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1.
Analysis of natural responses of karst springs provides information on the behavior of the aquifers they drain. Detailed monitoring and qualitative and quantitative analyses of natural responses, and environmental—total organic carbon (TOC), NO3 ?, Cl? and intrinsic fluorescence—and artificial (fluorescent dye) tracers, in the water drained by Villanueva del Rosario spring (southern Spain), suggest the existence of a conduit flow system with rapid flows and very short transit times of water through the aquifer. This is in agreement with uranine and eosin breakthrough curves and with simple numerical models done using these data. However, due to the low capacity for natural regulation, not all the recharge effects are simultaneously transmitted to the spring water; given a single input, the system modulates and transfers hydrodynamic variations faster than variations of chemical composition and of water temperature. Additionally, time lags between maximum concentrations of natural and artificial tracers show that the global system response (including diffuse infiltration) is faster and more sensitive than that produced from infiltration concentrated at a single point on the surface (sinkholes).  相似文献   

2.
系统评述了水体中溶解有机物的特性及测量方法。介绍了水体中溶解有机物的研究概况,指出了开展水体中溶解有机物定量监测的必要性;详述了水体中溶解有机物的激光诱导荧光测量方法、对水体中有机物荧光光谱进行分析的特征光谱荧光标记技术和荧光强度归一化处理技术,以及利用激光诱导荧光方法测量水体中溶解有机物浓度的标定方法;综述了多种因素对利用激光诱导荧光方法测量的影响。  相似文献   

3.
Continuous measurements of natural fluorescence of dissolved organic matter (DOM) in groundwater have been used to characterize infiltration through an unstable fractured hillslope at the event time scale. Within the gneissic Valabres rockfall area in the southern French Alps, two sites, in the unstable massif and in the collapse area, were continuously monitored for electrical conductivity and for DOM natural fluorescence using a field fluorometer, and analyzed weekly for hydrochemical data. Two main results were found. From a methodological point of view, DOM natural fluorescence was a relevant tracer of fast infiltration in fissured media, knowing that continuous measurements improved the study of infiltration processes at the event time scale. From a hydrogeological point of view, the unstable fractured massif showed delayed dilution phenomena and the collapse areas showed fast and slow infiltration by piston-type flows via more or less open fractures. Consequently, from this conceptual model one may suppose that, unlike the collapse zones, the fractured hillslope threatening the valley is not submitted to strong pore-water pressure variations.  相似文献   

4.
中国北方岩溶地下水污染分析   总被引:5,自引:0,他引:5  
近年来,受气候变化和强烈人类活动的影响,环境物质及能量多频次、大范围的输入,极大程度上改变着岩溶水系统的水环境质量,岩溶水生态环境遭受不同程度的威胁和破坏,岩溶水水质日趋恶化。本文归纳分析了我国北方岩溶水系统水质特征、污染现状、污染来源及污染途径。我国北方岩溶水水质类型中硫酸盐型水和氯化物型水的分布逐渐增加,主要污染组分为总硬度、SO42-、F-、NO3-和TDS等。其中硫酸盐和硝酸盐污染强度和范围最大,呈现出显著的人类活动影响特征。依据我国北方岩溶系统结构及水力学特征,将岩溶水污染途径概括为:①连续入渗型——主要包括岩溶区地表水(河流、水库等)渗漏污染,城镇污水渠或排污管道破损引起的污水渗漏污染;②越流型污染——污染孔/裂隙水(含矿坑水/老窑积水等)越流污染岩溶水;③间歇入渗型——固废淋溶入渗和污水灌溉渗漏污染等。据此提出了推进岩溶水水资源保护和污染防治的合理化建议。   相似文献   

