张掖市甘州城区及外围地下水位上升原因分析

采用传统的水均衡方法及环境同位素分析、氟里昂测年等技术,结合地震、地面物探、气象水文及地下水流场分析手段,分析了甘州城区及其外围地下水位上升的原因。结果表明:实施"黑河流域节水灌溉综合治理工程"引起水资源利用分配格局的变化不是引起地下水位大面积上升的原因;水位上升区第四系深层承压水与祁连山基岩裂隙水具有相同的水文地球化学特征和环境同位素特征。其结论:张掖盆地中心地带基底存在与祁连山区相连的北西向深大断裂带一直存在少量,且稳定的地下水越流补给量;自2003年10月山丹、民乐发生大地震以后,使得祁连山山前及盆地内基底断裂活动加剧,同时断裂活动错断了第四系松散层内的隔水层,基底断裂带变为导水通道,加快了祁连山区基岩裂隙水沿着这个通道向上越流补给盆地第四系孔隙水的速度,增大了越流补给量,使盆地地下水补给量大于排泄量,造成地下水位大面积上升。     

锡林河流域地下水位管理阈值研究

地下水资源是维系锡林河流域社会经济发展和生态环境稳定的关键因子。立足于地下水位这一关键性指标,采用地下水可持续性评价和数值模拟模型相结合的方法,探讨地下水安全利用方式。结果表明:现状年河谷平原的地下水可持续性较强,而开采集中的城市规划区及毛登牧场可持续性一般或较差;丰沛的降水及富水性较强的含水层增强了地下水资源可持续性,但农牧业快速发展和农灌集中开采,破坏了城市规划区周边及毛登牧场的地下水均衡关系,通过设置和对比不同开采方案,限制灌溉规模成为未来解决这一危机的首要途径,即2020年应减少903.23×104m3开采量,其管理地下水位阈值为0.13~0.55 m。     

Isotope implications of groundwater recharge,residence time and hydrogeochemical evolution of the Longdong Loess Basin,Northwest China

Groundwater plays a dominant role in the eco-environmental protection of arid and semi-arid regions.Understanding the sources and mechanisms of groundwater recharge,the interactions between groundwater and surface water and the hydrogeochemical evolution and transport processes of groundwater in the Longdong Loess Basin,Northwest China,is of importance for water resources management in this ecologically sensitive area.In this study,71 groundwater samples(mainly distributed at the Dongzhi Tableland and along the Malian River)and 8 surface water samples from the Malian River were collected,and analysis of the aquifer system and hydrological conditions,together with hydrogeochemical and isotopic techniques were used to investigate groundwater sources,residence time and their associated recharge processes.Results show that the middle and lower reaches of the Malian River receive water mainly from groundwater discharge on both sides of valley,while the source of the Malian River mainly comes from local precipitation.Groundwater of the Dongzhi Tableland is of a HCO3-Ca-Na type with low salinity.The reverse hydrogeochemical simulation suggests that the dissolution of carbonate minerals and cation exchange between Ca²⁺,Mg²⁺and Na+are the main water-rock interactions in the groundwater system of the Dongzhi Tableland.Theδ¹⁸O(from-11.70‰to-8.52‰)andδ2H(from-86.15‰to-65.75‰)values of groundwater are lower than the annual weighted average value of precipitation but closer to summer-autumn precipitation and soil water in the unsaturated zone,suggesting that possible recharge comes from the summer-autumn monsoonal heavy precipitation in the recent past(≤220 a).The corrected 14C ages of groundwater range from 3,000 to 25,000 a old,indicating that groundwater was mainly from precipitation during the humid and cold Late Pleistocene and Holocene periods.Groundwater flows deeper from the groundwater table and from the center to the east,south and west of the Dongzhi Tableland with estimated migration rate of 1.29-1.43 m/a.The oldest groundwater in the Quaternary Loess Aquifer in the Dongzhi Tableland is approximately 32,000 a old with poor renewability.Based on theδ¹⁸O temperature indicator of groundwater,we speculate that temperature of the Last Glacial Maximum in the Longdong Loess Basin was 2.4℃-6.0℃ colder than the present.The results could provide us the valuable information on groundwater recharge and evolution under thick loess layer,which would be significative for the scientific water resources management in semi-arid regions.     

