北京市地下水资源开采的现状和问题

目前北京市地下水资源已处在多年超量开采、地质环境质量不断下降的状况,建议：第四系地下水不宜扩大开采,应急水源地不应作为常规后备水源使用,北京市需依靠节水、扩大再生水利用、实施水资源联合调蓄等一系列措施解决北京市水资源问题,同时结合科学合理确定城市规模,调整经济产业结构等措施,启动涵养恢复地下水资源等工程,保证首都的供水安全。     

北京市潮白河、怀河地区奥运应急水源地CSAMT勘查研究

为查清奥运应急水源地的地下水赋存情况,应用可控源音频大地电磁法（CSAMT）在北京市潮白河、怀河地区进行了相关的勘查研究工作.通过与已知的地质和钻孔资料对比,CSAMT反演结果与实际资料对应一致,表明CSAMT法在研究地下水赋存方面有着独特之处,为应急水源地的研究工作提供了可靠的证据.     

江西省主要城市地下水系统防污性能分析评价

本文简单介绍了江西省主要城市自然和水文地质概况,采用DRASTIC方法对11个城市的地下水系统防污性能进行了分析评价。认为：全省11个主要城市地下水系统防污性能大部分为好-较好。地下水系统防污性能好-较好的面积大于70％的城市有鹰潭、抚州和萍乡．60％～70％的有景德镇、赣州、南昌、吉安和上饶,29％～38％的有新余和宜春,九江仅10．66％。讨论了地下水系统防污性能与城市规划建设的关系,并提出了相关建议。     

查清“家底”保护地下水资源——访中国地质环境监测院副院长田廷山

正地下水是"看不见的水源地"。我国600多个城市中有400多个都是以地下水为饮用水源。中国地质调查局专家曾提到,全国90%的地下水遭受了不同程度的污染,其中60%污染严重。我国的地下水污染形势不容乐观,但是每个地方的具体污染情况如何,却很难说清。因此需要开展地下水监测工作,摸清"家底",才能对地下水污染的形成、演化、发展趋势作出较为全面、客观、准确的评判。9月30日国土资源部发布通知公告对其     

地下水渗流系统灰色数值仿真模拟研究

根据灰集合、灰数及灰色运算规则, 建立了地下水渗流系统的灰色数值模型, 提出了求解这类模型的一整套灰色数值算法, 并从灰色数学的理论上证明, 普通灰色解法仅仅是灰色数值算法的一个特例. 同时, 对灰色数值算法、普通灰色解法和经典数值方法进行了全面比较, 论证了灰色数值算法较好地刻画了地下水系统的灰信息传递过程. 在理论分析基础上, 选择了矿井涌水量预测和水源地供水资源评价的两个基本地下水渗流实例, 分别就水文地质条件概化与灰化、灰色数值模型建立、模型识别和预测评价等进行了比较系统的分析研究. 提出运用灰色数值模型预测矿井涌水量时, 需保证疏降水位“灰带”的上界低于矿井安全生产的设计水位; 而在水源地可采资源评价时, 应保证地下水水位“灰带”的下界不低于临界控制水位.     

安徽省河流和湖库型饮用水水源地水质评价

饮用水水源地的保护问题是关系国计民生的重大问题,饮用水水源地的水质问题越来越受到社会的关注.运用单因子标准指数法以及卡尔森指数法对安徽省境内91个县级以上的饮用水水源地的水质状况以及31个湖库型水源地富营养化程度进行了综合评价,并提出相应的防护措施.结果表明,全省91个饮用水水源地中水质达标的有83个,达标率为91.2%,其中,河流型水源地达标率为93.3%,湖库型水源地达标率为87%,地下水型水源地达标率为87%.     

