南方岩溶含水系统结构识别方法初探

岩溶含水系统因其含水介质的高度不均匀性和各向异性而难以刻画。文章选取鄂西岩溶槽谷区典型的岩溶含水系统为研究对象,基于野外地面调查、裂隙测量、洞穴探测、多源高精度地下水示踪试验、地下水动态监测等传统手段,结合新技术、新方法来综合查明岩溶含水系统的结构,探讨岩溶含水系统的边界结构、岩溶发育主控方向、介质空间结构的识别方法,最终刻画出岩溶含水系统结构的概念模型。文章的研究成果旨在为岩溶山区1∶5万水文地质调查工作思路与方法应用提供参考,为提高全国新一轮1∶5万水文地质调查成果的精度与质量做贡献。      

Hydrogeological characterization and environmental effects of the deteriorating urban karst groundwater in a karst trough valley: Nanshan,SW China

The unique hydrogeology of karst makes the associated groundwater respond quickly to rainfall events and vulnerable to anthropogenic pollutions. In this study, high-frequency monitoring of spring discharge, temperature, electrical conductivity (EC) and pH, along with monthly hydrochemical and microbial analyses, was undertaken at the outlet of Laolondong karst underground river in Nanshan, southwestern China. The aim was to explore the environmental effects of the catchment’s urban area on the karst groundwater resources. The monitoring data of a tracer test and the response of discharge to rainfall events demonstrate that conduits and narrow fissures coexist in the Laolongdong karst aquifer. The EC, Na⁺, Cl^? and SO₄^2? values (840 μS/cm, 33.7, 38.6 and 137.2 μg/L, respectively), along with high concentrations of fecal coliform bacteria, at the outlet indicate considerable urban pollution in this area. The contaminants sulfate and nitrate showed different relationships with discharge and EC in different stages of a rainfall event. This behavior provided information about aquifer structure and the influence of transport properties. Meanwhile, the hydrological processes of groundwater flow could be modified by urbanization and result in increasing magnitude of urban floods in the underground river. In addition, sulfuric and nitric acids introduced by urbanization not only impact the karst groundwater quality, but also result in a significant perturbation to the carbon cycling system in the karst area.     

西南岩溶地区不同含水介质地球物理勘查技术

针对西南岩溶地区表层带岩溶水、管道型岩溶水(溶洞、暗河、管道等)、构造裂隙岩溶水等不同类型地下水赋存介质特点,通过适宜的地球物理方法使用条件以及找水特点的分析,提出不同含水介质中寻找地下水地球物理勘查要解决的地质问题、拟采用的综合物探方法,分别总结出了它们的电性参数(或曲线)的响应特征,形成了不同含水介质的地球物理勘查技术组合方案。最后通过实例验证其实用性,并对在西南岩溶地区地下水地球物理勘查工作中积累的技术经验进行了总结。      

Dynamics and anthropogenic impacts of multiple karst flow systems in a mountainous area of South China

The Xiangxi River basin, South China, is a steep terrane with well-developed karst features and an important Cambrian-Ordovician aquifer. Meteoric water in this mountainous area features a mean δ¹⁸O elevation gradient of –2.4?‰/km. This gradient was used to estimate mean recharge elevations of 760 m for Shuimoxi (SMX) spring, 1,060 m for Xiangshuidong (XSD) spring, and 1,430 m for drill hole ZK03, indicating multiple flow paths in the Cambrian-Ordovician karst aquifer. Mean residence times of 230 and 320 days and ～2 years were estimated for these features, respectively, using the damped running average model that predicts the isotopic variations in groundwater from those in precipitation. Groundwater in the regional karst flow system has the longest residence time, the highest recharge elevation, the longest flow paths, the lowest addition of anthropogenic components, and the greatest amount of water–rock interaction as indicated by its higher dissolved solids, Mg²⁺ concentrations and Mg/Ca ratios than the springs. In contrast, the local and shallow karst flow systems respond rapidly to recharge events. Artificial tracer tests prove that these shallow karst systems can also quickly transmit anthropogenic contaminants, indicating that they are highly vulnerable to human impacts, which include the enrichment of NO₃ ^–. The intensity of water–rock interaction and groundwater vulnerability are mainly determined by the structure and dynamics of the multiple karst flow systems.     