基于GMS的吐鲁番盆地地下水资源量模拟预测

吐鲁番盆地位于我国西北内陆,蒸发强烈,降水稀少,地下水是非常重要甚至是唯一的淡水资源。为了能够探明吐鲁番盆地地下水资源量的构成,通过数据收集、现场调查和水文地质实验获得了一系列的参数,利用GMS软件建立了吐鲁番盆地地下水的非稳定流模型;并且基于现状开采条件下对吐鲁番盆地的地下水做了20 a预测。模拟结果显示:吐鲁番盆地的地下水可采资源量约为4.42×10~8m~3·a~(-1),现状开采条件下到2031年的地下水位下降幅度最高为13 m。由于吐鲁番盆地开采地下水主要用于农业灌溉,故吐鲁番盆地的绿洲面积不会减少,但为了合理利用地下水资源,应该调节该地区的供水结构,加大农业用水节水设备的使用。     

甘肃梨园河流域地下水来源及其水化学特征

通过分析水化学与氢氧稳定同位素的关系,研究梨园河流域地下水的补给机理和水化学演化规律。地下水总溶解固体（TDS）自西南向东北递增,最大值为1 258 mg/L。沿流程方向,深层地下水的水化学类型由Ca-HCO₃→Ca-Mg-HCO₃、Mg-SO₄→Na-SO₄型。浅层地下水的水化学类型由Ca-HCO₃→Mg-HCO₃-SO₄→Mg-SO₄型。地表水的水化学类型无分异,主要为Ca-HCO₃型。深层和浅层地下水沿途均发生了水岩融滤作用。Na⁺含量沿程增大,一是地下水中Ca²⁺与岩石中Na⁺发生阳离子交换作用,二是硅酸盐矿物的风化作用产生Na+。Phreeqc软件模拟显示,深层地下水中方解石先沉淀后溶解;CO₂、石膏、白云石和岩盐溶解。浅层地下水中,方解石由不饱和逐渐变为饱和;石膏、岩盐一直溶解。地下水的δ²H和δ¹⁸O值大部分位于大气降水线上方,反应了山区现代降水或雪冰融水通过出山地表径流补给,交替更新快,且深层地下水向上补给浅层地下水和地表水。地表、地下水相互转化是该区水循环的主要特征。     

Hydrochemical characteristics and evolution of groundwater in the dried-up river oasis of the Tarim Basin,Central Asia

Intense human activities in arid areas have great impacts on groundwater hydrochemical cycling by causing groundwater salinization. The spatiotemporal distributions of groundwater hydrochemistry are crucial for studying groundwater salt migration, and also vital to understand hydrological and hydrogeochemical processes of groundwater in arid inland oasis areas. However, due to constraints posed by the paucity of observation data and intense human activities, these processes are not well known in the dried-up river oases of arid areas. Here, we examined spatiotemporal variations and evolution of groundwater hydrochemistry using data from 199 water samples collected in the Wei-Ku Oasis, a typical arid inland oasis in Tarim Basin of Central Asia. As findings, groundwater hydrochemistry showed a spatiotemporal dynamic, while its spatial distribution was complex. TDS and δ¹⁸O of river water in the upstream increased from west to east, whereas ion concentrations of shallow groundwater increased from northwest to southeast. Higher TDS was detected in spring for shallow groundwater and in summer for middle groundwater. Pronounced spatiotemporal heterogeneity demonstrated the impacts of geogenic, climatic, and anthropogenic conditions. For that, hydrochemical evolution of phreatic groundwater was primarily controlled by rock dominance and evaporation-crystallization process. Agricultural irrigation and drainage, land cover change, and groundwater extraction reshaped the spatiotemporal patterns of groundwater hydrochemistry. Groundwater overexploitation altered the leaking direction between the aquifers, causing the interaction between saltwater and freshwater and the deterioration of groundwater environment. These findings could provide an insight into groundwater salt migration under human activities, and hence be significant in groundwater quality management in arid inland oasis areas.     

松嫩平原高氟地下水的分布特征及防氟改水研究

选取具有典型意义的吉林省通榆县等地氟病高发区和松嫩平原作为研究区,对地下水及含水层进行系统取样,运用描述性统计分析及相关性分析等方法,综合研究松嫩平原地下水中氟的分布、来源及影响因素。结果表明:松嫩平原高氟地下水主要分布于第四系潜水中,平原四周及含水层组富氟的地质环境是其主要来源区,地貌条件、气候因素及水化学条件影响地下水中氟的富集与扩散,研究区第四系及前第四系承压水水量丰富,水质良好,氟含量低于规范要求,可作为地氟病区防氟改水的主要供水目的层。     

Quantification of groundwater recharge and evapotranspiration along a semi-arid wetland transect using diurnal water table fluctuations

