基于Landsat影像的近40年来(1982—2021年)三峡库区水面面积及其蒸发损失变化

三峡水库蓄水引起库区水位抬升,水面面积显著增加,对区域水文循环过程产生了一定影响。为揭示三峡水库蓄水前后水面面积及蒸发损失变化规律,选取三峡库区坝前至寸滩区间作为研究区,利用Landsat影像数据提取1982—2021年水面面积,分区建立水位与面积关系曲线,进而推求库区逐日水面面积。在估计三峡库区水面面积的基础上,结合站点潜在蒸发资料推求水面蒸发损失量。研究结果表明:2010年三峡水库全面运行后,坝前至寸滩库区平均水面面积由蓄水前的372.96km²,增加到761.31km²,较蓄水前增加了1.04倍。同时,三峡水库的蓄泄调节改变了库区河段原有的水文节律,使得库区水面面积的季节性变化特征较蓄水前发生了显著变化。蓄水后,冬季水面面积最大,平均为843.81km²,较蓄水前增加了1.89倍;秋季、春季次之,水面面积分别为818.73和735.28km²,较蓄水前分别增加了97.17%和1.28倍;夏季水面面积最小,为653.03km²,较蓄水前仅增加了39.06%。水库全面运行后,...     

2015年5月云南双柏ML4.1地震活动机理初探

2015年5月19日9时58分,云南双柏、峨山一带出现密集的小震活动,并于6月14日发生M_L4.1地震,形成显著的震群事件。本文利用双差定位法对该震群进行精定位,结果显示,重新定位后震中分布优势方向更明显,主要沿绿汁江南段断裂呈NNE向分布,震源深度为6～12km,其中,又以8～10km最具优势。与原始数据相比,重定位后残差明显减小,走时残差平方和由原来的0.303s降为0.034s,震源位置估算误差在EW方向平均为0.21km,在NS方向平均为0.173km,在垂直方向平均为0.175km;利用广义极性振幅技术（GPAT）方法,计算得到了24个M_L≥2.5地震的震源机制解,结果显示,此次震群的震源机制类型绝大部分表现为正断性质,与该区历史地震多为走滑的结果有所差异。结合震区附近的龙门水库蓄水水位和该震群的频度-震级关系分析认为,双柏震群活动与水库蓄水过程密切相关,该震群的发生是龙门水库水体载荷加载而引起正断层产生错动的结果。     

Sedimentation and new operational curves for Mosul Dam,Iraq

Abstract

Mosul Dam is one of the biggest hydraulic structures in Iraq. Its storage capacity is 11.11 × 10⁹ m³ at a maximum operation level of 330 m a.s.l. The dam became operational in 1986 and no survey has been conducted to determine its storage capacity and establish new operational curves since this date. A topographic map of scale 1:50 000 dated 1983 was converted into triangulated irregular network (TIN) format using the ArcGIS program to evaluate the operational curves. Then the reservoir was surveyed in 2011 to establish the reduction in its storage capacity and to develop new operational curves. The results indicated that the reduction in the storage capacity of the reservoir was 14.73%. This implies that the rate of sedimentation within the reservoir was 45.72 × 10⁶ m³ year^?1. These results indicate that most of the sediment was deposited within the upper zone of the reservoir where the River Tigris enters the reservoir.

Editor D. Koutsoyiannis

Citation Issa, E.I., Al-Ansari, N., and Knutsson, S., 2013. Sedimentation and new operational curves for Mosul Dam, Iraq. Hydrological Sciences Journal, 58 (7), 1456–1466.     

Hydrogeologic Controls on Induced Seismicity in Crystalline Basement Rocks Due to Fluid Injection into Basal Reservoirs

A series of M_b 3.8–5.5 induced seismic events in the midcontinent region, United States, resulted from injection of fluid either into a basal sedimentary reservoir with no underlying confining unit or directly into the underlying crystalline basement complex. The earthquakes probably occurred along faults that were likely critically stressed within the crystalline basement. These faults were located at a considerable distance (up to 10 km) from the injection wells and head increases at the hypocenters were likely relatively small (～70–150 m). We present a suite of simulations that use a simple hydrogeologic‐geomechanical model to assess what hydrogeologic conditions promote or deter induced seismic events within the crystalline basement across the midcontinent. The presence of a confining unit beneath the injection reservoir horizon had the single largest effect in preventing induced seismicity within the underlying crystalline basement. For a crystalline basement having a permeability of 2 × 10^?17 m² and specific storage coefficient of 10^?7/m, injection at a rate of 5455 m³/d into the basal aquifer with no underlying basal seal over 10 years resulted in probable brittle failure to depths of about 0.6 km below the injection reservoir. Including a permeable (k_z = 10^?13 m²) Precambrian normal fault, located 20 m from the injection well, increased the depth of the failure region below the reservoir to 3 km. For a large permeability contrast between a Precambrian thrust fault (10^?12 m²) and the surrounding crystalline basement (10^?18 m²), the failure region can extend laterally 10 km away from the injection well.     