粤北岩溶区土壤酸化的空间分异特征研究

为了解粤北岩溶区土壤酸化的空间分异特征,选择华南酸雨区的岩溶槽谷地貌和峰丛洼地地貌土壤为研究对象,对土壤pH数据进行空间插值预测,采用参数最优地理探测器分析岩溶槽谷地貌与峰丛洼地地貌中土壤酸化的空间特征及关键驱动力。结果表明：（1）区内土壤pH范围为4.62~8.19,主要以弱酸性（5.5≤pH <6.5）和酸性（4.5≤pH<5.5）为主。在不同地貌类型中,pH<6.5的土壤样品占比顺序为：岩溶槽谷（61.0%）< 峰丛洼地（69.2%）<非岩溶区（75.0%）;（2）岩溶区小生境复杂多样,在酸雨影响下,成土母质可能是研究区内控制土壤pH的关键因子,而土壤pH空间分异格局可能是多因子共同作用的结果;（3）坡度对土壤pH空间分异的影响仅次于成土母质,表现为土壤pH随坡度的增加而升高,且其与成土母质的交互作用对研究区内土壤pH空间分异的解释力最大。区内土壤酸化防治建议：（1）根据成土母质和坡度因子进行分区分类,并在岩溶槽谷和非岩溶区内设定土壤酸化重点监测区,进行精准防治;（2）除了对酸雨的防控外,还应该重视诸如氮肥使用、工业和矿业活动等外源性因素对土壤的影响。     

典型岩溶槽谷区地下水化学特征及地球化学敏感性分析

利用2012年4月—2013年3月的水化学数据研究了重庆老龙洞地下河流域地下水系统地球化学敏感性。结果表明,研究区表层岩溶泉和地下河水化学阳离子分别以Ca2+、Mg2+和Ca2+、Na+为主,阴离子以HCO3-、SO42-为主;表层岩溶泉雨季Mg2+/ Ca2+摩尔比和地下河雨季Na+/ Ca2+摩尔比旱季大于雨季,表层岩溶泉和地下河雨季 HCO3-/SO42- 摩尔比分别为3.428～6.524、3.122～5.966,旱季HCO3-/SO42-摩尔比分别为5.693～8.664、3.428～6.524,表现出低SO42-、高HCO3-的特征,主要受农业活动影响的表层岩溶泉主量元素地球化学敏感性依次为HCO3-> SO42->Ca2+> NO3-> Mg2+> Na+> K+>Cl-,而受农业活动、工业活动、城镇建设活动等多种因子共同影响下的地下河主量元素地球化学敏感性有所变化,依次为HCO3->Na+> Ca2+> K+> Cl-> Mg2+> NO3-> SO42-,随着人类影响的加剧,离子敏感指数将会有增加的趋势。      

兴文喀斯特与中国南方喀斯特旅游资源对比研究

中国南方喀斯特集中了中国最具代表性的喀斯特地形地貌。位于中国南方喀斯特区域内的兴文县拥有国内罕见的完整喀斯特景观,丰富独特的喀斯特景观被朱学稳研究员誉为“兴文式喀斯特”。本文运用比较法、德尔菲法与层次分析法,对兴文喀斯特与中国南方喀斯特世界自然遗产项目以及天坑、溶洞、石林等典型喀斯特旅游资源进行比较分析,总结其资源优势。研究认为,兴文县完整的喀斯特流域上发育了类型丰富多样、品位高、组合好且分布集中的喀斯特自然资源,形成了独特的喀斯特生态僰苗文化资源,与“世界自然遗产”中国南方喀斯特一、二期7个代表地一样具有代表性,具有列入世界自然遗产名录,进一步补充、完善中国南方喀斯特自然遗产资源的条件。      

Multi-scale characterization of a complex karst and alluvial aquifer system in southern Germany using a combination of different tracer methods