上海市防震减灾应急决策信息系统-GPS的应用

为了适应上海经济建设高速发展和超大型城市防震减灾工作的需要,建立城市防震减灾应急决策信息系统已成为必然．本文将地理信息系统（GIS）技术应用于上海市防震减灾应急决策信息系统（宝山试点区）,介绍了此系统各功能模块的结构和作用．此系统由７个功能模块组成,即地震地质基本信息、地震灾害快速评估子系统、地震应急决策信息子系统、信息查询、系统维护管理、帮助和退出等．其核心部分是地震灾害快速评估子系统和地震应急决策信息子系统．本文还介绍了彩红外航片遥感技术在上海市防震减灾应急决策信息系统中的应用．      

海南地下水污染风险评价研究

地下水是人们可以选择发展的重要物质资源之一,也是比较重要的自然资源。对于海南来说,地下水不仅作为区域发展的主要资源,也是城市发展的战略资源以及物质保障。根据相关的统计数据得知,当前我国97%的地下水受到了污染,其中40%的地下水污染程度不断上升,所以地下水资源的流动比较缓慢,交替速度很慢,自净能力不强。因此地下水资源受到污染的话就不能够很好的恢复,所以地下水污染风险的评价以及区域划分工作是水资源保护的重要决策依据,本文主要是从地下水污染的现状入手建立了地下水污染风险评价指标体系,对于海南地下水污染的风险进行了评价。     

淄博市王旺庄水源地地下水开采预测的数值模拟

王旺庄水源地是淄博市晴纶工程的后备水源地,设计供水能力20000m^2／d。利用Ritz有限元数值分析方法。结合单纯性线性规划,在完成了对山东省淄博市临淄区王旺庄一朱台地段的淄博市腈纶工程水源地的水文地质模型建造的基础上,成功地对水源地进行地下水开采模拟,同时对该水源地的未来10年开采作了两种大气降水条件下的地下水动态预测。为腈纶工程水源地地下水开采提供了充分的设计依据。     

基于GIS的城市震害单元化应急医疗救助辅助系统

在城市震害应急管理单元的基础上,提出了城市震害单元化应急医疗资源需求模型,并给出了该模型的GIS集成方案,进而整合现有震害应急救助相关理论和方法,结合面向对象与数据库技术,采用组件式集成二次开发方式,详细阐述了建立城市震害单元化应急医疗救助辅助系统的系统设计目标、技术路线、体系结构及功能构建等,形成了基于GIS的城市震害单元化应急医疗救助辅助系统的技术思路和解决方案,并以重庆邮电大学为应急管理单元,建立了初步试验系统。     

Identifying the origin of groundwater for water resources sustainable management in an arid oasis,China

ABSTRACT

Many oases are experiencing severe groundwater depletion due to increased population, expanding agriculture and economic development. For sustainable development, quantifying groundwater recharge resources are fundamentally important. In this study, stable isotope techniques were employed to identify recharge sources of groundwater and quantitatively evaluate their contribution ratios in the Dunhuang Oasis, northwest China. Our findings indicate that heavy isotopes in shallow groundwater are more negative than those in deep groundwater, which is attributed to shallow groundwater that was modern and deep groundwater that was old. Irrigated return water and lateral groundwater flow from the Qilian Mountains are considered as the two main sources of shallow groundwater, accounting for 35% and 65% of the total recharge, respectively. Thus, as the main groundwater source of the Dunhuang Oasis, the Qilian Mountain Front should be protected against over-exploitation. Our results provide not only fundamental knowledge for groundwater management of aquifers of the Oasis, but also valuable water management information for other similar arid oases worldwide.     

Assessment of groundwater resources of Quaternary aquifer system in concordance with avoidable negative impact on geoenvironment,south-eastern part of Lithuania

This paper focuses upon south-eastern Lithuanian Quaternary aquifer system groundwater resources formation modelling. Groundwater model calibration has been performed for a pre-development and transient flow conditions. The results demonstrate that there is an intense interaction between groundwater and surface water bodies which form groundwater resources and runoff. For Quaternary cover the majority of unconfined groundwater outflows to surface water streams, the remaining part discharges through the confined interglacial/interstadial aquifers and lateral outflows across the boundaries. Groundwater prognostic exploitable resources can be obtained without a significant negative impact on the geoenvironment. The main sources of exploitable resources formation are increase in groundwater recharge and lateral inflow (40.7%), decreased outflow via streams and lateral boundaries (41.2%) and drawing up additional flow from the hydraulically connected streams (14.5%).     

