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1.
Artificial recharge plays a pivotal role in the sustainable management of groundwater resources. This study proposes a methodology to delineate artificial recharge zones as well as to identify favorable artificial recharge sites using integrated remote sensing (RS), geographical information system (GIS) and multi-criteria decision making (MCDM) techniques for augmenting groundwater resources in the West Medinipur district of West Bengal, India, which has been facing water shortage problems for the past few years. The thematic layers considered in this study are: geomorphology, geology, drainage density, slope and aquifer transmissivity, which were prepared using IRS-1D imagery and conventional data. Different themes and their corresponding features were assigned proper weights based on their relative contribution to groundwater recharge in the area, and normalized weights were computed using the Saaty’s analytic hierarchy process (AHP). These thematic layers were then integrated in the GIS environment to delineate artificial recharge zones in the study area. The artificial recharge map thus obtained divided the study area into three zones, viz., ‘suitable,’ ‘moderately suitable’ and ‘unsuitable’ according to their suitability for artificial groundwater recharge. It was found that about 46% of the study area falls under ‘suitable’ zone, whereas 43% falls under the ‘moderately suitable’ zone. The western portion of the study area was found to be unsuitable for artificial recharge. The artificial recharge zone map of the study area was found to be in agreement with the map of mean groundwater depths over the area. Furthermore, forty possible sites for artificial recharge were also identified using RS and GIS techniques. Based on the available field information, check dams are suggested as promising artificial recharge structures. The results of this study could be used to formulate an efficient groundwater management plan for the study area so as to ensure sustainable utilization of scarce groundwater resources.  相似文献   

2.
A comparison of the d-excess values of precipitation and of spring water, streams, groundwater wells and submarine groundwater discharge indicated that the precipitation that occurred during winter season was an important source of groundwater recharge. Due to the steep slope of the island, most of the short duration and high intensity precipitation is lost through direct surface runoff. The comparison indicated that snowmelt is an important resource of groundwater recharge on Rishiri Island. Future climate change will continue to diminish the snowpack, and therefore, reduce groundwater recharge. It may cause the decline of the groundwater level in the coastal area and possibly shift the saline–freshwater boundary on the island. Chloride data indicated that saltwater intrusion is beginning to occur on the western flank of the island. A Piper diagram shows that the water samples are characterized by the dominance of the Ca–HCO3 and Na–Cl type. Their chemistry probably results from sea salt spray and the dissolution of minerals. These results support the need for the effective management of groundwater resources.  相似文献   

3.
In order to evaluate groundwater regional resources, a mathematical model of the Gdansk hydrogeological system (Poland) was developed. The research area covers about 2,800 km2. Groundwater occurs in Cretaceous, Paleogene and Neogene formations. The recharge zone is situated in the glacial upland of the Kashubian Lake District. The discharge zone spreads over the lowlands of Gdansk and beneath the Bay of Gdansk (Baltic Sea). The MODFLOW program was used to develop a three-dimensional steady-state model on the basis of data from over 1,700 boreholes. The research area was digitalized as a square network of sides 200 m in length. Simplification of groundwater occurrence allowed four aquifers to be distinguished: upper Pleistocene, Pleistocene-Miocene, Oligocene-Eocene, and Cretaceous and also four intervening aquitards. The mathematical model calculations showed that the system is recharged mainly by precipitation (infiltration recharge is 136 mm/year). The precipitation recharge amounts to 1,045,440 m3/day. The other part of the inflow constitutes lateral flows from beyond the area of research and also to some extent from losing rivers and lakes. The runoff from the system takes place mainly through gaining streams and through lateral outflow including under-sea and lake discharge.  相似文献   

4.
根据岩类组合特点、地质构造背景和构造活动性,扬子地台晚古生代沉积建造可分两大类型:台地型建造和台槽型建造.这两类建造在空间上和时间上展布规律和发育程度,都是与地质构造背景、沉积环境、古气候、岩浆活动和地壳活动等密切相关.  相似文献   

5.
黑河干流浅层地下水与地表水相互转化的水化学特征   总被引:14,自引:0,他引:14  
通过分析黑河干流地表水与地下水的水化学特征,识别沿黑河干流不同地带地下水与地表水的相互转化关系.研究结果表明:(1)在祁连山区,地下水与地表水的转化以地下水向河流排泄为主.(2)南部盆地,在山前戈壁带,出山河水入渗转化为地下水;溢出带地下水以泉的形式转化为地表水;进入细土平原后,汛期河水补给地下水,非汛期地下水补给河水;在农灌区引河水通过田间入渗补给地下水.(3)北部盆地,在金塔灌区,地下水主要接受引水灌溉入渗补给;在金塔灌区到额济纳旗,河流入渗转化为地下水.  相似文献   