Elimination of Nutrients in the Rozkoš-Reservoir

The reservoir, having a volume of 76 hm³, a surface area of 1001 ha and a maximum depth of 17 m, is divided by a dam into two parts. Half of the upper part with an area of 200 ha is densely covered by macrophytes (Elodea, Potamogeton). The three main tributaries with 2.6 m³/s on an average are highly polluted and show α-mesosaprobic conditions. The reservoir is investigated between September and March in its longitudinal section at eight stations. The organic load and the total solids show a total decrease by 60% and 66%, respectively, and 70% of this selfpurification occurs in the upper, separated part of the reservoir. In the same way, also the total nitrogen is reduced, whereas the total phosphorus is reduced already in the upper part of the reservoir by 71%, then decreasing to 21% in the second part of the reservoir. With phosphorus, besides the biological elimination obviously also precipitation by the dissolved iron occurs, the concentration of which is reduced by 44 or 76%, resp. The bacteriological load of water improved by two to three orders of magnitude.     

基于多源遥感数据的山西省交口县某尾矿库堆载过程回溯与失稳模式分析

2022年3月17日,山西省交口县某铝矿尾矿库发生溃坝事故,造成较大经济损失。为了探究尾矿库溃坝的原因,基于多时相光学卫星立体像对数据和SBAS-InSAR等遥感技术,回溯分析该尾矿库的堆载过程、库容变化和坝体形变,并采用GeoStudio软件Slope/W模块评价溃坝前边坡的稳定性。结果表明:(1)该尾矿库于2019年9月前已堆积至最大库容,2021年12月前在2^#坝后方子库堆载至96万m³,超出设计库容4.8万m³,从而降低了坝体的稳定性;(2)溃坝物源主要来自2^#坝以上库区,在2^#坝与1^#坝之间以及1^#坝到沟口区域均主要以堆积为主;(3)该尾矿库溃坝属于典型的渗流场诱发尾矿坝失稳,尾矿加载导致其坝体边坡稳定性安全系数由1.125降至0.991,是该尾矿库溃坝的直接诱发因素。     

近20年来三峡水库泥沙淤积及其对库区的影响

泥沙问题是三峡工程建设与运行中的关键技术问题之一,只有妥善处理好泥沙问题,才能保证三峡工程长期有效使用,维持水库功能的全面发挥。本文首先结合实测水文、河道地形观测资料,对三峡水库运行近20年来的泥沙淤积特性及水库排沙比进行了较为全面的分析研究,并与已有研究成果进行了对比;其次,围绕防洪、航运以及坝前段的泥沙淤积等方面,进一步分析了水库淤积产生的影响。结果表明:三峡水库蓄水以来,在不考虑区间来沙的情况下,三峡水库共淤积泥沙20.484亿t,近似年均淤积1.102亿t,水库排沙比为23.6%,水库年均淤积量为原论证预测值的33%。其中,库区干流段累计淤积泥沙17.835亿m³(变动回水区冲刷0.694亿m³;常年回水区淤积18.529亿m³),淤积在水库防洪库容内的泥沙为1.648亿m³(干、支流分别淤积1.517亿m³和0.131亿m³),占水库防洪库容的0.74%,“十一五”攻关阶段研究得出的多年平均淤积量及排沙比较实测值均偏大,变动回水区冲淤则出现反向的...     

