福建省东部浅层地下水地球化学

本文对福建东部地区3.8万平方公里陆地浅层地下水(井水)1206件样品中19种元素的含量特征、元素间的相关关系、元素空间分布特点与地质背景的关系等方面进行了研究。研究表明,该地区浅层地下水中以Ba、Cl-、F-、Fe、Mn、Sr、Zn元素含量高、变化幅度大为显著特征;元素含量与pH没有明显的相关关系,Cl-、Sr、Co、Ni、Pb等元素间则具显著的正相关关系,Cl-具有决定性作用;地下水中元素的空间分布特征受地质背景及地理条件的制约。     

陕北能源化工基地地下水开发的植被生态效应及对策

为了建立陕北能源基地基于生态良性循环的地下水开发利用模式,依据生态学和水文地质学原理,采用生态-水文地质调查与遥感定量分析相结合的方法,在研究陕北能源化工基地的植被生态空间分布特征、近30年来的演化趋势和影响因素的基础上,从植物类型、植物根系、植被指数与潜水埋深对比分析入手,建立了本区地下水位埋深与植被生态的依存关系,确定了影响植被生态的地下水位阈值,并开展了地下水开发的植被生态环境效应敏感性区划,提出了基于生态良性循环的地下水资源开发利用对策。     

南通市沿江地区潜水稀土元素地球化学特征及其指示意义

以粒径0.45μm为悬浮态和溶解态区分界限,采用高分辨电感耦合等离子体质谱(HR-ICP-MS)法,测定并分析了南通市沿江地区潜水的稀土元素质量浓度、形态、分布特征和分配模式,为识别地下水污染来源提供依据。结果表明:潜水中稀土元素质量浓度很低,溶解态稀土元素的质量浓度均值和空间分布均衡性高于悬浮态。潜水中溶解态轻稀土元素质量浓度、分布均匀性高于溶解态重稀土元素。潜水溶解态稀土元素质量浓度在Eh50mV时,与Eh值正相关;在Eh50mV时呈负相关。潜水溶解态稀土元素呈现Ce负异常,Eu正异常,北美页岩标准化分配模式则表现出轻稀土元素富集现象。溶解态轻稀土元素质量浓度与pH值呈负相关,溶解态重稀土质量浓度与pH值呈正相关。潜水溶解态轻稀土元素富集程度与水动力条件呈现显著的负相关关系,并在空间分布上呈现水平分带,这为从区域水动力条件角度认识地下水中物质的富集效应提供了新的途径。     

伊犁河支流大西沟河水与地下水转化关系研究

开展河流和地下水转换关系研究对于区域水资源合理开发利用具有重要意义。文章以大西沟河水与地下水转换关系为目标,在分析地下水动力场的基础上,通过水化学类型、溶解性总固体(TDS)、氯离子（Cl-）等水化学以及环境同位素18O、D、T等指标作为示踪剂,分析大西沟河和地下水的转换关系和转化强度。结果表明:研究区河流和地下水化学类型主要为HCO3—Ca,水化学类型空间分布特征相似;TDS和Cl-浓度表现为先增加后下降,但地下水的变化幅度大于河水。通过对大西沟河水和地下水中的水化学和环境同位素指标对比分析,发现研究区河流与地下水之间补给排泄关系具有明显的分段性;从河流出山口到下游地区,河水和地下水之间发生了三次转化关系:在山前倾斜砾质平原区以河水入渗补给地下水为主,补给量占该段潜水径流量的56%;到了细土平原区出现地下水补给河水地段,补给源为承压水越流补给潜水后的混合水体,潜水和承压水补给比例占该段河水径流量的20.4%与58.4%;风成沙漠区河水沿途渗漏补给地下水直至河流断流。本次研究结果为建立研究区水循环演化模式和水资源合理开发利用提供了理论和技术支持。     