Quantification of surface water and groundwater salinity sources in irrigated lowland area of North China Plain

Seasonally variation of water salinity is observed worldwide, the mechanisms of water salinity are not well understood due to natural factors and anthropogenic activities. Quantification water salinity source are challenging since complex influence factors, especially in agricultural regions irrigated with multi-water sources. In the lowland area of North China Plain, transferred water, brackish shallow groundwater and fresh deep groundwater were combinative utilized to relieve prominent contradictions between regional water shortages and grain production. In this study, influence factors of surface water (canal water, pond water) and shallow groundwater salinity were identified and quantified through statistical analysis, deuterium excess, and ionic relationship. Salinity of canal water and pond water increased in dry season and decreased in rainy season, while salinity of shallow groundwater decreased in dry season after water transfer and rainy season, but increased in dry season. Evaporation and mineral dissolution were main factors for surface water salinity in dry season, with mineral dissolution was the more important one. The contribution ratio of evaporation and mineral dissolution for canal salinity were 4.4 and 49.1% in dry season after water transfer, 7.1 and 34.4% in dry season, and that for pond water salinity were 12.4 and 18.3% in dry season, respectively. Precipitation and surface runoff were main factors for surface water salinity in rainy season. The contribution of surface runoff for canal water and pond water salinity were 66.1 and 45.8%, respectively. Salinity of canal water and shallow groundwater was temporary decreased by water transfer. Domestic sewage from rural areas had larger influence than agricultural activities for salinity increase of pond water and shallow groundwater. Mineral dissolution was the main contributor for shallow groundwater salinity, with contribution ratio larger than 60% in different periods. This study demonstrated and quantified salinity source of surface water and shallow groundwater and may deepen our understanding of water management under multi-water resources utilization.     

Current research in urban hydrogeology – A review

Urban groundwater is a heritage at risk because urban land use practises puts enormous and highly complex pressure on this resource. In this article, we review urban groundwater studies in the context of urban water management, discuss advances in hydrogeological investigation, monitoring and modelling techniques for urban areas and highlight the challenges. We present how techniques on contaminant concentration measurements, water balancing and contaminant load estimation were applied and further developed for the special requirements in urban settings. To fully understand and quantify the complex urban water systems, we need to refine these methods and combine them with sophisticated modelling approaches. Only then we will be able to sustainably manage our water resources in and around our urban areas especially in light of growing cities and global climatic change. We believe that over the next few years much more effort will be devoted to research in urban hydrogeology.     

Groundwater recharge sources in semiarid irrigated mountain fronts

High-elevation mountains often constitute for basins important groundwater recharge sources through mountain-front recharge processes. These processes include streamflow losses and subsurface inflow from the mountain block. However, another key recharge process is from irrigation practices, where mountain streamflow is distributed across the irrigated piedmont. In this study, coupled groundwater fluctuation measurements and environmental tracers (¹⁸O, ²H, and major ions) were used to identify and compare the natural mountain-front recharge to the anthropogenically induced irrigation recharge. Within the High Atlas mountain front of the Ourika Basin, Central Morocco, the groundwater fluctuation mapping from the dry to wet season showed that recharge beneath the irrigated area was higher than the recharge along the streambed. Irrigation practices in the region divert more than 65% of the stream water, thereby reducing the potential for in-stream groundwater recharge. In addition, the irrigation areas close to the mountain front had greater water table increases (up to 3.5 m) compared with the downstream irrigation areas (<1 m increase). Upstream crops have priority to irrigation with stream water over downstream areas. The latter are only irrigated via stream water during large flood events and are otherwise supplemented by groundwater resources. These changes in water resources used for irrigation practices between upstream and downstream areas are reflected in the spatiotemporal evolution of the stable isotopes of groundwater. In the upstream irrigation area, the groundwater stable isotope values (δ¹⁸O: −8.4‰ to −7.4‰) reflect recharge by the diverted stream water. In the downstream irrigation area, the groundwater isotope values are lower (δ¹⁸O: −8.1‰ to −8.4‰) due to recharge via the flood water. In the nonirrigation area, the groundwater has the highest stable isotope values (δ¹⁸O: −6.8‰ to −4.8‰). This might be due to recharge via subsurface inflow from the mountain block to the mountain front and/or recharge via local low altitude rainfall. These findings highlight that irrigation practices can result in the dominant mountain-front recharge process for groundwater.     

