五指山隧道岩溶发育及涌水的特征研究

五指山隧址区有10种岩溶形态,在隧址区地质调查基础上,分析了五指山地区岩溶发育的演化历史.采用径流模数法、年降雨有效渗入时间系数法及地下水动力系数法对各区段隧道涌水进行了计算,并对隧道贯通前后涌水动态变化进行了分析.五指山隧道主要涌水位置有5处,其中进口段的“8.6”断层突水和出口段的膏溶角砾岩突水,突水量大,给隧道施工和隧址区环境带来严重影响.     

通海隧道施工涌突水灾害与环境影响研究

通海隧道是中国云南国际铁路通道昆明-河口线上的主要工程,也是云南省在建的最长隧道。隧道全长10 302 m,全隧道为单面坡,最大坡度为20.4‰。该隧道在通海县境邻近杞麓湖,作为通海县重要的水资源,杞麓湖具有工农业用水、调蓄、防洪、航运、旅游、水产养殖等功能,是通海县社会经济发展的主体。隧道施工以来,在进出口的数个出水点涌出大量的地下水,由于工程区为生态敏感的岩溶地区,因此亟需查明隧道涌水与周边杞麓湖等水体的水力联系。通过对隧址区岩溶水文地质条件的研究,在充分了解区域构造环境、褶皱与断裂特征、掌握地下水含水岩组及其富水特性、地下水补径排特征的基础上,划分出隧址区的水文地质单元,结合隧道施工涌水状况以及已开挖段所揭示的地质条件等,利用地质原形研究和同位素分析等方法重点分析隧道涌水来源及其与杞麓湖的水力联系,明确隧道工程对周边地区水环境的影响。     

四川某隧道岩溶水文地质条件及涌水量初步研究

拟建隧道位于黄龙景区,通过段主要为强溶蚀岩溶-裂隙含水岩层,区内构造活跃、地形切割强烈,隧道遭遇岩溶涌突水的危险性较大.通过分析该隧道岩溶水文地质环境.论述了隧址区岩溶发育分布规律、岩溶水补径排条件及化学特征,并采用地下水径流模数法和大气降水入渗法2种方法对比计算对隧道涌水量做出初步预测评价,为施工提供依据.     

重庆走马岭隧道岩溶及岩溶水发育特征

走马岭隧道通过方斗山背斜可溶岩地区。岩溶发育强烈。在分析隧址区地质环境的基础上，详细论述隧址区岩溶发育分布规律和特征，岩溶水补、径、排条件及化学特征，为隧道安全施工提供科学依据并提出建议。     

走马岭隧道围岩变形监测及工程地质评价

基于隧址区地质环境条件的复杂性,有必要进行施工围岩变形监测。系统地介绍了隧道围岩变形监测的原理和方法分析;并以走马岭隧道施工过程的深部围岩变形监测为依据,获取围岩动态综合信息以分析围岩变形规律,指导施工;提出围岩变形监测为隧道大变形预测、优化二次支护时间等提供科学依据和施工建议,是岩土工程信息化设计、施工的重要手段。     

四川省会东县雷家湾金沙江河谷地段水化学特征

利用水化学、氢氧同位素分析,结合研究区水文地质条件,阐述了研究区水环境特征,为工程建设提供了参考依据。水化学、同位素分析表明,该区地下水径流条件较差,水交替性弱;溶滤作用和蒸发作用对于该区地下水中各化学组分的形成有较大的贡献;大气降水和雪山融水为该区水体主要来源。以石英砾岩（P1）为界的双层含水系统,上部的风化裂隙水为就近的大气降水渗入补给,下部含水系统接受长距离运移的高山补给源补给。     

滇东南弥勒盆地蓄水构造特征分析及找水方向

蓄水构造是富集地下水的地质构造形式,它是地下水形成、运动和蓄存的场所。在干旱地区寻找地下水主要是寻找有利的蓄水构造。通过分析弥勒盆地及其周边蓄水构造的特征,能为今后弥勒地区干旱年份寻找地下水提供水文地质依据。该文在对区域地质条件、地下水系统资料进行详尽分析并结合野外现场调查的基础上,基于蓄水构造的三要素,对滇东南弥勒盆地蓄水构造类型及其特征进行了分析,认为区内主要有汇水型蓄水构造、阻水型蓄水构造和风化带型蓄水构造三类,在干旱年份岩性分界面阻水型蓄水构造、断裂型蓄水构造和风化带型蓄水构造中的地下水具有供水意义。     

