Pollution pattern of underground river in karst area of the Southwest China

Investigation of groundwater pollution has been carried out on multiple typical karst underground river systems in recent years in order to reveal the characteristics and mechanism of underground river pollution. Through the summary of the survey results, five characteristics of underground river pollution have been revealed, including directionality, weak hysteresis, easier for reversibility, linear and intermittent(or seasonal); combining with karst geomorphic types, pollution sources(primordial, secondary pollution and compound), pollution ways and pollution receptors, three basic pollution patterns of the underground river were depicted: Recharge area pollution, runoff area pollution and discharge area pollution. At the same time, the study discloses the reality of the underground river pollution is the three basic patterns and their subgenera in combination with super imposition on the space and time. And from the angle of the hydrogeological model, the study expounds the process of underground river pollution. Finally, the study gives naming rules of pollution pattern of the underground river and sets up PISAB method of pattern recognition. The results provide scientific basis for pollution repair and management of underground river in the southwest karst region.

Distribution and Source of Organochlorine Pesticides in the Laolongdong Underground River Basin,China

The concentrations of organochlorine pesticides(OCPs) in the Laolongdong underground river basin in northern China were quantitatively analyzed using the gas chromatography-mass spectrometer(GC-MS).This study was to investigate the composition,distribution and source of OCPs in the waters.The concentrations of ∑OCPs ranged from 14.45 ng· L-1 to 307.92 ng· L-1 and the mean value is 79.42 ng· L-1.β-HCH and p,p '-DDT were the most abundant components in ∑HCHs and ∑DDTs,respectively.There are some differences among the temporal and spatial distributions of ∑OCPs in underground river basin,and the distributions of ∑HCHs and ∑DDTs were same with ∑OCPs.The sources of OCPs analysis indicated that HCHs mainly came from the input of lindane and DDTs was from the mixture input of newly technical DDTs and dicofol.

Polychlorinated biphenyls in the Nanshan Underground River,China

Abstract Karst areas have much higher ecological vulnerability and are easy to be contaminated by polychlorinated biphenyls(PCBs) which are introduced as health risk pollutants.PCBs concentrations were used to understand the transport behavior of PCBs conducted in the karst Nanshan Underground River,China.Water and sediments from the underground river water,and sediments and soil from the surface of the corresponding watershed were collected monthly in 2011 and 2012 and PCBs were analyzed.Seasonal variations were found in concentrations of PCBs both in the waters and sediments.PCBs concentrations varied from 0.3 to 29.9 ng·L-1 in the groundwater,while from 0.1 to 366.1 ng·g-1 in the underground sediments.Correlations were found in concentrations of PCBs in waters and sediments between the underground river and surface systems which indicate that the surface systems play a major role for the transport of PCBs and contamination in the underground river systems.Karst features are liable for the transport behavior.The underground river waters transport PCBs at mean 3 g·day-1.

A Preliminary Study of OCPs in Underground River Surface Sediments from Chongqing Typical Karst Areas

19 kinds of organochlorine pesticides(OCPs) in groundwater surface sediments of Chongqing typical karst areas were analyzed by GC-ECD.The total concentration range of OCPs was 4.73-286.03 ng/g,the concentration range of DDTs was 0.35-181.78 ng/g and the concentration range of HCHs was nd-23.53 ng/g.As compared with those of other rivers domestic and abroad, the organchlorine pesticides in sediments of Chongqing typical karst areas is in the high level which indicates that the underground river in Chongqing typical karst areas has been highly polluted.The DDE/DDD

Substances Transport in an Underground River of Typical Karst Watershed During Storm Events

Hydrologic process,turbidity,suspended particles matters(SPM),major cations and TOC concentrations during two storm events in late April 2008 were monitored at Jiangjia Spring which is the outlet of Qingmuguan underground river system.Scanning electron microscopy(SEM) and energy disperse spectroscopy(EDS) analyses of SPM were