Groundwater is a vital water resource in arid and semi-arid areas. Diurnal groundwater table fluctuations are widely used to quantify rainfall recharge and groundwater evapotranspiration(ET_g). To assess groundwater resources for sustainable use, we estimated groundwater recharge and ET_g using the diurnal water table fluctuations at three sites along a section with different depths to water table(DWT) within a wetland of the Mukai Lake in the Ordos Plateau, Northwest China. The water table level was monitored at an hourly resolution using a Keller DCX-22 A data logger that measured both the total pressure and barometric pressure, so that the effect of barometric pressure could be removed. At this study site, a rapid water table response to rainfall was observed in two shallow wells(i.e., Obs1 and Obs2), at which diurnal water table fluctuations were also observed over the study period during rainless days, indicating that the main factors influencing water table variation are rainfall and ET_g. However, at the deep-water table site(Obs3), the groundwater level only reacted to the heaviest rainfalls and showed no diurnal variations. Groundwater recharge and ET_g were quantified for the entire hydrological year(June 2017–June 2018) using the water table fluctuation method and the Loheide method, respectively, with depth-dependent specific yields. The results show that the total annual groundwater recharge was approximately 207 mm, accounting for 52% of rainfall at Obs1, while groundwater recharge was approximately 250 and 21 mm at Obs2 and Obs3, accounting for 63% and 5% of rainfall, respectively. In addition, the rates of groundwater recharge were mainly determined by rainfall intensity and DWT. The daily mean ET_g at Obs1 and Obs2 over the study period was 4.3 and 2.5 mm, respectively, and the main determining factors were DWT and net radiation.     

昌马水库运行后疏勒河流域盆地地下水补给资源及其水位变化分析

通过对昌马水库运行前后不同时期疏勒河流域各盆地地下水补给量与地下水水位动态变化分析表明:流域地下水资源呈减少趋势,地下水位表现为较强的区域性下降。昌马水库运行后,中游玉门踏实盆地地下水补给量大幅减少,比上世纪60年代、90年代末分别减少了3.11亿m3、2.95亿m3,下游安西敦煌、花海盆地地下水补给量小幅增加,中游昌马洪积扇前缘泉水量与60年代比削减了53.2%。各盆地水量补给减少区水位下降,增加区水位上升,下降(上升)幅度随补给量减少(增加)而增大。     

太原盆地地下水系统水化学-同位素特征研究

太原盆地孔隙水与周边岩溶水、砂岩裂隙水有密切的水力联系。本文应用示踪元素均衡分析的方法对盆地地下水系统之间的转化关系进行了定量研究。结果表明,太原市区以北地区主要接受岩溶水补给,其补给量占总补给量的30%以上。盆地东侧大部分地区以裂隙水补给为主,其中文水东南至平遥一带裂隙水补给量最高,占总给量的60%以上;应用环境同位素分析方法对盆地孔隙水的起源与更新能力进行了研究分析。指出含水层埋藏深度在50m以内的浅层水,主要接受大气降水和地表水的补给,更新周期在60年以下,更新能力较强;含水层埋深在50—200m之间的为混合水,是深层古水与浅层现代水混合形成,与现代水交换比例在40%以上,更新能力较强;含水层埋深在200m以下的,为深层古水,更新能力较差。     

中国西北中小型盆地天然地下水水化学特征——以公婆泉盆地为例

研究分析干旱气候条件下甘肃北山公婆泉盆地天然地下水水化学成分特征,结合水文地质条件与水化学特征Piper三线图表明:研究区存在4种类型地下水,白垩系深层水中钙镁离子含量相对高于其他类型水.地下水氚同位素结合水化学特征较好地区分了水源点的水文地质属性.氢氧同位素表明,该区地下水来源于大气降水,第四系浅层水受到强烈的蒸发作用,发生了一定程度的氧漂移,并影响"混合水"的同位素组成.最后分析了地下水主要离子的来源,以及地下水形成过程中所受到的溶滤、沉积和蒸发等水文地球化学作用.     

关中盆地地下水资源评价与解析

陕西关中盆地是西部经济最活跃的地区,而水资源不足成为经济进一步发展的制约因素.以地质和水文地质条件为依据,从影响地下水形成的诸因素出发,对关中地下水资源进行评价和解析.结果表明:受自然因素和人类活动的影响,区内天然资源量和可采资源量发生了变化,其中天然资源量和可采资源量分别减少了5.39×108 m3/a和4.53×108 m3/a.渭河以北地区地下水资源形成中,降水补给和灌溉补给占主导地位,二者占83.9%;渭河以南地区,降水补给和河水渗漏补给是地下水资源形成的主要因素,二者占94.2%.在此基础上,提出了水资源合理开发利用的对策和措施,以期实现水资源的永续利用和生态环境良性循环.     

