Basic environmental conditions of groundwater at a typical golf course

Taking a golf course as the object of investigation, this paper monitors the groundwater distribution of the course, uses the assessment method of groundwater quality and pollution status to evaluate the groundwater foundation of the course. The results show that shallow groundwater and deep groundwater are polluted to different degrees, and the pollution of shallow groundwater is very serious. In terms of distribution space, the monitoring well in the downstream direction of golf course is the most seriously polluted.     

Analysis of influence of the power plant ash storage yard on groundwater environment

The fluoride contained in the filter liquor produced by fly ash in the thermal power plant which takes the coal as fuel can lead to groundwater pollution. Therefore, it is of great significance to study the migration characteristics of the pollutants in groundwater, in order to control and prevent the groundwater fluoride pollution. By adopting the numerical modeling method, this paper takes the ash-storage yard of Shahe Power Plant in Xingtai City as an example, to study the characteristics of fluoride migration in phreatic water, and establish a two-dimensional groundwater flow and water quality model on the basis of the hydrogeological condition analysis in this study area. Meanwhile, based on the Vmodflow software, the migration regulation of the fluoride in groundwater has been simulated. Because the phreatic aquifer of this area belonging to the Shahe alluvial-diluvial sediments and with a coarse lithology as well as high permeability, the migration and diffusion ability of the fluoride in this area is relatively strong. It turns out that the longest migration distance in 5 years is 892 m and that within 8 years is 1 515 m.     

城市污水处理厂地下水环境影响评价技术方法

本次以池南区污水处理厂为研究对象,通过分析其水文地质条件,结合建立的水文地质概念模型和地下水流数值模型,运用MODFLOW对池南区污水处理厂地下水水流及水质的影响进行模拟预测,从而针对可能产生的不利影响提出保护措施。     

河南鸭河口电厂地下水化学成分背景调查

从研究区现有水井取水样１９件。通过水样的化学分析和地质资料研究了以下一些问题：①生活有机质的降解;②铝硅酸盐矿物的溶解;③来自河水的补给;④氟含量和氟石（ＣａＦ２）溶解度控制有关;⑤重金属的变化     

实际野外条件下的污染场地土壤和地下水污染限值计算(英文)

加拿大联邦及Alberta省级环境导则为石油烃污染场地提供了多级环境标准及评价方法。其中二级环境标准评价,准许根据污染场地的实际条件计算土壤和地下水污染限值。环境导则限定了计算污染限值的模型和方法。这些模型大都是基于十分简化的野外条件的解析解模型,并根据导则规定的方法使用,以简化应用与审批程序。这些模型的用途和方法与一般通用地下水和土壤污染物运移模型有所不同,在实际运用时这些差别常常被忽略。同时,在复杂野外条件下运用这些模型时,经常遇到确定模型输入参数的困难。介绍了加拿大环境导则中计算污染场地土壤和地下水污染限值以保护地表水环境的模型方法,强调这些模型方法只适用于计算污染限值的特殊目的,不适用于预测污染物运移或套用一般模型拟和调参方法。结合具体计算实例,探索运用Monte Carlo方法评价与表示模型输入参数带来的不确定性。这种方法用参数变化区间(或概率分布)来表示输入参数的变化或不确定性,以求得具有统计意义的保险污染限值。这种方法简单易行,却将二级环境标准评价方法推广到较为复杂(更真实)的野外条件。     

Hydrochemical evolution and variation of groundwater and its environmental impact at Sohag, Egypt

Groundwater resources of Sohag, Egypt are currently threatened by contamination from agricultural and urbanization activities. Groundwater in Sohag area has a special significance where it is the second source for fresh water used for agricultural, domestic, and industrial purposes. Due to growing population, agriculture expansion, and urbanization, groundwater quality assessment needs more attention to cope with the increasing water demand in this arid zones and limited water resources. The aim of this paper is to address the integrated role of geochemical processes, agriculture and urbanization in evolution of groundwater composition, and their impact on groundwater quality to help in management and protection of groundwater resources of study area using geochemical modeling techniques and geographical information systems. Spatial variation of groundwater hydrochemical properties, rock–water interaction, ion exchange, and assessment of groundwater quality were investigated. Results indicated that groundwater properties are varied spatially and its evolution in the study area is generally controlled by the prevailed geochemical processes represented by leaching, dissolution, and precipitation of salts and minerals, ion exchange, in addition to human activities represented by agriculture and urbanization as well as climatic and poor drainage conditions. Management alternatives should be followed in the study area to avoid degradation of groundwater quality and provide sustainable development.     