北方区域尺度地下水-包气带硝酸盐分布与变化特征

我国农业生产过程造成的地下水硝酸盐污染问题备受关注,作为硝态氮累积和存储的重要场所和硝酸盐淋失进入地下水的主要通道,包气带土壤中硝酸盐存储分布特征与地下水硝酸盐污染密切相关。本文以北方典型黑土、潮土和褐土区农田为研究对象,建立了北方地下水硝酸盐监测网（东北、华北、西北）,通过对不同区域地下水的采样和测定,比较了地下水硝酸盐污染的区域差异,结合历史数据对地下水硝酸盐时空变化进行了分析。进一步选择华北平原作为厚包气带的代表区域,实地取样分析了包气带硝态氮累积存储和分布特征。结果表明：东北黑土区地下水硝酸盐超标率最高,达39.6%;其次为华北潮土区,超标率为19.3%;西北褐土区的地下水硝态氮超标率最低,为14.9%。随时间推移,华北平原区域尺度浅层地下水硝酸盐超标率有增长趋势,2016—2018年403个采样点地下水超标率为18.9%,高于1998年的11.8%。华北平原区域厚包气带硝酸盐存贮总量可达1854万t,粮食种植对区域包气带硝酸盐累积存储的平均贡献率为78.3%;包气带0~6 m是华北平原区硝酸盐存储的主要土层,这部分存储的硝态氮对地下水构成了潜在的威胁。     

岩溶地区地下工程对环境影响的初步分析

在分析了岩溶地区地下工程对环境影响类型的基础上,以圆梁山深埋特长隧 道为例,从环境工程角度阐述了其主要环境地质问题,分析了水文地质特征,利用化学热力 学方法对隧道内水样的水质分析结果进行了侵蚀性评价分析,评价结果显示地下水对碳酸盐 岩与混凝土具有弱侵蚀性,最后提出了在岩溶地区防止因地下工程造成环境影响的措施.     

贵阳市水文地质条件及环境效应研究

为了查明水文地质条件以及产生的各种环境效应,通过野外调查贵阳市环境地质背景,分析了研究区的水文地质条件,对各含水岩组的富水性进行评价,同时根据研究区地层植被发育情况、地下水环境监测数据、具体工程实例和近3 a的地下水水质检测等资料,运用空间信息统计方法,探讨了水文地质条件下产生的城市生态环境效应、环境水文地质效应、环境工程地质效应、地下水环境污染效应。取得的主要结果有:①贵阳市地表水、地下水丰富,地下水以岩溶水为主,其次为基岩裂隙水;②贵阳市形成宽1～7 km,长逾70 km的环城林带,为贵阳市提供了良好的生态环境条件;③由于大量开采地下水资源,在和尚坡、三桥地段形成降落漏斗群,破坏水文地质结构,产生环境水文地质效应;④在工程建设中抽排地下水产生地面开裂、地表塌陷等环境工程地质效应;⑤由于工业废水和人类生活污水的排放,使地下水环境在不同程度上受到了污染,产生水环境污染效应。该研究结论可为贵阳市城市环境的保护和可持续发展提供依据。     

Environmental Impacts of Acid Leachate Derived from Coal-Storage Piles upon Groundwater