新疆车尔臣河流域地下水的可持续开发利用研究

地下水是一种宝贵的自然资源,是自然界水循环的重要组成部分,人类赖以生存和社会发展的重要物质基础,人类必须在合理开发的同时,确保地下水资源的采补平衡,使其得到永续利用。因此必须采取强有力的措施,遏制超采势头的发展,促进地下水资源的采补平衡和永续利用。文中根据且末绿洲实地考察、历年统计资料及水文概况分析的基础上,对研究区的水文地质条件、地下水的埋藏与分布规律、车尔臣河流域地下水的补给,径流,排泄及开采条件以及地下水开采利用现状进行了剖析。探讨了研究区合理开发利用和保护地下水资源的对策建议。     

Using statistical models and GIS to delimit the groundwater recharge potential areas and to estimate the infiltration rate: A case study of Nadhour-Sisseb-El Alem Basin,Tunisia

The water resources of the Nadhour-Sisseb-El Alem Basin in Tunisia exhibit semi-arid and arid climatic conditions. This induces an excessive pumping of groundwater, which creates drops in water level ranging about 1-2 m/a. Indeed, these unfavorable conditions require interventions to rationalize integrated management in decision making. The aim of this study is to determine a water recharge index (WRI), delineate the potential groundwater recharge area and estimate the potential groundwater recharge rate based on the integration of statistical models resulted from remote sensing imagery, GIS digital data (e.g., lithology, soil, runoff), measured artificial recharge data, fuzzy set theory and multi-criteria decision making (MCDM) using the analytical hierarchy process (AHP). Eight factors affecting potential groundwater recharge were determined, namely lithology, soil, slope, topography, land cover/use, runoff, drainage and lineaments. The WRI is between 1.2 and 3.1, which is classified into five classes as poor, weak, moderate, good and very good sites of potential groundwater recharge area. The very good and good classes occupied respectively 27% and 44% of the study area. The potential groundwater recharge rate was 43% of total precipitation. According to the results of the study, river beds are favorable sites for groundwater recharge.     

GIS-based assessment of non-equilibrium pattern between groundwater recharge and irrigation draft in a semi-arid region of Rajasthan,India

Over-exploitation of groundwater for irrigation can result in drastic reduction in groundwater level in Jodhpur district of western Rajasthan, India. In this study, we used the long-term trend analysis of seasonal groundwater level data to predict the future groundwater scenario in 33 villages of Jodhpur district, assessed the impact of water harvesting structures on groundwater recharge and explored the non-equilibrium between groundwater recharge and irrigation draft in the study area. Analysis of groundwater level data from 26 observation wells in 33 villages in the pre-monsoon period showed that groundwater level decreased continuously at the rate of 2.07 m/a. With this declining rate, most of the tube wells(including the well with the maximum depth of 193 m) are predicted to become completely dry by 2050. Behavior of temporal groundwater level data in the study period(from 2004 to 2012) can be explained by different geospatial maps, prepared using Arc GIS software. Statistical analysis of the interpolated maps showed that the area with the maximum positive groundwater recharge occupied 63.14% of the total area during 2010–2011 and the area with the maximum irrigation draft accounted for 56.21% of the total area during 2011–2012. Higher groundwater recharge is attributed to the increase in rainfall and the better aquifer condition. Spatial distribution for the changes of average groundwater recharge and draft(2008–2009 and 2011–2012) showed that 68.50% recharge area was in positive change and 45.75% draft area was in negative change. It was observed that the area of the irrigation draft exceeded that of the groundwater recharge in most of the years. In spite of the construction of several shallow water harvesting structures in 2009–2010, sandstone aquifer zones showed meager impact on groundwater recharge. The best-fit line for the deviation between average groundwater fluctuation due to recharge and irrigation draft with time can be represented by the polynomial curve. Thus, over-exploitation of groundwater for agricultural crops has result in non-equilibrium between groundwater recharge and irrigation draft.     

