济南泉域岩溶水质演变及其对人类活动的响应   总被引：5，自引：0，他引：5  

路洪海  章程 《水土保持研究》2007,14(6):242-244,249

地下水是岩溶地区水资源的重要赋存形式,也是岩溶地区经济发展的重要支撑点。由于岩溶含水层的本质脆弱性,岩溶水资源在人类活动胁迫下极易蜕变。以20世纪50年代末的地下水化学状况为背景值,结合近20年的水质监测资料,分析了济南泉域岩溶水质演化与人类活动的关系。结果显示：近20年来,地下水质总体呈恶化趋势,水质的区域性、阶段性变化与人类活动强度密切相关,东郊岩溶水质最差,且无污染物增长幅度明显高于市区和西郊。伴随土地利用方式的改变和人类活动强度的空间变化,地下水质从间接补给区、直接补给区到泉水排泄区,单项污染指数和综合污染指数依次升高;具有典型代表性的泉域东部大辛河流域,从上游、中游到下游,地下水污染物的浓度也渐次升高,且愈往下游污染物浓度增幅愈大,显示出与土地利用方式和人类活动的密切相关性。因此优化调整土地利用结构,减少人类活动对下水的污染,对岩溶水资源的可持续利用和济南“泉城”景观的保护有重要意义。  相似文献   

FEFLOW软件在地下水数值模拟中的应用——以柴达木盆地香日德绿洲为例   总被引：1，自引：0，他引：1  

毛军  贾绍凤  张克斌 《中国水土保持科学》2007,5(4):44-48

 作为我国内陆高寒干旱地区绿洲代表的青海柴达木盆地香日德绿洲,近年来由于大规模引水灌溉,使得下游局部地区生态环境恶化。为了定量分析灌溉引水对下游生态系统的影响,利用FEFLOW软件对研究区的地下水流进行数值模拟。结果表明:现状条件下潜水排泄量为3.93亿m3;区内用于绿洲灌溉合理可行的水资源量为1亿～1.5亿m3。所建立的模型合理可行,能够进行该地区地下水位动态预报,可为研究区水资源的合理开发提供科学依据。  相似文献   

河北曲周盐渍土区土壤元素特征   总被引：2，自引：0，他引：2  

李韵珠  陆锦文  吴金绥 《土壤学报》2002,39(5):627-635

研究了地处华北冲积平原的曲周盐渍土区土壤元素全量 (ST)、1∶1浸出液(SE)和土壤溶液 (SS)中各元素的浓度范围和特征 ,及其与地下水中元素的联系。土壤元素全量主要与土壤质地 (反映了矿物组成 )有关 ,只有盐渍化严重的土壤 ,易溶性元素对其全量的增加有一定影响。元素在土壤溶液和 1∶1浸出液中的浓度差异受土壤水分状况的影响。各土层元素在SE中的含量占全量的百分率 ,其平均值和变异系数在一定程度上说明了该元素的可溶性和移动性。土壤—地下水系统中 1m和 2m土层的大部分元素在 1∶1浸出液中的浓度平均值与地下水矿化度和与地下水中相应元素的浓度值之间呈显著或极显著相关 ,无相关关系的元素 ,大多属迁移系数较小的元素。文中还以例说明了不同盐渍化程度土壤 1∶1浸出液中元素浓度垂直剖面特征 ,以及与地下水中相应元素浓度的联系。  相似文献   

塔里木胡杨自然保护区地下水理化特性相互关系研究     

胡小韦  海米提．依米提  艾尼瓦尔．买买提  木巴热克  冯振忠 《水土保持研究》2007,14(5):293-295,299

通过对塔里木河胡杨林自然保护区的地下水理化特性相互关系的研究,结果表明：地下水埋深和pH与电导率、含盐量、矿化度的相关系数不大。电导率和含盐量、矿化度的相关系数分别为0.974和0.984,含盐量与矿化度相关系数为0.998,以此得出电导率与矿化度、含盐量回归模型。  相似文献   

