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1.
裂隙-管道介质泉流域水文地质模拟试验   总被引：2，自引：0，他引：2  
为了深入认识岩溶泉流域的流量过程影响因素和作用机制,以西南岩溶泉流域水文地质概念模型为原型,建立了实验室尺度下的裂隙-管道介质物理模型和数值模型。选取补给雨强、泉口直径、落水洞与开采井的位置作为影响因子,模拟了泉流量过程。试验结果表明:单次降水试验可以观测得到泉流量增加、平稳波动和衰减共三个阶段;同一泉口直径条件下,补给强度对泉流量衰减系数的影响极小,直径为3,4,5,7 mm的泉口直径对应的衰减系数分别为0.003 6,0.006 7,0.011 5,0.012 9,泉口直径与衰减系数呈近似对数关系;落水洞汇流水量占泉流量的比例远大于裂隙;2~3 mm是微小裂隙与较大裂隙的过渡区域,两种类型的介质泉流量过程差异明显;开采井分别位于泉口附近、模型中间位置和落水洞时,泉流量衰减系数依次减小。  相似文献   

2.
应用三种化学示踪剂,对桂林岩溶水文地质试验场“31号泉系统”的补给边界进行了研究。试验在雨期进行,示踪剂分别是降雨后投入落水洞随表层岩溶水带入地下;或在降雨前投入无水的落水洞中,待降雨后由地表产流带入地下。 试验表明,氯化锌、钼酸铵是较理想的示踪剂,地下水速度为4～250米/小时,速度差可能是由于包气带岩溶含水介质渗透性和水力坡度不同所致;泉口历时浓度曲线常呈多峰型,多是由于降雨脉冲影响所致;峰丛区高程不等的洼地多通道补给山边泉,峰丛区含水介质结构具有叠置性,即水平方向多通道,垂直方向多层次,故水均衡计算不可忽视;“31号泉系统”的补给边界,通过圈定有水力连系之洼地的地表分水岭来确定。   相似文献   

3.
磷石膏堆场特别是岩溶区堆场渗漏对地下水和地表水水质影响较大。根据现场连通试验、物探及钻探揭示资料分析,研究区主要有三种渗漏类型:裂隙型（双眼井泉）、裂隙-管道型（发财洞岩溶管道）和管道型（鸭草坝岩溶管道水系统）。天然不防渗条件下,库水通过地表落水洞、溶缝和溶隙等入渗地下水,产生岩溶渗漏。入渗补给独田地区的S1号泉、杨花冲地区的S23号泉、下摆郎地区的S13、S14号泉。其它泉水受隔水层的阻隔及地下水的补、排条件所限,没有受到污染。独田堆场运行后堆场存在渗漏情况,但是,防渗系统运行后渗漏的污染情况较之前有较为明显的下降。  相似文献   

4.
贾鹏宙 《中国煤田地质》2002,14(4):31-32,35
汾西矿区奥灰岩溶水属郭庄泉域岩溶水系统，它和整个系统既有密切的水力联系，又有其独特的赋存特征。根据多年勘探资料和郭庄泉的研究成果，探讨了矿区内奥灰岩溶水的赋存特征，并结合构造分布和水文地质规律，分析了岩溶水的富集和运移特性，初步总结了奥灰水在本矿区的分布规律。  相似文献   

5.
岩溶管道结构影响泉流量变化的数值模拟研究   总被引：2，自引：0，他引：2  
采用MODFLOW-CFP建立管道流数值模型,模拟岩溶含水系统在暴雨期的响应过程,以泉口流量峰值作为因变量,分别对控制管道结构的4个参数以及落水洞集中补给比例进行调整,研究管道结构如何控制泉流量变化过程。结果表明:管道直径、管壁渗透系数和落水洞补给比例对泉口流量峰值均表现为正相关,其中管壁渗透系数影响最大;管道弯曲度值较小时其增大促进出口流量峰值变大,当径流途径变长引起的流量减小幅度超过管壁面积变大引起的流量增大幅度时,流量峰值逐渐变小;管壁粗糙度在达到两个相对应的雷诺数临界值时水流状态发生突变,导致流量峰值也表现为两次突变。   相似文献   

6.
毛吉成  刘宏  左双英  胡宣 《中国岩溶》2019,38(4):539-545
为了弄清大龙井岩溶大泉形成机理以及地下水补径排关系。通过调查大龙井地形地貌、补径排关系以及对水化学分析等研究大龙井岩溶大泉的形成机理,通过调查得知:大龙井岩溶大泉是形成于低山－丘陵地区的石灰岩地区。是山盆期和乌江期的强烈岩溶作用以及河谷的不断下切,加上上寨台地地表峰丛之间发育洼地、漏斗,中间区域的落水洞,大气降雨沿着落水洞进入地下,在重力作用下从南向北径流,在这过程中水流逐渐集中,岩溶空间形态也逐步扩大,最终水汇集于龙洞沟呈泉集中排泄出地面,形成大龙井岩溶大泉以及大龙井水系统。   相似文献   