Water suppliers face major challenges such as climate change and population growth. To prepare for the future, detailed knowledge of water resources is needed. In southern Germany, the state water supplier Zweckverband Landeswasserversorgung provides 3 million people with drinking water obtained from a complex karst and alluvial aquifer system and the river Danube. In this study, a combination of different tracing techniques was used with the goal of a multi-scale characterization of the aquifer system and to gain additional knowledge about groundwater flow toward the extraction wells in the Danube Valley. For the small-scale characterization, selected groundwater monitoring wells were examined using single-borehole dilution tests. With these tests, a wide range of flow behavior could be documented, including fast outflow within just a few hours in wells with good connection to the aquifer, but also durations of many weeks in low-permeability formations. Vertical flow, caused by multiple flow horizons or uprising groundwater, was detected in 40% of the tested wells. A regional multi-tracer test with three injections was used to investigate the aquifer on a large scale. For the highly karstified connection between a swallow hole and a spring group, high flow velocities of around 80 m/h could be documented. Exceptionally delayed arrivals, 250 and 307 days after the injection, respectively showing maximum velocities of 0.44 and 0.39 m/h, were observed in an area where low-permeability sediments overlay the karst conduits. With the chosen methods, a distinct heterogeneity caused by the geological setting could be documented on both scales.

     

重庆中梁山岩溶槽谷区表土孢粉与现代植被的关系研究

本文选取重庆中梁山岩溶槽谷区的表土和苔藓样品做孢粉分析,探讨其与现代植被的关系,并初步推断中梁山岩溶洼地的花粉来源,为其洼地剖面花粉来源提供参考。结果表明:表土花粉组合与现代植被类型具有较好的对应关系,耕地、撂荒地、灌木丛、马尾松林以及竹林能够较好地反映母体植被的群落组成;混交林与母体植被群落对应关系较差。由于洼地对区域花粉的汇聚作用,其表土花粉谱更能反映整个区域的植被状况。洼地表层样品中松属花粉来源是中梁山地区与西南风区域的花粉;落叶栎属、桤木属、枫杨属、葎草属等的主要来源是周围山地;禾本科花粉来源相对复杂。本研究可为在这一地区利用孢粉学开展第四纪古植被、古气候和古环境等研究提供参考性依据。      

Geological structure, recharge processes and underground drainage of a glacierised karst aquifer system, Tsanfleuron-Sanetsch, Swiss Alps

The relationships between stratigraphic and tectonic setting, recharge processes and underground drainage of the glacierised karst aquifer system ‘Tsanfleuron-Sanetsch’ in the Swiss Alps have been studied by means of various methods, particularly tracer tests (19 injections). The area belongs to the Helvetic nappes and consists of Jurassic to Palaeogene sedimentary rocks. Strata are folded and form a regional anticlinorium. Cretaceous Urgonian limestone constitutes the main karst aquifer, overlain by a retreating glacier in its upper part. Polished limestone surfaces are exposed between the glacier front and the end moraine of 1855/1860 (Little Ice Age); typical alpine karrenfields can be observed further below. Results show that (1) large parts of the area are drained by the Glarey spring, which is used as a drinking water source, while marginal parts belong to the catchments of other springs; (2) groundwater flow towards the Glarey spring occurs in the main aquifer, parallel to stratification, while flow towards another spring crosses the entire stratigraphic sequence, consisting of about 800 m of marl and limestone, along deep faults that were probably enlarged by mass movements; (3) the variability of glacial meltwater production influences the shape of the tracer breakthrough curves and, consequently, flow and transport in the aquifer.     

