共查询到20条相似文献，搜索用时 125 毫秒
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以荣昌华江井为观测对象,开展详细的水温梯度测试。分析不同深度段水温潮汐响应和同震响应,统计该井不同深度处井水温微动态特征,认为:荣昌华江井特定深度段的水温能记录到微弱潮汐响应,可能是因为井水温梯度较小,水位变化引起的温度变化较小,而高频噪声相对较大,影响该井记录潮汐现象;随着观测深度的增加,荣昌华江井水温记录同震响应的能力增强。 相似文献
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昌黎井水温潮汐形成机理分析 总被引：4，自引：0，他引：4
昌黎井水温具有潮汐变化特征, 并且与该井水位的潮汐动态同步。 该文对比分析了井水温潮汐特征产生的可能原因。 认为井水温潮汐现象在井管内任何深度不一定都有反映, 能够显示温度潮汐周期性变化大体有两种模式: 一是井管水体具有足够大的温度梯度, 水体上下周期性运动时, 温度探头可以捕捉到水体的温度变化; 二是井-含水层系统地下水交换量的多寡引起水温同步的周期性变化。 研究结果表明, 昌黎井水温潮汐现象是次生效应, 水温潮汐动态与井孔管路特殊结构有一定关系。 相似文献
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为提升对山西省地下流体观测井承压性的进一步认识,以位于该省北、中、南部的朔州井、静乐井、祁县井、洪洞井和东郭井为研究对象,选取水位、气压观测数据,并利用井水位的理论固体潮数据,分别对井水位进行气压的阶跃响应函数计算、FFT频谱和潮汐相位响应分析,综合判定地下流体观测井—含水层类型,结果表明,5口观测井地下水埋藏类型均为半承压水。 相似文献
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该文对黄村冷水源井的水温固体潮现象进行了观测研究，初步解释了冷水源井的水温固体潮汐的形成机理.通过对黄村观测井进行水温梯度的详细观测及不同深度水温的对比观测研究，得到了黄村井水温潮汐现象的观测结果:① 黄村冷水源井的水温固体潮的相位与水位的相位是相反的；② 黄村井水温梯度曲线呈下凹型，特别是在含水层及受含水层进出水影响较大的附近区域下凹程度大，且随着与含水层底板距离逐渐变大，下凹程度也变小；③ 水温传感器的观测值与含水层观测距离存在一定的规律性:距离含水层越远，水温潮汐差越小, 直至潮汐变化消失.这说明冷水源井与热水井的水温潮汐现象是不同的，前者是吸热过程, 后者是放热过程，由此造成二者水-热动力学特征的不同. 相似文献
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以井-含水层系统潮汐理论为基础, 结合云南曲靖井水位观测资料实际情况, 利用Baytap-G提供的潮汐分析方法, 分别计算了曲靖井水位M2、 S2、 O1、 S1K1和M3共5个潮汐分波的振幅比、 相位和计算误差, 分析了井水位观测资料不同潮汐波振幅比和相位的动态变化特征, 认为能反映含水层参数的井水位潮汐振幅比和相位变化与附近的抽水和远距离大震引起的同震响应有关, 具体表现为, 2001年11月和2003年8月的振幅比和相位下降变化可能与抽水有关, 而几次大震后的井水位潮汐振幅比和相位小幅度上升和缓慢恢复过程, 则可能与中远场大震的地震波动力引起的含水层渗透系数增加有关． 相似文献
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中国大陆井水温度潮汐动态的统计与调和分析 总被引：1，自引：0，他引：1
用收集到的全国356个井水温度测点的数据, 分析了水温对地球固体潮汐的响应, 统计出 35个存在水温潮汐现象的测点。 利用Baytap-G调和分析方法, 计算了水温潮汐分波的振幅、 振幅比和相位差。 结果表明: 水温潮汐现象是一类较普遍的地球物理现象, 其机制与水位潮汐相关, 可用水动力学模式解释; 水温潮汐变化特征还受太阳辐射热、 含水层和地温的影响, 自流井水温记录潮汐现象的能力高于非自流井、 东部地区水温测点记录潮汐现象的能力高于西部, 与太阳辐射热的影响有关, 在含水层附近的水温测点, 其潮汐动态比其他井段显著, 在受地温影响较大的井段, 水温的潮汐变化幅度与水温梯度成正比; 水温的应力-应变灵敏度量级为0.01～10℃/10-6m·s-2。 相似文献
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地热井的观测规范要求尽可能将水温传感器放置在井下深处, 一般放置深度应当大于100 m, 小于200 m。 然而, 近几年的观测结果表明, 水温传感器的放置深度对水温动态特征的影响较大。 在多数观测井中, 同井水温与水位的时值动态、 潮汐效应、 同震响应及震后阶变等动态特征的相关性或一致性, 多与水温传感器的放置深度有关。 本文主要探讨了传感器放置深度对水温动态特征的影响, 水温传感器放置在观测含水层中, 都受井—含水层间水流运动的影响, 会造成水温动态随井水位变化而变化; 当放置在观测含水层下部时, 水温动态则不受井水位变化的影响, 多表现为动态相对稳定。 其原因是水温动态的形成受水热动力学与地热动力学两种不同机制的控制, 此外, 井—含水层系统的条件也会产生影响。 相似文献
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A method for the trace-level determination of bromate in raw and drinking water is reported. The procedure combines the quantitation of bromate by ion chromatography with a concentration step which in the main is composed of an unselective enrichment of all water constituents by means of a rotatory evaporator and a selective removal of the chloride ions. With this method, the reliable determination of bromate in raw and drinking waters is possible down to concentrations of at least 1 μg/L. The method is used for systematic examinations in several German waterworks which use ozone for the preparation of drinking water. The resulting data clearly prove that during the ozonation of bromide-containing waters, bromate is produced, whereby the concentration of bromate in the ozonated raw water can exceed 10 μg/L. Some correlations between the amount of bromate and the respective conditions of ozonation are pointed out. 相似文献
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This paper analyses the experiences acquired through several research projects on the history of water and sanitation services by two multidisciplinary teams. Challenges have been faced in identifying feasible objectives, realistic resources, time allocations and unexpected external factors. Water history can preserve cultural heritage, promote reputation management, record vanishing knowledge, and discover new facts. 相似文献
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《Limnologica》2015
