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1.
It is important to understand how groundwater recharge responds to precipitation variability in space and time, especially in those areas such as Yanqing Basin (China), where groundwater represents the sole water resource. A simple soil-water balance method is applied for spatio-temporal simulation of groundwater recharge in Yanqing Basin from 1981 to 2000. It was implemented on a monthly time step considering the effects of land use and soil texture. The area-average recharge associated with various land uses and soil textures was then compared with zonal analysis using a geographic information system (GIS). The main findings include: (1) the variation of groundwater recharge follows precipitation changes, either at yearly or seasonal intervals, (2) land use plays a more influential role in groundwater recharge than soil texture in this area, and (3) the water table quickly rises in response to recharge in the shallow parts of the aquifer, while there is a delay of 0.5–1.0?years where the groundwater level is at depth 4–10?m. The application demonstrates how spatio-temporal analysis can be utilized for groundwater-recharge estimation through distributed modeling and GIS.  相似文献   

2.
地表水与地下水相互转化是中国西北干旱内流盆地水循环的显著特征,转化机制研究是盆地水循环规律认知和水资源可持续管理的重要基础。以我国西北干旱内流河黑河流域中游的张掖盆地和盐池盆地为研究区,建立了黑河主干河道时变水平衡模型和地表水地下水耦合数值模型,研究了长周期水文变化和人类活动双重影响下地表水与地下水转化机制,得到如下认识:(1)补给条件由以天然条件下河流渗漏为主的线状补给演变为以河流与引水渠道渗漏的线状补给和灌区田间入渗面状补给,排泄条件由以泉水溢出和天然湿地排泄演变为以泉水溢出与地下水开采为主的排泄。(2)张掖盆地黑河干流河道入渗段和溢出段大致以G312 大桥为界,亦称为地表水与地下水转化的转折点。莺落峡—G312 大桥段为悬河渗漏段,河道入渗补给主要受控于进入河道的实际过水量。其中,莺落峡—草滩庄段河道入渗补给率为28.20 %;草滩庄—G312 大桥段河道入渗补给量与河道过水量的关系可用分段函数表达,河道过水量大于或等于0.37×108 m3/mon时呈幂函数关系,小于则呈线性函数关系。G312 大桥—正义峡段为地下水溢出段,其中G312大桥—平川大桥段地下水溢出量约占全部溢出量的70%,溢出峰值出现在高崖水文站下游约6 km处,其单长溢出量可达0.46 m3/(s·km)。(3)研究区是一个相对完整的河流—含水层系统,近31年来经历了连枯和连丰的水文变化,地下水补给排泄条件及与地表水转化机制均发生了相应的变化。地表水与地下水转化最强烈的地区为张掖盆地中部的黑河—梨园河倾斜平原。1990—2001 年连枯期,灌区引水量总体逐年减少,以河道入渗和渠系渗漏为主的补给量平均以0.06×108 m3/a速率减少,农田灌溉面积增加导致灌溉用水增加,地下水开采量显著增加,地下水水位逐年下降,储存量累计减少5.77×108 m3,地下水溢出量平均减少0.16×108 m3/a;而2002—2020 年连丰期,灌区引水量总体逐年减少,河道入渗量呈增加趋势,地下水总补给量平均增加0.15×108 m3/a,灌溉面积继续扩大,农灌开采量随之增加,以河道入渗量增加为主导,地下水水位持续上升,储存量累计增加5.45×108 m3,地下水溢出量平均增加0.08×108 m3/a。总之,补给和排泄条件变化较大,地下水储存量先减后增,地下水溢出总量变化较为平缓,反映了该区巨厚含水层系统的巨大调蓄功能。(4)位于张掖盆地东部的诸河倾斜平原地下水水位长期处于持续下降状态,这是由于地表水开发过度,补给量锐减。黑河侵蚀堆积平原地下水水位基本稳定。30 多年来盐池盆地倾斜平原地下水水位长期处于持续下降状态,这是由于移民开垦导致地下水过量开采。(5)内流盆地天然悬河入渗段是珍贵的地下水补给通道,无论连枯期还是连丰期,河道实际过水量是河道渗漏补给量的关键,保护上游天然河道和一定的河道实际过水量是内流盆地水资源可持续管理的关键。  相似文献   

