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祁县井水温和水位的奇异潮汐关系探讨 总被引:1,自引:1,他引:0
山西祁县井水温潮汐相位超前于水位,异于正常的水温和水位潮汐的动态关系。本文介绍了此现象的记录图像,通过水温和水位同震响应数据核实仪器时间系统,证实此现象是客观的;利用调和分析方法计算出逐月水温与水位潮汐变化的时间差,表明此现象存在于整个观测中。根据水温和水位潮汐相位相关性分析及观测条件调查,认为祁县井水温潮汐相位超前于水位的现象是在特定观测条件下,因井水流动不畅引起的特殊的水温水位关系。 相似文献
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Long-term temperature monitoring was carried out in a borehole drilled for investigation of the Nojima fault, an active fault in SW Japan, using the distributed optical fiber temperature sensing (DTS) technique. Temperatures in the borehole had been measured every 1 m along an optical fiber cable with a resolution of about 0.1 K over a period of 6 years. Water injection experiments were conducted in this borehole in 1997, 2000 and 2003. Monitoring of the temperature profile was started after the first injection experiment, and the temperature profile remained very stable until the start of the second injection experiment. During the second and third experiments, the temperatures in the borehole dropped due to cooling by the injected water but no appreciable temperature change was observed below about 580 m. It clearly shows that the water leaked out of the hole around this point and the leaking depth is estimated to be about 540 m based on the shape of the temperature profile. After the injection was stopped, the recovery of the temperature to the undisturbed profile was exceptionally slow around the leaking point, resulting in a local temperature anomaly, probably because the water leaking out of the hole had cooled the surrounding formations extensively. A very similar temperature anomaly was observed at the beginning of temperature monitoring, which suggests that water leaked out at the same depth in the first injection experiment as well. Between the second and third injection experiments, the top of the borehole was kept open to allow groundwater discharge for about 1 month in 2000 and 2003. In both periods, groundwater flowed out continuously and the shapes of the observed temperature profiles indicate that the groundwater entered in the hole at the same depth as the leaking point during the injection experiments. The temperature records also show that the rate of discharge had been nearly constant through the two test periods. The water discharge appears to have been little affected by the water injection. These results demonstrate that the optical fiber temperature monitoring system is a very effective tool for hydrological experiments. 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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The aim of this study is to assess the influence of sensor locations and varying observation accuracy on the assimilation of distributed streamflow observations, also taking into account different structures of semi-distributed hydrological models. An ensemble Kalman filter is used to update a semi-distributed hydrological model as a response to measured streamflow. Various scenarios of sensor locations and observation accuracy are introduced. The methodology is tested on the Brue basin during five flood events. The results of this work demonstrate that the assimilation of streamflow observations at interior points of the basin can improve the hydrological models according to the particular location of the sensors and hydrological model structure. It is also found that appropriate definition of the observation accuracy can affect model performance and consequent flood forecasting. These findings can be used as criteria to develop methods for streamflow monitoring network design. 相似文献
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The importance of aspect for modelling the hydrological response in a glacier catchment in Central Asia 总被引:2,自引:0,他引:2
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Hongkai Gao Yongjian Ding Qiudong Zhao Markus Hrachowitz Hubert H.G. Savenije 《水文研究》2017,31(16):2842-2859