In this study, we assessed the relationship between the occurrence of the invasive water hyacinth (Eichhornia crassipes) and water quality properties as well as macroinvertebrate diversity in a tropical reservoir, situated in western Ecuador. Macroinvertebrates and physico-chemical water quality variables were sampled at 32 locations (during the dry season of 2013) in both sites covered and non-covered by water hyacinth in the Daule-Peripa reservoir. The results indicated that, in terms of water quality, only turbidity was significantly different between sampling sites with and without water hyacinth (Mann–Whitney U-test, p < 0.01). The habitat suitability model showed that water hyacinth was present at sites with a low turbidity. The percentage water hyacinth cover increased with decreasing turbidity. The Biological Monitoring Working Party-Colombia score and the Margalef diversity index were significantly higher (Mann–Whitney U-test, p < 0.01) at sampling sites where water hyacinth was present compared to water hyacinth absent sites. However, there were no significant differences in the Shannon–Wiener index, Evenness index and Simpson index between the sampling sites with and without water hyacinth. Our results suggest that water hyacinth cover was an important variable affecting the diversity of macroinvertebrates in the Daule-Peripa reservoir, with intermediate levels of water hyacinth cover having a positive effect on the diversity of macroinvertebrates. Information on the habitat suitability of water hyacinth and its effect on the physico-chemical water quality and the macroinvertebrate community are essential to develop conservation and management programs for large tropical reservoirs such as the Daule-Peripa reservoir and the Guayas river basin, where water resources are being at high risk due to expansion of agricultural and industrial development activities. 相似文献
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研究输水对水库水质时空变化的影响有助于科学预测水体富营养化及防控水华暴发.本文以于桥水库为例，基于2011-2015年实测资料分析入库水质——水温、总氮（TN）、总磷（TP）与流量的相关关系；并以2012年为典型年，运用平面二维"水动力-水质"数学模型模拟库区水质变化随入库流量的响应关系.研究表明：（1）11月-次年4月水库水温受气温控制，入库与库区水温差异不明显；5-10月，非输水期库区上游水温最高，输水期入库温差随流量增大呈线性升高趋势，库区上游水温明显降低且出现谷值；（2）营养物（TN、TP）浓度变化规律全年基本一致，非输水期入库TN浓度高、TP浓度低，营养物在果河段汇集，库区营养物衰减浓度降低且浓度梯度平缓；输水期入库TN浓度随流量增大呈幂函数降低趋势、TP浓度呈线性升高趋势，营养物被输移至库区上游导致库区TN、TP浓度升高且浓度梯度增大；（3）库区水温谷值及TN、TP浓度峰值均滞后于果河流量变化，且库区南岸比北岸更易受果河来流影响污染更严重. 相似文献
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This paper evaluates the risk of a water crisis – a substantial, sudden reduction in water supply – in the Monterrey Metropolitan Area (MMA), posed by climate threats and the vulnerability of its water supply system. Our analysis of long-term precipitation, water supply and water availability data reveals that the MMA is highly vulnerable to recurring periods of exceptionally low precipitation and scarce surface water availability. We identify two episodes in the recent past (1998 and 2013) when the MMA water supply system almost collapsed as reservoirs neared depletion in the face of abnormally dry weather. Furthermore our climate projections point to warmer and drier future conditions for the region and consequently, heightened climate threats. We conclude that the risk of a water crisis in the MMA is substantial and probably will increase due to climate change. This establishes a clear and pressing need for a comprehensive package of adaptation measures to mitigate the consequences of a water crisis should one occur as well as to reduce the likelihood of such an event. 相似文献
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Modeling river/reservoir system management, water allocation, and supply reliability 总被引：6，自引：0，他引：6
Ralph A. Wurbs 《Journal of Hydrology》2005,300(1-4):100-113
The state of Texas has implemented a modeling system for assessing the availability and reliability of water resources that consists of a generalized simulation model called the Water Rights Analysis Package (WRAP) and input datasets for the state's 23 river basins. Reservoir/river system management and water allocation practices are simulated using historical naturalized monthly streamflow sequences to represent basin hydrology. Institutional systems for allocating streamflow and reservoir storage resources among numerous water users are considered in detail in evaluating basinwide impacts of water management decisions. The generalized WRAP model is a flexible tool that may be applied to river basins anywhere. The Texas experience in implementing a statewide modeling system illustrates issues that are relevant to water management in many other regions of the world. 相似文献
