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1.
A combination of isotopic and chemical indicators has been used to characterize rainfall, surface water and groundwater in the Heihe River Basin, China. Surface- vs. groundwater chemistry data enabled geographical zones and chemical types to be differentiated. The dissolution of halite, Glauber’s salt, gypsum, dolomite and calcite determine Na+, Cl?, Mg2+, Ca2+, $ {\text{SO}}^{{2 - }}_{4} A combination of isotopic and chemical indicators has been used to characterize rainfall, surface water and groundwater in the Heihe River Basin, China. Surface- vs. groundwater chemistry data enabled geographical zones and chemical types to be differentiated. The dissolution of halite, Glauber’s salt, gypsum, dolomite and calcite determine Na+, Cl, Mg2+, Ca2+, and chemistry, but other processes such as evaporation, ion exchange, and deposition also influence the water composition. The majority of deep confined groundwaters are tritium-free and less mineralized than in the shallow aquifer. Radiocarbon values in the deeper groundwaters range from 18.8 to 38.9 pmc, and 80 pmc probably represents the upper limit of initial 14C activity; this yields ages of approximately 5,960–11,971 years BP, which is about 3,000 years older than those calculated by models in previous work. The shallow aquifer exhibits fairly high and variable tritium activities (4–75 TU), evidence of recent recharge and low residence time (<60 years), which is in line with estimates from previous work. Isotopic signatures indicate formation of deeper groundwaters in a colder and wetter climate during the late Pleistocene and Holocene. The results suggested that significant changes are urgently needed in water-use strategy to achieve sustainable development.
Résumé Une combinaison de plusieurs indicateurs isotopiques et chimiques a été utilisée dans le but de caractériser les précipitations, les eaux de surface et les eaux souterraines dans le Bassin de la Rivière Heihe, en Chine. La confrontation des chimies des eaux souterraines et de surface a permis de différentier plusieurs secteurs géographiques et faciès chimiques. Les compositions chimiques en Na+, Cl, Mg2+, Ca2+, et sont déterminées par la dissolution de la halite, du sel de Glauber, du gypse, de la dolomite et de la calcite, mais d’autres processus peuvent également avoir une influence, comme l’évaporation, les échanges de bases et la sédimentation. La majorité des eaux souterraines captives profondes ne contiennent pas de tritium, et sont moins minéralisées que dans l’aquifère superficiel. Les valeurs de carbone 14 dans l’aquifère le plus profond sont comprises entre 18.8 et 38.9 pcm, pour une valeur maximum probable d’activité initiale de 80 pcm; les ages estimés correspondants sont compris entre 5,960 et 11,971 ans, soit environ 3,000 ans de plus que ceux calculés auparavant par les modèles. L’aquifère superficiel présente des activités tritium plut?t élevées et variables (4 à 75 UT), démontrant l’existence d’une alimentation récente et d’un temps de résidence faible (<60 ans), ce qui concorde avec les études antérieures. Les signatures isotopiques indiquent une alimentation des eaux souterraines les plus profondes au cours d’épisodes climatiques plus froids et plus humides qu’actuellement, à la fin du Pléistocène et à l’Holocène. Les résultats suggèrent que des changements significatifs dans la planification des usages de l’eau sont nécessaires et urgents dans des perspectives d’exploitation durable.

