Determining the groundwater potential recharge zone and karst springs catchment area: Saldoran region,western Iran

Assessing the groundwater recharge potential zone and differentiation of the spring catchment area are extremely important to effective management of groundwater systems and protection of water quality. The study area is located in the Saldoran karstic region, western Iran. It is characterized by a high rate of precipitation and recharge via highly permeable fractured karstic formations. Pire-Ghar, Sarabe-Babaheydar and Baghe-rostam are three major karstic springs which drain the Saldoran anticline. The mean discharge rate and electrical conductivity values for these springs were 3, 1.9 and 0.98 m³/s, and 475, 438 and 347 μS/cm, respectively. Geology, hydrogeology and geographical information system (GIS) methods were used to define the catchment areas of the major karstic springs and to map recharge zones in the Saldoran anticline. Seven major influencing factors on groundwater recharge rates (lithology, slope value and aspect, drainage, precipitation, fracture density and karstic domains) were integrated using GIS. Geology maps and field verification were used to determine the weights of factors. The final map was produced to reveal major zones of recharge potential. More than 80 % of the study area is terrain that has a recharge rate of 55–70 % (average 63 %). Evaluating the water budget of Saldoran Mountain showed that the total volume of karst water emerging from the Saldoran karst springs is equal to the total annual recharge on the anticline. Therefore, based on the geological and hydrogeological investigations, the catchment area of the mentioned karst springs includes the whole Saldoran anticline.     

Karstological study of the new Kunming airport building area (Yunnan, China)

In Kunming area (6.8 mio population), two big interventions are in progress: construction of a new airport, the 23 km² area of which will extend across karst terrain northeast of the city, and extensive uptake of water from karst aquifers for drinking and agricultural use. In the study, an interdisciplinary approach was utilized to demonstrate the need for holistic karstology studies prior to performing extensive interferences in the karst environment. This study included survey of surface karst features and microscopic analyses of rock samples in the area of the new airport location, accompanied by hydrogeological studies and microbiological analyses of two karst drinking water sources in its vicinity (Qinglongdong, Huanglongdong). Results showed the specific characteristics of the subsoil stone forest that indicated a high level of karstification. The direction and characteristics of groundwater flow from the sinking Qiaotou Stream at the margin of the new airport area toward the Huanglongdong Spring were defined with a single tracer test. Additional information about hydrogeological characteristics of the karst aquifer was obtained by individual measurements of physical and chemical parameters of the springs and sinking stream. Selected chemical and bacteriological parameters showed substantial pollution of both springs due to various types of human activities in the catchments. The results of the study pointed to the necessity of taking immediate measures for the springs’ protection and showed the importance of interdisciplinary research when planning anthropogenic activities in the karst.     

川藏铁路格聂山和察雅段构造岩溶发育规律及岩溶地下水循环模式研究

Construction of the Sichuan-Tibet Railway may face significant geological safety risks of water inrush and mud inrush in the plateau tectonic karst region. It is of great scientific and practical significance to carry out research on the evolution regularity of the plateau tectonic karst and the relevant karst groundwater circulation mode for the early prediction and identification of the water inrush and mud inrush disaster in the railway tunnel to be built. Based on the field survey and published literatures, this paper makes an in-depth analysis and draws some conclusions. The tectonic karst development shows obvious sequence characteristics and elevation zonation. The first level to fourth level karst development areas were formed before Miocene, late Miocene to Pliocene, Pliocene and Pliocene to Pleistocene, and occur in the elevation range of 4900?5300 m, 4000?4300 m, 3700?3800 m and 2900?3200 m, respectively. Active faults obviously control the distribution and enrichment of karst groundwater. Since the late Pleistocene, active faults have connected different karst areas and formed unique storage conditions for the tectonic karst groundwater in the plateau region. Karst groundwater system can be divided into high recharge area, remote pipeline flow area and concentrated discharge area. The high recharge area occurs in the first-level karst evaluation area, and the third-level and fourth-level are the concentrated discharge area which generally contain the outcropping springs with a discharge of more than 100 L/s. The groundwater system is appropriately divided into shallow and deep groundwater flow system. Karst springs are mainly supplied by ice and snow melting water, and exhibits the dynamic characteristics of the high water pressure, long flow path and deep water groundwater circulation. High CO₂ saturation concentration of the melting water and the salt effect of sulfate promote the formation of high TDS sulfuric acid karst groundwater of low temperature.     

