CS—1型声光多用测深仪的研制

该测深仪利用干簧继电器作为触发元件，通过电极的相对机械运动，使磁场作用于继电器，反馈于机内产生声光效果，从而测量出水位和相对高程。该测深仪最大的特点是一机多用，测量准确，使用简便，造价低廉。特别适用于即测水位又测相对高程，无固定测量设施和流动性大的户外测深和夜间测深。     

长江三峡河段水深测量中回声测深仪选型

以长江三峡地区水深测量中采用两种不同发射频率，不同换能器指向角的回声测深仪同步测点水深为依据，探讨了在斜坡河床中不同指向角回声测深存在着同步测点水深为依据，探讨了在斜坡河床中不同指向角回声测深仪测深存在着精度高低的客观性。合理地选择长江三峡河段水深测量所使用的回声测深仪，对提高该地区水深测量成果质量具有重意义。     

YW-Ⅲ型大地电场岩性测深仪的应用

对YW-Ⅲ型大地电场岩性测深仪的应用效果进行了总结,明确了大地电场岩性测深技术的4条标准,对推广应用大地电场岩性测深技术有一定指导意义.     

GPS-RTK配合测深仪及全站仪在塌陷区测图中的应用

探索了GPS-RTK与测深仪、全站仪相配合在塌陷区测图中的综合应用问题。总结了这三种仪器相配合进行塌陷区测图的作业方法,使三种仪器在实际测量中相得益彰,有效地提高了作业效率。     

利用GPS-RTK高程进行换能器升沉改正的研究

在传统走测方式下进行水下测量时,测量船不可避免地受水流、风浪等影响使换能器发生纵横摇摆和上下升沉,由此带来的测深误差影响大,且由于波浪具有随机性而难以消除。换能器升沉的影响,可以通过添加姿态测量设备进行消除,但由于姿态测量设备的成本较高以及其他多种原因,在滨海及内河流域未能得到广泛使用;无验潮水下测量模式可以对换能器升沉进行消减,但是该方法需要通过水准测量得到每个控制点的正常高,且仍需水位资料进行水位修正,工作量远大于验潮测量。分析了换能器升沉的改正方法和原理,研究了GPS-RTK高程数据中所包含的各类信息及升沉信号提取方法,提出在基于GPS-RTK定位的传统验潮模式下,利用GPS-RTK高程数据对波浪影响进行改正,消减波浪影响,提高测量精度。     

问与答

问我国目前水文测验工作中测深器具主要有哪些?如何选用? 答目前我国水文系统普遍采用的测深器具有测深杆、测深锤和铅鱼。在水深流急或缆道跨度较大的情况下,主要是采用各种类型的回声测深仪。此外,还有压力式测深仪等。下面着重介绍回声测深仪和压力式测深仪: 1.回声测深仪回声测深仪是利用声波在介质中传播时遇到不同     

CJ83型微机控制超声波测深仪

为了适应高流速时在水文缆道上测深的要求,我们经多年研究设计试制了一种用微处理机控制和进行信息处理的CJ83型超声波测深仪。该仪器与一般的数字显示式测深仪有着完全不同的工作方式,能在很强的水下噪声干扰环境中施测水深。1983年以来,我们使用该仪器多次在流速高达5～6米/秒的河道中进行了测深,最高在6.07米/秒流速时测到了水深,取得了大量实测对比资料。现将情况介绍于下:     

HYPACK水文测量软件在水下地形测量中的应用

HYPACK水文测量软件是一个功能齐全的用于水下地形数据采集和处理的软件包,可以支持多种定位设备和测深设备.近年来使用HYPACK软件配合GPS和测深仪,完成了长江河道、湖泊和水库等多个水下地形测量任务,介绍了其主要功能和应用实践.     