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We examine relationships between nationwide sparing use of water and farmer income of China in this article. As increasing implementation of water projects and irrigation system, the cost of water use has increased in many regions. However, as local policy-oriented urban expansion and ecological restoration have carried out during the past decade, water demand has increased. The spatial distributions of water use and farmer income are uneven and their relationships are ambiguous over time, especially it is uncertain that farmers can benefit from those so called water-saving programs when urban expansion grows faster in China. Based on consumption theory, empirical results of Blundell–Bond dynamic panel-data model with generalized method of moments (GMM) estimators indicate saving one percent of water has positive impacts at 0.085–0.35 percent on farmer income in the following statistical year. Population has negative impacts on farmer income. Particularly in Central China, one percent of increase in population will statistically significantly decrease 0.276 percent of contemporaneous farmer income. Particularly, in Eastern China with large population during years 2004 through 2012, the total amount of water use increases one percent, contemporaneous farmer income loses 0.04 percent. Thus, saving water can benefit future farmer income, and it indicates that urban expansion may induce the diversion of resources and agricultural production from rural to urban area. Policy implication of relationships between water allocation and farmer income distribution caused by water-saving programs needs to be further studied at regional scale, in particularly to the regions with large population and urban expansion in China. 相似文献
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Development of marine water quality criteria for the USA 总被引：6，自引：0，他引：6
Russo RC 《Marine pollution bulletin》2002,45(1-12):84-91
The US Environmental Protection Agency has developed guidelines for deriving numerical national water quality criteria for the protection of aquatic organisms and their uses. These guidelines provide the method for deriving water quality criteria, including minimum data base requirements, data evaluation procedures, and calculations. The guidelines have been in place for a long time, and states have used them to derive water quality standards for their water bodies. More recent efforts have been directed towards the development of technical guidance based on the concept that bioassessment and biocriteria programs for estuaries and near coastal waters are interrelated and are critical components of comprehensive water resource protection and management. This is a holistic approach to protection and management, integrating biological assessments into traditional chemical and physical evaluations and augmenting the established water quality criteria. The method for deriving water quality criteria and the approach for biocriteria development for marine systems are described. 相似文献
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A wide variety of sampling programmes may now be considered practical with the recent developments in data logger and water sampler technology. In ephemeral systems the water sampler remains idle for long periods between events. Two approaches are described which overcome the problems of sampling in ephemeral systems: short interval time dependent sampling (TDS) and automated flow proportional sampling (FPS). Both approaches utilize the data logger's ability to perform intermediate operations on incoming data to control the initiation of water sampling. The logger programs are described and allow many recorder/water sampler units to be controlled from one device. The relative merits of the two approaches are discussed in terms of experimental requirements and data precision. 相似文献