5.
Groundwaters were sampled from four research boreholes, a private supply well and a natural karst resurgence in southern County Durham, England. Time series data sets of piezometric levels, groundwater major ions, and fluorescence of dissolved organic matter (DOM) were interpreted in the light of new geological mapping to assess the movement of groundwater and its potential for the dissolution of gypsum. Three distinct groundwater facies were identified representing contact with gypsiferous strata, dolomitic limestone and Quaternary Till. Piezometric data indicated time varying transverse flow across the gypsifeorus strata, which was confirmed from gradational mixing of groundwater types and cation ratios. Fluorescence of dissolved DOM identified variations in protein and fulvic-like acid fluorescence. The former was taken to represent surface derived, short-lived material. Spatial and temporal variations in protein fluorescence offered a means to trace groundwater movement along the regional groundwater gradient and indicated rapid lateral movement of groundwater. It was concluded that gypsum dissolution is occurring beneath the town of Darlington, however, the presence of a thick deposit of Quaternary till effectively confines the small head differences of approximately 1 m, across the gypsum strata beneath the town. Further to the south, the lowering of the ground surface results in a greater upwards flow of water across the gypsum and is used to explain the presence of historic collapse sinkholes.  相似文献   

6.
The recharge of a karst aquifer, in terms of its quantity and spatial distribution, depends on various natural factors such as climate, topography, vegetation, soil, and geology. Selection of an adequate method for assessing recharge in karst is often a matter of dispute. Multi-parameter methods using Geographical information systems tools have recently been successfully developed and applied in karstic terrains of Spain and Lebanon. Specific local conditions such as highly karstified terrains could additionally complicate such an assessment. The Montenegro karstified terrains in the southern part of the External Dinarides are characterized by a very high precipitation rate, irregular seasonal distribution, and absence of surface waters (extremely high infiltration capacity of karst). Considering such conditions, an attempt to apply existing knowledge and experiences to the development of an appropriate multi-parameter method for assessing spatial distribution of autogenous recharge has been made. The KARSTLOP method has been developed, applied, and calibrated at catchments of several large karst springs of Montenegro. Obtained results in tested catchment areas confirm that with some further improvements the KARSTLOP method could be a useful tool to support research of karstic aquifers in similar highly karstified terrains.  相似文献   

7.
For about 10 years, environmental tracing development using dissolved organic matter (DOM) has been the subject of several studies. Particularly, the use of characterization techniques, like fluorescence emission–excitation matrices has enabled the identification of DOM sources and monitoring them within mainland or marine hydrosystems. Moreover, hydrogeologists have shown the significance of total organic carbon content used as a fast seepage tracer in karstic aquifers. The aim of this study consists in using DOM fluorescence signals to develop a transit time semi-quantitative tracer in heterogeneous hydrosystems. The Low-Noise Underground Laboratory (Vaucluse, France) cuts the network of Fontaine de Vaucluse (FV) karstic vadose zone randomly, and offers a special access to different unstructured dripwaters, with different hydrodynamic behaviour, inside its galleries, i.e. not hierarchical as in natural caves. Previous long-term hydrodynamic and hydrochemical studies allowed the understanding of their hydrogeological behaviour and the estimation of mean transit times. That is why this site is adequate to develop new transit time tracers. After identification of the different DOM sources (i.e. lithic and rendzic leptosols), fluorescence intensities monitoring from soil leachates and dripwaters, for certain excitation–emission wavelength pairs, allowed the development of punctual transit time tracing, by spotting infiltration periods of fluorescent compounds, and monitoring their transfer within a hydrosystem. A fluorescence index (humification index) and the mean transit time of each gallery groundwater, stemmed from previous hydrodynamic and hydrochemical studies, allowed the calibration of a logarithmic relationship. This one allows the development of a continuous transit time tracing method that estimates transit times without long-term studies. It has been tested on two springs of FV catchment basin, providing transit time estimations for karstic hydrosystems that do not present a mixture between recent and pluriannual waters.  相似文献   

8.
溶井微污染水供水就地处理技术研究   总被引:1,自引:0,他引:1  
溶井是西南岩溶区主要的分散式供水方式。本文在对典型地区溶井水污染特征分析基础上,通过对现有分散供水水处理工艺原理的分析,提出了溶井供水的水污染防治措施,并结合中试试验,对溶井快渗池的设计思路、设计参数、水处理工艺以及施工中的注意事项进行了详细说明。试验表明,溶井在采取水处理措施后,出水浊度均低于5度,微量有机物去除率大于35%,氨氮可削减60%以上,细菌总数最大可截留95%;溶井快渗池工艺在溶井水处理过程中不需要添加任何药剂,避免了混凝剂和消毒剂对水质产生的副作用和卫生问题,出水水质主要指标基本达到生活饮用水卫生标准。   相似文献   