塔里木盆地塔河北部“过溶蚀残留型”断溶体发育特征及其成因

为了研究塔里木盆地塔河北部强剥蚀区海西早期古岩溶洞穴发育特征,用古地貌恢复、岩溶水系统分析、测井-岩心洞穴识别和地震属性刻画等方法进行了YQ5井区的洞穴类型样式识别、缝洞结构刻画和洞穴成因演化研究。研究结果表明:YQ5井区在塔河油田Ⅱ号和Ⅲ号古岩溶台地北部的地势平缓区,总体为多期次岩溶叠加改造后的残留地貌,主要发育幅差较小的溶峰洼地、溶丘洼地和溶丘平原,南部发育NE向展布的峰丛垄脊沟谷。与塔河油田主体区及斜坡区不同,YQ5井区地下和地表水系的流向与地貌趋势不一致,岩溶水系统遭受构造作用破坏,导致补给、径流和排泄的岩溶水循环过程不完整。YQ5井区主要发育暗河型洞穴和“过溶蚀残留型”断溶体。暗河型洞穴充填较为严重,洞穴的有效储集空间受到破坏,影响油气开发效果。岩溶台地的构造抬升造成区域侵蚀基准面的下降,顺走滑断裂的垂向侵蚀作用有利于“过溶蚀残留型”断溶体的持续发育和保存,油气开发效果好。“过溶蚀残留型”断溶体的发育主控因素为走滑断裂、地层剥蚀强度和负向地貌。与塔河古岩溶台地演化过程一致,YQ5井区的岩溶演化经历深切曲流期、岩溶改造期和下渗断溶期3个阶段。暗河型洞穴被持续改造破坏,断溶体则持续建造。

基于用高斯分布生成管道的岩溶地下水流数值模拟

为更精确地模拟岩溶区地下水运动,以贵州省黔西南普安县某岩溶水文地质单元为研究区,用基于有限单元法的FEFLOW软件建立研究区岩溶管道等效多孔介质耦合地下水流数值模拟模型。模拟中,在地质条件控制下应用高斯随机分布生成地下暗河的管道,用非稳定三维地下水运动的偏微分方程描述等效多孔介质水流运动,用Manning-Strickler方程描述管道水流运动,将导水断层处理为强渗透条块,将落水洞汇水范围的降水入渗系数设置为1,将泉水处理为定水头的抽水井。流场模拟结果显示,25个观测点计算水位与实测水位关系的决定系数可达到0.9985,纳西效率系数达0.9982,极接近于1;表明基于这些处理建立的地下水模拟模型反映了岩溶地下水运动特征,具有较强的仿真能力,可用于提高岩溶区地下水资源评价精度。

Health risk assessment of heavy metal pollution in groundwater of a karst basin,SW China

To investigate the presence of metal elements and assess their health risk for the populace in the Nandong Underground River Basin(NURB),we conducted an analysis of eleven common heavy metals in the water body.A Health risk assessment(HRA)model was employed to analyze 84 water samples from the NURB.The detection results revealed the following order of heavy metals concentrations:Fe>Al>Mn>Zn>As>Cd>Pb>Cr>Ni>Cu>Hg.Correlation analysis indicated a certain similarity in material source and migration transformation among these eleven metal elements.Our study identified that the health risks for local residents exposed to metal elements in the water of NURB primarily stem from carcinogenic risk(10^(−6)–10^(−4)a^(−1))through the drinking water pathway.Moreover,the health risk of heavy metal exposure for children through drinking water was notably higher than for adults.The maximum health risks of Cr in both underground and surface water exceeded the recommendation standard(5.0×10^(−5)a^(−1))from ICRP,surpassing the values recommended by the Swedish Environmental Protection Agency,the Dutch Ministry of Construction and Environment and the British Royal Society(5.0×10^(−6)a^(−1)).The results of the health risk assessment indicate that Cr in the water of NURB is the primary source of carcinogenic risk for local residents,followed by Cd and As.Consequently,it is imperative to control these three carcinogenic metals when the water was used as drinking water resource.