基于地下水开发的岩溶地下水系统类型划分方案探讨

岩溶山区多年的地下水开发利用实践证明,传统的岩溶地下水系统划分不利于指导岩溶山区勘查找水和地下水资源的开发。为了更好地指导岩溶山区地下水资源的勘查和开发,文章从有利指导岩溶山区地下水勘查和开发利用的角度,在继承传统划分方法的基础上,提出了一种新的以地下水的赋存条件、富集条件,以及开发条件三个层次组合的地下水系统综合划分方法:根据岩溶地下水系统与供水目标在空间上的关系划分为“高位”和“低位”两种类型,根据控制地下水富集的水文地质结构划分为“开放”和“封闭”两个亚类,根据地下水的水动力和排泄特点划分为集中（地下河、岩溶泉）和分散排泄三类系统,并给出了“高位”型地下水系统开发成本低、“封闭型”地下水系统资源丰富,“封闭型地下水系统”是缺水区勘查找水的主要目标,合理的岩溶水系统的开发利用应按照“高位封闭型”、“高位开放型”、“低位封闭型”的顺序进行规划部署,“低位开放型”地下水系统则因富水性差、开发利用成本高可作为储备水源地的建议。      

A multi-method approach for groundwater resource assessment in coastal carbonate (karst) aquifers: the case study of Sierra Almijara (southern Spain)

Understanding the transference of water resources within hydrogeological systems, particularly in coastal aquifers, in which groundwater discharge may occur through multiple pathways (through springs, into rivers and streams, towards the sea, etc.), is crucial for sustainable groundwater use. This research aims to demonstrate the usefulness of the application of conventional recharge assessment methods coupled to isotopic techniques for accurately quantifying the hydrogeological balance and submarine groundwater discharge (SGD) from coastal carbonate aquifers. Sierra Almijara (Southern Spain), a carbonate aquifer formed of Triassic marbles, is considered as representative of Mediterranean coastal karst formations. The use of a multi-method approach has permitted the computation of a wide range of groundwater infiltration rates (17–60%) by means of direct application of hydrometeorological methods (Thornthwaite and Kessler) and spatially distributed information (modified APLIS method). A spatially weighted recharge rate of 42% results from the most coherent information on physiographic and hydrogeological characteristics of the studied system. Natural aquifer discharge and groundwater abstraction have been volumetrically quantified, based on flow and water-level data, while the relevance of SGD was estimated from the spatial analysis of salinity, ²²²Rn and the short-lived radium isotope ²²⁴Ra in coastal seawater. The total mean aquifer discharge (44.9–45.9 hm³ year^?1) is in agreement with the average recharged groundwater (44.7 hm³ year^?1), given that the system is volumetrically equilibrated during the study period. Besides the groundwater resources assessment, the methodological aspects of this research may be interesting for groundwater management and protection strategies in coastal areas, particularly karst environments.     

Hydrogeological characteristics of some deep siphonal springs in Serbia and Montenegro karst

In terms of hydrogeological, engineering-geological, and hydrotechnical tapping in karst in relation to ground waters, karst channels, springs and ponors, speleodiving is the only research method which enables direct observation, studying and exact geological mapping of karst channels and caverns. Data collected during speleodiving research contribute considerably to the analysis of karst evolution process in the given region, which is very important in evaluating the depth of karstification and determining the main direction of the groundwater flow. In the past 30 years in Serbia and Montenegro, speleodivers have investigated over 40 siphonal springs, active cave channels and ponors, of which more than 20 are proof of deep siphonal circulation in karstic aquifers. The karstic springs are the most interesting phenomenon from a hydrogeological view point, and their investigations need particular attention. Most of significant karstic springs are on the rims of erosion basins—perimeters of karst poljes, river valleys, sea coasts and contact areas between karst aquifers and hydrogeological barriers. General characteristics of the spring regime are the direct correlation between precipitation and spring discharge. Moreover, the hydrogeological regime of these springs also depends on the size of the catchment area, karstic aquifer retardation capacity, total porosity, as well as lithological and structural characteristics.     

喀斯特断陷盆地水资源高效开发利用模式构建

在调查研究典型喀斯特断陷盆地水文地质特征、地表水文过程、“五水”转换及水资源均衡,研发地下水高效开发利用、地表水调蓄、水污染风险评估与水质修复、农田节水灌溉及土壤保墒、水资源优化调控等系列技术的基础上,以可持续发展和系统科学理论为指导,构建了喀斯特断陷盆地水资源高效开发利用模式,包括理论与技术支撑体系和开发利用工程体系两个层次。前者的基本构成及内涵为:水资源高效开发利用工作流程、理论依据及技术支撑,是模式的理论与技术内涵;后者为沿着盆地地表、地下水的形成、运动和转换过程,从上游山区到下游河谷区,逐级分区部署的水资源开发利用工程体系,工程布局做到因地制宜、科学合理,大、中、小、微型并举,集中供水与分散供水兼顾,同时系统推进水质修复、水循环利用、节约用水等措施,实现水资源的高效和可持续开发利用。      

