山西离柳地区生态地球化学环境中氟与人群健康关系的研究   总被引：3，自引：0，他引：3  

胡忠毅  赵晓波  曹玉清  李树林 《吉林大学学报(地球科学版)》2002,32(1):58-63

为了研究不同生态地球化学区内元素对人体健康的影响 ,在山西离柳地区西部 ,以氟为例 ,运用地下水化学热力学、化学动力学及统计分析 ,得出 :(1)地氟病患病率及病情轻重程度 ,与水 (土 )中F-总量 (F总)及活度 (aF- )、络合物活度 (aMF)及其饱和指数 (βMF)呈正相关关系 ,符合一般规律 ;(2 )氟的不同存在形态的致病作用是aF- >F总 ,aNaF0 >aCaF+>aMgF+,βNaF0 >βCaF+>βMgF+;(3)水循环交替条件及有关组分含量与病情轻重密切相关。研究结果为防治地氟病和地方性病症提供了定性、定量依据 ,也为同类研究提出了新的途径  相似文献   

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《CT理论与应用研究》编辑部 《CT理论与应用研究》2006,15(1)

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岩溶水系统溶蚀速度的多重耦合模型——以山西太原东山水文地质系统为例   总被引：1，自引：1，他引：0  

曹玉清  胡宽王容  李彦斌  张文兵 《中国岩溶》1997,16(3):199-208

本文运用化学热力学与水文地质系统耦合理论,将太原东山水文地质系统划分成矿物溶解、沉淀各异的区带;通过各区带内的化学—数学与相关分析法的耦合模型,计算出各区带碳酸、硫酸盐岩的综合溶蚀模量;再将综合溶蚀模量和用化学动力学理论确定地下水实际速度的解析解公式与有限单元法耦合,计算确定出各节点的溶蚀速度。从而不仅有效地评价了水文地质系统内的溶蚀特点,还可反映区内地质构造和水文地质条件,以及含水层在倾向方向随埋深增大呈幂函数变化的规律;进而可确定出区内供水、矿井防治水的最佳勘探地段。这些不仅具有一定理论意义,也具有一定的社会和经济效益   相似文献   

济南泉域地下水年龄计算   总被引：1，自引：1，他引：0  

房佩贤  曹玉清  唐克旺  李祥之  王绍文 《中国岩溶》1989,8(1):47-52

本文应用环境同位素分析,估算了济南泉域地下水的年龄;根据碳酸盐矿物溶解动力学理论,又计算了泉水的化学年龄;并与同位素求出的年龄作出比较。   相似文献   

地下水NO3^-氮与氧同位素研究进展     

邓林曹玉清  王文科 《地球科学进展》2007,22(7):716-724

人为活动通常是地下水硝酸盐污染的主要原因。不同来源的NO3^-具有不同的氮、氧同位素组成,利用地下水NO3^-中的δ15N和δ18O值可有效识别地下水硝酸盐污染的来源。引起地下水中NO3^-含量显著减少的不同物理、化学和生物过程,所产生的氮、氧同位素分馏效应有明显差别。地下水系统中反硝化作用发生时,NO3^-中氮和氧同位素分馏系数呈一定比例。因此NO3^-中δ15N和δ18O值也是示踪地下水硝酸盐循环,尤其是反硝化作用的有效手段。利用NO3^-中氮和氧双同位素,并与其他环境同位素及化学分析技术相结合,示踪NO3^-来源及其循环是地下水硝酸盐污染研究的重要方向之一。综述了利用地下水硝酸盐中氮和氧同位素识别NO3^-污染源与循环的研究进展,简述了近年迅速发展的阴离子交换树脂取样法,概述了此方面研究存在的主要问题,并展望了今后的研究方向。  相似文献   

水文地质蓄水构造级、区带划分及其水资源分布特点     

胡宽瑢  曹玉清  胡忠毅 《吉林大学学报(地球科学版)》2000,30(3):246-250

为研究水资源对生态环境的影响 ,和寻求供排水的最佳勘察地段 ,根据我国地质构造、地貌规模和特点 ,提出蓄水构造的Ⅳ级划分 ;划分指标按具体地区的地质、含水层富 (透、导 )水性、水文地球化学资料统计确定 ;Ⅰ、Ⅱ级蓄水构造属区域性分区 ,Ⅲ、Ⅳ级水文地质区带属水文地质单元内部具体分级。巨厚含水层富 (透、导 )水性随垂向深度呈负指数 (y =Ax-B)变化 ,水平方向上随埋深标高呈幂函数 (y =AH±B)变化 ;饱和指数 (βj)与埋深标高呈负指数 (H =Aβ-Bj )变化 ;为建立水资源—生态环境多重耦合模型奠定基础 ;为确定供水和矿区防治水最佳勘察地带、点和深度指明方向。  相似文献   

Implications of sampling design and sample size for national carbon accounting systems     

Köhl M  Lister A  Scott CT  Baldauf T  Plugge D 《Carbon balance and management》2011,6(1):10