Leachate emanating from a coal-storage area at an electricutility plant in Northwest Indiana (U.S.A.) is impacting groundwater quality. This assessment is based on results of along-term groundwater monitoring program conducted at Purdue University's Wade Utility Plant where a monthly average of 32,000metric tons of both high- and low-sulfur coal are stored. Groundwater from both a perched and major aquifer (the WabashValley Aquifer) as well as surface water from a large retentionpond were sampled monthly for 34 consecutive months. Such a long-term, continuous sampling scheme proved beneficial in identifying seasonal trends and anomalies within the chemistryof ground- and surface waters. Data show elevated concentrationsof sulfate and hardness in the perched zones and the WabashValley Aquifer (WVA). Lead in the WVA has also been reported ata concentration greater than the state maximum contaminant level, while several metals (Be, Cd, Cu, Pb, Ni, Se, and Zn) containedwithin retention-pond sediments have the highest concentrationsin aquatic sediments ever reported within the State of Indiana.Due to the buffering capacity of carbonate minerals in underlyingunconsolidated deposits, the acidic pH of coal-pile leachate is raised to values typical for groundwater in carbonate terrain common in Northwest Indiana. Further ameliorating the input of acid percolation is the dilution capabilities of both the WVA and the recharge pond. Hence, sites without such advantages would exhibit a greater degree of groundwater contamination than what is observed at Purdue's coal-storage facility.     

坎儿井隧洞井壁剥落破坏原因与防渗加固

暗渠隧洞剥落坍塌破坏是坎儿井消亡的主要原因之一。该文选取典型坎儿井,通过现场实测调研、室内试验研究了坎儿井井壁的水份分布特征、来源以及土性参数;基于滤纸法获取的增湿土-水特征曲线,进行了坎儿井非饱和稳态渗流有限元分析。研究表明:冬季坎儿井井壁水分来源主要是毛细水,0.6 m以下为暗渠毛细水强烈影响区,井壁土为冻胀性土;井壁严重剥落高度(1.0~1.5 m)与起始冻胀含水率高度(1.1 m)基本一致,冻融循环后低围压下有效粘聚力降低显著,可明确冻融是井壁剥落破坏的主要原因;基于防渗止水的井壁抗冻胀思路,提出了在隧洞纵深负温范围内进行局部防渗衬砌的工程加固措施,该措施具有井壁抗冻胀、施工维护简单、不破坏坎儿井这一历史文物原貌等优点,具有一定的理论和技术推广价值。     

Influence of a riparian wetland on nitrate and herbicides exported from an agricultural field

Agrochemicals are a major source of nonpoint pollution. Forested corridors along stream channels (riparian zones) are thought to be potential sites for removal of agricultural contaminants from ground and surface waters. First-order riparian wetlands are reputed to be especially effective at groundwater remediation. The study site is a fairly typical (for eastern Maryland) small, first-order stream in an agricultural watershed. Preferential flow supplies most of the stream water within the riparian headwater wetland. This upstream area also contains the highest average stream N and pesticide loads in the entire first-order riparian system. Zones of active groundwater emergence onto the surface display high concentrations of nitrate throughout the soil profile and in the exfiltrating water, whereas inactive areas (where there is no visible upwelling) show rapid attenuation of nitrate with decreasing depths. Atrazine degradation products appear to penetrate more readily through the most active upwelling zones, and there is a correlation between zones of high nitrate and high atrazine metabolite levels. Deethylatrazine/atrazine ratios (DAR) seem to indicate that stream flow is dominated by ground water and that much of the ground water may have reached the stream via preferential flow. Remediative processes appear to be very complex, heterogeneous, and variable in these systems, so additional research is needed before effective formulation and application of riparian zone initiatives and guidelines can be accomplished.     

植被缓冲带在水源地面源污染治理中的作用

在山地丘陵区遭遇高强度降雨时,常常发生水土流失;水流携带泥沙下泄,过量施入农田的肥料、农药等化学物质随之进入河流、水库、湖泊等地表水和地下水水体,进而造成水体富营养化等面源污染,危害水源地安全。为梳理植被缓冲带能够控制水土流失、阻控污染物移动、解决水源地面源污染问题,明确该项技术措施减少和治理水源地面源污染的机制,为水源地面源污染防治和水环境改善提供参考。在概括介绍植被缓冲带的类型、功能的基础上,对该项技术措施减少和治理水源地面源污染的机制进行讨论。植被缓冲带治理水源地面源污染的机制主要有:①植物在生长过程中自身对氮磷等物质的吸收;②利用植被固结土壤,减少水土流失;③植被覆盖、拦蓄能够延长径流在地面的停留时间而增加水分入渗、减少氮磷等物质随地表径流流失;④植物根系参与土壤中多种物理、化学和生物过程,加速碳、氮、磷等物质的形态转化。针对水源地面源污染特点和植被缓冲带的建设技术及其应用要点,提出相关建议,并对今后该技术的发展进行了展望。     