冲击荷载作用下岩石破坏机理预测

将岩石看作由彼此之间有内摩擦的颗粒团组成。利用力学模型分析了在冲击荷载作用下岩石破坏过程,阐述了岩石破坏后的力学行为。认为冲击荷载区域的变形近似为一维变形状态。冲击荷载作用在岩石中产生的应力波可以看作类似于冲击波的短波,在波阵面附近的某个狭窄区域内将发生参数的急剧变化。根据岩石介质中粒子运动速度的强弱应力状态发生由弹性状态向内摩擦状态的转变,最终达到流体力学状态。     

输变电设施电磁辐射环境影响评价方法探讨

结合输变电设施周围电磁环境特点,对其电磁辐射环境影响评价方法进行探讨,提出相应的电磁辐射污染防治措施与建议,消除公众疑虑。在此基础上,总结当前电磁辐射环评工作中存在的问题,以期为后续同类问题深入研究提供思路。     

Numerical simulation and environmental impact prediction of karst groundwater in Sangu Spring Basin,China

The changes of development and utilization of karst groundwater in Sangu Spring Basin have made the original groundwater resource evaluation unable to meet the needs of future economic development. Based on analysis of existing data, combined with the characteristics of supplement, runoff and draining of regional karst groundwater, the Visual Modelflow software was used to build a numerical simulation model of Sangu spring Basin. The amount of karst groundwater resource and groundwater environment of the Basin were evaluated under different exploitation schemes, and the changes of karst groundwater environment in the future ten years were also predicted. The fitting error which is less than 0.5 m between the calculated value and measured value of the water level in the fitted borehole accounts for 93%. For the lithologically and structurally complex Sangu Spring Basin, the fitting effect of numerical simulation model was ideal. On the basis of the current mining amount of 111.80 million m³/a, the total redistributed exploited amount in the spring region was 61.79 million m³/a. Under the condition that the quantity of recoverable resources reached 173.59 million m³/a and under different precipitation schemes, all constraint conditions were satisfied, such as regional water level drawdown, maximum allowable water level drawdown in every simulated water source area and the flow rate of Guobi Spring. The results will provide a scientific basis for the rational development and utilization of karst groundwater in Sangu Spring Basin.     

重庆鱼田堡煤矿采动条件下顶板岩溶地下水运移规律探讨

重庆市位于我国西南地区,五大国有煤矿多位于岩溶发育的丘陵山区,地质条件复杂,为深入探讨重庆丘陵山区采煤条件下地下水的运移规律,在鱼田堡煤矿煤层顶板长兴段灰岩地表投放示踪剂,井下不同巷道水平以及不同采区布置多个接收点实施连通试验。实验结果表明:接收点水样在雨后呈现出Cl-含量升高、Cl-含量降低和Cl-含量不变3种变化趋势,综合连通试验结果及水化学分析得出顶板长兴段灰岩地下水在侵蚀基准面以下向开采工作面排泄,而开采结束覆岩相对稳定的采区基本无长兴段灰岩地下水排泄。研究不同采区的接收点示踪剂变化特征对深入了解地下水的运移规律,以及类似条件矿区布置防治水工作具有参考价值。      

Application of Visual MODFLOW to assess the Sewage Plant accident pool leakage impact on groundwater in the Guanting Reservoir area of Beijing

In this paper, Visual MODFLOW is used to simulate groundwater flow and transport within the study area based on a certain scenario, assessing the leakage impact of a Sewage Plant accidental pool on groundwater using NH₃-N as the assessment factor. In the model constructed, soil absorption and degradation was taken into account; the adsorption process of NH₃-N adopted the Langmuir equation and the degradation was simplified as a first-order dynamic reaction. The leakage process was defined as a recharge with contaminants in the case that where there are two accidents happening to the Sewage Plant within a one month interval. The result of the model indicated that the NH₃-N concentration of groundwater increased sharply when the Sewage Plant was malfunctioning. The peak of NH₃-N concentration under the accident pool was about 8.0 × 10⁻⁵ mg/L at the first accident. When the second accident happened, the NH₃-N concentration increased to a maximum of about 1.1 × 10⁻⁴ mg/L. At a location of about 20 m from the accident pool, the concentration declined to about one sixth of the center, which demonstrated that the NH₃-N concentration increase caused by leakage of the accident pool was little, and the spatial influence also was small. The paper provides a method of dealing with the transport of physically and chemically reactive substances in groundwater with Visual MODFLOW and assessing the Sewage Plant accident pool leakage impact on groundwater quantitatively.     

Agricultural activities impact on groundwater nitrate pollution

Concern over agricultural diffuse pollution sources in integrated water quality management has been growing recently. High nitrogen fertilizers application rates may increase the potential groundwater pollution. These effects were investigated in Andimeshk and Susa plains that cover an area of 1100 km² between the Dez and Karkhe rivers in north of Khozestan-Iran. This region divided to 4 sub-regions A, B, C, and D. Additionally 168 groundwater samples were collected from 42 water wells during the months April, May, August, and September of 2004. The Hackspectrophotometer nitrate test was used to measure the NO₃ ^? concentration in water samples. Information about further nitrate data was obtained. A questionnaire procedure was used for collection N-fertilizers application rate data in studied area. The results demonstrated that all of the groundwater samples have NO₃ ^t- concentration below the EPA MCL (44.27 mg/l) and WHO guideline (50 mg/l). The mean nitrate concentrations are 16.1, 19.5, 13.3, and 7.9 mg/l in sub-regions A, B, C, and D respectively. There are different amount of N-fertilizers applied in sub-regions A, B, C, and D. Correlation between NO₃t- concentrations and N-fertilizers rate suggests a inverse correlation between Nfertilizers application rate and ground waters nitrate concentrations in studied area (r=?0.69).     

