基于HJ-CCD的漫湾坝区河流悬浮物浓度遥感反演

坝区河流悬浮物浓度监测对于评估水利水电工程对河流水质影响具有较大的意义。HJ\|CCD重返周期短、空间分率高等优点,应用于漫湾这种中小尺度坝区水体悬浮物浓度监测有着重要的现实意义。大气校正采用暗像元、FLAASH以及QUick Atmospheric Correction(QUAC)几种常见的基于图像的大气校正方法。大气校正结果表明:暗像元法效果较好,其第2波段和第3波段的平均相对误差分别为16.1%和17.9%。然后,应用其大气校正较好的波段构建适用于研究区的悬浮物浓度反演模型。结果表明,该模型的决定系数为0.92,均方根误差(RMSE)为4.83 mg/L,平均相对误差为33.1%。最后,将此反演模型应用于2014年影像质量较好的HJ\|CCD数据上,得到了其悬浮物浓度空间分布图,反映了漫湾坝区附近的悬浮物浓度的变化规律。     

基于时序InSAR技术的三峡大坝及周边地区形变监测

相对于需要投入大量人力物力且耗时较长的传统测量手段,采用InSAR技术进行大坝变形监测精度和范围都有了很大提升,全天候、全时间段可工作的特性也使观测周期大大缩短.基于PS-InSAR技术,利用2018年1月6日?2020年4月25日期间的66景哨兵1号卫星影像对三峡大坝周边的地表形变进行变形监测,分析并提取三峡大坝及周...     

尾矿库渗流溃坝模型实验研究

渗流破坏是尾矿库溃坝的重要诱导因素之一,但目前针对渗流破坏对尾矿库溃坝影响的研究还比较少,因此本文以云南某尾矿库为工程背景,采用自制的尾矿库溃坝实验装置,开展尾矿库室内堆(溃)坝模型实验研究,分析在渗流破坏情况下尾矿库溃坝过程、溃口发展、下泄泥砂沉积规律。结果表明：空隙中的可动颗粒被渗出水流带走,造成初始渗流通道建立并扩大,坝肩中部出现“砂流溢出”和“沼泽化”现象;随着坝体集中渗流通道的扩展,出渗点位置上部饱和坝体在自重作用下发生沉降和垮塌,并向上游呈牵引式发展,随后库内水流漫过坝顶垮塌部分的最低点,导致溃口的形成,坝体破坏模式由逆向牵引破坏向溢流侵蚀破坏转变;溃口的发展主要是由溃坝水流对坝体的掏蚀、冲刷所造成,在溃坝的不同时刻溃口发展是不同的,初中期以下切为主,后期为横向展宽以主;由于水流的分选作用,下泄泥砂在坝体下游的沉积随演进距离的增加,表现出由粗到细的规律,且不同位置出现了粒径的分级现象。以上研究成果能为矿山的防灾减灾提供理论基础。     

Experimental methods for local-scale characterization of hydro-morphodynamic dam breach processes. Breach detection, 3D reconstruction,flow kinematics and spatial surface velocimetry

A set of tests on failure by overtopping of earth dams was performed under hydraulic and geotechnical controlled conditions in a medium-scale facility located at the Portuguese National Laboratory for Civil Engineering. The flow over the breaching dam is three-dimensional and exhibits several length scales. Instrumentation must be able to capture this complexity and scale amplitude and must be non-intrusive. This work presents a summary of the instrumentation layout as well as its main components and measuring methods that were used and/or developed to address these issues. The emphasis is placed on post-processing analysis of digital imagery, for which there is detailed exposition of the adopted methods and an evaluation of its suitability for its intended purpose.     

丰满大坝重建工程泄洪兼导流洞变形监测资料分析

本文对丰满大坝重建工程泄洪兼导流洞监测项目进行了介绍;为了判断泄洪兼导流洞的变形量的变化情况,首先对监测数据进行可靠性检查,然后绘制时空分布曲线和建立统计模型,对变形物理量进行定性和定量分析,得出泄洪兼导流洞变形基本稳定的结论.     