隧道岩溶施工处置技术研究

岩溶隧道处置技术一直是工程界的重点及难点问题,结合某高速铁路贵州区段施工状况,将隧道岩溶分为串珠型或管道型的线状溶洞、洞穴型溶洞及洞厅型溶洞,根据其不同的填充性质提出了不同的施工处置措施。并具体结合丫口寨隧道、斗磨隧道、大独山隧道,对典型岩溶,包括无充填型溶洞群、暗河、富水填充型岩溶、过水通道型岩溶及黏土填充型岩溶的处置措施进行分析,主要结论为,针对岩溶隧道,应综合考虑岩溶类型和特征,因地制宜进行设计、施工。

空地一体技术在地下暗河探测中的应用研究

地下排水管涵是城市排水的主要渠道之一,掌握地下排水管涵信息对于城市防汛具有重要意义。受拆迁、道路改造施工等影响,地下排水管涵的部分井盖、井筒遭到掩盖、掩埋,使其成为难以探明的地下暗河。针对现场条件复杂的地下暗河,单一探测技术难以实现地下暗河的完整探测。因此,采用了测量型无人机、全地形机器人、三维激光扫描仪和GNSS-RTK协同作业的方案,形成了一种空地一体测绘技术,实现了测区地形、地下暗河的精确测绘,提高了城市疑难地下暗河的作业效率和数据质量。

沿海中小河流域地表-地下水库联合调控洪水资源利用研究:Ⅱ.实例应用

以山东半岛乳山河流域为例,构建了时、日、月多时间尺度嵌套的乳山河流域地表-地下水库联合调控模型,通过对地表水库泄流、河道闸坝控制水位、地表-地下水库供水等调控规则的优化,提出了地表-地下水库联合调控洪水资源利用方案。研究结果表明:在洪水来临之前通过地表-地下水库联合调控抬升河道控制水位、加大地下水库供水比例、增加河道入渗量,可将地表水库多余水量适时转移到地下水库,腾空地表水库拦洪库容,有效增加流域洪水资源利用量;联合调控方案下,乳山河流域洪水资源的丰(2007年)、平(1994年)、枯(1967年)年,洪水资源利用量分别增加了846.96万、728.77万、106.35万m^(3),验证了地表-地下水库联合调控模型的实际应用效果。

黄河三角洲中深层地下淡水资源可持续保护探讨

21世纪以来,黄河三角洲地区工农业经济快速发展,造成南部区域中深层地下水超量开采,对地下淡水资源的可持续利用构成较大压力。基于当前黄河流域生态保护和高质量发展的需求,为保障地下淡水的环境安全,结合该区域中深层地下水环境现状,提出了控制中深层地下淡水合理开采、优化水资源配置等地下淡水开发利用保护的建议。

黄河冲积地层临河深基坑变形特性研究

依据黄河冲积地层某采用地下连续墙加内支撑支护结构的临河深基坑开挖监测数据,研究了地下连续墙墙体水平位移、地下连续墙墙顶竖向位移和地下连续墙墙后地表沉降的变化规律,验证了采用稳定安全系数法估算深基坑变形在该地区的适用性。研究结果表明:地下连续墙墙体水平位移具有显著的时空效应,墙体最大水平位移随监测点与深基坑边缘距离的增大呈对数型增长趋势,墙体最大水平位移与深基坑开挖深度成线性正相关;底板浇筑前地下连续墙墙体最大水平位移为0.15%H(H为基坑总深度),位于92.3%H深度处。地下连续墙墙顶竖向隆起,底板浇筑后土体自重应力获得一定程度的恢复,地下连续墙墙顶竖向位移基本保持稳定。地下连续墙墙后地表沉降呈凹槽形分布,墙后最大地表沉降为0.11%H。采用稳定安全系数法估算地下连续墙墙体最大水平位移为0.38%H,地下连续墙墙后最大地表沉降实测值为地下连续墙墙体最大水平位移实测值的73%,符合稳定安全系数法估算结果,可为类似地区深基坑变形特性研究提供参考。