巴丹吉林沙漠潜水蒸发的数值模拟研究

为了确定巴丹吉林沙漠潜水蒸发强度与地下水埋深的关系,基于巴丹吉林沙漠的气候背景、砂土特征和不同地下水埋深时的典型植被特点设计了54种情景,利用Hydrus-1D建立不同情景下的SPAC水分运移模型,对周期性气象条件驱动下的潜水蒸发开展数值模拟。模拟结果表明:多年平均潜水蒸发量有着随地下水埋深增大而非线性减小的趋势;不同情景的极限埋深都大于3m,在埋深等于3m时潜水蒸发量都小于最大值的5%;当地下水埋深为0.5~1.5m时,潜水蒸发量对地下水埋深的变化最为敏感;当地下水埋深为1m时,潜水蒸发量对包气带岩性的变化也很敏感;在地下水埋深小于0.5m和大于1.5m的区间,气候、岩性、地下水埋深的变化对潜水蒸发量的影响变得微弱。另外,多年平均潜水蒸发量和地下水埋深的这种非线性关系可以用一个新提出的经验公式进行较为准确的拟合,将这个研究结果用于评价巴丹吉林沙漠湖泊集中区地下水的蒸发消耗,发现潜水蒸发总量显著大于湖面蒸发总量,前者约为后者的2.5~2.6倍,必须在沙漠水分平衡的分析中加以考虑。     

陕北能源化工基地资源开发引起的植被生态风险

地下水和煤炭资源开发是否会破环生态环境,以及会给生态环境安全带来多大的风险,是陕北能源化工基地资源开发和生态环境保护中不可逾越的课题。以陕北能源化工基地生态环境最为脆弱的风沙滩地区为研究区,在研究地下水位埋深与植被生态关系的基础上,建立了不同地貌类型、不同潜水水位埋深对应的植被群落类型和植被指数的分布关系,利用Modflow软件建立了风沙滩地区地下水流数值模拟模型,采用蒙特卡洛方法建立了植被生态随机模型,根据地下水水位埋深与植被生态的关系实现了地下水流模型和植被生态模型的耦合求解,对地下水资源和煤炭资源开发可能引起的植被生态变化进行预测和风险评估。     

湖南新田富锶地下水水化学特征与成因分析

研究湖南新田富锶地下水水化学特征及成因,为富锶地下水的可持续利用与开发提供理论依据。对研究区21个下降泉、30个机井富锶地下水样品的水化学类型、化学成分含量特征、成分间相关性以及离子比值的研究。结果表明：下降泉水化学类型全部为HCO3-Ca型,机井水化学类型以HCO3-Ca、HCO3-Ca·Mg型为主。相关分析表明,下降泉和机井中SO42-与Ca2+、Mg2+均表现显著相关或极显著相关,HCO3-与Ca2+、SO42-与NO3-在下降泉与机井中的相关性具有差异,下降泉、机井Sr与Ca2+、Mg2+、HCO3-均表现为极显著相关。Gibbs图表明下降泉和机井的水化学组成主要受水-岩相互作用的控制,下降泉、机井c(Ca2+)/c(Mg2+)、c(HCO3-)/c(SO42-+Cl-)、c(Na+)/c(Cl-)、c(Cl-)/c(Ca2+)系数比值具有差异。结果表明富Sr地下水的形成受碳酸盐岩成分影响显著,赋存条件的差异导致富锶地下水在下降泉、机井中的水化学特征、相关性以及离子系数比值的差异。     