高频变频测深仪的研制

电磁频率测深法已取得了可喜成果,但现有仪器的探测深度最浅一般40米左右。高频端所测曲线因元器件的频率特性和干扰因素及测量装置的影响,其精度较差,因此对地表浅部地质构造的探测,尤其对解决水文地质和工程地质问题无能为力。更重要的是,当对频磁曲线作定性定量解释时,由于缺少首支曲线,在国产量板上不能求出定量解释的第一个十字点,从而影响定量解释的精度,限制电磁频率测深法的应用。因此,研制精度高、体积小、重量轻、工作可靠的浅层电磁频率测深仪就具有现实意义。     

GPS测量技术在陕西省地下水监测站高程引测及坐标测量中的应用研究

国家地下水监测工程(水利部分)陕西省地下水监测站高程引测及坐标测量工作需完成全省558处地下水监测站的"校核水准点、附近地面、井口保护筒固定点"的高程值以及"校核水准点、监测井位置"的坐标值测量工作。本次测量任务通过建立E级GPS测量控制网,采用GPS静态定位及拟合高程联测等方式,获取相关高程及坐标数据。该方法相对水准测量,具有工期短、投入少等优点,并且拟合高程计算是基于大地水准面精化模型而来,其精度计算满足《地下水监测工程技术规范》(GB/T 51040-2014)中高程测量的精度要求。GPS测量方法技术可靠,因其高精度、全天候、高效率、操作简便等特点可以在今后地下水监测站的测量中广泛应用和推广。     

基坑降水自动控制系统的探讨

针对目前基坑降水时所配置的潜水泵偏大,常出现空转现象,及所使用的自动控制系统结构复杂,存在难以维修的问题,研制出一种水位自动控制装置。该装置由浮球拉动杠杆,杠杆推动微动开关按钮,开关再与继电器联接,构成一种新箝位液位开关。在该装置中,配置一深一浅两个箝位液位开关,浅的控制水位深度,深的控制水泵位置,从而组成一个纯电工电路的自动控制系统,达到有水则抽,无水则停,自动降水的目的。该装置的特点是:节能、延长机械寿命、节省劳动力成本、维修方便。     

三峡水库运行前后洞庭湖洲滩面积变化遥感认识

为研究三峡水库运行前后洞庭湖洲滩面积的变化特征及原因,利用1994-2016年128个时相的多平台卫星遥感数据,结合城陵矶多年水位观测资料、洞庭湖的多年泥沙出入资料,建立水位与洲滩面积的关系曲线.结果表明,三峡水库运行后,洞庭湖水位和洲滩面积的变化幅度小于运行前,二者呈线性关系.洞庭湖洲滩面积在不同时间段线性趋势不同,总体呈先扩张后萎缩的特征.与三峡水库运行前相比,三峡水库运行后同一水位下洞庭湖洲滩面积更大;且水位越高,增幅越大.三峡水库运行前,洞庭湖泥沙处于不断淤积的状态;运行后,泥沙淤积量降低直至负数,洲滩高程以1.59 mm/a的速率降低.三峡水库的运行和湖砂开采,是影响洞庭湖洲滩面积变化的重要原因.      

Changes in beach water table elevation during neap and spring tides on a sandy estuarine beach, Delaware Bay, New Jersey

A field investigation of temporal and spatial changes in wind and wave characteristics, runup and beach water table elevation was conducted on the foreshore of an estuarine beach in Delaware Bay during neap (April 9, 1995) and spring (April 16, 1995) tides under low wave-energy conditions. The beach has a relatively steep, sandy foreshore and semi-diurnal tides with a mean range of 1.6 m and a mean spring range of 1.9 m. Data from a pressure transducer placed on the low tide terrace reveal a rate of rise and fall of the water level on April 16 of 0.09 mm s⁻¹ resulting in a steeper tidal curve than the neap tide on April 9. Data from three pressure transducers placed in wells in the intertidal foreshore reveal that the landward slope of the water table during the rising neap tide was lower than the slope during spring tide, and there was a slower rate of fall of the beach water table relative to the fall of the tide. Wave heights were lower on April 9 (significant height from 17.1 min records <0.16 m). The water table elevation was 0.08 m higher than the water in the bay at the time of high water, when maximum runup elevation was 0.29 m above high water and maximum runup width was 2.0 m. The elevation of the water table was 0.13 m higher than the maximum elevation of water level in the bay 74 min after high water, when wave height was 0.12 m and wave period was 2.7 s. The use of mean bay water level at high tide will underpredict the elevation of the water table in the beach, and demarcation of biological sampling stations across the intertidal profile based on mean tide conditions will not accurately reflect the water content of the sandy beach matrix.     