塔河油田岩溶峡谷区伏流坍塌型古暗河缝洞系统

为研究塔河油田中—下奥陶统古岩溶发育特征,通过恢复海西运动早期古地貌和古水系,划分了岩溶峡谷区洞穴类型,构建了塔河油田岩溶峡谷区伏流坍塌型缝洞成因演化模式。研究结果表明:研究区发育海西运动早期古岩溶作用,岩溶古地貌总体北东高南西低,微地貌以低幅度溶丘、溶峰和洼地的组合为主,古水系主要为峡谷明流、伏流、暗河与干谷的组合;主干水系具有南段深切曲流峡谷、中段峡谷和北段伏流-天窗的分段结构,分支水系为树枝状暗河网络;伏流坍塌型地下河洞穴可识别,划分为暗河型、伏流型、顺河潜流型和穿洞型4种类型;研究区古暗河系统发育演化可分自由曲流型、伏流-深切曲流型和坍塌天窗伏流型。

湖北某抽水蓄能电站建设中地下河系统多元信息综合分析评价

岩溶发育特征是岩溶区水电工程建设中必须查明的水文地质条件,岩溶渗漏问题更是工程建设成败的关键。湖北某抽水蓄能电站上水库位于岩溶洼地区,工程区地下水系统边界不清、条件不明,可能面临严重的岩溶渗漏问题,本次研究将区域构造分析、地貌成因识别、地下河追踪溯源、微动态自动化监测等多种技术手段有机结合,提取多元信息综合分析,对工程区地下河系统进行了有效识别。结果表明:上水库周边不存在隔水层及阻水构造,子良坪背斜控制了地下水系统的基本格局;地下河岩溶管道具有单支管道状结构特征,南北向岩溶管道不发育,上水库存在向南西侧发生管道式渗漏的风险;上水库内垂向溶蚀作用强烈,建议进行库底土工膜全库盆防渗处理,工程蓄水后应防范可能发生的不均匀沉降和岩溶塌陷问题。

基于“三源模式”的岩溶地下河区污染场地修复治理——以遵义坪桥地下河系统为例

在分析岩溶地下河系统范围内水源、污染源特性的基础上,建立了双源调查、源汇追踪和源头阻控为主要内容的岩溶地下河污染修复治理模式——三源模式。以遵义市坪桥地下河系统为例,利用三源模式对该地下河污染进行修复治理实践。结果表明:研究区分布有各类水点25处,以钻孔、岩溶泉点、地下河出口为主,特征污染物为以NH_(4)^(+)、NO_(3)^(-)、SO_(4)^(2-)、Mn^(2+)、Se^(2+)为主;分布有各类污染源点15处,以工业废渣堆放场为主,主要分布在地下河系统下游坪桥工业园区一带,特征污染物同样为以NH_(4)^(+)、NO_(3)^(-)、SO_(4)^(2-)、Mn^(2+)、Se^(2+)为主;地下河系统范围内有3条地下水污染通道,均分布在地下河出口与坪桥工业园区Z1(1^(#)、2^(#))废渣处置场之间;通过对2^(#)废渣处置场排洪竖井-地下河出口这一污染通道上游段进行帷幕工程修复后,地下河出口可减排污水排放量47244 m^(3)·a^(−1),NH_(4)^(+)、Mn^(2+)浓度可降低66%~78%,其中NH_(4)^(+)最低削减量为16250 kg·a^(−1),Mn^(2+)最低削减量为10960 kg·a^(−1)。研究结果可为类似地区岩溶地下河系统污染修复治理提供参考。

桂林市会仙岩溶湿地水资源特征及有效调控

会仙湿地是“漓江之肾”,对漓江补水和生态环境改善具有重要作用,但湿地水资源调蓄功能较弱,严重制约了湿地功能的发挥。本研究以会仙湿地为示范区,对湿地核心区狮子岩地下河系统和睦洞湖分散排泄系统流量进行了一个水文年的观测,并实施水资源调控措施。结果表明:会仙湿地岩溶含水层对大气降雨具有一定的调蓄作用,但调蓄功能较弱,雨季后若连续2个月无降雨地下河基本断流;会仙河通过桂柳古运河补给睦洞湖,补水效果取决于会仙河大坝的蓄水高度,当会仙河大坝蓄水高度小于149.25 m时,会仙河无法对湿地进行有效补水,对该大坝重修可增加对睦洞湖湿地的补水效果。针对狮子岩地下河系统具有管道集中径流、流量大、水量充足的特征,在地下河采取了上游“蓄”和“引”,中游“堵”,下游“拦”的三级调控工程使地下河水位从出口到八仙湖段1 km范围内提高70 cm,可缩短狮子岩地下河溶洞湿地低水位期1个月以上。针对睦洞湖分散排泄系统地下水具有分散排泄的特征,采取出口“拦”的水资源调控技术,成功将出口水位抬高30 cm,核心区水位抬高10~20 cm,使睦洞湖湿地低水位期推迟2个月以上。