The reservoir-associated earthquakes of April 1983 in western Thailand: Source modeling and implications for induced seismicity

On 22 April 1983, a very large area of Thailand and part of Burma were strongly shaken by a rare earthquake (m _b=5.8,M _s=5.9). The epicenter was located at the Srinagarind reservoir about 190 km northwest of Bangkok, a relatively stable continental region that experienced little previous seismicity. The main shock was preceded by some foreshocks and followed by numerous aftershocks. The largest foreshock ofm _b=5.2 occurred 1 week before the main shock, and the largest aftershock ofm _b=5.3 took place about 3 hours after the main shock. Focal mechanisms of the three largest events in this earthquake sequence have been studied by other seismologists using firts-motion data. However, the solutions for the main shock and the largest aftershock showed significant inconsistency with known surface geology and regional tectonics. We reexamined the mechanisms of these three events by using teleseismicP-andS-waveforms and through careful readings ofP-wave first motions. The directions of theP axes in our study range from NNW-SSE to NNE-SSW, and nodal planes strike in the NW-SE to about E-W in agreement with regional tectonics and surface geology. The main shock mechanism strikes 255°, dips 48°, and slips 63.5°. The fault motions during the main shock and the foreshock are mainly thrust, while the largest aftershock has a large strike-slip component. The seismic moment and the stress drop of the mainshock are determined to be 3.86×10²⁴ dyne-cm and 180 bars, respectively. The occurrence of these thrust events appears to correlate with the unloading of the Srinagarind reservoir. The focal depths of the largest foreshock, the main shock, and the largest aftershock are determined to be 5.4 km, 8 km, and 22.7 km, respectively, from waveform modeling and relative location showing a downward migration of hypocenters of the three largest events during the earthquake sequence. Other characteristics of this reservoir-induced earthquake sequence are also discussed.     

Gravity change and its mechanism after the first water impoundment in Three Gorges Project

Introduction During and before the construction of the Three Gorges Project, the annual observation was continuously undertaken by the Three Gorges gravity observation network established around the head area of the reservoir (the section between Sandouping and Badong). This network has pro-vided substantial high precise data related to seismic activity. However, the annual gravity survey together monitoring of the existed observation stations can hardly effective monitor some potential sei…     

The 2008 West Bohemia earthquake swarm in the light of the WEBNET network

A swarm of earthquakes of magnitudes up to M _L = 3.8 stroke the region of West Bohemia/Vogtland (border area between Czechia and Germany) in October 2008. It occurred in the Novy Kostel focal zone, where also all recent earthquake swarms (1985/1986, 1997, and 2000) took place, and was striking by a fast sequence of macroseismically observed earthquakes. We present the basic characteristics of this swarm based on the observations of a local network WEBNET (West Bohemia seismic network), which has been operated in the epicentral area, on the Czech territory. The swarm was recorded by 13 to 23 permanent and mobile WEBNET stations surrounding the swarm epicenters. In addition, a part of the swarm was also recorded by strong-motion accelerometers, which represent the first true accelerograms of the swarm earthquakes in the region. The peak ground acceleration reached 0.65 m/s². A comparison with previous earthquake swarms indicates that the total seismic moments released during the 1985/1986 and 2008 swarms are similar, of about 4E16 Nm, and that they represent the two largest swarms that occurred in the West Bohemia/ Vogtland region since the M _L = 5.0 swarm of 1908. Characteristic features of the 2008 swarm are its short duration (4 weeks) and rapidity and, consequently, the fastest seismic moment release compared to previous swarms. Up to 25,000 events in the magnitude range of 0.5 < M _L < 3.8 were detected using an automatic picker. A total of nine swarm phases can be distinguished in the swarm, five of them exceeding the magnitude level of 2.5. The magnitude–frequency distribution of the complete 2008 swarm activity shows a b value close to 1. The swarm hypocenters fall precisely on the same fault portion of the Novy Kostel focal zone that was activated by the 2000 swarm (M _L ≤ 3.2) in a depth interval from 6 to 11 km and also by the 1985/1986 swarm (M _L ≤ 4.6). The steeply dipping fault planes of the 2000 and 2008 swarms seem to be identical considering the location error of about 100 m. Furthermore, focal mechanisms of the 2008 swarm are identical with those of the 2000 swarm, both matching an average strike of 170° and dip of 80° of the activated fault segment. An overall upward migration of activity is observed with first events at the bottom and last events at the top of the of the activated fault patch. Similarities in the activated fault area and in the seismic moments released during the three largest recent swarms enable to estimate the seismic potential of the focal zone. If the whole segment of the fault plane was activated simultaneously, it would represent an earthquake of M _L ~5. This is in good agreement with the estimates of the maximum magnitudes of earthquakes that occurred in the West Bohemia/Vogtland region in the past.     