An empirical approach simulating evapotranspiration from groundwater under different soil water conditions

Based on the approaches of FAO24 and FMP1, a new empirical approach simulating evapotranspiration from groundwater (ET_gw) under different soil water conditions was proposed in present study. Then, through the data from volumetric lysimeter, the new approach was compared with the two approaches of FMP1, C1 and C2. The new approach gave acceptable simulation results for the treatments under different water conditions, and especially gave better results for the treatments influenced markedly by precipitation or irrigation than the other approaches. The large errors in the late stage in 2009 might be due to the effect of the early maturity of winter wheat. It also indicated that the critical soil water storages in the equation in FAO24 were not suitable to describe the relationship between ET_gw and soil water storage in root zone when water table was at or above 150?cm depth, and could be replaced with the storage corresponding to the field capacity and the steady storage. The new approach was more suitable for estimating the ET_gw under different soil water conditions comparing with C1 and C2.     

不同环境条件下堆石料变形特性的试验研究

探讨了对处于受压状态的堆石料进行干湿、冷热变化等环境因素作用下力学性质研究的试验方法。使用新研制的堆石料风化试验仪,对某种泥质粉砂岩堆石料进行了干湿循环、冷热循环以及湿冷-干热耦合变化三种环境条件下的长期变形特性试验研究,探讨了堆石料长期劣化变形的机制。试验结果表明,干湿循环试验和湿冷-干热耦合循环均可导致堆石体产生较大幅度的附加变形,其变形机制包括湿化变形、堆石体颗粒湿胀和干缩循环变形以及堆石料的劣化变形等。环境因素的循环变化可导致堆石体颗粒的劣化,堆石体劣化变形是高土石坝后期变形的重要组成部分。     

极端酸性环境下形成的施威特曼石（schwertmannite）及其环境学意义

施威特曼石(schwertmannite)是近年来发现存在于含SO42-丰富的极端酸性环境下的一种次生羟基硫酸高铁矿物,其结晶度较差,形态特殊,表面基团活性强,对其存在环境中有毒重(类)金属元素的迁移与钝化有重要影响。本文详细地介绍了施威特曼石的形成、组成结构、稳定性能、溶解度及其与重(类)金属元素的相互作用等方面的研究进展,并对其在地下水除砷中的应用前景进行了讨论。     

Study of shallow groundwater quality evolution under saline intrusion with environmental isotopes and geochemistry

Evolution of the shallow groundwater quality under saline intrusion in porous aquifer system has been studied with environmental isotopes and geochemistry in the Laizhou Bay area, China. Two campaigns of water sampling from various sources were carried out in spring and winter for environmental isotopic and chemical analyses. The origin of groundwater salinity from intrusion of both modern seawater and deep brine water was identified by analysing the correlations between ¹⁸O, D, T, Cl⁻, SO₄²⁻ and electrical conductivity. The results indicate that the brine is originated from evaporating and concentrating of intruded seawater and its δD and δ¹⁸O are different from modern seawater but similar to those of mixture of seawater with fresh groundwater. It is hard to distinguish the salinity origin in this area by the δD–δ¹⁸O relationship alone. The relations between δ¹⁸O and conductivity, Cl⁻ and SO₄²⁻ have been used to identify the salinity origin due to the distinct difference in salinity between the brine and seawater, conjunctively with use of T. A threshold of T = 12 TU was adopted to identify the origin of saline groundwater.     

Optimizing groundwater monitoring systems for landfills with random leaks under heterogeneous subsurface conditions

Landfills are one of the most common human activities threatening the natural groundwater quality. The landfill may leak, and the corresponding plumes may contaminate an area, entailing costly remediation measures. The objective of the installation of monitoring systems at landfill sites is to detect the contaminant plumes before they reach the regulatory compliance boundary in order to enable cost-effective counter measures. In this study, a classical decision analysis approach is linked to a stochastic simulation model to determine the optimal groundwater monitoring system given uncertainties due to the hydrogeological conditions and contaminant source characteristics. A Monte Carlo approach is used to incorporate uncertainties. Hydraulic conductivity and the leak location are the random inputs of the simulation model. The design objectives are to: (1) maximize the detection probability, (2) minimize the area of contamination at the time of detection, and (3) minimize the total cost of the monitoring system. A synthetic test case based on a real-world case in the Netherlands is analyzed. The results show that monitoring systems located close to the source are optimal except for the cases with very high unit installation and sampling cost and/or very cheap unit remediation.