Resumen Se ha utilizado una combinación de indicadores isotópicos y químicos para caracterizar la precipitación, el agua superficial y el agua subterránea en la Cuenca del Río Heihe, China. Los datos químicos de aguas superficiales frente a las subterráneas no permiten diferenciar zonas geográficas y tipos químicos. La disolución de halita, sal de Glauber, yeso, dolomita y calcita determina la química de Na+, Cl, Mg2+, Ca2+, y , pero otros procesos, como evaporación, intercambio de iones y precipitación influyen también en la composición del agua. La mayoría de las aguas subterráneas profundas confinadas no tienen Tritio y están menos mineralizados que el acuífero superficial. Los valores de radiocarbono en las aguas subterráneas más profundas oscilan entre 18.8 y 38.9 pmc, y el valor de 80 pmc representa probablemente el límite superior de la actividad inicial de 14C; proporcionando edades de aproximadamente 5,960–11,971 a?os BP, que son unos 3,000 a?os más antiguas de las calculadas mediante modelización en trabajos previos. El acuífero superficial tiene actividades de tritio bastante más altas y variables (4–75 UT), evidenciando una recarga reciente y unos tiempos de residencia bajos (<60 a?os), lo cual está en la línea de lo estimado en trabajos previos. Los datos isotópicos apuntan a la formación de aguas subterráneas más profundas en un clima más frío y húmedo durante el Pleistoceno superior y el Holoceno. Los resultados sugieren que se necesita hacer cambios significativos en la estrategia de uso del agua para alcanzar un desarrollo sostenible.
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2.
Agricultural practices, hydrology, and water quality of the 267-km2 Big Spring groundwater drainage basin in Clayton County, Iowa, have been monitored since 1981. Land use is agricultural; nitrate-nitrogen (-N) and herbicides are the resulting contaminants in groundwater and surface water. Ordovician Galena Group carbonate rocks comprise the main aquifer in the basin. Recharge to this karstic aquifer is by infiltration, augmented by sinkhole-captured runoff. Groundwater is discharged at Big Spring, where quantity and quality of the discharge are monitored. Monitoring has shown a threefold increase in groundwater nitrate-N concentrations from the 1960s to the early 1980s. The nitrate-N discharged from the basin typically is equivalent to over one-third of the nitrogen fertilizer applied, with larger losses during wetter years. Atrazine is present in groundwater all year; however, contaminant concentrations in the groundwater respond directly to recharge events, and unique chemical signatures of infiltration versus runoff recharge are detectable in the discharge from Big Spring. Education and demonstration efforts have reduced nitrogen fertilizer application rates by one-third since 1981. Relating declines in nitrate and pesticide concentrations to inputs of nitrogen fertilizer and pesticides at Big Spring is problematic. Annual recharge has varied five-fold during monitoring, overshadowing any water-quality improvements resulting from incrementally decreased inputs. Electronic Publication  相似文献   

3.
The report discusses the stable isotope values and major solute compositions of 16 springs and river-water samples along a topographic gradient in the main rift valley of southern Ethiopia. Most of the springs used for drinking water supplies discharge from local flow systems at scales of only tens of meters. The δ18O and δD values of waters unaffected by shallow evaporation form a local meteoric water line of δD=8.1δ18O+19.0, almost identical to that for the eastern Mediterranean area. The δ18O values show an altitude effect of –0.5‰ per 100-m elevation rise. Total dissolved nitrogen concentrations locally exceed 6 mg/L (as N), and phosphate concentrations were elevated above background levels in some springs, exceeding 0.2 mg/L PO4, probably due to agricultural practices upgradient of the springs. Modest well-head protection should be considered to protect public health from the effects of pollution by agricultural waste, given the very local scale of the flow systems providing spring water to Ethiopian villages. Electronic Publication  相似文献   

4.
 The Dawu well field, one of the largest in China, supplies most of the water for the Zibo City urban area in Shandong Province. The field yields 522,400–535,400 m3/d from an aquifer in fractured karstic Middle Ordovician carbonate rocks. Much of the recharge to the aquifer is leakage of surface water from Zihe Stream, the major drainage in the area. Installation of the Taihe Reservoir in 1972 severely reduced the downstream flow in Zihe Stream, resulting in a marked reduction in the water table in the Dawu field. Since 1994, following the installation of a recharge station on Zihe Stream upstream from the well field that injects water from the Taihe Reservoir into the stream, the groundwater resources of the field have recovered. An average of 61.2×103 m3/d of groundwater, mostly from the Ordovician aquifer, is pumped from the Heiwang iron mine, an open pit in the bed of Zihe Stream below the Taihe Reservoir. A stepwise regression equation, used to evaluate the role of discharge from the reservoir into the stream, confirms that reservoir water is one of the major sources of groundwater in the mine. Received, May 1998 / Revised, May 1999 / Accepted, June 1999  相似文献   

