the form of NO3−. The range of both Eh and pH scales was from −381 to 193 mV and from 6.84 to 7.32, respectively, which involved two types of reduction, dissimilatory nitrate reduction to ammonia and denitrification, and the inhibition of the oxidation pathway by nitrification. In groundwater, NH4+ accounted for 50%–90% of the total concentration of dissolved inorganic nitrogen, in accordance with the Eh-pH diagram. This study reveals the severe contamination of groundwater by NH4+ in the riparian zones of Li and Yuan. It provided a theoretical basis to predict nitrogen pollution preliminarily and facilitate management and protection of wetlands.

The identification of transient groundwater contaminant sources in terms of source locations, contaminant magnitudes, and active durations remains a challenge. The problem becomes more complex due to spatial heterogeneity, sparse observation data, concentration measurement errors, and unexpected uncertainty. This study addresses this challenge by proposing a modified self-organizing maps (SOM) algorithm; this algorithm can improve the physically-based models by reducing the computational burden more efficiently. The method sufficiently increases the accuracy and efficiency for identifying the contaminant source, because the trained SOM-based surrogate models can identify the source characteristics independently without necessarily operating a formal linked simulation-optimization model. The performance of the proposed method was assessed on a hypothetical heterogeneous aquifer model; the assessment considered unknown observation data, concentration measurement errors, and an unknown pumping well. The proposed SOM-based surrogate model can not only approximate the results from the groundwater flow and transport simulation models, but it can also be used in lieu of the optimization model in a more efficient way for identifying the unknown transient contaminant sources in groundwater systems.

The average depth of Yamansu hydropower station foundation pit is 70 m. The foundation pit was excavated with five-level slopes. The lowering of groundwater level is significant for excavation. Drainage and pumping were adopted in dewatering. Pumping tests were performed to reverse hydraulic parameters and calibrate numerical models. Numerical simulations were performed to evaluate the dewatering scheme. In the first stage, powerhouse tailrace canal was excavated and utilized as a drainage channel to lower the groundwater level. The drawdown and hydraulic gradient were evaluated to prevent potential water inrush, erosion, piping, and slope failure. In the second stage, cutoff wall and pumping wells were evaluated to lower the groundwater level. The influences of depth, permeability, and thickness of the cutoff wall were evaluated. Dewatering scheme was revised accordingly based on the evaluation. The optimized dewatering scheme, which can be referred by similar engineering, was performed and verified successfully.

Two-dimensional (2-D) numerical models have been widely used to predict soil water-salt transport under mulched drip irrigation. However, conventional 2-D models often neglect the spatial variation of soil water-salt transport along drip lines and over-simplifies it by averaging values. This calls for a more robust model to better reflect the actual spatial and temporal variation of soil water-salt distribution in the field, especially in arid regions using brackish water with additional salt. In this study, mulched drip irrigation with brackish water was applied to a cotton field with loam soil in an arid region of southern Xinjiang, northwest China. The changes of soil water potential and total dissolved solid (TDS) of soil water over two irrigation events were intensively measured on hourly base to establish and calibrate a 3-D model, and another five irrigation cycles were monitored on daily base to validate the 3-D model. The mean absolute relative errors between measured and calculated soil water potential and TDS of soil water were 13.7% and 10.7% during hourly-based model calibration, even though there might be bias inevitably introduced by pre-determined sampling intervals and volumes. The calculated values during model validation were reasonably in line with the temporal patterns of soil moisture and TDS before and after irrigation at different irrigation cycles. This 3-D model was then applied to predict the spatial and temporal variations of soil water-salt transport during and after irrigation. Our results show that (1) the 3-D model with additional consideration on point-source discharge from individual drippers effectively reflected the wet front interferences along the drip lines. (2) A semi-elliptic cylindrical wet bulb together with relatively low salinity was formed along the drip lines, which matched well with the cotton layout (one mulch, two drip lines and four rows). However, the uneven overlapping of wet front interferences among individual drippers required to optimize the design of dripper intervals and irrigation regime to provide desirable soil water-salt conditions for cotton growth in this loam soil. (3) During the 96 h after irrigation, the TDS of soil water was always greatest in the dense root zone, increasing from approximately 3.8 g L−1 to 7.0 g L−1 as a result of root water uptake. Such localized re-salinization patterns demand repeated leaching in continued irrigation cycles to ensure cotton growth. Our study suggests that a smaller interspace between drippers with short but more frequent irrigation cycles would be much more helpful to timely and spatial-precisely meet plant water demanding.