6.
The spatial and temporal changes of the composition of the groundwater from the springs along the Wadi Qilt stream running from the Jerusalem–Ramallah Mountains towards the Jericho Plain is studied during the hydrological year 2006/2007. The residence time and the intensity of recharge play an important role in controlling the chemical composition of spring water which mainly depends on distance from the main recharge area. A very important factor is the oxidation of organics derived from sewage and garbage resulting in variable dissolved CO2 and associated HCO3 concentration. High CO2 yields lower pH values and thus under-saturation with respect to calcite and dolomite. Low CO2 concentrations result in over-saturation. Only at the beginning and at the end of the rainy season calcite saturation is achieved. The degradation of dissolved organic matter is a major source for increasing water hardness. Besides dissolution of carbonates dissolved species such as nitrate, chloride, and sulfate are leached from soil and aquifer rocks together with only small amounts of Mg. Mg not only originates from carbonates but also from Mg–Cl waters are leached from aquifer rocks. Leaching of Mg–Cl brines is particularly high at the beginning of the winter season and lowest at its end. Two zones of recharge are distinguishable. Zone 1 represented by Ein Fara and Ein Qilt is fed directly through the infiltration of meteoric water and surface runoff from the mountains along the eastern mountain slopes with little groundwater residence time and high flow rate. The second zone is near the western border of Jericho at the foothills, which is mainly fed by the under-groundwater flow from the eastern slopes with low surface infiltration rate. This zone shows higher groundwater residence time and slower flow rate than zone 1. Groundwater residence time and the flow rate within the aquifer systems are controlled by the geological structure of the aquifer, the amount of active recharge to the aquifer, and the recharge mechanism. The results of this study may be useful in increasing the efficiency of freshwater exploitation in the region. Some precautions, however, should be taken in future plans of artificial recharge of the aquifers or surface-water harvesting in the Wadi. Because of evaporation and associated groundwater deterioration, the runoff water should be artificially infiltrated in zones of Wadis with high storage capacity of aquifers. Natural infiltration along the Wadis lead to evaporation losses and less quality of groundwater.  相似文献   

7.
环境同位素研究证实,陕西渭北东部岩溶地下水系统中部上王-西头-黑池一带为岩溶地下水强径流带,是渭北东部岩溶地下水的主要径流区域.强径流带内岩溶水积极参与现代水循环,平均滞留时间为51年,具有较强的更新能力.与此对应,14C的证据显示强径流带以南、以北及东南部的岩溶地下水具有万年以上的形成历史,属难以恢复的不可再生资源.同位素EPM模型计算表明,强径流带内隐伏岩溶水系统天然补给量为87.55mm/a,储存量为9.62×109m3/a,平均储水系数为0.029.以上结论均与水文地质勘探结果基本吻合.环境同位素的研究成果提供了岩溶地下水的循环强度和可更新性的直接证据,补充和丰富了岩溶地下水运动的重要信息,为定量评价研究区隐伏岩溶地下水资源的可更新性提供了关键性数据.  相似文献   

8.
The present work studies the environmental isotopes assess groundwater characteristics of the different parts of the main aquifer in the northeast Missan Province in south of Iraq.Water samples of groundwater and surface water were collected for two dry and wet seasons during the water year of 2011–2012.The study shows that most of the groundwater in the aquifer falls above the global meteoric water line,and all the samples fall below the Mediterranean meteoric water line,indicating that these samples are a mixture of two water types.The tritium content of these samples supports this conclusion.The overall conclusion of this study indicates that there are two sources of groundwater recharge in the studied area:the ephemeral streams(Teeb and Dewerge) and major precipitation sources.According to the tritium levels at or below one tritium unit(TU) obtained from the water,supply wells are highly confined or "not vulnerable".Overall,the 3H results imply that recent recharge has taken place during the last four to five decades.In the recharge area,the high tritium content in the southern part of the Teeb area suggests that the recharge originates from rapid infiltration of surface runoff.Therefore,the groundwater resources in the study area should be protected from contamination,because it will influence the aquifer in a relatively short period of time if any contamination enters the recharge areas of the aquifer.  相似文献   