5.
 The purpose of this research is to describe a water-storage method that is more reliable than reservoirs, and to study the efficacy of interception and storage of surface runoff in ponds. In this method, a series of ponds is laid out along a streambank so that interception of surface runoff can be increased and more water can be stored in the wet season for use in the dry season. The simulated results show that the structure of a pond, vegetation and the extent of land development, topographic slope, and the degree to which a pond penetrates an aquifer affect the efficacy of interception and storage of surface runoff in ponds. Received, May 1996 Revised, July 1997, March 1998 Accepted, October 1997  相似文献   

6.
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   

7.
东北地区地下水资源可持续利用的主要问题和对策浅析   总被引:2,自引:0,他引:2  
在概述东北地区自然地理和水文地质条件的基础上,从地下水供需矛盾、地下水超采及其环境效应、地下水污染等方面阐述了影响地下水资源可持续利用的主要问题,并从社会发展、科学技术、开采历史、水资源管理、立法与执法等5个层面进行了分析。针对东北地区国民经济发展对水资源的需求、目前存在的影响地下水资源可持续利用的主要问题,提出了不同地区的地下水资源勘查开发、节约用水、地下水理论研究等地下水资源的可持续利用对策,对区域宏观水资源管理具有参考价值。  相似文献   

8.
 "Capture" is the increase in recharge and the decrease in discharge that occurs when pumping is imposed on an aquifer system that was in a previous state of approximate dynamic equilibrium. Regional groundwater models are usually used to calculate capture in a two-step procedure. A steady-state solution provides an initial-head configuration, a set of flows through the boundaries for the modeled region, and the initial basis for the capture calculation. The transient solutions provide the total change in flows through the boundaries. A difference between the transient and steady-state solutions renders the capture calculation. When seasonality is a modeling issue, the use of a single initial hydraulic head and a single set of boundary flows leads to miscalculations of capture. Instead, an initial condition for each season should be used. This approach may be accomplished by determining steady oscillatory solutions, which vary through the seasons but repeat from year to year. A regional groundwater model previously developed for a portion of the San Pedro River basin, Arizona, USA, is modified to illustrate the effect that different initial conditions have on transient solutions and on capture calculations. Received, September 1996 · Revised, October 1997 · Accepted, October 1997  相似文献   

9.
Historically, rights in water originated as public property and only later became individualized rights to utilize the public resource, in a manner consistent with the public welfare needs of society, but protected by principles of property law. Five basic regulatory systems for rights in groundwater in the United States have evolved to date. The problems raised by the hydrologic differences between groundwater hydraulically connected to stream systems and groundwater in non-replenished aquifers have been resolved to some extent by a couple of leading court cases. Numerical modeling and other technical methodologies have also evolved to evaluate the scientific issues raised by the different hydrologic conditions, but these are not immune from criticism. The current role of aquifers is evolving into that of storage facilities for recycled water, and their utilization in this manner may be expanded even further in the future. The policy implications of the choices relating to joint management of ground and surface water cannot be overstated. As this paper demonstrates, proactive administration of future groundwater depletions that affect stream systems is essential to the ultimate ability to plan for exploitation, management and utilization of water resources in a rational way that coordinates present and future demand with the reality of scarcity of supply. The examples utilized in this paper demonstrate the need for capacity building, not just to develop good measurement techniques, or to train talented lawyers and judges to write good laws, but also for practical professional water managers to keep the process on a rational course, avoiding limitless exploitation of the resource as well as conservative protectionism that forever precludes its use.
Charles T. DuMarsEmail: Phone: +1-505-3460998Fax: +1-505-3460997
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10.
Over the last several decades, water users in the western United States have increasingly turned to groundwater resources to support economic development, but few institutional arrangements were in place to govern groundwater use. Over time, numerous groundwater problems have emerged. Two closely related explanations for this are explored. Surface water sources were the first to be developed, and institutional arrangements to allocate surface water were the first to be devised. These arrangements are not particularly well suited for governing groundwater. Furthermore, the physical differences between rivers and aquifers lead to differences in the development of each type of water, and in production and organization costs. Groundwater development involves low upfront production costs, which individual water users can cover. Once groundwater users have individually invested in productive activities problems emerge, such as declining water tables. Thus, unlike surface water users, groundwater users are faced with devising institutional arrangements to coordinate their water uses after they have invested in and developed productive economic activities. Most western states regulate pumping, although groundwater users, in general, resist pumping limits. The discussion concludes with proposals for modifying the prior appropriation doctrine to better accommodate the active management of groundwater basins for long-term sustainability.
Edella SchlagerEmail: Phone: 520-621-5840
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11.
In order to solve water resources problems in the North China Plain, this paper explored human-nature compound water circulation system from three aspects including urban flood control, surface drainage and saline water in the central and eastern of the North China Plain. Results show that: (1) The technical methods have achieved zero increase in rainwater runoff in urban areas, (2) surface drainage depletion problems can be solved through abandoned water and river water separation method, (3) and technical method through promoting rainwater infiltration would be used to solve problem of saline water in the central and eastern parts. This research provides a new perspective to the ultimate solutions to water resources problems in the North China Plain, and a fresh research direction for the development of hydro-geological science.  相似文献   