3.
北京市平原区地下水更新能力变化的动态均衡证据   总被引:1,自引:0,他引:1  
对北京市地下水更新能力的时空变化进行分析,为地下水资源管理提供依据。用地下水动态均衡法对北京市平原区地下水,尤其是开采层地下水的补给量、更新周期、更新速率和补给速率等参数做了计算,进而对地下水更新能力及其时空变化做评价和分析。研究结果表明:在自然状态下,地下水更新能力总体上自山前至平原区腹地由强变弱,但总体上更新能力较强;含水层接受外来水源补给的边界条件和赋水条件良好,降水量的多寡是影响地下水更新能力的瓶颈因素;2001-2008年的地下水平均补给速率(0.28 m/a)比1981-2000年减少了35.6%,更新能力明显减弱;近些年地下水开采强度连年大于其更新能力,导致与自然状态下相比地下水位埋深平均下降幅度已达19.73 m,含水层中地下水减少量达101×108 m3。以上证据表明,在气候变化和人类活动的双重影响下,北京市未来的地下水资源可持续供水问题十分严峻。  相似文献   

4.
An overview is presented of existing groundwater-age data and their implications for assessing rates and timescales of recharge in selected unconfined aquifer systems of the United States. Apparent age distributions in aquifers determined from chlorofluorocarbon, sulfur hexafluoride, tritium/helium-3, and radiocarbon measurements from 565 wells in 45 networks were used to calculate groundwater recharge rates. Timescales of recharge were defined by 1,873 distributed tritium measurements and 102 radiocarbon measurements from 27 well networks. Recharge rates ranged from?<?10 to 1,200?mm/yr in selected aquifers on the basis of measured vertical age distributions and assuming exponential age gradients. On a regional basis, recharge rates based on tracers of young groundwater exhibited a significant inverse correlation with mean annual air temperature and a significant positive correlation with mean annual precipitation. Comparison of recharge derived from groundwater ages with recharge derived from stream base-flow evaluation showed similar overall patterns but substantial local differences. Results from this compilation demonstrate that age-based recharge estimates can provide useful insights into spatial and temporal variability in recharge at a national scale and factors controlling that variability. Local age-based recharge estimates provide empirical data and process information that are needed for testing and improving more spatially complete model-based methods.  相似文献   

5.
在鄂尔多斯盆地都思兔河流域供水水文地质详查的基础上,通过水文地质钻探、抽水试验、样品分析等手段,查明了流域含水层的结构、埋深以及含水层和隔水层在水平和垂直方向上的变化规律,探讨了各含水层之间的水力联系,并求取了含水层的水文地质参数;对比圈定了包乐浩晓、巴彦布拉格、好勒包勒吉3处富水区;采用地下水流数值模拟方法对上述3处富水区地下水开采量进行计算,提出了27种地下水开采方案,并经过对比得到地下水开采推荐方案。结果表明:包乐浩晓、巴彦布拉格、好勒包勒吉3处富水区主要补给为侧向径流及大气降水入渗补给,排泄方式以潜水面蒸发及向河流排泄为主;在地下水浅埋区,结合含水层单井涌水量的大小,确定采用管井开采方式、中段悬挂式非完整井结构,平均布井,井深300m,单一开采白垩系环河组的地下水,最大限度夺取潜水蒸发排泄量;根据推荐方案,上述3个富水区总开采量达到123500m3/d,可为该地区地下水资源开发与利用提供技术保障。  相似文献   

6.
In a semiarid region, the karst aquifer generally forms a large groundwater reservoir that can play an important role in regional water supply. But because of the specific physical properties of karst aquifers, they are vulnerable to pollution and anthropogenic impacts. Karst groundwater management strategies are vital. As representative of karst springs in a semiarid area, Niangziguan Springs is located in the east of Shanxi Province, China with an annual average rate of discharge of 10.34 m3/s (1956–2003) (Y. Liang, unpublished data). The Niangziguan Spring Basin covers an area of 7,394 km2 with an annual average precipitation of 535 mm (1958–2003) (Hao et al. in Carsologica Sinica 23(1):43–47, 2004). Over the past three decades, accelerated groundwater exploitation has caused water-table decline in the aquifer, reduction of the spring discharge, and deterioration of water quality. In this study, three protection zones were defined to ensure the quality and capacity of this resource. The confluence of the 11 spring systems and the discharge areas were defined as I protection zone, the recharge basin was II protection zone, and the slack water area where there is little surface recharge was the III protection zone. Management strategies for each zone were suggested and evaluated to provide a scientific foundation for sustainable utilization.  相似文献   