Source and Quality of Groundwater Surrounding the Qinghai Lake,NE Qinghai-Tibet Plateau

Comprehensive studies on the spatial distribution, water quality, recharge source, and hydrochemical evolution of regional groundwater form the foundation of rational utilization of groundwater resources. In this study, we investigated the water levels, hydrochemistry, and stable isotope composition of groundwater in the vicinity of the Qinghai Lake in China to reveal its recharge sources, hydrochemical evolution, and water quality. The level of groundwater relative to the level of water in the Qinghai Lake ranged from −1.27 to 122.91 m, indicating most of the groundwater to be flowing into the lake. The local evaporation line (LEL) of groundwater was simulated as δ²H = 6.08 δ¹⁸O-3.01. The groundwater surrounding the Qinghai Lake was primarily recharged through local precipitation at different altitudes. The hydrochemical type of most of the groundwater samples was Ca-Mg-HCO₃; the hydrochemistry was primarily controlled by carbonate dissolution during runoff. At several locations, the ionic concentrations in groundwater exceeded the current drinking water standards making it unsuitable for drinking. The main source of nitrate in groundwater surrounding the Qinghai Lake was animal feces and sewage, suggesting that groundwater pollution should be mitigated in areas practicing animal husbandry in the Qinghai-Tibet Plateau, regardless of industrial and urbanization rates being relatively low in the region. The scientific planning, engineering, and management of livestock manure and wastewater discharge from animal husbandry practices is a crucial and is urgently required in the Tibetan Plateau.     

What impact will climate change have on rural groundwater supplies in Africa?

Abstract

One of the key uncertainties surrounding the impacts of climate change in Africa is the effect on the sustainability of rural water supplies. Many of these water supplies abstract from shallow groundwater (<50 m) and are the sole source of safe drinking water for rural populations. Analysis of existing rainfall and recharge studies suggests that climate change is unlikely to lead to widespread catastrophic failure of improved rural groundwater supplies. These require only 10 mm of recharge annually per year to support a hand pump, which should still be achievable for much of the continent, although up to 90 million people may be affected in marginal groundwater recharge areas (200–500 mm annual rainfall). Lessons learnt from groundwater source behaviour during recent droughts, substantiated by groundwater modelling, indicate that increased demand on dispersed water points, as shallow unimproved sources progressively fail, poses a much greater risk of individual source failure than regional resource depletion. Low yielding sources in poor aquifers are most at risk. Predicted increased rainfall intensity may also increase the risk of contamination of very shallow groundwater. Looking to the future, an increase in major groundwater-based irrigation systems, as food prices rise and surface water becomes more unreliable, may threaten long-term sustainability as competition for groundwater increases. To help prepare for increased climate variability, it is essential to understand the balance between water availability, access to water, and use/demand. In practice, this means increasing access to secure domestic water, understanding and mapping renewable and non-renewable groundwater resources, promoting small-scale irrigation and widening the scope of early warning systems and mapping to include access to water.     