基于Gassmann方程的流体替换方法在珊溪水库地震研究中的应用

引入基于Gassmann方程的流体替换方法,在分析地震波P波速度、波速比与岩石孔隙度和饱和度关系的基础上,应用于珊溪水库地震波速比和P波速度变化特征研究,得到:(1)珊溪水库震中区岩石始终处于接近水饱和的饱水状态,波速比和P波速度"下降-回升"的变化实质上反映了震中区岩石"孔隙度增大(饱和度减小)-饱和度增大"的变化,每一丛地震的波速比由极小值逐渐增大为极大值是由于岩石从不饱和状态变化到饱和状态;(2)根据每一丛地震波速比的变化,计算得到珊溪水库流体扩散率αs=1.06×104 cm2 s-1,该数值与美国南卡罗莱纳水库、巴西Acu水库、广东新丰江水库的流体扩散率基本一致;(3)震源区岩石孔隙度上限值为8.7%~2.0%,该数值与华东勘测设计研究院通过室内岩石物理力学性质试验测定的珊溪水库坝址区新鲜流纹斑岩的孔隙度平均值一致。     

丹江口水库的浮游甲壳动物

为了合理开发利用丹江口水库的渔业资源,1992年12月至1993年9月对丹江口水库的浮游甲壳动物进行了四次调查。结果显示丹江口水库浮游甲壳动物有26属36种,其中枝角类11属17种,桡足类15属19种。浮游甲壳动物年平均数量为31.0个/L,年平均生物量为0.6311mg/L,水库每年可提供浮游动物食性鱼类的年生产潜力为5.87×10~5kg。     

Study of the flood control scheduling scheme for the Three Gorges Reservoir in a catastrophic flood

The Three Gorges Project is the world's largest water conservancy project. According to the design standards for the 1,000‐year flood, flood diversion areas in the Jingjiang reach of the Yangtze River must be utilized to ensure the safety of the Jingjiang area and the city of Wuhan. However, once these areas are used, the economic and life loss in these areas may be very great. Therefore, it is vital to reduce this loss by developing a scheme that reduces the use of the flood diversion areas through flood regulation by the Three Gorges Reservoir (TGR), under the premise of ensuring the safety of the Three Gorges Dam. For a 1,000‐year flood on the basis of a highly destructive flood in 1954, this paper evaluates scheduling schemes in which flood diversion areas are or are not used. The schemes are simulated based on 2.5‐m resolution reservoir topography and an optimized model of dynamic capacity flood regulation. The simulation results show the following. (a) In accord with the normal flood‐control regulation discharge, the maximum water level above the dam should be not more than 175 m, which ensures the safety of the dam and reservoir area. However, it is necessary to utilize the flood diversion areas within the Jingjiang area, and flood discharge can reach 2.81 billion m³. (b) In the case of relying on the TGR to impound floodwaters independently rather than using the flood diversion areas, the maximum water level above the dam reaches 177.35 m, which is less than the flood check level of 180.4 m to ensure the safety of the Three Gorges Dam. The average increase of the TGR water level in the Chongqing area is not more than 0.11 m, which indicates no significant effect on the upstream reservoir area. Comparing the various scheduling schemes, when the flood diversion areas are not used, it is believed that the TGR can execute safe flood control for a 1,000‐year flood, thereby greatly reducing flood damage.     

Seismicity and reservoir induced crustal motion study around the Tehri Dam, India

The Tehri Dam is located in a seismotectonically active region in the Indian Himalayan belt. This 260.5 m high dam has a live water storage of 2615 × 10⁶ m³ and is capable of generating crustal deformation corresponding to water fluctuation. Filling of the reservoir started in October 2005. Seismic data around the dam between 2000 and 2010 shows that seismicity is corresponding to drawdown levels of the reservoir rather than to higher water levels. GPS data at twelve local benchmarks were collected from 2006 to 2008 during filling and drawdown reservoir levels. The velocity vectors show ground motion to be between ～0.69–1.50 mm in the different filling-drawdown cycles with reference to the permanent station at Ghuttu. The motion appears to be inwards into the reservoir when the reservoir is filled and outwards when the reservoir is drained. This ground motion corresponds to elastic deformation and rebound due to effect of the oscillating water levels.     