12.
Groundwater mounds and hinge lines are important features related to the interaction of groundwater and lakes. In contrast to the transient formation of groundwater mounds, numerical simulations indicate that permanent groundwater mounds form between closely spaced lakes as the natural consequence of adding two net sinks to a groundwater flow system. The location of the groundwater mound and the position of the hinge lines between the two lakes are intimately related. As the position of the mound changes there is a corresponding shift in the position of the hinge line. This results in a change in the ratio of groundwater inflow to outflow (Qi/Qo) for the lake. The response of the lake is an increase or decrease in the lake level. Our simulations indicate that the movement of the hinge line in a natural system is a consequence of the dynamic interrelationships between recharge, the slope of the water table upgradient and downgradient of the lake, and the loss of water from the lake by evaporation. The extent of the seasonal movement of the hinge line will vary from one year to the next depending on local changes in the magnitude of the hydrologic variables. Electronic Publication  相似文献   

13.
On the basis of the isotopic composition of water in the northern part of Epirus, Greece, from springs at different altitudes with well-defined recharge areas, the altitude effect on the δ18O value of groundwater is –0.142±0.003ö (100?m)–1 and is uniform over the entire study area. Using the δ18O composition of surface water and groundwaters, the contribution of Ioannina Lake and the channel draining the lake water to the Kalamas River to the recharge of springs and boreholes was confirmed and quantitatively defined. In contrast, the Voidomatis and Vikos Rivers are not sources for recharge of the big springs along their banks. However, water from the Aoos River does replenish the aquifer in the unconsolidated deposits underlying the plain of Konitsa. In addition, limestones of Senonian–Late Eocene ages, dolomites, and limestones of the "Vigles" facies are hydraulically interconnected, and the limestones of the "Pantokrator" facies are hydraulically isolated from the other carbonate formations.  相似文献   