7.
再生水在北京被广泛用于补给河道,2007年底至2017年共有2.3×108 m3再生水补给至潮白河顺义段。其污染物本底值较高(Cl?浓度约62~122 mg/L),通过河床入渗补给到周边的含水层中,对周边地下水产生一定影响,尤其是浅层地下水。为了定量评价再生水补给河道对周边浅层地下水的影响,基于10年(2007—2017)的地下水监测数据,建立了再生水补给河道周边的地下水水流和溶质运移模型,模拟了受水区浅层地下水的水位和Cl?浓度的变化,分析了浅层地下水水量、Cl?负荷和NO3-N负荷的变化。结果表明,再生水补给河道后的前2年(2007—2009),河道周边浅层地下水水位迅速抬升了3~4 m,之后在再生水的持续补给下保持稳定。但受深层地下水开采影响,2007—2014年研究区整体浅层地下水的水量仍在下降。2014年底实施地下水压采措施后,浅层地下水水量从2014年底的3.76×108 m3恢复到了2017年底的3.85×108 m3。周边浅层地下水中的Cl?浓度从再生水补给前的5~75 mg/L变化到了补给后的50~130 mg/L,之后保持稳定。浅层地下水水质受再生水影响的范围从2008年底的11.7 km2扩大到2017年的26.7 km2,影响区内的Cl?负荷从2008年底的1.8×103 t增加到2017年底的3.8×103 t,NO3-N负荷从2008年的29.8 t下降到2017年的11.9 t。尽管研究显示影响范围外的浅层地下水质受再生水影响不明显,但潜在的咸化和污染的隐患不容忽视,需要在后续研究中进一步明确。  相似文献   

8.
山区地下水对平原区的侧向径流补给量是一个长期争议且悬而未决的难题,这个量在西北内陆干旱盆地,被估算得或很小或很大。在总结前人研究的基础上,采用地质水文地质调查、物探、钻探、抽水试验、地下水动态观测、水化学测试、盆地地下水水位统测和综合研究等技术方法,查明了黑河中游盆地南部山盆交接带的地质构造接触关系、地层岩性接触关系及梨园河口白垩系风化壳含水层结构和水文地质参数。通过山区不同流域等级的地表水与地下水转化关系分析,将山区地下水对平原区侧向径流补给带划分为大中型河流河谷补给段和小微型河流或冲沟群流域构成的浅山带补给段。河谷补给段勘探资料较为丰富,多用达西断面流方法计算;针对浅山带补给段极为缺乏勘探资料的实际,以梨园河口断面径流量为参照,构建了浅山带岩性、汇水区面积、降水量等3 个变量的山区地下水对平原区侧向径流补给量的估算方法。估算出黑河中游盆地南部山区浅山带地下水对平原的侧向径流补给量为0.40×108 m3/a,河谷段基岩侧向补给量为0.07×108 m3/a;推算出河谷段第四系地下水补给量为0.30×108 m3/a;3 项补给量之和为0.77×108 m3/a,占盆地地下水资源量的3.0%。该研究为西北内陆干旱盆地山区地下水对平原区侧向径流补给量的估算提供了一个可供借鉴的实例。  相似文献   