9.
龙涧泉岩溶水系统特征   总被引:2,自引:2,他引:0  
文章以地下水系统理论为指导,对龙涧泉岩溶水系统的边界条件、人工干预条件下地下水动力场演化特征等方面进行了系统的研究。根据区域地质、构造、地形地貌和水文地质条件,探究了龙涧泉岩溶水系统,圈定了系统的范围、边界性质、流动系统内部及其与外部系统之间的关系,确定龙涧泉为系统的唯一天然排泄口,龙涧泉岩溶水系统与白浪岩溶水系统无直接水力联系。龙涧泉岩溶水系统岩溶水补给来源主要是大气降水、河流入渗及侧向径流补给,现状条件下总补给量为864.42万m3/a,多年平均补给量为836.81万m3/a;排泄主要是水源地开采和矿山排水,现状开采量为4 117.2万m3/a。由于开采量大于允许开采量,并超过了总补给量,区内岩溶水一直处于超采状态。2004—2008年矿区岩溶水实测年均下降1.61 m/a,多年(1984—2008)水位平均降幅为5.68 m/a,最大降幅17.42 m/a。此外还讨论了岩溶水系统的补给、排泄条件,提出了龙涧泉岩溶水开发、保护、复泉与管理龙涧泉岩溶水系统的建议。   相似文献   

10.
A simple method based on high-performance size-exclusion chromatography (HPSEC) has been developed for rapid quantification of humic and fulvic acids (HA and FA) in stream waters. A Tsk-gel column was used to separate natural dissolved organic matter (DOM) into two components: peak A and B. In terms of HPSEC chromatograms and fluorescence patterns, peak A and B were similar to the corresponding XAD-extracted HA and FA, respectively. It is suggested that peak A fraction mainly consisted of HA, and peak B fraction FA. The similar separation of HA and FA using HPSEC and a conventional XAD method suggests the consistency of molecular size distribution and physical–chemical properties of DOM. HPSEC offers a simple and rapid method for the quantification of HA and FA instead of tedious extractions of humic substances. Analyses of natural water samples show that the calculation of HA/FA based on UV absorbance was under- or over-estimated, the calibration using the extracted HS allows a more accurate quantification. The fast screening of HA and FA provides useful quantitative and qualitative information that can be used in environmental or monitoring studies.  相似文献   

11.
Previous studies showed that water chemistry and concentrations of dissolved organic matter (DOM) could affect its molecular conformation and binding characteristics with hydrophobic organic contaminants (HOCs). However, the conformational change of DOM resultant from water chemistry and concentrations of DOM was not extensively investigated; therefore, the contradictory reports regarding the binding property with HOCs were available in literature. In this study, the effects of ionic strength, pH and DOM concentrations on the fluorescence properties of two humic acids (HA), namely Fluka HA and Amherst HA, were investigated by three-dimensional excitation-emission matrix fluorescence spectroscopy (3DEEM) and steady-state fluorescence polarization (FP) techniques. The results not only corroborated previous observations obtained by other investigators, but revealed some new information about the fluorescence properties and molecular conformation of the humic acids under different water chemistry and DOM concentration conditions, which could shed light on its binding mechanisms and binding properties with HOCs.  相似文献   