14.
Analysis of base flow trends in urban streams, northeastern Illinois, USA   总被引:2,自引:1,他引:1  
Statistical analysis shows that mean annual base flows in three unregulated urban streams in northeastern Illinois do not display significant trends during periods of substantial watershed urbanization. However, statistically-significant upward trends in median annual base flow (probably emblematic of overall changes in the time-distribution of the base flow), characterized by increases in lower base flow rates, affected the flows in all three streams. The analysis reveals no trends in annual and monthly precipitation during these periods. These results are in contrast to results from studies of other urban streams that have shown decreases in base flow, but these results may be partially explained by the low permeability of the near-surface materials in the watersheds investigated. This study employs formal hypothesis-testing of Kendall tau-a trend statistics computed for monthly and annual base flow and precipitation rates to assess the impact of urban development on base flow rates.
Resumen El análisis estadístico muestra que el flujo base anual medio en tres arroyos urbanos no regulados en el noreste de Illinois no ostenta tendencias significativas durante los periodos de urbanización sustancial de la cuenca. Sin embargo, el flujo en los tres arroyos fue afectado por tendencias al incremento en el flujo base annual medio. Esto es probablemente emblemático en cambios globales en el tiempo-distribución del flujo base caracterizado por incrementos en las tasas de flujo base bajo y afecta a los tres arroyos. El análisis no revela ninguna tendencia en la precipitación annual y mensual durante estos periodos. Estos resultados contrastan con los resultados de estudios de otros arroyos urbanos que muestran un decrecimiento en el fujo base. Sin embargo, estos resultados pueden explicarse parcialmente por la baja permeabilidad de los materiales cercanos a la superficie en las cuencas investigadas. Este estudio emplea las estadísticas de tendencia tau-a de la hipótesis de prueba formal de Kendall - calculadas según los flujos base mensuales y anuales y las tasas de precipitación. El objetivo es evaluar los impactos del desarrollo urbano sobre las tasas de flujo base.

Résumé Une analyse statistique démontre que la moyenne annuelle de lécoulement de base dans trois rivières urbaines non réglementées du nord est de lIllinois ne montre pas de tendance significative lors de périodes durbanisation massive du bassin versant. Par contre, une tendance statistiquement significative à la hausse de lécoulement de base médian, probablement représentatif de lensemble des changements dans la distribution temporelle de lécoulement de base caractérisé par une augmentation des faibles taux découlement de base, affecte lécoulement dans les trois rivières. Lanalyse ne révèle pas de tendance dans les précipitations annuelles et mensuelles lors de ces périodes. Ces résultats contrastent avec les résultats dautres études de rivières en milieu urbain qui ont montré une diminution de lécoulement de base. Les résultats obtenus lors de cette étude peuvent partiellement être expliqués par la faible perméabilité des dépôts de surface dans le bassin versant étudié. Cette étude utilise le test dhypothèse tau de Kandall, une tendance statistique calculée pour lécoulement de base annuel et mensuel et des taux de précipitation dans le but de déterminer limpact du développement urbain sur les taux découlement de base.
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15.
Relation of streams, lakes, and wetlands to groundwater flow systems   总被引:24,自引:10,他引:14  
 Surface-water bodies are integral parts of groundwater flow systems. Groundwater interacts with surface water in nearly all landscapes, ranging from small streams, lakes, and wetlands in headwater areas to major river valleys and seacoasts. Although it generally is assumed that topographically high areas are groundwater recharge areas and topographically low areas are groundwater discharge areas, this is true primarily for regional flow systems. The superposition of local flow systems associated with surface-water bodies on this regional framework results in complex interactions between groundwater and surface water in all landscapes, regardless of regional topographic position. Hydrologic processes associated with the surface-water bodies themselves, such as seasonally high surface-water levels and evaporation and transpiration of groundwater from around the perimeter of surface-water bodies, are a major cause of the complex and seasonally dynamic groundwater flow fields associated with surface water. These processes have been documented at research sites in glacial, dune, coastal, mantled karst, and riverine terrains. Received, April 1998 · Revised, July 1998, August 1998 · Accepted, September 1998  相似文献   

16.
华北平原地下水演变机制与调控   总被引:6,自引:0,他引:6  
自20世纪70年代以来,华北平原长期的地下水过量开采形成了复杂的地下水降落漏斗,并引发了一系列环境地质问题。为建立区域社会经济发展与地下水资源与环境之间的协调机制,国家973项目"华北平原地下水演变机制与调控"在大量前人研究基础上,进一步分析了近50年来地下水动力场演变特征及其对人类活动的响应,揭示了包气带结构变化影响下包气带水力参数的变化,研究了深层地下水开采引起的地面沉降、咸水移动和资源量转换机理;利用改进的地下水数值模拟技术,建立了2001—2010年华北平原地下水流数值模型,计算了最新的地下水资源量。分析了地下水资源承载力的主要影响因素,进行了华北平原地下水资源承载力定量评价,给出了华北平原地下水的优化调控途径,目前正在以高精度地下水流数值模型为核心,模拟各区的地下水优化调控方案。  相似文献   