基于多项式分布滞后模型的上海市地面沉降验证与预测     

曹伟伟  李明广  史玉金  夏小和 《水土保持通报》2020,40(2):177-181

[目的]对上海市地面沉降进行验证与预测,为地下工程建设和地下水开采格局的科学调整提供参考。[方法]基于地下水抽灌量、地面沉降和土层分层变形等长期监测数据,研究地面沉降量与地下水开采量、土层分层变形量之间的相关性,并结合上海市地面沉降特性及原因,建立考虑地下水开采量和第4含水层变形量的地面沉降多项式分布滞后模型(PDL模型)。[结果]①上海市累计地下水开采量、第4含水层累计变形量与累计地面沉降量之间均具有高度的正相关性,但由于砂土蠕变、弱透水层释水缓慢等原因,地面沉降相对于地下水开采量和第4含水层变形都有着一定的滞后性;②采用考虑滞后效应的多项式分布滞后模型预测地面沉降,其计算结果相对误差较小、拟合效果较好;③若以当前采灌格局及第4含水层变形量作为参考进行预测,地面沉降在2019—2024年间将会发生稳定的轻微回弹现象。[结论]上海市地面沉降与地下水开采量和土层变形量之间有着较高的相关性,且控制地下水开采能够有效缓解地面沉降的发展。  相似文献   

田块尺度上土壤/地下水中硝态氮动态变化特征及模拟     

王志敏  林青  王松禄  徐绍辉 《土壤》2015,47(3):496-502

以青岛市大沽河下游地区冬小麦–夏玉米轮作农田为对象,通过田间试验和室内分析,研究了不同深度土壤和地下水中NO3–-N在一个轮作周期内的动态变化特征,探讨了不同氮肥施用量和灌溉量对土壤-地下水系统中NO3–-N时空分布的影响,并基于土壤水动力学和溶质运移理论对土壤中NO3–-N运移过程进行了数值模拟。模拟结果表明:小麦季施氮(N)量达到380 kg/hm2,玉米季施氮量达到290 kg/hm2时,季末剖面深度130~160 cm土壤NO3–-N含量超过10 mg/kg;由地下水NO3–-N月累计量估算模型得出,NO3–-N在6月和8月向浅部地下水的淋失量最大,分别为7.20、7.67 mg/L。  相似文献   

黄河三角洲地区浅层地下水与耕层土壤积盐空间分异规律定量分析   总被引：18，自引：3，他引：18  

姚荣江  杨劲松 《农业工程学报》2007,23(8):45-51

为研究黄河三角洲地区地下水作用条件下耕层土壤的积盐规律，运用GIS和地统计学的原理与方法，结合地下水埋深的空间分布以及临界埋深的划分标准对研究区域进行分区，并从空间尺度对各分区地下水矿化度与耕层土壤积盐规律进行了定量分析。结果表明：地下水埋深、矿化度和耕层土壤盐分均属于中等变异强度，在东西方向和南北方向上均具有2阶的趋势效应；受结构性因素和随机性因素的共同作用，地下水埋深呈中等的空间自相关性，地下水矿化度与耕层土壤盐分呈弱空间自相关性；耕层土壤盐分与地下水矿化度的空间分布具有一定的相关性，与地下水埋深呈负相关性。对空间尺度上的地下水矿化度与耕层土壤盐分定量分析结果表明，耕层土壤积盐与地下水矿化度呈极显著的相关关系，而地下水埋深增加使其相关性减弱，采用分区研究法使地下水矿化度对耕层土壤积盐规律分析更加客观准确。该结果对研究黄河三角洲地区土壤盐渍化的发生机理以及预测与评估该地区土壤盐渍化的发生发展具有重要意义。  相似文献   

Molecular Monitoring of SRB Community Structure and Dynamics in Batch Experiments to Examine the Applicability of in situ Precipitation of Heavy Metals for Groundwater Remediation (15 pp)     

Joke Geets  Brigitte Borremans  Jaco Vangronsveld  Ludo Diels  Dani?l van der Lelie 《Journal of Soils and Sediments》2005,5(3):149-163