Estimating Net Primary Productivity and Nutrient Stock in Plant in Freshwater Marsh,Northeastern China

We have investigated the contributions of three dominant macrophyte species, Deyeuxia angustifolia, Carex lasiocarpa, and Carex pseudocuraica (covering about 10 304 km²), to carbon (C), nitrogen (N), and phosphorus (P) stocks in the largest freshwater marsh (17 300 km²) in China for a 3‐year period (from 2002 to 2004). The monthly biomass, seasonal, and annual net primary productivity (NPP), and nutrient concentrations of three species were measured. All three plant species showed rapid growth in the rainy season. The maximum and minimum production rates in the freshwater marsh were ～36.19 and ～9.92 g m^?2 day^?1, respectively. The total NPP accounts 1900–2700 g m^?2 year^?1 in the studied area. Total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP) concentrations in roots were higher than those in stem and leaf tissues. The vast beds of the three studied species comprise 80% of the grass covered marsh of Sanjiang plain, contributing annual nutrient stocks of ～10.99 × 10⁶, ～788.36 × 10³, and ～18.10 × 10³ t (tonnes) for TOC, TN, and TP, respectively. Our results suggest that the nutrient bioaccumulation capacity in freshwater marshes depend mainly on plant species, which are decided by hydrological conditions. The nutrient stocks in the Sanjiang plain marsh have been greatly reduced because some of the area occupied by C. lasiocarpa was replaced by D. angustifolia as a result of succession caused by the changes of water table.     

115 years of sediment deposition in a reservoir in Central Europe: Topographic change detection

Reservoirs have become an important component in the worldwide river sediment flux. Reservoirs prevent downstream sediment transport and have become a major sediment sink. In this study, sediment deposition during the last 115 years in the Urft Reservoir in western Germany is reconstructed. The Urft Reservoir is the oldest reservoir in the Eifel Mountains and was almost completely drained in 2020. This enabled a detailed mapping of the lake bottom using an unmanned aerial system and the computation of a high-resolution digital surface model. Topographic maps with a nominal resolution of 1:1000 from the time prior to the construction of the dam (around 1900) were used to construct a pre-reservoir elevation model. A digital elevation model of difference (DoD) was calculated from these two datasets for the reservoir floor (0.72 km²). Based on the DoD, a net sediment accumulation of 1.16 × 10⁶ m³ was calculated alongside a propagated volume error of 6.91 × 10⁵ m³, resulting in a mean accumulation of 1.54 m. Conservative vertical error propagation results in an average level of detection (LoD) of 1.8 m. In contrast, the comparison of the DoD with 47 cores in the upper part of the reservoir showed a mean difference of −0.11 m, indicating a high, independently assessed accuracy of the DoD. Three depositional hotspots were identified in the reservoir. One is close to the Urft dam where very fine sediments are draped across the pre-reservoir topography. Two areas are related to reservoir management. Sediment deposition in the Urft Reservoir has been comparably low in comparison to other regions globally, resulting in a 3.25% ± 1.93% loss of reservoir volume between 1905 and 2020. To analyse the effect of strong flooding events, a subset of the reservoir was analysed after an extreme event in July 2021, but accumulation did almost entirely not exceed the LoD.     

紫坪铺水库附近都江堰震群小震震源机制解分析

2008年2—4月,位于汶川大震初始破裂点的紫坪铺水库附近发生了一系列的小震活动,它们与汶川地震和紫坪铺水库小震的关系值得研究。本文采用CAP方法,反演了紫坪铺水库7个专用数字地震台站的数据,得到震级大于M_L 1.0的28个震源机制解。结果表明:有19个地震事件集中在紫坪铺水库东南方向的都江堰附近,最大地震为逆冲型,发震机制为逆冲型带走滑分量,少量带正断层分量;从深度剖面看,地震震源深度主要集中分布在地下13km附近区域,都江堰震群丛集在前山断裂带上,其它地震散布在中央断裂带上;发震最大主压应力方向随时间的变化具有从最大主压应力方向变化比较大到趋向一致的演化过程。这些现象说明龙门山断裂带在都江堰附近存在1个凸凹体,形成应力集中点,引发都江堰震群活动,由此迫使龙门山断裂带前山断裂发生逆冲性活动,从而加剧了龙门山断裂带中央断裂的活动,在一定程度上加速了汶川地震的发生。     

Geological and seismological evidence of increased explosivity during the 1986 eruptions of Pavlof volcano,Alaska

We present results of study of the best-documented eruptions of Pavlof volcano in historic time. The 1986 eruptions were mostly Strombolian in character; a strong initial phase may have been Vulcanian. The 1986 activity erupted at least 8×10⁶ m³ of feldspar-phyric basaltic andesite lava (SiO₂=53–54%), and a comparable volume of wind-borne tephra. During the course of the eruption, 5300 explosion earthquakes occurred, the largest of which was equivalent to an M _L =2.5 earthquake. Volcanic tremor was recorded for 2600 hours, and the strongest tremor was recorded out to a distance of 160 km and had an amplitude of at least 54 cm² reduced displacement. The 1986 eruptions modified the structure of the vent area for the first time in over two decades. A possible pyroclastic flow was observed on 19 June 1986, the first time such a phenomenon has been observed at the volcano. Overall, the 1986 eruptions were the strongest and longest duration eruptions in historic time, and changed a temporal pattern of activity that had persisted from 1973–1984.     