7.
《地下水》2017,(3)
通过对贵州猴子沟煤矿区进行水文地质调查与水样采集、测试、分析,揭示了岩溶管道水文地质、水岩反应以及硫、氧同位素特征。研究结果显示,地表径流、大气降水以及酸性矿山水多种端元水混合后通过落水洞进入岩溶管道与管道水混合,管道水在岩溶管道内径流通畅,流速较快,最终排泄到地表河流中。大气降水与泥盆系上统的碳酸盐岩接触,其携带的H~+在入渗过程中与碳酸盐岩发生水岩反应,形成Ca(Mg)-HCO_3型水;黄铁矿在开采巷道内氧化与巷道水形成硫酸,向水中进一步释放SO_4~(2-)和H~+,使巷道水pH进一步降低。巷道水同位素分馏作用强烈,轻同位素被利用,重同位素被留下,形成δ~(34)SSO_4值+1.24‰,δ~(18)OSO_4值+2.54‰的偏正同位素特征值。酸性矿山水通过落水洞进入岩溶管道,管道水流通顺畅,流速较快,微弱的分馏作用使得δ~(34)SSO_4值仅升高+0.05‰。  相似文献   

8.
在岩溶水文地质调查的基础上 ,采用高分辨率野外自动化荧光仪、人工取样和放置活性炭的方法 ,对青木关地下河系统投放的示踪剂荧光素钠接收情况进行检测。 结果表明: ( 1)姜家泉是青木关地下河系统的主要出口 ,岩口落水洞投放的示踪剂在姜家泉的回收量为 93. 9% ,初现时间为 33. 3h ,地下水最大视流速为222. 2m /h,平均视流速为 176. 6m /h,众数视流速为 172. 1m /h,说明本试验段内地下径流为典型的紊流流态 ,岩溶含水介质极不均匀 ,可能有规模较大且无岔道的岩溶管道存在 ; ( 2)岩口落水洞与大木水窝泉、纸厂泉没有直接的水力联系 ,出口姜家泉与纸厂泉也无直接的水力联系; ( 3)野外自动化荧光仪精度和自动化程度高 ,携带方便 ,大大节约了试验成本 ,在我国西南岩溶区的地下水示踪试验中具有较大的推广和应用价值。   相似文献   

9.
用扫描电镜技术识别广州市大气颗粒物主要种类   总被引：19，自引：2，他引：19  
董树屏  刘涛等 《岩矿测试》2001,20(3):202-207
利用扫描电镜技术对大气颗粒物的来源进行识别，采取手动分析与自动分析两种方法，得出的结果在总趋势上相互一致。手动方法和自动方法各有特点。自动分析在细颗粒，特别是含硫颗粒分析方面有优势，而手动分析在形貌观测和确定有机粗颗粒污染状况方面有独到之处。实验结果表明，大气颗粒物的来源是多样的，治理措施也应是综合性的，既要注意工业点源的污染治理和排放控制，如燃煤飞灰，钙质颗粒富铁颗粒等，也要注意面源排放，如土壤扬尘和碳质颗粒，碳质颗粒的来源复杂，可以是工业过程，燃烧过程，机动车尾气，生物质燃，树木自然排放。  相似文献   

10.
岩溶关键带及其碳循环研究进展   总被引：1，自引：0，他引：1  
岩溶关键带的范畴包含了大气-(降水)-植被-土壤-裂隙-基岩-水组成的“碳-水-钙”循环强烈的表层岩溶带以及岩溶管道-洞穴-地下河-隔水层组成的巨大岩溶地下空间,岩溶关键带碳循环是岩溶地球系统科学研究的前沿方向。总结概括了岩溶地球系统科学发展至今的岩溶关键带范畴内碳循环及其对大气CO2源汇效应的研究成果,包括早期碳运移模型、当前主流的区域岩溶碳汇量的计算方法和结果以及“生物碳泵”的新发现等,讨论了当前岩溶碳循环研究框架过于单一或不一致以及碳周转时间尺度等问题,提出应对岩溶关键带碳输入、赋存以及碳输出的各个环节做出系统化监测,通过联网在线高分辨率监测站点的建设以及“3S”技术实现点位到区域的研究,使岩溶碳汇在全球碳循环模型中的重要性更具说服力。  相似文献   