南方岩溶区地下水资源特征与水资源保障对策

【研究目的】中国南方岩溶地区干旱缺水等问题异常突出,岩溶地下水赋存和分布的复杂,开发利用率低,基于多年调查研究工作为基础,系统总结南方岩溶区地下水资源特征,研讨水资源保障对策。【研究方法】基于南方岩溶区地下水资源特点、地下水系统类型、地下水系统空间结构的叠置性和时空分布不均性分析,提出南方岩溶区水资源保障对策。【研究结果】南方岩溶区可从以下三方面充分发挥地下水资源安全保障作用,一是掌握地下水赋存分布规律,发挥分散供水和应急供水作用;二是加强调蓄工程建设,解决水资源时空分布不均问题;三是建立与生态重建和经济发展相结合的地下水资源可持续利用模式。【结论】南方岩溶区地下水赋存条件复杂,具有表层带岩溶水系统、岩溶地下河与管道流系统、岩溶大泉系统以及分散排泄地下水系统多种类型,规模大小不一,开发利用形式多样;在垂向上具有叠置性,水空分布严重不均;开发利用潜力较大。在地球科学系统论的指导下,查明岩溶水资源赋存分布规律,科学评价地下水资源量,因地制宜制定水资源开发利用和保护方案,为脱贫攻坚、生态文明建设和乡村振兴提供技术支撑。创新点：以系统水文地质环境地质综合调查和地下水开发利用示范工作为基础,系统总结南方岩溶区地下水资源特点;针对岩溶区水资源安全保障问题,分析其主要原因,提出了水资源保障对策。     

典型背斜槽谷区岩溶水资源空间分布格局与水质特征——以宜居河流域为例

文章选取典型背斜槽谷区——宜居河流域作为研究对象,结合不同水文地质单元对流域岩溶泉进行出露特征及水质分析,研究结果表明:(1) 二叠系、三叠系含水层的调查泉点水化学类型全部属于HCO3-Ca型水,而寒武系、奥陶系含水层部分泉点属于HCO3·SO4-Ca型水,这可能与该地区的岩性及人类活动有关;流域内93.8%的岩溶泉点水质等级为优良和良好,可作为饮用水源;(2)流域内岩溶泉流量<10 L·s-1的岩溶泉数量占78%,平均流量仅为0.84 L·s-1;流量≥10 L·s-1的岩溶大泉平均流量达76.56 L·s-1;此外,发现不同岩性地层在岩溶泉发育的数量和流量上皆有差异,表现出岩溶泉发育的极不均一性;(3) 在可溶岩与非可溶岩接触带、断裂构造带、陡崖处、地势较低的弱承压泄流区、深切河谷及峡谷两侧切割处5类地点易出露岩溶泉。      

岩溶高原山区表层岩溶泉绿能与高效开发利用模式

为解决岩溶高原山区缺水的问题,合理开发利用表层岩溶水,开展了水文地质详细调查。查明区内表层岩溶泉出露13个,流量0~67.53 L·s?1,动态变化与降水关系密切。文章总结了表层岩溶水“泉－池（窖）－库”优化调控、绿能高效开发利用模式:①在有砂泥岩夹层分布的凹部山岩溶洼地,采用防渗帷幕灌浆,建设悬挂式凹部山水库,积蓄地表水、表层岩溶水形成自流供水;②在湾半孔表层泉处建设蓄水池直接引流利用;③在湾半孔表层泉附近建设水泵站、光伏电站,平水期时通过光伏电站发电,由泵站自动控制抽取表层岩溶水补给凹部山水库,形成地表、地下水优化调控,联合调度调蓄利用25.3万m3·a?1,解决了区内13 000余人的生活生产用水困难问题。      

滇东南南洞地下河系统源区洞穴特征及其成因演化机制

滇东南岩溶地貌发育,岩溶洞穴是该区典型空洞体系。文章以滇东南南洞地下河系统源区典型岩溶洞穴为研究对象,基于地学理论和地球化学分析,对该区地貌特征、成因及演化机制开展科学研究。研究表明,NW向的张性断裂、区内可溶部分最高个旧组碳酸盐岩以及杨柳河向西流动的水动力作用是南洞地下河系统源区洞穴发育的主要成因;全新世中期6 kaBP以来,该地区洞穴演化过程经历了三个阶段,其中,主体形成时间为6~4 kaBP;此外,建立石洞洞穴与地下河发育模式。本次研究对南洞地区地下水资源评价具有实际意义。      