12.
选取桂林丫吉试验场硝盐洞为研究对象,通过示踪试验和高分辨率水文水化学监测,确定滴水补给来源,研究典型岩溶包气带洞穴滴水对降雨响应的水文过程。研究结果表明,硝盐洞XY5滴水主要受到两种径流成分补给,即集中补给的管道流和弥散流。硝盐洞上部包气带中可能存在表层岩溶带含水层,长期维持滴水流量。滴水流量、电导率和示踪剂浓度的峰值均出现在强降雨时段,表现出快速响应的管道流特征,存在降雨阈值引起硝盐洞滴水降雨响应。降雨前岩溶含水层水分条件是包气带水文响应差异的主要原因,雨季滴水对降雨响应迅速,XY5滴水对降雨响应的滞后时间为10 h;而旱季对降雨的响应滞后明显,滞后时间达9.8天,体现了土壤和表层岩溶带的调蓄作用。74.4 mm降雨量是旱季转雨季滴水响应的降雨阈值。借助于洞穴滴水的水文动态变化和示踪试验技术对于研究包气带水文过程,深入了解岩溶含水层结构及特征,揭示岩溶区降雨入渗补给机制具有重要作用。  相似文献   

13.
The fluorescence properties of groundwaters from sites in two UK aquifers, the Penrith Sandstone of Cumbria and the Sherwood Sandstone of South Yorkshire, were investigated using excitation–emission matrix (EEM) fluorescence spectroscopy. Both aquifers are regionally important sources of public supply water and are locally impacted by pollution. The Penrith Sandstone site is in a rural setting while the Sherwood Sandstone site is in suburban Doncaster. Fluorescence analysis of samples from discrete sample depths in the Penrith Sandstone shows decreasing fulvic-like intensities with depth and also shows a good correlation with CFC-12, an anthropogenic groundwater tracer. Tryptophan-like fluorescence centres in the depth profile may also provide evidence of rapid routing of relatively recent applications of organic slurry along fractures. Fluorescence analysis of groundwater sampled from multi-level piezometers installed within the Sherwood Sandstone aquifer also shows regions of tryptophan-like and relatively higher fulvic-like signatures. The fluorescence intensity profile in the piezometers shows tryptophan-like peaks at depths in excess of 50 m and mirrors the pattern exhibited by microbial species and CFCs highlighting the deep and rapid penetration of modern recharge due to rapid fracture flow. Fluorescence analysis has allowed the rapid assessment of different types and relative abundances of dissolved organic matter (DOM), and the fingerprinting of different sources of organic C within the groundwater system. The tryptophan:fulvic ratios found in the Penrith Sandstone were found to be between 0.5 and 3.0 and are characteristic of ratios from sheep waste sources. The Sherwood Sandstone has the lowest ratios (0.2–0.4) indicating a different source of DOM, most likely a mixture of terrestrial and microbial sources, although there is little evidence of pollution from leaking urban sewage systems. Results from these two studies suggest that intrinsic fluorescence may be used as a proxy for, or complementary tool to, other groundwater investigation methods in helping provide a conceptual model of groundwater flow and identifying different sources of DOM within the groundwater system.  相似文献   

14.
Analysis of dissolved organic matter (DOM) concentration and composition is essential to quantifying biological and chemical oxygen demand and atmosphere?Cocean heat flux exchange in natural waters. However, manual water sampling is costly and time consuming over large areas. The purpose of this research was to analyze the applicability of airborne laser-induced fluorescence light detection and ranging (LiDAR) for the detection of DOM in estuarine ecosystems impacted by agriculture. A fluorescence LiDAR system (Airborne Marine) (FLS-AM) was used to assess the DOM concentration of the Annapolis River and Basin, Nova Scotia, Canada, as well as three rivers and their estuaries in Prince Edward Island, Canada. Two FLS-AM flight missions were conducted in the summers of 2008 and 2009 and the resulting datasets were compared with spectral fluorescence signature (SFS DOM) and dissolved organic carbon (DOC) analysis of in situ water samples. Significant positive correlations were found at five of seven sites between the FLS-AM DOM and SFS DOM relationship which indicates that the FLS-AM sensor is a good surrogate for traditional sample collection of DOM data in estuaries in this region. Positive correlations were also found at all sites between FLS-AM DOM values and DOC. FLS-AM DOM patterns show that DOM values are significantly higher in rivers and estuaries that drain watersheds which are heavily impacted by agricultural practices. The results of this study show that the FLS-AM can be used efficiently as a general indicator for how estuaries are affected by runoff from agricultural watersheds in real time and thus reduce the requirement for traditional water sample collection and laboratory analysis methods.  相似文献   