Groundwater pollution has been a major concern for human beings, since it is inherently related to people's health and fitness and the ecological environment. To improve the identification of groundwater pollution, many optimization approaches have been developed. Among them, the genetic algorithm (GA) is widely used with its performance depending on the hyper-parameters. In this study, a simulation–optimization approach, i.e., a transport simulation model with a genetic optimization algorithm, was utilized to determine the pollutant source fluxes. We proposed a robust method for tuning the hyper-parameters based on Taguchi experimental design to optimize the performance of the GA. The effectiveness of the method was tested on an irregular geometry and heterogeneous porous media considering steady-state flow and transient transport conditions. Compared with traditional GA with default hyper-parameters, our proposed hyper-parameter tuning method is able to provide appropriate parameters for running the GA, and can more efficiently identify groundwater pollution.

It is vital to determine the critical distance between a mining roadway and a natural vertical water-blocked body (VWBB) where a substantial water level difference and seepage gradient have developed between the two sides of the VWBB. A VWBB critical distance was defined and then determined using a 3D numerical simulation method based on the strength reduction method. The primary value of the VWBB critical distance was determined in consideration of the potential equivalent plastic strain zone induced by the roadways. In consideration of the other influencing factors, the VWBB critical distance was suggested as 105.00 m.

Summary Mulched drip irrigation for cotton field is an effective measure for the utilization of saline water, and the regulation of soil water and salt. However, the reasonable methods for quantifying actual evapotranspiration (ET) and deep percolation of recharge to groundwater are still not very well understood, which restricts the accurate regulation of soil water and salt for cotton growth in oasis. In this paper, a set of experiments of mulched drip irrigation with brackish water were conducted in a typical arid region of Tarim basin in southern Xinjiang, China. The irrigation events were recorded, and ET and fluctuations of groundwater table were carefully measured for two consecutive irrigation periods of flowering and bolling stages. A group of upscaling conversion methods were used to quantify the ET, in which canopy structure was considered to estimate the transpiration from leaf scale to a unit of field scale. The groundwater table had a significant response to the irrigation events, thus the deep percolation was estimated using water-table fluctuation method (WTF). Results showed that during the two irrigation events of flowering and bolling stages, the total ET was 31.1 mm with the soil surface evaporation of only 0.4 mm. The total percolation of recharge to groundwater was 48.2 mm which contributed to the groundwater run-off of 22.1 mm. Transpiration of 30.7 mm accounted for 98.6% of the total ET of 31.1 mm and 34.3% of the irrigation water of 90.6 mm. Compared with transpiration, the deep percolation accounted for 53.2% of irrigation water, indicating a serious excessive irrigation that recharged to groundwater. Soil salt budget showed that the salt leached into groundwater was 1.56 times of the input from brackish irrigation water and fertilization during the two irrigation periods. Even for the irrigation practice with brackish water, the accumulated salt of soil profile could also be leached out under large amount of irrigation water (e.g. 90.6 mm for the two irrigation periods, 10 days). However, the waste of enormous water which for instance occupied 53.2% of the irrigation water in this study was not conducive to the sustainable utilization of water resources in the arid oasis. Furthermore, the methods introduced in this paper for ET and deep percolation calculation of cotton filed could be used to quantify the oasis hydrologic cycle of micro-irrigation, to gain a better understanding of the ecological process.