Understanding how explicit consideration of topographic information influences hydrological model performance and upscaling in glacier dominated catchments remains underexplored. In this study, the Urumqi glacier no. 1 catchment in northwest China, with 52% of the area covered by glaciers, was selected as study site. A conceptual glacier‐hydrological model was developed and tested to systematically, simultaneously, and robustly reproduce the hydrograph, separate the discharge into contributions from glacier and nonglacier parts of the catchment, and establish estimates of the annual glacier mass balance, the annual equilibrium line altitude, and the daily catchment snow water equivalent. This was done by extending and adapting a recently proposed landscape‐based semidistributed conceptual hydrological model (FLEX‐Topo) to represent glacier and snowmelt processes. The adapted model, FLEXG, allows to explicitly account for the influence of topography, that is, elevation and aspect, on the distribution of temperature and precipitation and thus on melt dynamics. It is shown that the model can not only reproduce long‐term runoff observations but also variations in glacier and snow cover. Furthermore, FLEXG was successfully transferred and up‐scaled to a larger catchment exclusively by adjusting the areal proportions of elevation and aspect without the need for further calibration. This underlines the value of topographic information to meaningfully represent the dominant hydrological processes in the region and is further exacerbated by comparing the model to a model formulation that does not account for differences in aspect (FLEXG,nA) and which, in spite of satisfactorily reproducing the observed hydrograph, does not capture the influence of spatial variability of snow and ice, which as a consequence reduces model transferability. This highlights the importance of accounting for topography and landscape heterogeneity in conceptual hydrological models in mountainous and snow‐, and glacier‐dominated regions. 相似文献
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在2015年4月24日一次意外供电故障中,发现宁波地震台高精度温度计在井水温度同层平行观测中有明显的互相干扰现象。认为目前水温观测到的是水井内实际温度与传感器工作时的"升温值"之和,而"升温值"是动态值,其取决于每套仪器的系统特性,一般可能会在0.01℃以上;相互影响可能在0.005℃以上,如果是捆绑式平行观测可能会更高。所以水温测值的波动范围为10~(-4)℃的观测井中,这种干扰不可忽视,并可能影响前兆异常的提取。因此,在水温波动比较小的观测井(泉)中,不主张做同层平行对比观测。最好在一个传感器内安装2套探测温度装置,既免互相干扰,又可相互验证。 相似文献
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东太湖水温变化与水-沉积物界面热通量初探 总被引:1,自引:0,他引:1
水温对沉水植被的生长和分布具有重要作用,水-沉积物界面热通量对浅水湖泊水温变化的影响值得关注.东太湖是我国东部典型的草型浅水湖区,采用自2013年11月至2015年10月对东太湖湖心进行的不同深度水体及沉积物温度高频观测数据,结合东太湖表层沉积物的热力学性质计算了水-沉积物界面热通量,分析了东太湖水温和水-沉积物界面热通量的变化特征并探讨了其影响因素.结果表明:东太湖各深度水体日升温过程随水深增加后延,升温过程夏季延长,冬季缩短;表层水温日变幅最大,底层水温日变幅次之,沉积物温度日变幅最小,各深度温度日变幅夏季最小、冬季最大;春季和夏季升温过程中各深度日均温变化沿水深存在约1天的延迟,秋季和冬季无此现象;2015年与2014年东太湖温度变化趋势相同,同比月均温差与气温差呈线性相关.沉积物8:00-19:00向水体放热增加或从水体吸热减少,19:00至次日8:00放热减少或吸热增加;3-9月从水体吸热,为热汇,10月至次年2月向水体放热,为热源,沉积物全年为湖泊热源;逐日水-沉积物界面热通量每月6至15日存在相对年变幅较小幅度的正弦式波动.水温和水-沉积物界面热通量的变化主要受太阳辐射和气温的影响,二者对气象参数的响应具有迟滞现象;水-沉积物界面热通量与水温呈负相关,其变化相对水温迟滞,水-沉积物界面热交换的主要作用为缓冲湖泊水体的热量变化;夏季,沉水植物能降低湖泊各层水温和垂向水温差. 相似文献
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K. P. Paaijmans A. F. G. Jacobs W. Takken B. G. Heusinkveld A. K. Githeko M. Dicke A. A. M. Holtslag 《水文研究》2008,22(24):4789-4801
Water temperature is an important determinant of the growth and development of malaria mosquito immatures. To gain a better understanding of the daily temperature dynamics of malaria mosquito breeding sites and of the relationships between meteorological variables and water temperature, three clear water pools (diameter × depth: 0·16 × 0·04, 0·32 × 0·16 and 0·96 × 0·32 m) were created in Kenya. Continuous water temperature measurements at various depths were combined with weather data collections from a meteorological station. The water pools were homothermic, but the top water layer differed by up to about 2 °C in temperature, depending on weather conditions. Although the daily mean temperature of all water pools was similar (27·4–28·1 °C), the average