15.
 The complex functioning of karst systems depends on several factors (e.g., geology, karstification status, climate) which influence flow conditions. Understanding a system requires monitoring that includes a sampling interval well adapted to the system's size, and the use of hydrodynamic and geochemical approaches. From our own observations, the general physical and geochemical characteristics of the aquifers are perennial and representative of karst evolution at a given moment. The Notre-Dame-des-Anges karst system, which is situated in France on the rim of the Vaucluse karst region, was studied during 2 water years. This study demonstrates that several parameters are not definitive, and that they do not provide information about the actual status of the karst evolution of the system. We were able to observe that hydrological parameters in particular are dependent on the configuration of the outlets, which can dramatically change. For example, a heavy storm (300 mm of rain in 4 h), which occurred in the intake area on 22 September 1992, produced a piston effect in the aquifer, which was expressed by extensive unclogging of the whole aquifer. The appearance of a new gryphon at the outlet induced a change in the flow rate and added to the unclogging. The other major result of this study is the demonstration of intensive, even preponderant, participation of water originating in the infiltration zone in the behavior of the system. This contribution, often minimized in previous studies, is closely dependent upon flow conditions and especially upon the recharge status of the infiltration zone. Physical and chemical parameters allowed us to trace this water, and to demonstrate the existence of an actual hanging reserve which plays not a negligible part in flow, during both high and low water levels. This paper demonstrates the necessity of coupling a hydrodynamic study with a hydrochemical approach, and of questioning the representativeness of parameters during a given period, for a better understanding of the functioning of the karst system. This is especially true if the infiltration zone of the karst system is heavily developed, and if external factors (e.g., river, landslip, clogging) influence the outlet Received: 10 June 1996 / Accepted: 11 November 1996  相似文献   

16.
The hydraulic behaviour of the karst aquifer in the Hubelj spring catchment area (SW Slovenia) was studied by using an indirect research method based on natural tracers. The variations of natural tracers (in precipitation and in groundwater) during the storm event made possible the separation of the Hubelj spring storm hydrograph by the three-component separation technique. The results produced information on the aquifer recharge, storage and discharge processes, as well as on the mechanisms that affected them. They verified the so-called epikarst hypothesis presuming that an important part of a karst aquifer recharge reaches rapidly and intensively from the epikarst zone. It was demonstrated that epikarst water could occupy up to 50% of the spring discharge during precipitation events. This phenomenon could have important consequences on protection and management of the problems of karst aquifers, including engineering problems in karst areas. With this respect the results could give way to new engineering ideas.  相似文献   

17.
Urban karst systems are typically considered more vulnerable to contamination and excess storm discharge because of potential source areas, increased sediment loading, and focusing of water from impervious surfaces. However, urban hydrology can lead to unexpected patterns, such as pirating of recharge into man-made storm systems. Valley Creek Basin in southeastern Pennsylvania, presents such an urban karst system. Four springs were monitored for suspended sediment, water chemistry, and storm response for an 18-month period. The baseflow suspended sediment concentrations were low, less than 4.0 mg/l. Furthermore, trace metal analysis of baseflow water samples and spring mouth sediment showed only low concentrations. The response to storms within the system was rapid, on the order of 1–3 h. The maximum water stage increases at the urban springs were typically less than 15 cm, with springs from more commercialized areas showing <2 cm increase. A nearby retention basin, in contrast, had water level rises of 100 cm, suggesting that pirating of recharge into stormwater systems occurs. Thus, the concept of an urban karst system as a contaminant conduit is not the only one that applies. In Valley Creek Basin, reduced infiltration due to paving led to smaller storm response and less contaminant input, and the smaller capture area due to diversion of stormwater led to short flow paths and rapid storm response. Although contaminant levels have not increased due to urbanization, the springs may be at risk for future contamination. Short flow paths may reduce flushing, which means that the system will not cleanse itself if contamination occurs.  相似文献   