9.
The objective of this study is to refine the understanding of recharge processes in watersheds representative for karstic semiarid areas by means of stable isotope analysis and hydrogeochemistry. The study focuses on the Granada aquifer system which is located in an intramontane basin bounded by high mountain ranges providing elevation differences of almost 2900 m. These altitude gradients lead to important temperature and precipitation gradients and provide excellent conditions for the application of stable isotopes of water whose composition depends mainly on temperature. Samples of rain, snow, surface water and groundwater were collected at 154 locations for stable isotope studies (δ18O, D) and, in the case of ground- and surface waters, also for major and minor ion analysis. Thirty-seven springs were sampled between 2 and 5 times from October 2004 to March 2005 along an altitudinal gradient from 552 masl in the Granada basin to 2156 masl in Sierra Nevada. Nine groundwater samples were taken from the discharge of operating wells in the Granada basin which are all located between 540 and 728 masl. The two main rivers were monitored every 2–3 weeks at three different altitudes. Rainfall being scarce during the sampling period, precipitation could only be sampled during four rainfall events. Calculated recharge altitudes of springs showed that source areas of mainly snowmelt recharge are generally located between 1600 and 2000 masl. The isotope compositions of spring water indicate water sources from the western Mediterranean as well as from the Atlantic without indicating a seasonal trend. The isotope pattern of the Quaternary aquifer reflects the spatial separation of different sources of recharge which occur mainly by bankfiltration of the main rivers. Isotopic signatures in the southeastern part of the aquifer indicate a considerable recharge contribution by subsurface flow discharged from the adjacent carbonate aquifer. No evaporation effects due to agricultural irrigation were detected.  相似文献   

10.
Quantitative evaluations of the impact of groundwater abstraction on recharge are rare. Over a period (1975??007) during which groundwater abstraction increased dramatically in the Bengal Basin, changes in net groundwater recharge in Bangladesh are assessed using the water-table fluctuation method. Mean annual groundwater recharge is shown to be higher (300??00?mm) in northwestern and southwestern areas of Bangladesh than in southeastern and northeastern regions (<100?mm) where rainfall and potential recharge are greater. Net recharge in many parts of Bangladesh has increased substantially (5??5?mm/year between 1985 and 2007) in response to increased groundwater abstraction for irrigation and urban water supplies. In contrast, net recharge has slightly decreased (??.5 to ???mm/year) in areas where groundwater-fed irrigation is low (<30% of total irrigation) and where abstraction has either decreased or remained unchanged over the period of 1985??007. The spatio-temporal dynamics of recharge in Bangladesh illustrate the fundamental flaw in definitions of “safe yield??based on recharge estimated under static (non-pumping) conditions and reveal the areas where (1) further groundwater abstraction may increase actual recharge to the shallow aquifer, and (2) current groundwater abstraction for irrigation and urban water supplies is unsustainable.  相似文献   

11.
This study investigates the hydraulic conductivity field and the groundwater flow pattern as predicted by a calibrated steady state groundwater flow model for the Keta Strip, southeastern Ghana. The hydraulic conductivity field is an important parameter in evaluating aquifer properties in space, and in general basin-wide groundwater resources evaluation and management. This study finds that the general hydraulic conductivity of the unconsolidated unconfined aquifer system of the Keta Strip ranges between 2 m/d and 20 m/d, with an average of 15 m/d. The spatial variation in horizontal hydraulic conductivity appears to take the trend in the variations in the nature of the material in space. Calibrated groundwater recharge suggests that 6.9–34% of annual precipitation recharges the shallow aquifer system. This amount of recharge is significant and suggests high fortunes in terms of groundwater resources development for agriculture and industrial activities in the area. A spatial distribution of groundwater recharge from precipitation is presented in this study. The spatial pattern appears to take the form of the distribution in horizontal hydraulic conductivity, and suggests that the vertical hydraulic conductivity takes the same pattern of spatial variation as the horizontal hydraulic conductivity. This is consistent with observations in other areas. The resulting groundwater flow is dominated by local flow systems as the unconfined system is quite shallow. A general northeast – southwest flow pattern has been observed in the study area.  相似文献   

12.
The Nyamandhlovu aquifer is the main water resource in the semi-arid Umguza district in Matebeleland North Province in Zimbabwe. The rapid increase in water demand in the city of Bulawayo has prompted the need to quantify the available groundwater resources for sustainable utilization. Groundwater recharge estimation methods and results were compared: chloride mass balance method (19–62 mm/year); water-table fluctuation method (2–50 mm/year); Darcian flownet computations (16–28 mm/year); 14C age dating (22–25 mm/year); and groundwater modeling (11–26 mm/year). The flownet computational and modeling methods provided better estimates for aerial recharge than the other methods. Based on groundwater modeling, a final estimate for recharge (from precipitation) on the order of 15–20 mm/year is believed to be realistic, assuming that part of the recharge water transpires from the water table by deep-rooted vegetation. This recharge estimate (2.7–3.6% of the annual precipitation of 555 mm/year) compares well with the results of other researchers. The advantages/disadvantages of each recharge method in terms of ease of application, accuracy, and costs are discussed. The groundwater model was also used to quantify the total recharge of the Nyamandhlovu aquifer system (20?×?106–25?×?106 m3/year). Groundwater abstractions exceeding 17?×?106 m3/year could cause ecological damage, affecting, for instance, the deep-rooted vegetation in the area.  相似文献   