9.
陇东盆地西部岩溶地下水形成机制研究   总被引:3,自引:1,他引:3       下载免费PDF全文
陇东盆地西部处于鄂尔多斯盆地西缘逆冲推覆构造带,新元古-下古生界碳酸盐岩裸露或浅埋,构成-南北向展布的岩溶水富集带。通过运用构造控水分析、水化学同位素等方法,对岩溶裂隙水系统进行了深入的分析与讨论。指出本区岩溶水的空间分布明显受南北向逆冲推覆构造控制,储水空间以岩溶裂隙为主,构造条件是岩溶发育和岩溶水富集的主要制约因素。岩溶水化学特征具有明显的南北差异,在补给条件优越的中南部平凉-华亭地区,水化学主要由含水层岩性及其赋存条件决定。岩溶地下水以大气降水来源为主,对于埋藏型岩溶水表现为多源水混合而成。根据岩溶水的空间分布与水动力场特征及其补径排条件,全区可划分为平凉、华亭和环西3个相对独立的岩溶水系统.并以此可作为水资源评价的基础。这些认识对于深入了解西北干旱-半干旱地区岩溶水赋存及富集规律、形成与演化机理和在该区开发利用岩溶地下水资源具有重要的科学意义。  相似文献   

10.
Groundwater is an important decentralized source of drinking water. Being underground, it is relatively less susceptible to contamination. In addition to domestic needs, it is extensively used for irrigation and industrial purposes. It is therefore necessary to implement groundwater recharge systems by capturing the rainwater runoff. In the present study, GIS-based hydrological assessment of watershed has been used to identify the potential sites for locating the groundwater recharge structures. Based on land use, soil and topography, rainfall runoff modelling was carried out in GIS for a sub-watershed of River Kanhan, in Nagpur District, Maharashtra State, India. Five potential sites with maximum flow accumulation were delineated using the rational method for peak runoff estimation. As the groundwater recharge potential also depends on the geological and geomorphological characteristics of land, analytic hierarchy process (AHP) with expert’s judgement was used for ranking the sites. The criteria considered in AHP were geological features, i.e. lineament density, depth to bedrock and soil cover; geomorphological features, i.e. drainage density, slope, landforms and land use/land cover; and water table level fluctuation. The site P5 with maximum flow accumulation and sandstone rock formation was ranked first. The site P1, where catchment has well-developed drainage and geological formation shows rock with secondary porosity, was ranked second.  相似文献   

11.
甘肃西部平原区地下水同位素特征及更新性   总被引:8,自引:4,他引:8  
大量同位素资料研究表明,甘肃西部黑河流域南部平原区地下水补给和更新的特征是,具有非均一性和有限性;潜水较年轻又更新快,承压水较老又更新慢;东部地下水更新较快,西部更新较慢;祁连山前戈壁带地下水更新较快,细土平原更新较慢;近河道带地下水更新速率大,远离河道则小。上述特征与出山地表径流量及其补给源属性密切相关。因此,结合地下水更新特征,充分利用祁连山前戈壁带较强的入渗条件和调蓄功能,与地表水联合优化调控,有利于该区水资源可持续利用。  相似文献   

12.
鄂尔多斯地区早古生代岩相古地理*   总被引:6,自引:4,他引:2       下载免费PDF全文
鄂尔多斯地区早古生代沉积了一套以海相碳酸盐岩夹碎屑岩为主的沉积建造,沉积厚度巨大,沉积类型多样,可以划分为海岸沉积、碳酸盐岩台地沉积、台地边缘沉积和深水斜坡—海槽沉积4大沉积类型以及数个亚相和微相,并对各个沉积相带的沉积特征和时空展布进行了归纳和总结。在此基础上,编制了早古生代岩相古地理图1套。岩相古地理研究表明,早寒武世仅在鄂尔多斯西南缘环陆发育了一套泥砂坪、泥云坪沉积;中寒武世海侵扩大,广大的鄂尔多斯中东部逐渐由砂泥坪发展为局限—开阔台地沉积,在其西缘发展为台地边缘—深水海槽沉积;晚寒武世开始海退,中东部主体演变为局限台地云坪沉积,而西侧的深水斜坡—海槽则继续发育。早奥陶世鄂尔多斯主体为一古陆,仅在东南缘形成环陆泥云坪和云灰坪相沉积;中奥陶世的大规模海侵使鄂尔多斯大部地区形成了广阔的浅水陆表海沉积,在陕北凹陷发育膏盐湖沉积,向外依次发育局限台地和开阔台地沉积,中奥陶世晚期西南侧开始发育台地前缘斜坡—深水海槽沉积;晚奥陶世的加里东运动使鄂尔多斯整体抬升为陆,仅在西南缘的狭窄海域接受沉积,由碳酸盐岩台地很快过渡为深水斜坡—海槽沉积,并在南缘发育生物礁建造,形成陆缘海型镶边台地沉积。  相似文献   