南沙海槽岩石圈热-流变结构与动力学演化分析

南沙海槽前陆盆地是我国南海南缘陆架区重要的含油气盆地,海槽之下陆壳减薄的原因、前陆区逆冲推覆构造的变形机制是南海地球动力学研究的重要科学问题。利用地震、重磁、地热观测资料,依据地震沉积地层分析、重磁反演分析、地幔流应力场分析、热-流变学分析方法,文中计算了南沙海区地壳结构特征、南沙海槽逆冲推覆热-流变学结构。结果表明:南沙海区Moho面深度在18~26km,其中海槽区Moho面最浅,由海槽中心向东南至陆坡,Moho面由20km快速下降到26km深度,说明南沙海区陆壳结构曾发生过强烈的构造变动。南沙海区地壳累积流变强度FC与岩石圈累积流变强度FL之比小于80%,显示为一个整体陆壳地块,岛礁区大部分地段地壳热流QC与海底热流Q0之比大于60%,为"热壳冷幔"型热结构,而海槽区情况正相反,QC/Q0小于40%,为"冷壳热幔"型热结构。南沙海槽Moho面温度在300~700℃,地壳整体温度较低,地温梯度在垂向上高、低相间成层分布,地壳浅层地温梯度在15~30℃/km,深层地温梯度大于45℃/km。南沙海槽南北两侧应力分布特征不同,北侧挤压,南侧伸展。北侧挤压区,地层挤压收缩量由深向浅减小,南侧伸展区,地层伸展量由深向浅增大,类似手风琴风箱结构。北侧黏滞系数高、流变强度大,南侧黏滞系数低、流变强度小。南侧的黏滞系数、流变强度大约比北侧低2~3个数量级,因此南沙海槽南侧比北侧更容易发生构造变形。由计算结果推测,南沙Moho面起伏或陆壳减薄与"地壳重力均衡作用"和"地幔热隆升作用"有关,海槽东南缘逆冲推覆体构造变形机制主要是"地壳缩短"作用,其次是"重力滑脱"作用。文中没有涉及南沙陆块不同地质时期Moho面、"地壳均衡"、"地幔热隆升"之间的演化关系,也没有涉及南沙海槽基底变形中"弹性挠曲"和"逆冲推覆"之间的关系。     

Groundwater vulnerability assessment for the karst aquifer of Tanour and Rasoun springs catchment area (NW-Jordan) using COP and EPIK intrinsic methods

Groundwater vulnerability maps were constructed for the surface water catchment area of Tanour and Rasoun spring (north-west of Jordan) using the COP and EPIK intrinsic groundwater vulnerability assessment methods. Tanour and Rasoun springs are the main water resources for domestic purposes within the study area. A detailed geological survey was carried out, and data of lithology, karst features, precipitation, vegetation and soil cover, etc. were gathered from various sources for the catchment area in order to determine the required parameters for each method. ArcGIS software was used for map preparation. In the resulting COP vulnerability map, spatial distribution of groundwater vulnerability is as follows: (1) high (37%), (2) moderate (34.8%), (3) low (20.1%), and (4) very low (8.1%). In the EPIK vulnerability map, only two out of four vulnerability classes characterize the catchment area: very high vulnerable areas (38.4%) and moderately vulnerable areas (61.6%). Due to limited soil thickness, the low vulnerability class is absent within the catchment. The high percentage of very high to moderately vulnerable areas displayed by both the COP and EPIK vulnerability assessment methods are reflected by different pollution events in Tanour and Rasoun karst springs especially during the winter season. The high sensitivity of the aquifer to pollution can be explained by different factors such as: thin or absent soil cover, the high development of the epikarst and karst network, and the lithology and confining conditions of the aquifer.     

新太古界Campbellrand亚群白云岩岩溶系统对南非Postmasburg锰矿田的影响

为分析新太古界Campbellrand亚群白云岩基底形成的岩溶系统对南非Postmasburg锰矿田发育和分布的影响,利用XRF和偏光显微镜鉴定技术,结合野外地质调查和岩芯钻探,对矿石的矿物成分、矿体中的Mn、Fe空间分布、Doornfontein砾岩的结构特征、白云岩容矿构造的形态进行了研究。结果表明：Maremane穹隆上的Campbellrand亚群白云岩遭受了两次大规模的溶蚀。溶蚀构造引起沉积物分异,沉积建造底部Mn质最为富集,向外、向上逐渐由Fe质主导,形成褐锰矿—方铁锰矿—赤铁矿的序列,顶部则演变为铝土质岩。沉积序列中Mn+Fe质和Al质含量呈现出较强的负相关性。溶坑的特殊形态导致矿体受层控,但并不呈现规则的层状形态。东矿带的Wolhaarkop硅质角砾岩与白云岩中的燧石和硅质白云岩密切相关,而混合带和西矿带普遍发育的Doornfontein砾岩则是岩溶作用影响下锰质的成岩作用被推迟所形成,它们都是成矿期岩溶系统发育的间接产物。溶坑底部的锰土混合物揭示了成矿后期溶蚀作用的发生和沉积序列的坍塌破碎,小型的断层也造成了矿体的严重破碎和顶板地层的褶曲。Gamagara低山脊两侧分布的小型堆积型矿体也与后期地表岩溶系统长期的发育有关。     