Stable isotope (2H, 18O and 87Sr/86Sr) and hydrochemistry monitoring for groundwater hydrodynamics analysis in a karst aquifer (Gran Sasso,Central Italy)

This paper deals with chemical and isotope analyses of 21 springs, which were monitored 3 times in the course of 2001; the monitoring program was focused on the groundwater of the Gran Sasso carbonate karst aquifer (Central Italy), typical of the mountainous Mediterranean area.Based on the hydrogeological setting of the study area, 6 groups of springs with different groundwater circulation patterns were distinguished. The hydrogeochemistry of their main components provided additional information about groundwater flowpaths, confirming the proposed classification. The spatial distribution of their ion concentrations validated the assumptions underlying the hydrogeological conceptual model, showing diverging groundwater flowpaths from the core to the boundaries of the aquifer. Geochemical modelling and saturation index computation elucidated water–carbonate rock interaction, contribution by alluvial aquifers at the karst aquifer boundaries, as well as impacts of human activities.The analysis of ¹⁸O/¹⁶O and ²H/H values and their spatial distribution in the aquifer substantiated the hydrogeology-based classification of 6 groups of springs, making it possible to trace back groundwater recharge areas based on mean isotope elevations; the latter were calculated by using two rain monitoring stations. ⁸⁷Sr/⁸⁶Sr analyses showed seasonal changes in many springs: in winter–spring, the changes are due to inflow of new recharge water, infiltrating into younger rocks and thus increasing ⁸⁷Sr/⁸⁶Sr values; in summer–autumn, when there is no recharge and spring discharge declines, changes are due to base flow groundwater circulating in more ancient rocks, with a subsequent drop in ⁸⁷Sr/⁸⁶Sr values.The results of this study stress the contribution that spatio-temporal isotope monitoring can give to the definition of groundwater flowpaths and hydrodynamics in fissured and karst aquifers, taking into account their hydrogeological and hydrogeochemical setting.     

Hydrogeological controls of variable microbial water quality in a complex subtropical karst system in Northern Vietnam

Karst aquifers are particularly vulnerable to bacterial contamination. Especially in developing countries, poor microbial water quality poses a threat to human health. In order to develop effective groundwater protection strategies, a profound understanding of the hydrogeological setting is crucial. The goal of this study was to elucidate the relationships between high spatio-temporal variability in microbial contamination and the hydrogeological conditions. Based on extensive field studies, including mapping, tracer tests and hydrochemical analyses, a conceptual hydrogeological model was developed for a remote and geologically complex karst area in Northern Vietnam called Dong Van. Four different physicochemical water types were identified; the most important ones correspond to the karstified Bac Son and the fractured Na Quan aquifer. Alongside comprehensive investigation of the local hydrogeology, water quality was evaluated by analysis for three types of fecal indicator bacteria (FIB): Escherichia coli, enterococci and thermotolerant coliforms. The major findings are: (1) Springs from the Bac Son formation displayed the highest microbial contamination, while (2) springs that are involved in a polje series with connections to sinking streams were distinctly more contaminated than springs with a catchment area characterized by a more diffuse infiltration. (3) FIB concentrations are dependent on the season, with higher values under wet season conditions. Furthermore, (4) the type of spring capture also affects the water quality. Nevertheless, all studied springs were faecally impacted, along with several shallow wells within the confined karst aquifer. Based on these findings, effective protection strategies can be developed to improve groundwater quality.     

泸西喀斯特断陷盆地地表水与地下水流域边界与水动力性质

在详细调查基础上,采用系统科学及水文地质分析方法,依据地形地貌、地层岩性、地质构造、示踪试验、地下水排泄基准面、喀斯特发育条件及发育规律等剖析论证流域边界,并通过钻探及示踪试验进行验证。研究结果:（1）对泸西喀斯特断陷盆地南东部的水系统边界向北移进行了修正,证实了三塘一带深部不发育的喀斯特是地下水分水岭边界,使得泸西喀斯特断陷盆地流域的径流系统和边界圈化更加准确;（2）泸西喀斯特断陷盆地流域地表水、地下水转化频繁,地表水径流特征主要以小江河在水库、河流、伏流间的径流转化过程为体现,地下水在侵溶山区接受大气降水补给后,上层径流以泉、暗河的形式在泸西盆地底面排泄后转化成地表水,最终汇集于盆地南部、通过工农隧洞及落水洞排向小江,而下层径流则以小江水面为基准,通过深层径流排泄。      