In recent years, ultra-high-intensity rainfall at home and abroad has caused frequent urban waterlogging disasters, posing a severe threat to people’s lives, property and city’s safety. Based on the satellite image data of Shanghai Waigaoqiao Free Trade Zone in different periods and the Storm Water Management Model (SWMM), this paper establishes a model of heavy rainfall under the underlying surface of a complex city, and analyses topographic features, different land use types, rainfall infiltration intensity and the characteristics of the drainage pipe network. The rainwater accumulation under different rainstorms and urbanization levels is simulated and analysed. The research results show that urban rainstorm accumulation is closely related to land use changes. With the increase of surface impermeability and rainfall intensity, the risk of waterlogging in the study area tends to increase: From 1994 to 2019, the construction area has increased from 2.5096km2 to 5.8662km2 in the study area. Compared with 1994, under the same rainfall conditions, the simulated flooding node and runoff coefficient in 2019 both increased significantly.

Dongting Lake is the second largest freshwater lake in China. It is suffering from significant eutrophication as a result of excessive nutrients inputs, among which nitrogen (N) is becoming a major contributor. The objective of this study is to document the occurrence and controls on N transport and transformation in riparian zones of Dongting Lake wetland. Field experiments were conducted in the cultivated Li River (LR) and uncultivated Yuan River (YR) regions of the wetlands from June to November, 2014. Groundwater depth, redox potential (Eh), pH, and temperature were measured in situ. Groundwater and surface water samples were collected to determine concentrations of nitrate nitrogen (NO3 (-)-N), nitrite nitrogen (NO2 (-)-N), and ammonia nitrogen (NH4 (+)-N). The results showed that NH4 (+)-N was the dominant N pollutant with maximum average value of 2.7760 mg L(-1). All the groundwater samples were rated to Class V based on NH4 (+)-N content according to the groundwater quality standard, indicating the load of N in riparian zones had exceeded their capacity for assimilation and purification. Internal controls (including Eh and pH, temperature, and groundwater depth) and external controls (including surface water, land use, and rainfall) were analyzed in detail. The results suggested that Eh and pH were more significant in controlling N transport and transformation than temperature and groundwater depth; external controls influenced N fates through imposing an effect on internal controls. This study will provide important insights and a scientific basis for N pollution treatment and better protection of the Dongting Lake wetlands.

As an essential component of proteins and genetic material for all organisms, nitrogen (N) is one of the major limiting factors that control the dynamics, biodiversity and functioning of lacustrine wetlands, in which intensified N biogeochemical activities take place. Reactive N loaded into wetland ecosystems has been doubled due to various human activities, including industrial, agricultural activities and urbanization. The main driving mechanisms of N transport and transformation in lacustrine wetlands are categorized to pushing forces and pulling forces in this study. Geomorphology, wetland age, N concentrations, and temperature are the main pushing forces (passive forces); whereas water table variation, oxygen concentration, other elements availability, oxidation-reduction potential (Eh) and pH, and microorganisms are the predominant pulling forces (active forces). The direction and kinetic energy of reactions are determined by pulling forces and then are stimulated by pushing forces. These two types of forces are analyzed and discussed separately. Based on the analysis of driving mechanisms, possible solutions to wetland N pollutions are proposed at individual, regional and global scales, respectively. Additional research needs are addressed to obtain a thorough understanding of N transport and transformations in wetlands and to reduce detrimental impacts of excessive N on such fragile ecosystems.

In the process of exploiting and using water resources of river basin, the benefit conflict problems among upper and lower river districts and among different departments restrict to sustainable exploiting and using water resources of river basin. In this paper, the water resources conflict management of Nyabarongo River and Kagera River watershed is studied. The Nyabarongo is a major river in Rwanda, begins in Nyungwe Forest, and flows up to the north-western part of the country, then down through the center to the south-east, eventually forming the main tributary of the Kagera River watershed, the main affluent of Lake Victoria, which drains into the Nile River. The basin is shared among 11 riparian states. This trans-boundary character of the Nile presents a great challenge of water conflicts; national interests have historically been promoted at the expense of regional interests. The framework of this paper is as follows: the water resources bulletin is firstly described, and then the cooperation and regional conflicts are discussed; finally a sustainable framework for governing the water resources is proposed to meet water management in riparian states.