13.
海河流域地下水资源保护   总被引:8,自引:2,他引:8  
地下水资源在海河流域至关重要的资源。海河平原的浅层和深层含水层大面积处于严重超采状态。地下水资源的的过量开采造成了严重环境问题。为了保护地下水资源,评价了可行的技术。利用洪水和废水进行人工回灌已进行了试验。在很多地区可以应用地表回灌系统,城市地区实施深层含水层的回灌。更好地策略是减少地下水的抽取量,特别是为了减缓地面沉降和海水入侵。应该联合运用减少地下水抽水量和人工回灌,以解决地下水位持续下降和含水层恢复的问题。  相似文献   

14.
大兴迭隆起隐伏岩溶水资源评价及开采方案预测   总被引:2,自引:2,他引:0  
大兴迭隆起地区隐伏岩溶地下水是北京市的重要水源,为保障水源地能持续为大兴、通州地区提供优质的城镇生活用水,需对研究区岩溶地下水进行水资源评价和开采规划预测分析。利用数值模拟法,应用GMS模拟软件对研究区岩溶水系统进行地下水流数值模拟及水位变化预测。建立的岩溶水系统模型分为5层,模拟验证期为12年9个月。由模型评价的岩溶水系统补给资源量为14 425.74×10^4m3/a,可开采资源量为14 310.52×10^4m3/a,其中岩溶含水层可开采量为2 309.36×10^4m3/a。在模型识别验证后,分4种开采方案对水源地进行开采预测,通过对典型观测孔水位过程线拟合和研究区水均衡分析可知,按2020年之前维持现状开采,2020年后停采念坛水源地,2025年后全区按可开采量进行开采的开采方案最为合理,可分批逐次实现水源地的采补平衡。  相似文献   

15.
华北平原区域水资源特征与作物布局结构适应性研究   总被引:11,自引:1,他引:11  
据野外调查、遥感和综合研究表明, 近50年来华北平原粮食产量持续增加导致农业区地下水开采量不断增大, 同时灌溉节水水平的不断提高有效地缓解了农业开采量增加的速率。在1977年之前, 每增产10000t小麦和玉米, 多年平均实际开采量增加0.14?108 m3; 在1978年以来, 每增产10000t小麦和玉米, 多年平均实际开采量增加0.04?108 m3。以2001~2005年平均耗用地下水的开采强度(0.53 m3/kg)计算, 粮食增产促使地下水开采量平均每五年递增2.45×108 m3/a, 实际平均每五年少增加9.45×108 m3/a。降水量减小, 补给量变少, 开采量增大; 降水量增大, 补给量较多, 开采量减小。在连续枯(丰)水年份, 当年降水量减少(增加)10%时, 地下水系统水量减少7.98% (增加7.67%)。因此, 需要大力发展抗旱节水作物及高产节水技术, 合理调控农业种植结构, 对于缓解研究区地下水不断恶化态势具有实质性促进作用。  相似文献   

16.
Environmental isotopes have been applied to analyze confined groundwater recharge in the lower reaches of the Heihe River,Inner Mongolia.CFC is regarded as a tracer that determines the date of groundwater,the date being less than 45 a.The confined groundwater within the Gurinai area and Ejin Basin other than the surface water of Heihe River might have originated from precipitation from Qilian Mountain or/and the Tibetan Plateau.The deep confined groundwater overflows into an upper aquifer and emerges into the ground,forming springs and lakes within the low-lying area.The recharge volume is estimated to be around 400 million-cubic meters.  相似文献   