祁连山地区生态系统服务间权衡的社会-生态环境响应机制研究

生态系统服务间权衡和协同关系存在显著的空间异质性,现有研究较少从社会-生态环境的角度进行分析,难以对将生态系统服务纳入实际政策制定过程中。以祁连山地区为研究区,利用InVEST模型和CASA模型对2019年五项调节服务（碳固定、碳储存、产水量、土壤保持和水质净化）和一项支持服务（生境质量）进行计算,结合多元回归树分析法,研究服务间关联的空间异质性及其对社会-生态环境的响应。结果显示,全区尺度上六项服务间呈协同关系,主要受到土地利用类型、降雨和植被覆盖度的影响。植被覆盖区的服务供给量整体高于无植被覆盖区。研究区可被分为5个聚类,不同聚类内服务间关联存在差异。无植被覆盖且年均降雨量低于440.2 mm的区域与植被覆盖度高于0.559的非耕地区内,服务间关联均呈显著协同,后者服务整体较高。降雨升高可促使无植被覆盖区内产水量和土壤保持与其他服务间呈权衡关系,植被覆盖度较低或耕地区内服务间关联变弱。研究成果可为生态管理和政策制定提供有效参考。     

黄河三角洲浅层地下水埋深动态与降水的时空响应关系

为探究黄河三角洲浅层地下水埋深动态对降水的时空响应关系及其驱动因素,基于2006—2010年黄河三角洲14口监测井的浅层地下水埋深数据和气象站降水量数据,利用Kendall's秩相关、交叉小波变换和小波相干方法,分析黄河三角洲地下水埋深动态和降水之间不同的时空响应模式,结合土地利用、微地貌类型和土壤质地资料,利用地理探测器方法对地下水埋深-降水响应关系进行定量归因研究。结果表明:（1）地下水埋深时间序列与降水量时间序列呈负相关关系,根据降水量对地下水埋深的影响强弱,可划分为3种空间模式:模式1强负相关（-0.45~-0.30）、模式2负相关（-0.30~-0.15）和模式3弱负相关（-0.15~-0.01）,空间差异性明显。（2）从模式1到模式3,地下水埋深对降水的响应延迟时间逐渐变小,分别为178.36 d、146.43 d和35.51 d,在所有模式中,地下水埋深对强降水的响应都很敏感。（3）土地利用、微地貌类型和土壤质地对地下水埋深-降水的响应关系都有显著的影响,解释贡献率分别为微地貌类型（0.280 7） > 土地利用（0.244 1） > 土壤质地（0.163 8）,驱动因子之间均表现出非线性增强作用,土地利用和微地貌类型的协同增强作用最大,为0.749 0。研究揭示了黄河三角洲浅层地下水埋深变化与降水之间不同的时空响应模式并对其进行定量归因,为黄河三角洲地区水循环过程研究及地下水资源管理和生态保护提供科学依据。     

黑河下游额济纳绿洲荒漠植被与地下水位埋深的 定量关系

干旱区植被生长与地下水的依存关系是生态水文地质学研究的热点之一。由于降水稀少,中国西北地区植被的生长发育与地下水的关系极为密切,从大尺度上研究地下水变化的生态效应问题对生态环境的保护和恢复具有重要的意义。借助遥感方法,结合地下水观测数据,在区域尺度上定量地研究了我国黑河下游额济纳绿洲荒漠植被发育与地下水埋深的关系。结果表明:适宜植被生长的地下水埋深范围约为2~5 m,当地下水埋深超过5.5 m时,由于植被根系缺水,不能维持冠层正常生长,几乎没有植被发育。     

Groundwater and surface-water interactions and impacts of human activities in the Hailiutu catchment,northwest China

The interactions between groundwater and surface water have been significantly affected by human activities in the semi-arid Hailiutu catchment, northwest China. Several methods were used to investigate the spatial and temporal interactions between groundwater and surface water. Isotopic and chemical analyses of water samples determined that groundwater discharges to the Hailiutu River, and mass balance equations were employed to estimate groundwater seepage rates along the river using chemical profiles. The hydrograph separation method was used to estimate temporal variations of groundwater discharges to the river. A numerical groundwater model was constructed to simulate groundwater discharges along the river and to analyze effects of water use in the catchment. The simulated seepage rates along the river compare reasonably well with the seepage estimates derived from a chemical profile in 2012. The impacts of human activities (river-water diversion and groundwater abstraction) on the river discharge were analyzed by calculating the differences between the simulated natural groundwater discharge and the measured river discharge. Water use associated with the Hailiutu River increased from 1986 to 1991, reached its highest level from 1992 to 2000, and decreased from 2001 onwards. The reduction of river discharge might have negative impacts on the riparian ecosystem and the water availability for downstream users. The interactions between groundwater and surface water as well as the consequences of human activities should be taken into account when implementing sustainable water resources management in the Hailiutu catchment.     