Nitrogen (N) is one of the most important components and ecological factors for natural wetland ecosystems. It is mainly derived from runoff input, atmospheric deposition, and biological N fixation. The transport and transformation of N in natural wetlands primarily occur in the hyporheic zone (HZ), a buffer area of intensified biogeochemical activity that is often regarded as the sink, source, and converter of N in wetlands. The main ways of N attenuation in the HZ are denitrification, anaerobic ammonia oxidation (anammox), and wetland plant adsorption. The effects of internal and human factors on the N cycle are illustrated in this article. The results indicate that N sources are influenced by human factors such as agricultural activities and fossil combustion, while N attenuation is affected by internal factors, including oxygen concentration, carbon and phosphorus availability, pH and Eh changes, and microorganism actions. Finally, some research trends are provided to get a better understanding of the N cycle in the HZ of natural wetlands. This study may provide a clear perspective of N cycle in the HZ and their interactions between various factors.

Urbanization is a common development trend of countries all over the world, which is a mark of civilization and progress of human beings. The number of urbanization-induced environmental geological hazards has grown steadily in recent years and is receiving increased attention throughout the world. The purpose of this paper is to generalize China’s urbanization process and induced environmental geological hazards. Driving forces and characteristics of urbanization are briefly introduced in this study; specifically, the distribution of urban agglomerations is principally related to water resources, transportation and energy. Common geological hazards and particular ones in mountain city, mining city and coastal city are also summarized. The type and severity of hazards are different due to the differences of natural conditions and various urban functions. Main environmental geological hazards in cities are land subsidence, landslide and seawater intrusion, etc. Accordingly, reasons for these urbanization-induced geological hazards in different type of cities are analyzed and discussed. The research results may provide a clear perspective for urban geological hazard prevention, and suggestions for urban geological hazard control are pointed out.

During the survey, design and construction of underground engineering, groundwater is always the very crucial issue. It directly affects the properties and behaviors of rock and soils as a part of component of them, as well as some kind of underground construction environment, it also has great influence on the stability and durability of engineering projects.

Finite Difference Method (FDM), Finite Element Method (FEM), Boundary Element Method, and Finite Volume Method are the common methods of numerical calculation for engineering groundwater. These calculation methods have been deduced in detail in related textbooks and monographs. In this section, only the basic principle of the common methods will be introduced.

Karst rocky desertification is one of the major ecological and environmental problems that threaten the sustainable development of southwestern China. This study focuses on a case study of the small watershed in Chenqi where karst rocky desertification is particularly severe. This paper considers samples of soils from six different land use patterns in Chenqi village. Various correlations are observed by using fractal theory, including an emerging model for studying soil aggregates. This study demonstrates how the fractal characteristics of soil structure and the stability of soil aggregates are crucial to better understanding karst rocky desertification. The fractal dimension of different land use patterns can be used to indicate the magnitude of soil destruction. Soil fractal dimension can be applied using different methods to characterize the changes in factors influencing the stability of soil structure. The results indicate a significant negative relationship between fractal dimension of soil aggregates and large aggregate content (of diameters 5–10 mm) and a significant positive relationship between fractal dimension and micro-aggregate content (