遵义市坪桥地下河系统污染源及污染通道研究

岩溶山区地下河系统发育,且水文地质条件复杂,含水层渗透性强、防污性能差,一旦发生污染,污染源精准识别和污染通道的精准查证的难度大,本文以坪桥地下河系统为例,通过环境水文地质调查、水地球化学、物探、钻探、测井、水质分析等技术的优化组合应用,精准识别该地下河系统的主要污染源为工业废渣处置场,并精准查证了工业废渣处置场2#坝东部抽排竖井—CK8—J02监测井—CK6、CK11钻孔一线是该系统的污染通道之一,为该地下河系统的污染修复治理提供了技术依据,构建了岩溶山区地下水污染源精准识别和污染通道精准查证的勘查技术体系,该技术体系可复制、可推广应用于其他同类型岩溶地区。

旅游活动输入岩溶地下河系统的水化学指纹记录

地下河系统是岩溶地质景观的重要组成部分,利用特殊岩溶地形地貌建立的国家重大科技基础设施成为科研和旅游的胜地。为了解旅游活动对岩溶地下河系统水化学的影响,文章分析了大小井地下河系统入口和出口在不同旅游时段的水化学特征。结果表明:受旅游人数影响,污水水化学变化较大;大小井水化学类型为Ca-HCO_(3)型,水岩相互作用产生的Ca^(2+)、Mg^(2+)和HCO_(3)^(-)从入口到出口逐渐增加,而人类活动输入的K^(+)、Na^(+)、Cl^(-)、NO_(3)^(-)和SO_(4)^(2-)则表现出差异性特征。小井地下河系统因受沿途城镇生活排放污水和农业活动影响,水化学波动较大,出口K^(+)、Na^(+)、Cl^(-)和NO_(3)^(-)升高;大井地下河虽受旅游活动输入影响,但K^(+)、Na^(+)、Cl^(-)、NO_(3)^(-)和SO_(4)^(2-)随着地下径流长度增加而降低。HFE-D和Gibbs模型以及离子比例系数分析显示,地下河系统受到了城镇生活排放、旅游和农业等人类活动输入的影响,这一现象应引起足够的重视。

南洞地下河流域水质分析及灌溉适用性评价

为查明云南南洞地下河流域水质特征和农业灌溉适用性,分别在雨季和旱季共采集32组地表河水样和24组地下河水样,进行12种常规指标和9种金属元素检测。利用内梅罗综合指数法进行水质评价,利用钠含量法(SC)、钠吸附比法(SAR)、残余碳酸钠法(RSC)和渗透指数法(PI)揭示雨季和旱季水体的农业灌溉适用性。结果显示,区内水体主要呈弱碱性,Ca^(2+)和HCO_(3)^(-)为主导型离子。地表河水,常规指标仅NH4+含量超过我国相关水质标准限值,金属元素Al、Pb、Mn和As含量超标,旱季超标率总体高于雨季。地下河水的金属元素Al、Pb、Zn、Cr、Mn和As含量超标,雨季超标率总体高于旱季。工矿业活动排放和裸露型岩溶水文地质是导致水体金属元素含量超标的重要原因。据水质评价结果,区内水质整体较好,旱季和雨季水质处于良好及以上级别分别占比89.29%和85.71%。灌溉适用性评价结果显示,区内水体灌溉适用性整体较好,仅在旱季地表河水As含量(54.70μg·L^(-1))高于农田灌溉水质标准中蔬菜和水作标准限值,不适合周边蔬菜和稻田的灌溉。