Groundwater-related thallium transfer processes and their impacts on the ecosystem: southwest Guizhou Province,China

The small karstic watershed of Lanmuchang, in a Hg–Tl mineralized area in SW Guizhou Province, China, exhibits an enrichment of toxic Tl in groundwater and related stream water. This affords an excellent demonstration of the natural processes of Tl dispersion, and the resultant impact on the local ecosystem. The distribution of Tl in the water system follows a decreasing concentration pattern from deep groundwater to stream water to shallow groundwater. Tl shows high levels (13–1100 μg/L) in deep groundwater within the Tl-mineralized area, decreasing with distance away from the mineralized area to background levels (0.005 μg/L). The distribution of Tl in the water system is constrained by Tl mineralization, water–rock interactions and hydrogeological conditions. Tl concentrations in waters generally correlate with concentrations of total dissolved solids, sulphate, Ca and pH values, suggesting the contribution of water-rock interactions to water geochemistry. Water–rock interactions are driven by weathering of Tl-bearing sulfides which decreases pH values in groundwater, and by dissolution of limestone enhanced by acid fluids. Tl in stream water in both the base-flow and flood-flow regimes shows higher concentrations than it does in shallow groundwater that serves as the stream's source (mainly springs, dug-well flows and karstic cave waters). Concentrations of Tl in stream water in the flood-flow regime are generally lower than in the base-flow regime due to dilution effects, but those in the waters of mid-stream are almost the same as in the base-flow regime, probably due to contribution from Tl-rich soil water seepage or from acid mine drainage (AMD). Unexpectedly, Tl concentrations in stream water in both regimes are remarkably higher (2–30 fold) downstream than up- and mid-stream. These pronounced increases of Tl concentration are likely caused by unidentified discharges of deep groundwater through fractured zones to the downstream trace. The groundwater-related Tl transfer processes affect the ecosystem through contamination of water supply and arable soil and ultimately the food chain with undoubted risks to human health. Therefore, the results of this study are important for environmental planning and regulations, and will also serve as baseline data for future research on Tl natural dispersion processes.     

Ecohydrology of Groundwater Dependent Ecosystems: A Review

Groundwater Dependent Ecosystems (GDEs) are ecosystems that must have access to groundwater to maintain their ecological structure and function. In other words, the vegetation dynamics moisture dynamics, and water-salt balance in GDEs are significantly affected by and directly related to the groundwater. This work reviews the most recent research advances in the ecohydrology of GDEs from: ①the interactions between groundwater and vegetation, ②the interactions between groundwater and soil moisture dynamics in the vadose zone, the interactions between ground and ③surface-water systems, ④the interactions between groundwater and salt accumulation dynamics, ⑤the responses of GDEs to climate changes and human disturbances, and ⑥the ecohydrological modeling works toward sustainable management of GDEs. It is pointed out that several issues need to be taken into account in the managements of GDEs, i.e., how does the vegetation of GDEs response to fluctuations and decreases in the groundwater level, whether there is a catastrophic loss of the functions of GDEs, and what is the threshold value below which such a catastrophe may occur. The key to solving those issues lies in how to delineate the different ecohydrological processes occurred in the soil medium from the top of the ground surface to the water table. Therefore, observation and modeling efforts are needed and will be important research priorities in the future, especially for GDEs in arid environments. We also argued that four more difficulties should be addressed towards sustainable management of GDEs in future: ①how to identify GDEs in the field, and determine which habitats and species are reliant on groundwater for their persistence in the landscape, ②what groundwater regime is required to sustain the existence of GDEs, ③how to manage GDEs with limited social resources, and ④what measures of ecosystem function can be monitored to determine that management is effective?     