13.
In the southeastern Holstein region, located to the east of the metropolitan zone of Hamburg, northern Germany, a groundwater investigation program was conducted from 1984 to 2000 by the State Agency for Nature and Environment (Landesamt für Natur und Umwelt, LANU) of Schleswig-Holstein, Germany, with the aim of providing long-term, ecologically acceptable groundwater management plans for the region. The focal point of the investigation comprised the determination of groundwater recharge rates. The investigation method was based on the transfer of available lysimeter results from other regions to comparable regions within the area studied. With the help of lysimeter equations, potential amounts of percolation water were calculated. The groundwater recharge rate was then determined after subtraction of the surface runoff which was calculated for the entire area. All computations were performed with a spreadsheet program. Groundwater recharge rates were calculated for two areas. One consisted of roughly determining groundwater recharge rates for the total region (1,392 km2) of southeastern Holstein. The overall goal of these investigations was to identify potential areas of water exploitation. Areas in which groundwater recharge rates are high and groundwater outflow is low are particularly suited to water exploitation, since inflow rates into deeper aquifers are high. These areas are located on the flanks of the Elbe and Stecknitz River valleys. Subsurface groundwater runoff to these lowlands would be reduced through groundwater withdrawal. However, the resulting decline in shallow groundwater tables would be so small that it would have no detrimental ecological effects. Groundwater recharge rates were also calculated for a 110-km2 area in the outskirts of Hamburg (Grosshansdorf model area) which is intensively developed for water supply. These investigations showed that the amount of groundwater recharge is already being withdrawn to a large extent. Approximately 65% of the recharge rate is currently withdrawn by the waterworks in this area, thus making further increases in exploitation rates unjustifiable from an ecological point of view. Electronic Publication  相似文献   

14.
综合分析沂南县气候、自然、地理,尤其是地质与水文地质条件,及2011年国土资源抗旱打井工作成果,结合沂南地下水含水岩组分布、赋存、地下水运移特征、构造对岩溶发育与地下水运动的控制等。得出沂南县岩溶地下水补给径流区的构造破碎带及其附近地下水相对富集。地下水富集特征可分为:构造带控水型、火成岩体阻挡富水型、断裂影响带强富水型及远离构造破碎带弱富水型等几种类型。根据岩溶地下水补给径流区地下水富集规律的分析研究,为今后贫水山区找水定井提供参考。  相似文献   

15.
Geochemical data were collected to investigate the effects of topography and focused recharge on the transport of agricultural chemicals to groundwater through sandy soils. The research was done at a topographically high (upland) site and a depressional (lowland) site within a corn field. Agricultural chemicals that move readily with water were most directly affected by focused recharge to the lowland site. Surface runoff of water to the lowland site was the primary cause for the generally greater flux of chloride, nitrate nitrogen, and sulfate compared with the upland site. Based on data from the unsaturated zone, for example, the average annual fluxes of these chemicals in 1992–1993 were 5.1, 3.4, and 1.7 times greater, respectively, at the lowland site. Study results indicate that consideration should be given to modifying site-specific management farming technology to account for varying recharge rates in different topographic settings. By reducing chemical application rates in topographic depressions, where focused recharge of chemicals occurs because of surface runoff, farmers could improve ground-water quality as well as reduce expenditures for agricultural chemicals. Electronic Publication  相似文献   

16.
The spatial distribution of arsenic (As) concentrations along three classified hydrogeomorphological zones in the Brahmaputra River Valley in Assam (India) have been investigated: zone I, comprising the piedmont and alluvial fans; zone II, comprising the runoff areas; and zone III, comprising the discharge zones. Groundwater (150 samples) from shallow hand-pumped and public water supply wells (2–60 m in depth) was analysed for chemical composition to examine the geochemical processes controlling As mobilization. As concentrations up to 0.134 mg/L were recorded, with concentrations below the World Health Organization and the Bureau of Indian Standards drinking-water limits of 0.01 mg/L being found mainly in the proximal recharge areas. Eh and other redox indicators (i.e., dissolved oxygen, Fe, Mn and As) indicate that, except for samples taken in the recharge zone, groundwater is reducing and exhibits a systematic decrease in redox conditions along the runoff and discharge zones. Hydrogeochemical evaluation indicated that zone I, located along the proximal recharge areas, is characterized by low As concentration, while zones II and III are areas with high and moderate concentrations, respectively. Systematic changes in As concentrations along the three zones support the view that areas of active recharge with high hydraulic gradient are potential areas hosting low-As aquifers.  相似文献   