Effects of atmospheric exposure on chlorophyll a,biomass and productivity of the epilithon of a tailwater river

Field experiments were conducted to determine the effects of atmospheric exposure on the chlorophyll a content, biomass and gross primary productivity (GPP) of littoral epilithon in the Colorado River below Glen Canyon Dam, Arizona. The chlorophyll a content of the epilithon was much more sensitive to exposure than the biomass. The epilithon was rapidly bleached during summer daytime exposures, but algal filaments remained attached for several weeks after reinundation. The percentage of initial chlorophyll a remaining after one day of exposure was not different from the percentage remaining after two days of exposure. However, significant reductions in chlorophyll a content were detected for daytime exposures as short as six hours. Overall, there were close inverse relationships (r² ≥ 0–73) between the time exposed or cumulative solar radiation (400–700 nm) and the percentage of initial chlorophyll a remaining after reinundation. The GPP of Cladophora glomerata-dommaled epilithon from the permanently inundated channel was 10 times higher than the GPP of epilithon from the zone of daily water level fluctuation. Experimental atmospheric exposure of the epilithon from each zone reduced the GPP, but not the assimilation ratio (GPP per unit of chlorophyll a) of the epilithon. The Glen Canyon epilithon has low resistance to exposure disturbances, and recolonization is slow under hydropower peaking flow regimes. Cladophora glomerata has an important structural role in Glen Canyon, the disruption of which is likely to precipitate effects at higher trophic levels.     

大化水电站大坝变形监测资料分析

通过对大化水电站大坝变形监测资料的分析，揭示出大坝水平位移，垂直位移及接缝的变化规律及影响因素，对某些监测量的物理成因做了解释，为今后大坝安全管理提供有益的依据。     

Modelling effects of discharge on habitat quality and dispersal of juvenile humpback chub (Gila cypha) in the Colorado River,Grand Canyon

A two‐dimensional hydrodynamic model was applied to seven study reaches in the Colorado River within Grand Canyon to examine how operation of Glen Canyon Dam has affected availability of suitable shoreline habitat and dispersal of juvenile humpback chub (Gila cypha). Suitable shoreline habitat typically declined with increasing discharges above 226–425 m³/ s, although the response varied among modelled reaches and was strongly dependent on local morphology. The area of suitable shoreline habitat over cover types that are preferred by juvenile humpback chub, however, stayed constant, and in some reaches, actually increased with discharge. In general, changes in discharge caused by impoundment tended to decrease availability of suitable shoreline habitat from September to February, but increased habitat availability in spring (May–June). Hourly variation in discharge from Glen Canyon Dam substantially reduced the amount of persistent shoreline habitat at all reaches. Changes in suitable shoreline habitat with discharge were shown to potentially bias historical catch per unit effort indices of native fish abundance up to fourfold. Physical retention of randomly placed particles simulating the movement of juvenile humpback chub in the study reaches tended to decline with increasing discharge, but the pattern varied considerably due to differences in the local morphology among reaches and the type of swimming behaviour modelled. Implications of these results to current hypotheses about the effects of Glen Canyon Dam on juvenile humpback chub survival in the mainstem Colorado River are discussed. Copyright © 2004 John Wiley & Sons, Ltd.     

我国水利枢纽建筑物建设的进展—为纪念《人民长江》创刊40周年而作

我国兴修坝工历史悠久，但规模小，建国后，随着社会政治的稳定、国民经济的发展和科学技术的进步，水利事业得到了空前发展，迄今修建的大坝多达８４０００座，水电总装机容量已达４９０３ＫＷ。文章介绍了自５０年代以来中个时期兴建的各种类型、不同规模的水利枢纽工程，并阐述了其中一些中大型工程建设中出现的复杂技术难题，以及取得的可贵经验；同时还介绍了不同形式的水电站厂房和水轮发电机组的规模和布置情况，因时因地制宜     

百色水利枢纽导流隧洞堵头温控计算分析

介绍了百色水利枢纽导流隧洞堵头施工及运行过程温控计算及仿真分析的计算参数、计算模型、边界条件等,分析了封堵堵头温度场和温度徐变应力场的计算成果,为设计和施工提供理论参考。