Formation and movement of groundwater in the thick loess-palaeosol sequences of the Chinese Loess Plateau

Permeability and water-bearing space are important hydrological characteristics of the loess strata. In this study a systematic experiment was conducted to measure the magnetic susceptibility, grain size, porosity, and infiltration rate of the loess and palaeosol layers on a loess tableland of the central Chinese Loess Plateau, in order to investigate the differences in hydrological conditions between the loess and palaeosol layers. The magnetic susceptibility of the loess layer was lower than that of the palaeosol layer, but the average quasi-steady infiltration rate was about 0.31 mm min~(-1) higher, the coarse silt and very fine sand contents were about7.1% greater, and the porosity was about 5.7% higher. These differences were mainly due to pedogenesis, which was affected by the Quaternary climate. The pedogenesis differences between the loess and palaeosol layers resulted in hydrological property differences in terms of permeability and water-bearing space. The loess layer had a higher permeability and more water-bearing space than the palaeosol layer, which meant that the loess layer is more likely to form aquifers and the palaeosol layer is more prone to form aquitards.The groundwater in the loess strata had a multilayered characteristic, which depended on the relative impermeability of palaeosol layer and the alternate deposition of loess-palaeosol layers. The hydrological characteristics of the loess strata demonstrated that the Quaternary climate had an important control function on the formation and movement of groundwater. This knowledge provides a reliable theoretical basis for water resource development and utilization on the Chinese Loess Plateau, and this study extends the application of Quaternary climate change theory to hydrological systems in loess deposits.     

石羊河流域绿洲农业发展对地表水与地下水转化关系的影响

基于绿洲农业发展对水资源的依赖性，分析了天然河道渠网化、灌溉面积扩大、渠道引水量增加、渠系高标准衬砌及地下水大量开采对流域平原区地表水与地下水转化关系的影响。结果表明：绿洲农业对水资源的开发利用，在造就了高效和集约化绿洲农业生态系统的同时，也使地表水与地下水之间的转化条件、转化数量及水体质量发生了明显变化，其负面效应已引发了严重的生态环境问题，并直接威胁着绿洲的稳定和发展。     

涉水交通工程水土保持准入条件

 港口码头、独立大桥与隧道、海堤防等涉水交通工程占地性质多为永久占地,土地的原有功能完全转变;由于涉河涉水兴建此类工程,其环境敏感性强,引发的水土流失危害及环境影响较为直接;土石方挖填量大,施工过程中发生的水土流失直接进入江河湖海。根据我国有关法规、政策、规划、标准等规定,结合涉水交通工程项目的特点,提出了此类项目准入、限批、缓批的主要条件,从项目水土保持准入方面提出了修正完善主体设计、修改完善水土保持方案后再报批的条件,以及水土保持方案准入排序意见。     

Model‐based evaluation of agri‐environmental measures in the Federal State of Brandenburg (Germany) concerning N pollution of groundwater and surface water

GIS‐based modeling of soil‐crop interactions and hydrological processes is a valuable instrument to assess land‐use effects on N pollution of water resources from the agricultural sector. A case study is presented using spatial information on soils, climatic zones, land use, and distribution of agri‐environmental measures within the federal State of Brandenburg (Germany) to assess the reduction effect of EU‐funded measures on N pollution of water resources. In a first step, the area was classified concerning the risk for groundwater and surface‐water pollution. For this, spatially distributed model calculations of the soil‐solution exchange frequency were intersected to a vulnerability map for groundwater derived from geological data and zones of different transit times from the root zone into surface waters. In a second step, model calculations of water and N dynamics in the soil‐crop system for different crop and management systems were performed to calculate nitrate leaching from the root zone and to estimate the effect of present agri‐environmental measures to reduce N pollution on groundwater and surface waters. The results indicated that 75% of the agri‐environmental measures were placed in areas with low impact on groundwater and surface waters. Therefore, the effectiveness of the agri‐environmental measures concerning water‐protection aims was moderate.