Background  

Countries willing to adopt a REDD regime need to establish a national Measurement, Reporting and Verification (MRV) system that provides information on forest carbon stocks and carbon stock changes. Due to the extensive areas covered by forests the information is generally obtained by sample based surveys. Most operational sampling approaches utilize a combination of earth-observation data and in-situ field assessments as data sources.  相似文献   

Vulnerability indicators of sea water intrusion   总被引：5，自引：0，他引：5  

Werner AD  Ward JD  Morgan LK  Simmons CT  Robinson NI  Teubner MD 《Ground water》2012,50(1):48-58

In this paper, simple indicators of the propensity for sea water intrusion (SWI) to occur (referred to as "SWI vulnerability indicators") are devised. The analysis is based on an existing analytical solution for the steady-state position of a sharp fresh water-salt water interface. Interface characteristics, that is, the wedge toe location and sea water volume, are used in quantifying SWI in both confined and unconfined aquifers. Rates-of-change (partial derivatives of the analytical solution) in the wedge toe or sea water volume are used to quantify the aquifer vulnerability to various stress situations, including (1) sea-level rise; (2) change in recharge (e.g., due to climate change); and (3) change in seaward discharge. A selection of coastal aquifer cases is used to apply the SWI vulnerability indicators, and the proposed methodology produces interpretations of SWI vulnerability that are broadly consistent with more comprehensive investigations. Several inferences regarding SWI vulnerability arise from the analysis, including: (1) sea-level rise impacts are more extensive in aquifers with head-controlled rather than flux-controlled inland boundaries, whereas the opposite is true for recharge change impacts; (2) sea-level rise does not induce SWI in constant-discharge confined aquifers; (3) SWI vulnerability varies depending on the causal factor, and therefore vulnerability composites are needed that differentiate vulnerability to such threats as sea-level rise, climate change, and changes in seaward groundwater discharge. We contend that the approach is an improvement over existing methods for characterizing SWI vulnerability, because the method has theoretical underpinnings and yet calculations are simple, although the coastal aquifer conceptualization is highly idealized.  相似文献   

Using MODFLOW 2000 to model ET and recharge for shallow ground water problems     

Doble RC  Simmons CT  Walker GR 《Ground water》2009,47(1):129-135

In environments with shallow ground water elevation, small changes in the water table can cause significant variations in recharge and evapotranspiration fluxes. Particularly, where ground water is close to the soil surface, both recharge and evapotranspiration are regulated by a thin unsaturated zone and, for accuracy, must be represented using nonconstant and often nonlinear relationships. The most commonly used ground water flow model today, MODFLOW, was originally designed with a modular structure with independent packages representing recharge and evaporation processes. Systems with shallow ground water, however, may be better represented using either a recharge function that varies with ground water depth or a continuous recharge and evapotranspiration function that is dependent on depth to water table. In situations where the boundaries between recharging and nonrecharging cells change with time, such as near a seepage zone, a continuous ground water flux relationship allows recharge rates to change with depth rather than having to calculate them at each stress period. This research article describes the modification of the MODFLOW 2000 recharge and segmented evapotranspiration packages into a continuous recharge-discharge function that allows ground water flux to be represented as a continuous process, dependent on head. The modifications were then used to model long-term recharge and evapotranspiration processes on a saline, semiarid floodplain in order to understand spatial patterns of salinization, and an overview of this process is given.  相似文献   

Multilevel samplers as microcosms to assess microbial response to biostimulation     

Baldwin BR  Peacock AD  Park M  Ogles DM  Istok JD  McKinley JP  Resch CT  White DC 《Ground water》2008,46(2):295-304

Passive multilevel samplers (MLS) containing a solid matrix for microbial colonization were used as in situ microcosms in conjunction with a push-pull biostimulation experiment designed to promote biological U(VI) and Tc(VII) reduction. MLS were deployed at 24 elevations in the injection well and two downgradient wells to investigate the spatial variability in microbial community composition and growth prior to and following biostimulation. The microbial community was characterized by real-time quantitative polymerase chain reaction (Q-PCR) quantification of bacteria, NO(3)(-)-reducing bacteria (nirS and nirK), delta-proteobacteria, Geobacter sp., and methanogens (mcrA). Pretest cell densities were low overall but varied substantially with significantly greater bacterial populations detected at circumneutral pH (t-test, alpha= 0.05), suggesting carbon substrate and low pH limitations of microbial activity. Although pretest cell densities were low, denitrifying bacteria were dominant members of the microbial community. Biostimulation with an ethanol-amended ground water resulted in concurrent NO(3)(-) and Tc(VII) reduction, followed by U(VI) reduction. Q-PCR analysis of MLS revealed significant (1 to 2 orders of magnitude, Mann-Whitney U-test, alpha= 0.05) increases in cell densities of bacteria, denitrifiers, delta-proteobacteria, Geobacter sp., and methanogens in response to biostimulation. Traditionally, characterization of sediment samples has been used to investigate the microbial community response to biostimulation; however, collection of sediment samples is expensive and not conducive to deep aquifers or temporal studies. The results presented demonstrate that push-pull tests with passive MLS provide an inexpensive approach to determine the effect of biostimulation on contaminant concentrations, geochemical conditions, and the microbial community composition and function.  相似文献