recorded difference between the daily minimum and maximum temperature was 14·4 °C in the smallest versus 7·1 °C in the largest water pool. Average water temperature corresponded well with various meteorological variables. The temperature of each water pool was continuously higher than the air temperature. A model was developed that predicts the diurnal water temperature dynamics accurately, based on the estimated energy budget components of these water pools. The air–water interface appeared the most important boundary for energy exchange processes and on average 82–89% of the total energy was gained and lost at this boundary. Besides energy loss to longwave radiation, loss due to evaporation was high; the average estimated daily evaporation ranged from 4·2 mm in the smallest to 3·7 mm in the largest water pool. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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数字地震深井水温水位观测系统的研发与应用 总被引:1,自引:1,他引:0
菏泽市地震局研制开发的数字地震深井水温水位观测系统,观测数据连续可靠,趋势变化平稳,微动态显示清晰,基本无干扰现象,设备安装方便简捷。 相似文献
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研究发现三马坊水温对应某些构造带上的地震,其前兆异常有相似性和重复性特征.对应北西向张渤构造带上的地震,其前兆异常形态为突降型,对应东西向阴山-燕山构造带上的地震,其前兆异常形态为上升型,表明水温前兆异常的相似性和重复性特征受活动性构造体系所控制.深入研究三马坊水温前兆异常特征与活动构造带间的关系,可能是突破该地区地震短临预报的有效途径. 相似文献
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水温、光能对春季太湖藻类生长的耦合影响 总被引:3,自引:2,他引:3
环境因素对藻类生长的影响机制是探讨蓝藻水华暴发的基础,其中水温和光能均是影响藻类生长的关键物理因子.基于2015年春季于太湖观测的11次藻类总初级生产力、水温廓线和营养盐浓度等,探讨水温、光能及营养盐对藻类生长过程的影响.结果表明:春季,水温、光能是影响藻类生长的关键因素,而营养盐的影响贡献相对较弱.深层水体中光能是藻类生长的关键性限制因子,浅层表现为水温、光能的共同影响,而表层主要表现为光能的抑制.水温的升高促进藻类对光能的获取和利用,提高光抑制的光能阈值,造成深层水体中光能限制程度的加强,藻类生长呈现光限制的深度变浅.本研究有利于确定气候变化下水生生态系统演变的方向,为水生生态系统的恢复提供理论依据. 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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The importance of incorporating diurnally fluctuating stream discharge in stream temperature energy balance models
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Although stream temperature energy balance models are useful to predict temperature through time and space, a major unresolved question is whether fluctuations in stream discharge reduce model accuracy when not exactly represented. However, high‐frequency (e.g., subdaily) discharge observations are often unavailable for such simulations, and therefore, diurnal streamflow fluctuations are not typically represented in energy balance models. These fluctuations are common due to evapotranspiration, snow pack or glacial melt, tidal influences within estuaries, and regulated river flows. In this work, we show when to account for diurnally fluctuating streamflow. To investigate how diurnal streamflow fluctuations affect predicted stream temperatures, we used a deterministic stream temperature model to simulate stream temperature along a reach in the Quilcayhuanca Valley, Peru, where discharge varies diurnally due to glacial melt. Diurnally fluctuating streamflow was varied alongside groundwater contributions via a series of computational experiments to assess how uncertainty in reach hydrology may impact simulated stream temperature. Results indicated that stream temperatures were more sensitive to the rate of groundwater inflow to the reach compared with the timing and amplitude of diurnal fluctuations in streamflow. Although incorporating observed diurnal fluctuations in discharge resulted in a small improvement in model RMSE, we also assessed other diurnal discharge signals and found that high amplitude signals were more influential on modelled stream temperatures when the discharge peaked at specific times. Results also showed that regardless of the diurnal discharge signal, the estimated groundwater flux to the reach only varied from 1.7% to 11.7% of the upstream discharge. However, diurnal discharge fluctuations likely have a stronger influence over longer reaches and in streams where the daily range in discharge is larger, indicating that diurnal fluctuations in stream discharge should be considered in certain settings. 相似文献