哈尔滨西泉眼水库夏季浮游植物群落结构动态特征

西泉眼水库作为哈尔滨市第二水源地,事关居民的饮用水安全,而浮游植物群落特征则是水库生态系统健康状况监测与评估的重要研究内容之一,能为水库生态系统健康提供科学支撑.本研究设置13个采样点,对库区和入库河流的浮游植物群落进行对比分析,采样时间为蓝藻水华易发的7月和8月.经镜检,共鉴定浮游植物7门169种,其中绿藻门最多,83种,占总种数的49.11%;硅藻门次之,47种,占总种数的27.81%;蓝藻门15种,占总种数的8.88%;隐藻门最少,仅有2种.浮游植物丰度在10.92×105~88.44×105cells/L之间,均值为51.6×105cells/L,以8月的3#采样点最高;生物量在2.61~22.44 mg/L之间,均值为10.37 mg/L,以8月的5#采样点最高.Shannon-Wiener指数在2.46~4.69之间,均值为3.33,以7月12#采样点最高.研究水域浮游植物优势种群以梅尼小环藻(Cyclotella meneghiniana)、肘状针杆藻(Synedra ulna)、阿氏席藻(Phormidium allorgei)和游丝藻(Planctonema sp.)为主.同时,典范对应分析表明:1)既将西泉眼水库库区和入库河流区分为两个相对独立的生态系统,又展现了同一生态系统内的月份变化趋势,说明西泉眼水库库区和入库河流区的浮游植物群落的时空分布异质性显著;2)库区内河流入库口处、库心和大坝口处浮游植物群落梯级差异显著,入库河流区水质明显优于库区;3)氨氮、硝态氮、总氮和总磷是影响浮游植物种群的主要驱动因子.研究认为,西泉眼水库水体总体上已处于中度富营养水平,并存在进一步富营养化的风险.建议水库管理部门建立水生态系统健康监测与评估预警体系,配套相应的水生态管理制度,并采取适宜的生态修复技术等生态治理措施,以确保哈尔滨市供水水源安全.     

Near‐bed shear stress,turbulence production and dissipation in a shallow and narrow tidal channel

Near‐bed, highly resolved velocity profiles were measured in the lower 0.03 m of the water column using acoustic Doppler profiling velocimeters in narrow tidal channels in a salt marsh. The bed shear stress was estimated from the velocity profiles using three methods: the log‐law, Reynolds stress, and shear stress derived from the turbulent kinetic energy (TKE). Bed shear stresses were largest during ebbing tide, while near‐bed velocities were larger during flooding tide. The Reynolds stress and TKE method gave similar results, while the log‐law method resulted in smaller bed shear stress values during ebbing tide. Shear stresses and turbulent kinetic energy followed a similar trend with the largest peaks during ebbing tide. The maximum turbulent kinetic energy was on the order of 1 × 10^{? 2} m²/s². The fluid shear stress during flooding tide was approximately 30% of the fluid shear stress during ebbing tide. The maximum TKE‐derived shear stress was 0.7 N/m² and 2.7 N/m² during flooding and ebbing tide, respectively, and occurred around 0.02 m above the bed. Turbulence dissipation was estimated using the frequency spectrum and structure function methods. Turbulence dissipation estimates from both methods were maximum near the bed (~0.01 m). Both the structure function and the frequency spectrum methods resulted in maximum dissipation estimates on the order of 4 × 10^{? 3} m²/s³. Turbulence production exceeded turbulence dissipation at every phase of the tide, suggesting that advection and vertical diffusion are not negligible. However, turbulence production and dissipation were within a factor of 2 for 77% of the estimates. The turbulence production and dissipation decreased quickly away from the bed, suggesting that measurements higher in the water column cannot be translated directly to turbulence production and dissipation estimates near the bed. Copyright © 2015 John Wiley & Sons, Ltd.