Transformation among precipitation,surface water,groundwater, and mine water in the Hailiutu River Basin under mining activity

Coal mining has changed the hydrogeological conditions of river basins, and studying how the relationship among different types of water body has changed under the influence of coal mining is of great significance for understanding the regional hydrological cycle. We analyzed the temporal and spatial distribution of hydrochemical properties and environmental isotopes in the Hailiutu River Basin (HRB), China with a mixed model. The results showed that: (1) human activity (e.g., coal mining and agricultural production) causes considerable changes in the hydrochemical properties of surface water in and around the mining areas, and leads to significant increases in the concentrations of Na⁺ and SO2- 4; (2) precipitation is the main source of water vapour in the HRB. The transformation between surface water and groundwater in the natural watershed is mainly affected by precipitation; and (3) in the mining areas, the average contribution rates of precipitation to the recharge of surface water and groundwater increased by 2.6%-7.9% and 2.7%-9.9%, respectively. Groundwater in the Salawusu Formation constitutes up to 61.3%-72.4% of mine water. Overall, this study is beneficial for quantifying the effects of coal mining on local hydrological cycles. The research results can provide a reference for local water resources management and ecological environment improvement.     

密怀顺研究区地下水NO3--N时空变化分析

密怀顺地区是北京市重要的水源涵养区,直接影响着主城区的供水安全。2014年南水北调盈余水量通过潮白河河道回补地下水,地下水位不断抬升,使常年积累在耕地土壤中NO₃^--N对地下水环境风险不断增加。通过对地下水中NO₃^--N和耕地属性地块研究。结果表明:1)2015-2018年研究区地下水NO₃^--N浓度有升高趋势;2)2015-2018年研究区水质稳定区面积达到164.26km²,占比33.78%;其次为水质略变差区和水质变差区,面积分别为136.76km²和112.74km²,占比分别为28.12%和23.18%。3)耕地属性不变的7个有监测地块地下水NO₃^--N浓度均有不同程度升高,MW-3和MW-1地块超过地下水Ⅲ类水质标准;4)地下水NO₃^--N含量变化与地下水回补有一定关联。     

黑河干流中游地区季平均地下水位变化分析

黑河流域水 -生态 -经济矛盾极为突出 ,干流中游荒漠绿洲农业与下游生态用水分配问题是诸多矛盾的焦点。国务院黑河分水方案实施两年多来 ,下游生态环境恶化得到了初步的遏制 ,相应中游地区的可用水资源量减少。本文应用 53个长期地下水观测井资料 ,对中游地区近 2 0 a来各季节地下水埋深变化趋势进行了分析 ,并计算了分水实施前后地下水位的变化幅度。结果表明 ,近 2 0 a来张掖甘州区地下水位降低趋势最明显 ,其次是临泽县和高台县 ;分水后以甘州区地下水降幅最大 ,其次是高台县 ,临泽县地下水降幅最小。分水后以夏秋季节变化最大 ,冬春季节相对较小。     

合理开发利用地下水是新疆盐渍化耕地改良的重要途径

新疆地处内陆干旱区,土壤积盐严重,根据中巴地球资源卫星2005年遥感影像解译和实际调查,新疆现有耕地面积5.05×106 hm2,其中盐渍化耕地面积1.62×106 hm2,占耕地总面积的32.07%,占新疆中低产田60%以上,土壤盐渍化是影响新疆农业发展的主要因素。盐渍化耕地大多分布在地下水较高的地区,如冲积扇扇缘地...     

塔克拉玛干沙漠浅层地下水位对单井抽水的响应过程研究

为了研究人工抽水行为对周边地下水位的影响,在塔里木沙漠公路防护林生态工程第69号水源井处布设了抽水试验观测场,利用连续定位观测数据,分析了地下水位降深与时间的关系、地下水位的空间差异性规律;在此基础上利用Neuman井流模型方法,分析了含水层的传导性和贮水性,确定了该区域的相关水文地质参数;并利用Theis预报方法,对抽水引起的水位变化进行了短期预报。研究结果表明:抽水过程水位上升和下降过程均可分为快速和慢速两个阶段,含水层具有弹性释水和重力释水作用的特征;计算得出部分水文地质参数为:T=1.50E+1m3/d,Kh=3.74E+1 m/d,σ=1.12E-2;预测得出持续抽水1000 min时的抽水影响半径约为400m。文中研究所得出的水文地质参数符合该地区的水文地质条件,可作为相似区域水文地质学研究的参考;地下水位在抽水行为结束后,能够恢复到抽水前的水平;抽水行为对周边地下水位的影响范围不大,多个水源井之间不会形成相互干扰,不会引起天然地下水位的持续下降。研究结果可为沙漠公路沿线地下水资源的可持续利用和防护林生态工程整体的稳定性及长久运行提供一定的理论依据。