A Search for Freshwater in the Saline Aquifer of Coastal Bangladesh

In the polder region of coastal Bangladesh, shallow groundwater is primarily brackish with unpredictable occurrence of freshwater pockets. Delta building processes, including the codeposition of fresh-to-saline porewater and sediments, have formed the shallow aquifer. Impermeable clay facies and the lack of a topographical gradient limit the flow of groundwater and its mixing with surface water so controls on spatial variability of salinity are not obvious. By characterizing groundwater-surface water (GW-SW) interactions, this study attempted to identify areas of potable groundwater for the polder communities. We used transects of piezometers, cores, electromagnetic induction, and water chemistry surveys to explore two sources of potential fresh groundwater: (1) tidal channel-aquifer exchange and (2) meteoric recharge. Fresh groundwater proved difficult to find due to heterogeneous subsurface lithology, asymmetrical tidal dynamics, extreme seasonal fluctuations in rainfall, and limited field data. Geophysical observations suggest substantial lateral variability in shallow subsurface conductivity profiles. Piezometers show varying degrees of tidal pressure attenuation away from the channels. Nevertheless, the active exchange of freshwater appears to be limited due to low permeability of banks and surface sediments. Results indicate that pockets of fresh groundwater cannot be identified using readily available hydrogeological methods, so alternative drinking water sources should be pursued. By better understanding the hydrogeology of the system, however, communities will be better equipped to redirect water management resources to more feasible and sustainable drinking water options.     

Recharge seasonality based on stable isotopes: Nongrowing season bias altered by irrigation in Nebraska

The sustainability of groundwater resources for agricultural and domestic use is dependent on both the groundwater recharge rate and the groundwater quality. The main purpose of this study was to improve the understanding of the timing, or seasonality, of groundwater recharge through the use of stable isotopes. Based on 768 groundwater samples collected from aquifers underlying natural resources districts in Nebraska, the isotopic composition of groundwater (δ²H and δ¹⁸O) was compared with that of precipitation by (a) mapping the isotopic composition of groundwater samples and (b) mapping a seasonality index for groundwater. Results suggest that for the majority of the state, groundwater recharge has a nongrowing season signature (October–April). However, the isotopic composition of groundwater suggests that in some intensively irrigated areas, human intervention in the water cycle has shifted the recharge signature towards the growing season. In other areas, a different human intervention (diversion of Platte River water for irrigation) has likely produced an apparent but possibly misleading nongrowing season recharge signal because the Platte River water differs isotopically from local precipitation. These results highlight the need for local information even when interpreting isotopic data over larger regions. Understanding the seasonality of recharge can provide insight into the optimal times to apply fertilizer, specifically in highly conductive soils with high leaching potential. In areas with high groundwater nitrate concentrations, this information is valuable for protecting the groundwater from further degradation. Although previous studies have framed nongrowing season recharge within the context of future climate change, this study also illustrates the importance of understanding how historical human intervention in the water cycle has affected groundwater recharge seasonality and subsequent implications for groundwater recharge and quality.     

Recharge sources and hydrogeological effects of irrigation and an influent river identified by stable isotopes in the Motril‐Salobreña aquifer (Southern Spain)

Measurement of the stable isotopes oxygen‐18 and deuterium in water is an important tool to characterize aquifer recharge sources. In the driest areas of the Mediterranean, this application is of special interest due to the scarcity of water and the resulting common incidence of human influence on natural hydrological systems. The Motril‐Salobreña detrital aquifer (southern Spain) is a clear example of such an impact as inhabitants have designed irrigation systems and a dam was recently built across the course of the Guadalfeo River, which feeds the aquifer. The sampling of (river or ground) water has allowed the determination of stable isotope contents (oxygen‐18 and deuterium), both temporally and spatially, and the relative importance of the main recharge sources in certain sectors. In addition, we were able to infer seasonal trends and to improve existing knowledge of the main flow paths and the position of a seasonal groundwater divide. Data analysis shows evaporation plays a minor role (despite the high temperatures in the zone), scarce rainwater influence, and the overwhelming contribution of recharge from the Guadalfeo River and from the carbonate aquifer (Escalate aquifer) in contact with the Motril‐Salobreña aquifer. Irrigation return flow during the summer months comprises the main recharge due to the significant volumes of water that infiltrate. The construction of the dam will almost certainly entail great changes in the current dynamics of the hydrogeology of the Motril‐Salobreña aquifer; therefore, knowledge of its behaviour is crucial in order to carry out sustainable use of its groundwater resources. Copyright © 2011 John Wiley & Sons, Ltd.