Dynamics and interaction of organic carbon, turbidity and bacteria in a karst aquifer system

The dynamics of organic carbon (OC), turbidity, faecal indicator bacteria and physicochemical parameters was studied in a karst system near Yverdon, Switzerland. Online measurements and sampling were done at a swallow hole draining an agricultural surface (the input), and two groups of springs (the outputs) that often show bacterial contamination. A fluorescent tracer that was injected into the swallow hole during low-flow conditions first arrived at the springs 10–12 days after injection; the total recovery rate was 29%. Previous tracer tests during high-flow conditions gave shorter travel times. After a major rainfall event, a primary turbidity peak was observed at the springs. It coincides with the rising limb of the hydrograph, indicating remobilisation of autochthonous particles from the aquifer. A secondary turbidity peak occurs several days later, suggesting the arrival of allochthonous particles from the swallow hole. Wider peaks of OC and bacteria were observed simultaneously. Applying methods from molecular microbiology (PCR-DGGE) allowed characterisation of the bacterial communities at the swallow hole and the springs. The results demonstrate that the swallow hole is an important source of groundwater contamination, while its contribution to aquifer recharge is insignificant. OC appears to be a better indicator for bacterial contamination than turbidity.     

Recharge rate estimation in the Mountain karst aquifer system of Figeh spring, Syria

Figeh watershed spring is one of the important groundwater aquifer, which is considered a major source for drinking waters of Damascus city and countryside. The origin identification and recharge estimates of groundwater are significant components of sustainable groundwater development in this Mountain karst aquifer of Figeh spring. During the period 2001–2009, monthly groundwater and precipitation samples were taken and the isotopic compositions of δ¹⁸O, δ²H, and chloride contents were analyzed to identify groundwater origins and to estimate recharge rates. The δ¹⁸O, δ²H of the groundwater show that the groundwater recharge is of meteoric origin. The chloride mass balance (CMB) method was used to quantify recharge rates of groundwater in the Mountain karst aquifer of Figeh spring. The recharge rate varies from 192 to 826 mm/year, which corresponds to 43 and 67% of the total annual rainfall. Recharge rates estimated by CMB were compared with values obtained from other methods and were found to be in good agreement. This study can be used to develop effective programs for groundwater management and development.     

重庆市喀斯特槽谷地区农村居民点分布与地貌形态要素关系研究

选取喀斯特槽谷地区——重庆市石柱土家族自治县鱼池镇团结村农村居民点为研究对象,借助ArcGIS空间分析和地统计法,综合应用地貌-面积频度分布指数和信息熵分析了不同海拔、坡度、坡向、地形起伏度、地表粗糙度、剖面曲率和平面曲率7个地貌形态要素间农村居民点的分布特征。结果表明:①农村居民点分布的优势地形位分别为高程956.2~1000m,坡度5°~15°,坡向SW、W、NW和E,地形起伏度0~1m,地表粗糙度1.0~1.1,剖面曲率和平面曲率0°~5°的低地形位上;②在槽谷谷底,农村居民点信息熵的最大值为1.15,最小值为0.02,说明农村居民点在低地形位上分布的有序性较高。      