Impacted by groundwater, faults, lithology, and other factors, the slope of the Shengli no. 1 open-pit coalmine has been in a state of instability. Among these factors, groundwater in the quaternary aquifer is considered primary. Thus, an optimum design for dewatering well pumping rates is presented in this paper. A two-dimensional groundwater simulation model is built to characterize the groundwater flow of the study area. A steady-state model was applied to the observed data (head and discharge) to verify and calibrate the groundwater model. The pilot point method, with a regularization option provided by parameter estimation, was used to identify the hydraulic conductivity field. Afterward, a groundwater optimization model is integrated with the calibrated simulation model to realize groundwater dewatering optimization in the studied open-pit coalmine, and an optimization method called modified Pareto dominance-based real-coded genetic algorithm is adopted. Taking into account the safety of the mine, slope and dewatering wells, seepage discharge is added to objective function and the maximum aquifer saturated thickness is set as the constraint condition in the optimization model. The results indicate that the dewatering optimization procedure developed in this paper can serve as a useful template and framework for solving mining related water problems.

The dynamic tensile strength of steel fibre reinforced concrete is experimentally investigated. Cylindrical specimens are first fabricated with three different fibre volume fractions of 0, 0·75% and 1·5%. These specimens are then tested by using the Hopkinson pressure bar technique. Their dynamic tensile strengths are measured under medium strain rate impact. In these tests, the stress histories are recorded by way of the strain gauges symmetrically mounted on the specimen and the post-test fracture modes are photographed. The test results indicate that the superposition of waves induces first compressive stress and then tensile stress. Once the tensile stress reaches its critical value, a spalling phenomenon occurs. Both volume fraction of fibres and strain rate exert a significant influence on the dynamic tensile strength of concrete. Furthermore, the strain-rate-induced enhancement of tensile strength is related to the compressive strength of the concrete matrix.

Karst is widely distributed in the southwest of China, especially in Guizhou Province. The phenomenon of desertification in these areas is very serious. And soil erosion is the key link in the process of desertification. Through field monitoring, underground soil leakage is derived to the main mode of soil loss in this area. Shear strength tests and creep experiments were carried out with the aim of analyzing the creep mechanism in underground soil loss. It is shown that the water content can lead to the great influence on the shear strength of the brown clay. This variation has been combined with creep characteristics besides the structural geology, hydrology condition and brown clay distribution circumstance (field observation). A conceptual creep model of the brown clay sliding along the karst conduits has been unveiled to show the detailed inference of the creep mechanism in the underground soil loss: geology and hydrology control the development of the karst conduit system; and penetration of water induces the weakening of the shear strength of the surface soil and accelerates the creeping and sliding of the brown clay along the karst conduit system. This understanding of the creep mechanism has significant implications for the future management of the soil erosion in the karst area.

Summary The rapid economic development has caused heavy pollution in the Pearl River Delta Region (PRDR) and neighboring regions. In order to investigate the polluted characteristics, a coupled modelling approach has been deployed and the study area in the Pear River Delta is divided into two modelling systems: a river network that is simulated by a 1D hydrodynamic and water quality model, and an estuary that is modelled by a 3D model. The 1D river network model is coupled with the 3D estuary model based on the mass conservation criteria. The hydrodynamic (HD) model is based on 1D hydrostatic shallow water equations, and is solved by the Alternating Direction Implicit Approach. The water quality (WQ) model component is based on advection–diffusion equations. Some physical and bio-chemical processes are included in the WQ model to address the water pollution problems by different pollution substances, in particular, to the chemical oxygen demand (COD). The water quality data of the main rivers from 2004 to 2007 were collected, processed and evaluated. Because no detailed water quality data in the river is available, the COD source pollution intensity in the water quality model is taking the pollutant load from the confluence of the main five outlets of the Pearl River Estuary (PRE) for 1996–2007 as surrogate. The results show that the pollutants from the PRDR have a large impact on the quality of the Hong Kong seawater and much more serious in the wet season with high river discharge. An insight of the flow and transportation mechanism in the river and estuary system has been obtained through the paper, and a reliable basis to control water pollution of the Pearl River Delta is provided in this paper.