18.
Maatouk  E.  Samrani  A. El  Sawan  R.  Salameh  R. Bou Ghosn  Kazpard  V.  Matar  Z. 《Aquatic Geochemistry》2022,28(2):111-133

This work focuses on the characterization of a typical coastal karst watershed by addressing its physico-chemical parameters. The concentrations of the main ions clearly indicate the dominance of Ca2+ and HCO3? with a carbonate weathering rate equivalent to 230t/Km2/year; that is a typical weathering of karst watersheds. The spatio-temporal variability of dissolved organic matter (DOM) is also assessed in the watershed. Many samples were collected under different hydrological conditions from three representative sites. The evolution of OM composition along an urbanization gradient from upstream to downstream Kadisha watershed reveals the very strong impact of urban discharges on the receiving waters. Substantial differences in DOC results are highlighted in relation to the urban or natural origin of the DOM. Upstream OM flux is quantified and compared to downstream OM flux showing that, during the low flow period, the downstream flux is 29 times higher than the upstream. Also, a large fraction of non-humic substances, including hydrophilic organic matter HPI, is detected in the downstream section impacted by urban discharges. The higher values of SUVA noticed for DOM at upstream compared to downstream, reflects the low aromaticity and non-humic character of DOM in downstream. These outcomes show the impact of the Tripoli urban discharges on the quality and quantity of OM in the receiving waters downstream of the Kadisha catchment. This is typical at low water period when the dilution factor of urban discharges in the receiving waters is the least.

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19.
The management of groundwater flow systems in karst regions appears, at present, to be the most important procedure for solving water deficiency problems during periods of low rainfall. Faced with a lack of data for characterizing the water supply potential of karst aquifers, analyses of spring hydrographs may provide valuable indirect information regarding the structure of karst hydrogeological systems. To estimate the optimal exploitation capacities of karstic sources, a stochastic-conceptual approach was applied in case studies from the Serbian karst. Water supply potentials were initially evaluated on the basis of groundwater budgets. Further steps towards defining optimal “exploitable” regimes included analyses of storage changes in karst water reservoirs under natural conditions and calculation of the potential expansion of currently tapped sources. The results obtained through these analyses are a significant contribution to feasibility studies and aid in the avoidance of problems of overexploitation.  相似文献   

20.
《Geodinamica Acta》2013,26(1-3):89-100
The study presents natural hazards in Slovenia's karst, focusing on flooding in karst poljes. A specific study was done on the flood dynamics of two typical and connected karst poljes (Cerknica and Planina) of the Classical Karst region. In the case of particularly extreme hydrological conditions in the autumn of 2008, detailed analyses of the recharge-discharge regime and the interrelationship of flooding on the two poljes were done. Daily precipitation, discharge, and water level values from several monitoring sites were analyzed and cross-correlated, and additional hydrological analyses were done using a digital elevation model in order to acquire water level increase and decrease intensity, flood water volumes, and the extent of flooding and to understand the conditions controlling karst flooding. The results reveal that the hydrological functioning of the studied karst poljes is influenced by the hydrogeological and temporary hydrological conditions in the catchment area. The response of the binary karst system (i.e., the influence of autogenic and allogenic recharge) is especially distinct. The study shows that during extremely intense recharge, the reactions of karst aquifer systems to precipitation are as rapid as the response of surface waters (the water level of Cerknica Lake increased with an intensity of 38-63 cm/day or 55 m3/s respectively) while retention capacities are negligible. In contrast to flash floods, floods in karst areas may last from several weeks to several months. For the observed period a three-dimensional simulation of the flooding was made. At the maximum recorded water level, the volume of water on the Cerknica polje was 51 million m3, and 26 million m3 on the Planina polje. The maximum extent of flooding on the Cerknica polje was 23 km2 and on the Planina polje 9.5 km2. On the basis of the study, information was provided regarding future hazard mitigation. However, the study demonstrated that a sufficiently dense monitoring network is necessary to predict the occurrence and duration of floods with greater certainty.  相似文献   

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