11.
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.  相似文献   

12.
In a karst system, the characterization of transport properties is based on the comparison of natural tracers observed at the inlet (a swallow hole on the karst plateau) and the outlets of the system (a spring and a well). At Norville, northwest France, electrical conductivity (EC) and turbidity (T) were used as natural tracers for characterizing dissolved elements (surface water geochemistry) and particulate matter transport, respectively. Two methods were used for this study: (1) a comparison of the relations between EC, T and spring discharge (Q) by means of normalized EC–T–Q curves, and (2) a principal component analysis (PCA) including water geochemistry data in addition to EC, T and Q. Three different characteristic flood events have been chosen for the analyses. EC–T–Q curves highlighted the direct transfer, resuspension and deposition of particles during their transport in the karst network. Transport from the swallow hole to both the spring and the well appeared to be dominated by karst-conduit flow. On the other hand, PCA results showed a diffuse source of contamination of groundwaters by nitrate and a point-source contamination of groundwaters by streaming/runoff surface waters with high turbidity and phosphate concentration infiltrated at the swallow hole.  相似文献   

13.
The structure, diversity and dynamics of microbial communities from a swallow hole draining agricultural land and two connected karst springs (Switzerland) were studied using molecular microbiological methods and related to hydrological and physicochemical parameters. Storm responses and an annual hydrological cycle were monitored to determine the short- and long-term variability, respectively, of bacterial communities. Statistical analysis of bacterial genetic fingerprints (16S rDNA PCR-DGGE) of spring water samples revealed several clusters that corresponded well with different levels of the allochthonous swallow hole contribution. Microbial communities in spring water samples highly affected by the swallow hole showed low similarities among them, reflecting the high temporal variability of the bacterial communities infiltrating at the swallow hole. Conversely, high similarities among samples with low allochthonous contribution provided evidence for a stable autochthonous endokarst microbial community. Three spring samples, representative for low, medium and high swallow hole contribution, were analysed by cloning/sequencing in order to identify the major bacterial groups in the communities. The autochthonous endokarst microbial community was mainly characterized of δ-Proteobacteria, Acidobacteria and Nitrospira species. A high percentage of unknown sequences suggested further that many karst aquifer bacteria are still undiscovered. Finally, the potential use of groundwater biomonitoring using microbial communities is discussed.  相似文献   

14.
The concurrent use of karst aquifers as drinking water resources and receptors of combined sewer overflow lacking appropriate pre-treatment may cause conflicts between drinking water supply and storm water management. A storm water tank (SWT) for combined wastewater is identified as the source of sporadic contamination of a karst spring (Gallusquelle, “Schwäbische Alb”, SW Germany) used for public water supply. Spring water quality was examined by routine and event sampling and by evaluating physicochemical and microbiological parameters. The total number of microbial colonies growing at 20°C and the number of Escherichia coli colonies rose to values up to four orders of magnitude higher than background, 2–5 days after overflow of the SWT. High concentrations of chloride, sodium, and total organic carbon (TOC) and high values of turbidity coincide with this increase. However, high bacterial contamination is also observed while turbidity and TOC are low. Several wastewater-related organic micro-pollutants such as chlorinated and non-chlorinated organophosphates were detected in the SWT and, depending on their Kow values and their biodegradability, in lower concentrations at the spring.  相似文献   

15.
Field data from 25 karst springs were collected during the summer of 2008 near Verrettes, Haiti, to gain a better understanding of water quality in fresh water springs used as the primary source of potable water in rural Haiti. Two water samples were taken at each spring for bacterial analysis: one sample was submitted to a local hospital for analysis, while a duplicate sample was cultured using inexpensive and commercially available Coliscan® Easygel® Kits. Both capped and uncapped springs were sampled in order to evaluate whether capping improves water quality. Water quality parameters and flow volume estimates were recorded at each spring; however, no correlations between field water parameters and the presence of E. coli or total coliform bacteria were found. Spring flow rates varied from 0.4 to 268.5 L/min. Geologic contacts and regional structures trend in a northwest direction and appear to be exerting a primary control on spring locations. E. coli and total coliform colony counts from the local hospital and Coliscan® Easygel® Kits yielded different results for the same springs due to sample handling and analysis complications common in rural Haiti. Water sample analysis and storage problems encountered during this study likely resulted in underprediction, rather than overprediction, of bacterial contamination. Water from 71 to 100% of the springs was unsafe to drink based on the World Health Organization (WHO) drinking water standard. Both capped and uncapped springs had bacterial counts in excess of the WHO standard, suggesting that water treatment from all sources is necessary to ensure clean and safe drinking water. Negatively impacted subterranean microbial ecosystems, poor sanitation practices, shallow karst aquifers with open flow paths, and high spring water temperatures, averaging 26.5°C, may be contributing to the observed bacterial abundance.  相似文献   