The loss of surface soil and water in the karst rocky desertification area of carbonate rock in Chenqi village, Puding County, Guizhou Province was monitored in this study. The results show that the major form of surface soil loss in the area is the loss of soil through underground channels. A creep test of red clay formed by loss through underground channels was conducted. The results of the test show that the creep curve of the red clay samples includes two stages: attenuation creep stage and stable creep stage. The creep law for the red clay samples in the karst cave can be described by Buger’s model. The parameters of Buger’s equation were deduced by fitting the creep curve, which provides the reference for analyzing the surface soil loss leaking through the underground channels.

Shanghai is a typical area of soft soil distribution, Metro railway construction is now being developed in Shanghai City on a large scale and the planning of Metro stations are often located in densely populated districts with tall buildings. Metro station constructions are mostly taking pit dewatering measures, while the dewatering of aquifer may cause soil layer compression, land subsidence, foundation's deformation, cracking and tilting of the buildings, and so on. In order to control the land subsidence effectively, the underground continuous concrete wall is often used in the deep foundation pit dewatering. The depth of underground continuous concrete wall and the filter tube position of pumping well affect drawdown outside the pit and land subsidence directly. This study refers to the deep foundation pit dewatering project of Hangzhong Road station of Shanghai Metro Line No.10. The excavation depth of foundation pit is 15.60–17.60 m, and the design depth of underground continuous wall is 28 m in the standard part and 30 or 31 m in the end well. Three-dimensional finite differences method is used to simulate the pit dewatering through the inversion of permeability parameters based on the field pumping tests. The hydraulic barrier function of the underground continuous wall is simulated at four different depths including primary design depth, increasing 3 m, 4 m and 6 m. The result of the numerical simulation indicates that the drawdown of the aquifer decreases with the increase of the underground continuous concrete wall depth. When the underground continuous concrete wall increases 4 m on primary design basis, the drawdown outside the pit and land subsidence can be controlled effectively. The monitored results indicate that the drawdown outside the pit at a distance of 1–5 m to the wall is less than 2 m, while the maximum land subsidence is 7.97 mm, which is of nearly no influence on the environment around the pit during dewatering.

The earthquake characteristics and geological structure of the site to sitting the Qinshan Nuclear Power Station are closely related. According to site investigation drilling, sampling, seismic sound logging wave test in single-hole and cross-hole, laboratory wave velocity test of intact rock, together with analysis of the site geological conditions, the seismic wave test results of the site between strata lithology and the geologic structure were studied. The relationships of seismic waves with the site lithology and the geologic structure were set up. The dynamic parameters of different grades of weathering profile were deduced. The results assist the seismic design of Phase III Qinshan Nuclear Power Plant, China.

This case study describes the effects of a grouting process developed to decrease groundwater flow exiting from a ruptured mine ventilation shaft lining in Luling coal mine at Huaibei, China. The primary purpose of grouting at this site is to prevent groundwater flow into the mine from adjacent aquifers. The study supports a transport perspective to describe the miscible grout movement, and provides an approximate analytical method to determine grout concentration based on Wilson and Miller’s (1978) model. This study shows that the breakthrough curves (BTCs) established from the Wilson and Miller’s model match the experimental BTCs obtained from test grouting performed at the site, and Rd a retardation factor of 1.1 is determined. The retardation factor and the BTC are subsequently used to guide the actual production grouting. The monitored result shows that the groundwater inflow at the disrupted ventilation well has been reduced by 47% after drilling and grouting just one borehole. The discharge rate was measured at no more than 4 m3/h after completion of four injection boreholes, which is about 13% of the 30 m3/h before grouting.

The behavior of dark green silty soil of the 6th storey is studied by means of scanning electron microscopy (SEM). The shape, size and contact condition of the basic elements of the soil microstructure, and the shape and the size of the pore are further studied. In addition, a comparative study is made to analyze the experiment results of Cu and dynamic test. The mechanic characteristics of common soil and those of melted soil are presented and their influences on dark silty soil after being frozen are theoretically illustrated from a microscopic perspective.

Hydrogeological parameters of aquifer are the essential and crucial basic data in the designing and construction progress of geotechnical engineering and groundwater dewatering, which are directly related to the reliability of these parameters.