西南某岩溶区地下水系统示踪试验与解析

以西南某典型岩溶区为例,解析示踪试验在岩溶管道连通性以及获取水文地质参数中的应用。选择落水洞为投放点,分别从落水洞西侧和东侧寻找地下水出露点作为接收点,判别落水洞地下径流的实际去向以及落水洞与接收点之间的水力联系。结合Qtracer2软件对示踪试验成果进行定量解析,确定示踪剂回收率、地下水平均流速、最快流速,估算出岩溶管道结构特征和水文地质参数。结果表明：落水洞与接收点JS01、JS03之间不存在直接水力联系;落水洞与接收点JS02存在水力联系且岩溶管道极为发育,含水介质不均匀,地下水运移路径较为通畅,为典型的紊流流态;落水洞地下径流的主要方向是由西向东,但在丰水期雨量较大期间,接收点JS04能够接收到荧光素钠,说明丰水期水位上涨后两者间会有水力联系,导致部分水量向落水洞西侧排泄。     

Sustainable yield of a karst aquifer system: a case study of Jinan springs in northern China

Based on the long-term monitoring data of rainfall, groundwater levels, groundwater abstraction, spring flow rates and groundwater quality, an assessment has been undertaken of the sustainable yield of a karst aquifer system in Shandong Province, northern China, to maintain perennial outflow of the karst springs while meeting water demands. One of the fundamental indicators for sustainable yield of groundwater is identified as maximum allowable water-level drawdown. A regional three-dimensional finite-difference numerical model has been developed to optimize the schemes associated with well fields and their locations and sustainable yields, in the Jinan spring catchment and its adjacent karst groundwater catchments, with the aim of maintaining the water level higher than the allowable lowest water level of 27.5?m above sea level. Furthermore, measures necessary to move towards sustainable use of the karst groundwater are outlined, drawing on contingency plans of water-source replacement and artificial recharge, dual water supply (based in water quality), use of the spring waters themselves, and groundwater quality protection.     

The types,structure and results of the dike-pond system in South China

Conclusion The dike-pond system is an excellent artificial ecological agriculture system. With its special structure, it has many advantages compared with the other agricultural productions. In the system, the fertilizer, water and soil can be readjusted automatically, and flood and drought calamities can be prevented, so that the inferior land can be made fertile. The residues from planting and from stock/poultry raising can be recycled within the system. It is the most important that the fertilizer and feeds can be satisfied from within the system. This in itself could be a kind of break-through in agricultural development. A new form of fish feed supply is created saving input of purchased fertilizer and feeds as well as enhancing the development of planting, fishery and animal husbandry.The system has been attracting more and more attention from home and abroad. It has spread quickly to some other parts of China, and has begun to be appear abroad. The system is suitable for the areas with resembling the Pearl River delta elsewhere in Asia, Africa and South America, especially for lowlying water-logged land which is normally reclaimed by constructing water conservancy projects. In the latter case, the cost of pumping water is high, but the system is generally unstable compared with the stable, high yield dike-pond system. So a brilliant future can be envisaged for the dike-pond system.     

北京昌平高崖口-南口隐伏岩溶水系统地质构造新认识

高崖口-南口岩溶水系统是北京七大岩溶水系统之一,其东北部位于昌平南口,是隐伏岩溶地下水排泄区。查明该区地质构造发育情况,可以为评价岩溶水资源及北京优选战略后备水源地提供依据。本文在分析前人区域性重磁资料基础上,完成了5条总长30 km、总测点数626个的可控源音频大地电磁测深(CSAMT)剖面,采用SCS2D程序对CSAMT数据进行了二维反演解释,并实施了4眼勘探孔。物探和钻探研究结果表明:南口-孙河断裂是该系统的北东边界,走向北西,倾向南西,在雪山村附近断层落差达1017.5 m,是目前发现的断距最大的地区;断裂上盘蓟县系碳酸盐岩与侏罗系火山岩的地层界线,向西移动了2.4 km;南口山前断裂是山区裸露岩溶与平原隐伏岩溶的分界断裂,断裂走向北东,倾向南东,断距大于700 m,断裂上盘曹庄至南口一带有燕山期二长岩侵入,流村-葛村一带有燕山期闪长岩侵入。广泛发育的断层、岩体和火山岩,使这一区域岩溶含水层空间受到较大制约。