Hydrological Conditions Control P Loading and Aquatic Metabolism in an Oligotrophic, Subtropical Estuary

Using high-resolution measures of aquatic ecosystem metabolism and water quality, we investigated the importance of hydrological inputs of phosphorus (P) on ecosystem dynamics in the oligotrophic, P-limited coastal Everglades. Due to low nutrient status and relatively large inputs of terrestrial organic matter, we hypothesized that the ponds in this region would be strongly net heterotrophic and that pond gross primary production (GPP) and respiration (R) would be the greatest during the “dry,” euhaline estuarine season that coincides with increased P availability. Results indicated that metabolism rates were consistently associated with elevated upstream total phosphorus and salinity concentrations. Pulses in aquatic metabolism rates were coupled to the timing of P supply from groundwater upwelling as well as a potential suite of hydrobiogeochemical interactions. We provide evidence that freshwater discharge has observable impacts on aquatic ecosystem function in the oligotrophic estuaries of the Florida Everglades by controlling the availability of P to the ecosystem. Future water management decisions in South Florida must include the impact of changes in water delivery on downstream estuaries.     

Review: Safe and sustainable groundwater supply in China

Exploitation of groundwater has greatly increased since the 1970s to meet the increased water demand due to fast economic development in China. Correspondingly, the regional groundwater level has declined substantially in many areas of China. Water sources are scarce in northern and northwestern China, and the anthropogenic pollution of groundwater has worsened the situation. Groundwater containing high concentrations of geogenic arsenic, fluoride, iodine, and salinity is widely distributed across China, which has negatively affected safe supply of water for drinking and other purposes. In addition to anthropogenic contamination, the interactions between surface water and groundwater, including seawater intrusion, have caused deterioration of groundwater quality. The ecosystem and geo-environment have been severely affected by the depletion of groundwater resources. Land subsidence due to excessive groundwater withdrawal has been observed in more than 50 cities in China, with a maximum accumulated subsidence of 2–3 m. Groundwater-dependent ecosystems are being degraded due to changes in the water table or poor groundwater quality. This paper reviews these changes in China, which have occurred under the impact of rapid economic development. The effects of economic growth on groundwater systems should be monitored, understood and predicted to better protect and manage groundwater resources for the future.     

晋祠泉域岩溶水生态系统健康评价

文章尝试性地提出岩溶水生态系统的概念,从系统的特征、功能和面临的威胁三方面论述了其内涵,基于驱动力-压力-状态-影响-响应(DPSIR)模型,综合考虑自然因素和人类活动叠加影响,构建了岩溶水生态系统健康评价指标体系;用层次分析法(AHP)确定指标权重,用综合评价法确定岩溶水生态系统所处健康状态,并将其分为很健康、健康、亚健康、不健康和病态五级。并以晋祠泉域为例,采用ArcGIS空间分析技术确定岩溶水生态系统健康评价等级。结果表明:泉域煤矿开采区处于不健康状态,东部平原区和中部径流区均处于亚健康状态,碳酸盐岩裸露区和汾河周边区域处于健康状态,分别占晋祠泉域总面积的29%、31%和40%。     

Research hotspots and trends of groundwater and ecology studies: Based on a bibliometric approach

Groundwater, as a critical component of the hydrological cycle, is essential for sustainable ecosystem development. To clarify the current status of domestic and overseas research, and to identify hotspots, frontier and future trends of groundwater and ecology research, this study utilizes bibliometric methods and CiteSpace software to examine relevant published articles in the Web of Science (WOS) and CNKI databases from 1978 to 2022. Specifically, this study analyzes (1) the annual number of published papers; (2) research institutions; (3) keywords; and (4) evolution of research hotspots. The findings reveal that the United States, China, and Germany are the top three countries in groundwater and ecology research. International research hotspots mainly focus on microbial ecology, climate change, groundwater-surface water interactions in the hyporheic zone, biodiversity, and submarine groundwater discharge, while domestic research hotspots mainly focus on ecological water conveyance, ecological flow, groundwater development and utilization, groundwater pollution, and groundwater and ecological protection. Both domestic and international research hotspots exhibit interdisciplinary features with diverse research objects and assessment methods. Future research in this area is expected to focus on topics such as contamination, groundwater quality, framework, mechanism, spatial distribution, and dissolved organic matter. Additionally, the study of ecological recharge, ecological flow, ecological protection, water intake and use will continue to be the hot topics domestically.     