17.
西北地区水资源若干问题探讨   总被引:8,自引:0,他引:8  
在对我国西北地区水资源及开发利用现状进行分析的基础上,针对如何认识西北地区的缺水问题,如何评价西北地区地下水资源的重要性,怎样看待深层地下水资源以及开采地下水可能引起的环境地质问题等,进行了较深入的分析论述。指出进一步查清西北地区地下水资源,尤其是中深层地下水资源,并加以科学、适度的开发和合理利用,是解决西北地区水资源短缺问题的重要途径之一。  相似文献   

18.
中国北方岩溶水变化特征及其环境问题   总被引:5,自引:14,他引:5  
随着自然条件改变和人类活动强度的加大,我国北方岩溶水系统从输入、输出到结构、水资源要素转换关系均发生了巨大变化,在短短几十年内有近30%岩溶大泉断流,80%泉水流量大幅度衰减,区域岩溶地下水位每年以1~2m速度持续下降,同时,有20%以上的岩溶水系统主排泄带的水质在Ⅲ类以下且总体趋向恶化,此外,还存在着矿坑突水,岩溶塌陷、地裂,海水入侵,旅游功能降低,生态功能丧失等诸多的岩溶水环境问题,极大地加剧了水资源的紧张状况。本文根据前人成果和实地调查资料并采用一些典型事例归纳总结了岩溶水环境问题及其发展演化趋势,展示北方岩溶水面临的严峻形势,以引起社会各界对此问题的关注,加大岩溶水资源调查研究与保护力度,同时,也为广大学者开展相关立项与研究提供参考。   相似文献   

19.
The demand of water is increasing with the socioeconomic development, and the contradictions between supply and demand of water resources in regional scale have become increasingly intensified. Scientifically evaluating the risk caused by the contradictions between supply and demand of water resources has become a useful way to solve the imbalance of water resources effectively. In the current study, the utilization of water resources in Songliao Basin was analyzed based on the water quantity, water quality, and socioeconomic data in 1999?C2006. Accordingly, a risk-evaluation index system of water resources utilization was generated, which included ten indicators, such as the total quantity of regional water resources. Three common factors (i.e., high water-demand, high water-supply, and low-quality water) were identified by factor analysis. These factors were then evaluated with spatial clustering. Thus, the risk distribution of water resources was made in the study area. The results indicate that (1) the pattern of water resources utilization in Songliao Basin was high risk in Songnei Plain and low risk in Changbaishan Mountain, and (2) Nenjiang and Songhua Rivers were high risk; however, Tumen and Wusuli Rivers were low risk.  相似文献   

20.
北京平原地下水可持续开采方案分析   总被引:4,自引:1,他引:3       下载免费PDF全文
地下水过量开采已经引起北京平原地下水位持续下降,降落漏斗逐年扩大以及一系列环境问题。控制地下水开采,增加地下水补给以达到地下水可持续开采应当成为北京市水资源管理的重要任务。本文根据北京市中长期供水规划、水资源特点和地下水开采现状设计了4种地下水开发利用开采方案:即维持现状开采、增加补给量、减少开采量以及联合方案。运用已建北京平原地下水数值模拟模型对4个方案进行了模拟,分析了地下水系统水均衡量变化,地下水流场变化以及地下水动态变化,以此确定可能的可持续开发方案。结果表明,维持现状开采必将使含水层地下水疏干;增补和减开单独实施虽能改善现状,但难以实现。只有应用增补和减开的联合方案,才有可能实现地下水可持续开发。其为北京平原地下水资源的合理开发提供重要的依据。  相似文献   

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