17.
Source, type, and quantity of various components of groundwater, as well as their spatial and temporal variations were determined by different hydrochemical methods in the alluvial aquifer of the upper Rhone River valley, Bois de Finges, Wallis Canton, Switzerland. The methods used are hydrochemical modeling, stable-isotope analysis, and chemical analysis of surface water and groundwater. Sampling during high- and low-water periods determined the spatial distribution of the water chemistry, whereas monthly sampling over three years provided a basis for understanding seasonal variability. The physico-chemical parameters of the groundwater have spatial and seasonal variations. The groundwater chemical composition of the Rhone alluvial aquifer indicates a mixing of weakly mineralized Rhone River water and SO4-rich water entering from the south side of the valley. Temporal changes in groundwater chemistry and in groundwater levels reflect the seasonal variations of the different contributors to groundwater recharge. The Rhone River recharges the alluvial aquifer only during the summer high-water period. Electronic Publication  相似文献   

18.
黑河流域水资源转化特征及其变化规律   总被引:5,自引:3,他引:2  
黑河流域水资源主要以冰雪水资源、 地表水资源与地下水资源的形式存在.上游祁连山区分布有现代冰川428条, 发育大小河流共计29条, 多年平均出山径流量37.83×108m3·a-1; 中下游走廊平原由松散沉积的第四系盆地组成, 接受出山河水及引灌河水的入渗补给, 是地表水资源的重复表现形式, 地下水补给量为25.637×108m3·a-1.受构造-地貌条件的制约, 自南部山区至北部盆地, 地下水与河水之间经过5个不同地带有规律的、 大数量的、 重复的转化过程, 形成完整统一的"山区地下水-出山地表水-中游盆地地下水-中游盆地地表水(泉水)-下游盆地地下水"水资源循环转化系统.  相似文献   

19.

Particularly in arid and semiarid areas, more and more populations rely almost entirely on imported water. However, the extent to which intentional discharge into transiting river systems and unintentional leakage may be augmenting water resources for communities along and down gradient of the water transfer scheme has not previously been subject to research. The objective of this study was to assess both the potential of a large-scale water transfer (WT) scheme to increase groundwater availability by channel transmission losses in a large dryland aquifer system (2,166 km²) in Brazil, and the capability of the receiving streams to transport water downstream under a prolonged drought. An integrated surface-water/groundwater model was developed to improve the estimation of the groundwater resources, considering the spatio-temporal variability of infiltrated rainfall for aquifer recharge. Aquifer recharge from the WT scheme was simulated under prolonged drought conditions, applying an uncertainty analysis of the most influential fluxes and parameters. The annual recharge (66 mm/year) was approximately twice the amount of water abstracted (1990–2016); however, the annual recharge dropped to 13.9 mm/year from 2012 to 2016, a drought period. Under similar drought conditions, the additional recharge (6.89 × 106 m³/year) from the WT scheme did not compensate for the decrease in groundwater head in areas that do not surround the receiving streams. Actually, the additional recharge is counteracted by a decrease of 25% of natural groundwater recharge or an increase of 50% in pumping rate; therefore, WT transmission losses alone would not solve the issue of the unsustainable management of groundwater resources.

  相似文献   

20.
金沙江断裂带中段碳酸盐岩分布区水文地质结构复杂、岩溶水量丰富, 是工程地质安全的重要威胁之一。文章在岩溶地貌和水文地质调查的基础上, 采用水化学和新型同位素测年与示踪的方法, 研究了金沙江断裂带中段岩溶发育特征, 分析了岩溶水补给、径流和排泄过程。结果表明: 岩溶空间分布和地下水补给、径流、排泄均受构造控制; 在垂向上主要存在3个高程级别的岩溶发育分区, 其中二级和三级顶部岩溶的发育时间分别为晚中新世至晚更新世和上新世至晚更新世; 岩溶水补给区海拔4400~4600 m, 主要补给源为大气降水和冰湖水, 水中228Ra/226Ra数据显示非定曲断裂控制范围内水源难以形成跨断裂影响范围的补给; 岩溶水循环速度快, 岩溶大泉的85Kr年龄<15 a, 且基本没有年龄较大的地下水混合; 径流过程中碳酸盐岩溶蚀和阳离子交换作用不充分。在工程中应充分考虑活动断裂影响下岩溶水径流通道空间分布、高水压影响和特殊天气条件带来的地质灾害威胁。   相似文献   

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