黑河下游典型生态系统水分补给源及优势植物水分来源研究

通过对黑河源区降水、 黑河下游河岸林生态系统、 人工梭梭林生态系统梭梭及戈壁红砂生态系统土壤水和浅层地下水稳定氢氧同位素组成(δD、 δ¹⁸O)的测定, 对黑河下游典型生态系统土壤水和浅层地下水的补给源进行了研究. 同时通过对比分析河岸林生态系统胡杨和柽柳、 人工梭梭林生态系统梭梭及戈壁红砂生态系统红砂等优势植物根系水及其对应的土壤水及浅层地下水的δ¹⁸O, 对黑河下游典型荒漠植物水分来源进行了研究, 并对不同潜在水源对植物水分来源的贡献率进行了计算. 结果表明: 河岸林生态系统和人工梭梭林生态系统的土壤水和浅层地下水来自黑河源区的降水, 源区降水通过黑河河道输水补给河岸林进而形成土壤水和浅层地下水, 但人工梭梭林的土壤水蒸发作用强烈. 戈壁红砂生态系统由于远离黑河, 土壤水不受黑河源区中上游输水的补给. 就植物水分来源而言, 在河岸林生态系统中, 乔木胡杨主要利用40~60 cm的土壤水和地下水, 灌木柽柳主要利用40~80 cm的土壤水; 人工梭梭主要利用200 cm至饱和层土壤水和地下水; 戈壁红砂主要利用175~200 cm的土壤水. 因此, 在黑河下游极端干旱区, 土壤水和地下水是维持荒漠植物生存、 生长及发育的主要来源.     

地下水生态系统保护探讨

从生态保护的角度,指出现行地下水管理存在的问题;提出维持地下水生态系统健康发展的可持续开采量的概念;探讨了不同地下水生态系统环境用水量的计算方法。地下水的开发利用应以可持续开采量作为最大闽值。通过预留环境用水量,确定生态水位,建立生态缓冲带,实施生态调度,制定合理开发利用方案等措施,可有效修复和保护日益恶化的生态环境。     

Combined electrical resistivity tomography and magnetic resonance sounding investigation of the surface-water/groundwater interaction in the Urema Graben,Mozambique

This study focusses on the hydrogeology of Urema Graben, especially possible interactions between surface water and groundwater around Lake Urema, in Gorongosa National Park (GNP). Lake Urema is the only permanent water source for wildlife inside GNP, and there are concerns that it will disappear due to interferences in surface-water/groundwater interactions as a result of changes in the hydraulic environment. As the lake is the only permanent water source, this would be a disaster for the ecosystem of the park. The sub-surface geology in Urema Graben was investigated by 20 km of electrical resistivity tomography (ERT) and three magnetic resonance sounding (MRS) surveys. The average depth penetration was 60 and 100 m, respectively. The location of the ERT lines was decided based on general rift morphology and therefore orientated perpendicular to Urema Graben, from the transitional areas of the margins of the Barue platform in the west to the Cheringoma plateau escarpments in the east. ERT and MRS both indicate a second aquifer, where Urema Lake is a window of the first upper semi-confined aquifer, while the lower aquifer is confined by a clay layer 30–40 m thick. The location and depth of this aquifer suggest that it is probably linked to the Pungwe River which could be a main source of recharge during the dry season. If a dam or any other infra-structure is constructed in Pungwe River upstream of GNP, the groundwater level will decrease which could lead to drying out of Urema Lake.