17.
南水北调是国家级的重大水利工程,调水效果最终依赖于接收调水地区对调水的具体利用,引水补源工程是南水北调工程在邹平市的具体利用。为评价引水补源工程对黛溪河流域地下水的补给效果,在分析邹平市引水补源工程实施后黛溪河流域地下水资源的各个补给项的基础上,采用水均衡法计算各个地下水补给量,确定了黛溪河流域引水补源的总补给量。将总补给量视为本区地下水可开采资源量,将地下水可开采资源量与本区用水所需的地下水开采量相比较,对本区地下水资源可开采潜力进行了评价,论证了引水补源工程可有效缓解区内地下水超采问题。另外,还充分利用年地下水动态和多年地下水位动态变化等监测资料,揭示了引水补源工程对区内地下水的有效补充作用,为区内合理开发利用地下水资源提供了依据。  相似文献   

18.
The South-to-North Water Diversion Project is a major national water conservancy project, but the effect of the water transfer depends on the utilization of water in the receiving areas. Water Diversion and Source Supplement Project is a specific utilization of the South-to-North Water Diversion Project in Zouping City. In order to analyze the effect of Water Diversion and Source Supplement Project on groundwater recharge in Daixi River Basin, the authors adopted the water balance method to calculate the groundwater recharge and total recharge of water diversion sources, based on the analysis of the groundwater recharge items in Daixi River Basin after carrying out this project. The total recharge is regarded as the amount of exploitable groundwater resources. The exploitable potential of groundwater resources in this area is evaluated by the comparison of the amount of exploitable groundwater resources and the actual amount of groundwater exploitation, and the effect of Water Diversion and Source Supplement Project on the over-exploitation of groundwater on the remission area was also demonstrated. Besides, the effective replenishment effect of this project on the groundwater in the study area was also revealed based on the annual groundwater and multi-year groundwater level dynamic monitoring data, which provides some reference for the rational development and utilization of groundwater resources in this region.  相似文献   

19.
 The Heretaunga Plains, Hawke's Bay, New Zealand, is underlain by Quaternary fluvial, estuarine-lagoonal, and marine deposits infilling a subsiding syncline. Within the depositional sequence, river-channel gravels form one of the most important aquifer systems in New Zealand. An interconnected unconfined–confined aquifer system contains groundwater recharged from the Ngaruroro River bed at the inland margin of the plain, 20 km from the coast. At the coast, gravel aquifers extend to a depth of 250 m. In 1994–95, 66 Mm3 of high quality groundwater was abstracted for city and rural water supply, agriculture, industry, and horticulture. Use of groundwater, particularly for irrigation, has increased in the last 5 years. Concern as to the sustainability of the groundwater resource led to a research programme (1991–96). This paper presents the results and recommends specific monitoring and research work to refine the groundwater balance, and define and maintain the sustainable yield of the aquifer system. Three critical management factors are identified. These are (1) to ensure maintenance of consistent, unimpeded groundwater recharge from the Ngaruroro River; (2) to specifically monitor groundwater levels and quality at the margins of the aquifer system, where transmissivity is <5000 m2/d and summer groundwater levels indicate that abstraction exceeds recharge; (3) to review groundwater-quality programs to ensure that areas where contamination vulnerability is identified as being highest are covered by regular monitoring. Received, January 1998 / Revised, August 1998, March 1999 / Accepted, April 1999  相似文献   

20.
黑龙洞泉域地下水流数值模拟与预测   总被引:2,自引:0,他引:2  
张勇  田胜龙  赵云云 《地球科学》2008,33(5):693-698
为了对黑龙洞泉域水资源进行评价, 通过对地质条件、水位观测资料的深入研究, 以水均衡原理、地下水渗流理论为基础, 建立了黑龙洞泉域地下水渗流数值模型.以灰色序列预测模型为辅助手段, 结合历年的降水规律, 对未来现状开采条件下的年均降水量、地下水流场、水位及泉流量进行了不同保证率条件下的预测, 若2010年为丰水年(保证率20%)、平水年(保证率50%)、枯水年(保证率75%), 黑龙洞泉汛期地下水位标高分别为超过130m、达到130m、低于130m, 汛期泉流量分别为超过10m3/s、7m3/s、5m3/s.计算结果有利于指导黑龙洞泉域地下水资源的管理和开发利用.   相似文献   

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