Water quantity analysis can be categorized into simple analysis, full analysis, special analysis, and professional analysis based on different purposes. The current special analysis in engineering geological investigation mainly refers to groundwater corrosivity assessment to building materials

The concept about fissure water in hydrogeological literature was first introduced by former Soviet Union scholar, Г.H. Кaмeнcкий and A.H. Ceмиxaтoв. In their book named Soviet Hydrogeology written in 1932.

With the development of social economy, the improvement of modern industrialization and urbanization, and the increase of population, the shortage of urban ground space becomes more and more serious. To take full advantages of limited land, it has been paid attention on the high-level space and underground space. In recent years, the emergence of a large number of high-rise buildings, and underground projects such as the subway, underground commercial street, underground power plants, and pumping stations are well developed.

In general, the deep foundation pit is defined as follows: excavation pit is over 5 m (including 5 m), or even though the depth is no greater than 5 m, the geological and surrounding environment conditions are very complex, or the excavation affect the safety of adjacent buildings.

Compared with pumping-test well, dewatering well has the same basic structure and functions of each part. In loose sediments, both are composed of well pipe and surrounding back-fill material. Well pipe consists of wall, filter tube (filter) and sedimentation tube, and other parts.

KEYWORD: Datong Lake; Channel inflow; TN concentration; Numerical model ABSTRACT: The total nitrogen (TN) concentration of Datong Lake has exceeded the standard concentration due to some artificial causes. Inflow from channels may be an effective method to help lower TN concentration and improve water quality. In this paper, a lake-channel network numerical model is set up for Datong Lake to simulate and study the effects of inflow from channels. The model simulation result shows that under the water level condition of 50% cumulative probability, TN concentration in Datong Lake can reduce to the concentration of class in 80 days after III inflow.

Boshan is an industrial city in the center of Shandong Province where ground water is the only source for the urban water supply. The major water resource is fracture-karst water in the middle Ordovician carbonate rocks. Based on the hydrogeologic investigation and mapping in this area, the authors studied the geologic and hydrogeologic settings, the major pollution sources and the pathways of contamination, the principal contaminants, and their spatial distribution in ground water. The ground-water quality has also been estimated by the fuzzy mathematic method. The geostatistical method, such as the kriging method, was taken to simulate spatial distribution of the contaminants. The grey system method was adopted to forecast future contamination. An attempt at the remediation of Cr{sup 6+} contamination in fracture-karst water was also discussed. Finally, some proposals for the protection of the ground-water environment in Boshan District are offered.

Wetlands are among the most productive life-support systems in the world and are of immense socio-economic and ecological importance to mankind. They are critical for the maintenance of biodiversity and perform a great role in the biosphere. Wetlands serve as a source, sink or transfer of nitrogen (N). The concentration, movement and transformation of nitrogen in wetland soil will significantly influence the structures and functions of wetland ecosystems. So study on nitrogen in wetland soils has significance to protect the environment. In this paper, the inputs, outputs and biogeochemical cycle of nitrogen in wetlands are introduced. The influence of wetland nitrogen cycle to the nature environmental change is also discussed.

The regional stability and regional geologic structure are closely related. On the basis of the regional geological structure and earthquake geology records, the regional earthquake characteristics and stability were analyzed and assessed in this paper. The research results show that there is no trace of new structure activity at the radius of 320 km around the site of Phase III Qinshan Nuclear Power Plant, the earthquake activity is weak and the basic intensity of the site earthquake is VI degree. The geologic structure of the site and seismic wave tests were studied, the relationships between seismic waves and the geologic structure and the site strata lithology were built based on the analysis of site geological conditions through in-situ investigations, drilling, sampling, seismic wave test of rock samples. The dynamic parameters of the site rock mass were deduced. The reliable basis was provided for the design earthquake prevention of Phase III Qinshan Nuclear Power Plant, China.