滇东南高原斜坡区某拟建铁路岩溶水文地质问题及对策建议

研究区位于云贵高原南缘滇东南高原斜坡区,属珠江源头河段南盘江流域与红河流域的地表分水岭地带,侵蚀切割强烈,地形条件复杂,广泛出露的三叠系中统个旧组含水层组富水性强,岩溶强烈发育,地下河管道、洼地、落水洞等广布。通过野外调查、观测、示踪试验、实验测试等手段,利用水文地质学、岩溶学等理论方法,分析研究区岩溶含水层富水性、岩溶发育强度、大泉地下河及管道分布、地热分布情况,及其对拟建铁路选线的影响,计算隧道涌水量,提出隧道施工尽量避开地下水富集区、岩溶强发育区、大泉地下河主管道径流区、地热异常区、岩溶砂岩地层区等建议措施,减少拟建铁路施工可能面临的岩溶水文地质危害及其对地下水环境造成的破坏,为强岩溶发育区的工程建设提供参考建议。      

北京西山泉域岩溶水系统特征探讨

北京西山地区岩溶地下水主要以相对独立的岩溶地下水系统进行循环,其水文地质条件、系统结构模式及其水资源的重要性等,在北方具有代表性。文章主要以北京西山鱼谷洞泉域岩溶水系统、黑龙关泉域岩溶水系统、玉泉山泉域岩溶水系统为研究对象,从岩溶含水层结构、地下水循环、地质构造等方面,总结出北京西山泉域岩溶水系统特征主要为:双层含水层结构、多个子系统构成且多点排泄、系统内岩溶水转化关系复杂多样、岩溶水富集带及系统边界集中在逆冲断层处。      

西南岩溶地下河流量重复统计问题及对策探讨

西南岩溶区的地下河数量及总流量是有关职能部门和专业技术人员关心的两个重要数据。20世纪80年代对西南6省进行统计,结果为2 836条,流量1 482 m3/s;20世纪90年代对西南8省进行统计,并经过近年的数据库校核为2 523条,总流量1 321.7 m3/s;其中流量大于2 000 L/s有120条,合计流量699.7 m3/s,占总流量的52.94%;流量在50~500 L/s地下河最多,有1 311条,占总数的51.55%,其次为流量小于50 L/s的有723条,占总数的28.43%。文章针对上述统计方法存在岩溶地下河流量重复统计、与岩溶大泉流量交叉重复统计两种问题,以大小井和寨底地下河系统为例,给出了具体重复统计量。基于1∶20万水文地质普查资料,大小井和寨底地下河重复统计量分别占总出口流量的57.1%、7.1%;而基于最新调查资料,重复统计量则分别可增加到134.3%, 86.1%。因此,随着1∶5万水文地质调查面积越多,所发现的地下河出口越多,按传统的统计方法其重复统计量则越大。引起上述重复统计问题主要原因是把地下河系统和子系统混合在一起。文章最后讨论了地下河系统的空间属性,提出避免重复统计措施,对西南岩溶区地下河流量正确统计以及具有相同特征的岩溶大泉流量统计有一定指导意义。      

西南岩溶石山区断陷盆地岩溶水系统分类及供水意义

笔者根据岩溶区水文地质条件及特征的差异，以地下水循环的特征为纲，应用系统分析方法，将岩溶水系统分为三级，对各级系统进行了分类。第一级为岩溶水系统，第二级分为浅循环和深循环岩溶水系统、第三级分别进一步分为裸露型、裸露-覆盖型、裸露-埋藏型、滞水型及层控型和断裂带型6类基本的岩溶水文地质单元。并论述了各类型的水文地质特征，指出了各类系统的供水意义，对断陷盆地岩溶水资源的勘查和开发有较大的参考价值。     

滇东南岩溶区找水打井经验——以云南省广南县珠琳地区为例

以1996-2012年期间抗旱打井实例,总结了找水技术方法、勘查工作流程,提出了滇东南高原斜坡地带岩溶区找水要点:分水岭弱径流带,主要目标是在古溶蚀台面上接近区域分水岭的地段、规模较大的溶蚀洼地中的扬起端寻找浅层岩溶水;缓坡区较强径流带,主要目标是寻找面积较大、产状较平缓的悬托弱透水层之上的滞水型岩溶水;斜坡区强径流带,主要应寻找暗河天窗、竖井中的岩溶水。确定井位应遵循区域调查分析+井位附近详细调查分析的工作程序,必要时配合开展物探准确定位;不宜在排泄区、强径流区、峰丛洼地区、大泉、地下河附近、负地形最低部位布井,物探成果应用须与水文地质调查成果紧密结合。