Background, Aims and Scope   Sulfate-reducing bacteria (SRB) are known for their capacity to reduce and precipitate heavy metals (HM) as metal sulfides, offering the opportunity to create an in situ reactive zone for the treatment of heavy metal-contaminated groundwater, a process called in situ metal precipitation (ISMP). The applicability of the ISMP technology first has to be investigated at a laboratory scale before going into an on site application. The evaluation and optimization of the ISMP process is facilitated when physical/chemical analysis techniques are combined with molecular tools that specifically monitor the abundance, diversity and dynamics of the indigenous sulfate reducing microbial community. In this study, batch experiments were conducted in order to investigate the feasibility of ISMP as a groundwater remediation strategy for an industrial site contaminated with elevated levels of Zn, Cd, Co and Ni. Methods   The potential of different types of carbon source/ electron donor (lactate, acetate, methanol, ethanol, Hydrogen Release Compound?, molasses) to stimulate the sulfate reduction and metal precipitation activity of the naturally present (or indigenous) SRB community was explored. In addition, the effect of amending vitamin B12 and yeast extract was evaluated. The ISMP process was monitored by combining analytical analyzes of process parameters (SO42-concentration, heavy metal concentrations, pH, Eh) with molecular tools such as SRB subgroup and genus specific PCR, denaturing gradient gel electrophoresis (DGGE), and phylogenetic analysis of clone sequences, based on either the 16S rRNA or the dsr (dissimilatory sulfite reductase) gene. Results and Discussion   The efficiency of different carbon-sources to stimulate the ISMP process followed the order HRC 〉 molasses 〉 methanol 〉 lactate 〉 ethanol 〉 acetate. Within 10 weeks, the highest sulfate and metal removal efficiencies ranged from 85% to 99%. Addition of yeast extract boosted the ISMP process, whereas vitamin B12 negligibly affected SRB activity. Analysis of the sulfate reducing population by SRB subgroup and genus specific PCR demonstrated that members of the genus Desulfosporosinus dominated in all batch tests, while 16S rDNA DGGE profiles additionally revealed the presence in the microbial communities of non-sulfate reducing bacteria within the family Clostridium and the -proteobacteria. The dsrB-based DGGE profiles allowed us to assess the diversity and dynamics of the sulfate reducing community and added to a better understanding of the effects of different batch conditions on the ISMP process. Remarkably, all dsrB sequences affiliated with the dsrB gene sequence cluster found in Desulfotomaculum, which received their xenologous dsrB gene from the -proteobacteria. Conclusions   The batch experiments, which aimed at stimulating the activities of the indigenous SRB communities, demonstrated that these communities were present and that their activities could be used to obtain efficient in situ precipitation of the contaminating heavy metals. This opens the possibility to test this concept in the future as an on site demonstration as part of the groundwater strategy for the heavy metal contaminated site. Although batch setups are suitable for preliminary feasibility studies for ISMP, they do not reflect the in situ situation where sulfate and heavy metal and metalloid polluted groundwater are supplied continuously. A sulfate reducing strain JG32A was isolated from whose 16S rRNA gene affiliated with the genus Desulfosporosinus, while its dsrB gene sequence clustered with Desulfotomaculum dsrB gene sequences, which received their xenologous dsr genes from -proteobacteria. Therefore we hypothesize that the batch experiments enrich members of the Desulfosporosinus genus that possess a non-orthologous dsrB gene. Recommendation and Perspective   The next step towards an on site pilot test for ISMP will be the setup of a series of column experiments, with process conditions that are selected based on the above mentioned results. This will allow to define optimal ISMP process conditions and to test its long-term efficacy and sustainability before going into an on site bioremediation application. By applying the described molecular tools together with physical-chemical analyzes, it can be investigated whether the same SRB community is enriched and which type of C-source is most effective in promoting and sustaining its growth and sulfate-reduction activity.  相似文献   

Thermal regime in the hyporheic zone of two contrasting salmonid spawning streams: ecological and hydrological implications   总被引：1，自引：0，他引：1  

I. A. MALCOLM  C. SOULSBY  & A. F. YOUNGSON 《Fisheries Management and Ecology》2002,9(1):1-10

The temperatures of stream water and hyporheic water were monitored in spawning areas of an upland stream (Girnock Burn) and a degraded lowland stream (Newmills Burn). Both streams are located in North-east Scotland and are spawning streams for Atlantic salmon, Salmo salar L., and brown trout, S. trutta L. Monitoring between the spawning and hatching of ova revealed significant differences in the thermal regimes of the two sites. Whilst temperatures in stream and hyporheic water were similar in the Girnock, notable attenuation in the Newmills Burn resulted in increasing moderation of thermal regime with hyporheic depth. This probably reflects contrasting groundwater–surface water interactions in the two systems. In the Girnock an open gravel stream bed and lack of groundwater influence resulted in stream water downwelling through the gravel. In contrast, fine bed sediments and local groundwater inputs resulted in more complex stratification of temperatures in Newmills Burn. However, even in the conditions of the Newmills Burn, temperature based salmonid embryo development models predicted that egg burial depth has an insubstantial effect on ova development.  相似文献   

甘肃梨园河流域地下水来源及其水化学特征   总被引：1，自引：0，他引：1  

张清寰  齐识  马金珠 《干旱区研究》2012,29(5):898-906

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。  相似文献