16.
The Alburni massif (1742m a.s.l.) stretches NW–SE, about 23km long and 9–10km wide, covering 246km2 with an average elevation of about 940m a.s.l. This massif, with more than 500 caves, is the most important karst area in southern Italy. The karst channel network is hierarchically organized: some channels feed a major spring (1m3/s) with a very short transit time while others communicate directly with the basal water table related to other springs (Q > 3m3/s).There are several dolines and swallow holes just above the basal water table and in the urbanized areas; for years a swallow hole directly transferred pollutants into the aquifer. The contamination vulnerability map shows that the prevalent vulnerability degree ranges from high to very high, due to the widespread karstification of the area and to the presence, on the plateau, of large vegetated areas with gentle slopes favouring fast infiltration.Hence it is important to ascertain the human impact on the area and the consequent contamination risk of the aquifer of the Alburni karst area. Three main layers were created to assess groundwater contamination risk: the vulnerability map, the hazard map, and the value map.The groundwater contamination risk map stresses the importance in a park area of aquifer vulnerability, which strongly influences the risk: indeed, the prevalent moderate degree of risk in the final map depends on the high vulnerability and the low hazard degree. However, in the future it is crucial to take into account the nature of the agricultural land use allowed in the park, which could increase the hazard degree and consequently the risk degree.  相似文献   

17.
娘子关泉域群泉是中国北方最大的岩溶泉,泉域汇水面积达7 436 km2,前人认为:泉域内岩溶水由北、西、南3面向娘子关一带径流汇集,由于娘子关一带下奥陶系燧石团块或条带白云岩相对隔水层隆起,并被桃河侵蚀出露,使岩溶地下水溢出地表成泉群,其主要含水层为中奥陶系含石膏碳酸盐岩。但各泉的水化学、同位素特征有差异,娘子关泉群并不是出自统一源。文章通过水化学、同位素、水文地质剖面等方法研究得出: 娘子关泉域存在两个含水层、三个子系统:中奥陶系灰岩含水层和中上寒武系白云岩含水层;西部奥陶系岩溶水系统、东部奥陶系岩溶水系统和东部中上寒武系岩溶水系统。泉域内城西泉与程家泉出露于中奥陶系下马家沟组泥灰岩之上,含水层为中奥陶系灰岩裂隙、溶隙水,由于区域下马家沟组泥灰岩隆起隔水出露地表成泉,属于东部奥陶系岩溶水系统;坡底泉、五龙泉、河北泉、水帘洞泉、苇泽关泉其补给主要来源于中上寒武系含水岩组,为承压上升泉,属于东部中上寒武系岩溶水系统。   相似文献   

18.
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.  相似文献   

19.
Analysis of Total Organic Carbon (TOC) and NO3 ? contents in the water at six springs in the province of Malaga (Southern Spain), sampled under different hydrologic conditions, revealed two different hydrochemical behaviour patterns for these natural tracers of infiltration. TOC content increased during every recharge period, following the rapid arrival of water infiltrating through the soil. On the other hand, NO3 ? content only rose during the first flood episodes (normally in autumn), and fell during the winter and spring ones. This difference is consequence of the distinctive biogeochemical kinetics of nitrogen with respect to organic carbon, both in the soil and within the aquifer. Unlike the mineralisation undergone by TOC from the surface to the spring, the NO3 ? ion remains in the aquifer almost unaffected, due to the oxidizing conditions prevailing within the karst medium, which do not allow its denitrification and favour its preservation within the saturated zone. In non-polluted aquifers, TOC and NO3 ? have a common origin in the soil and can be used to determine infiltration processes and the hydrogeological functioning of karst aquifers. Their different hydrochemical evolution provides information about mineralization and degradation processes of organic matter within karst aquifers, which can be used to validate the vulnerability to contamination in this type of medium.  相似文献   

20.
The Tam Duong karst area in NW Vietnam is among the poorest and remotest regions in the country. The local population largely depends on water from two main karst springs. Due to agricultural activity and untreated domestic wastewaters, the spring water is often microbiologically contaminated. In order to provide a scientific basis for groundwater protection in the area, different field methods have been applied including hydrogeological framework investigations, tracer tests, and hydrochemical and microbiological sampling and analyses. All methods had to be adapted to the conditions of a poor and remote area. These adaptations included, amongst other measures, the use of a portable microbiological water_testing kit and the involvement of the local population in the sampling campaign. The tracer tests showed simple and direct connections between two important swallow holes and the two main springs, and made it possible to determine the linear groundwater flow velocities, which are extremely high (up to 875 m/h). The hydrochemical and microbiological data confirmed the strong impact of the streams sinking into the swallow holes on the spring water quality. Future groundwater source protection strategies should consequently focus on the reduction of polluting activities near the sinking streams and within their catchment areas.  相似文献   

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