Unravelling the microfacies signatures of parasequences using computer-optimized similarity matrices

The microfacies of a Lower Cretaceous carbonate drillcore from Oman are characterized using optimizing matrices of Jaccard's similarity coefficients of community. Other than systems tract boundaries, there is no obvious evidence of individual parasequences in the core. However, diagnostic patterns in microfossil distribution identify environmental gradients recording changes in water depth. These gradients are used to define individual parasequences, parasequence sets, stacking patterns and key surfaces. The patterns suggest that deposition was controlled by successive fourth‐ to fifth‐order (high‐frequency) relative sea‐level cycles superimposed on an underlying third‐order relative sea‐level rise. Although the correlation of these depositional subunits to systematic changes in water depth and the rate of carbonate accumulation alone is not incontrovertible proof of such a sea‐level control, concurrent multiorder relative sea‐level cyclicity provides by far the most likely explanation. A microfacies deposited when the water depth was shallowing is characterized by a relay of microfossils with affinities that shallow upwards. Conversely, a microfacies that records a gradual increase in water depth has a relay of microfossils with affinities that deepen upwards. Microfacies characterized by an assemblage of microfossils with similar affinities record deposition when the benthic environmental conditions remained stable, either because of an equilibrium between shallow water carbonate deposition and rising sea level, or in deeper water where sediment composition was relatively insensitive to changes of water depth. Microfacies characterized by mixed affinity assemblages record syndepositional reworking. During periods of embedded multiorder sea‐level changes, individual parasequences within systems tracts are shown to record more complex environmental gradients than simply the repetition of successive shallowing‐up units as traditionally represented in carbonate sequence stratigraphic models. The microfacies of an individual parasequence may shallow up, or may record both deepening‐up and shallowing‐up depositional phases, as well as periods of sedimentation when benthic environments remained stable. Individual parasequence boundaries may be submarine or subaerial unconformities, or be conformable, as part of a predictable stratigraphic pattern related to the temporal position of an individual parasequence within the underlying third‐order cycle of relative sea‐level change. The hitherto ubiquitous use of assemblages to describe carbonate microfacies, coupled with the widespread use of the metre‐scale shallowing‐up template to identify parasequences, may have led to such complexities previously being overlooked.     

Changes in saltmarsh surface elevation due to variability in evapotranspiration and tidal flooding

We examine the potential for diurnal variation in elevation of saltmarsh surfaces as a source of error in long-term experiments; errors particularly critical in high precision studies that employ the surface elevation table (SET) as a means to monitor elevations. The field study was carried out along the New Brunswick coast of the Bay of Fundy in high and low zones at three marshes with different tidal ranges. We used a total of 16 benchmark pipes and controlled for daily variability in evapotranspiration (ET), as well as timing of tidal flooding, two factors that affect soil water storage, and consequently soil volumes. In six of nine trials we detected significant elevation change over periods as short as 5 d. Marsh-wide averages ranged from 1.2 to 3.0 mm, greater than the yearly increase in relative sea level in many regions. Wood Point marsh had the highest tidal range, but lowest soil organic matter content, giving its soils the lowest compressibility and little sensitivity to ET during two of three trials; the average change in elevation in Wood Point high marsh stations was 4.0 mm during the last trial. Greater differences later in the growing season (while temperature changes were minor) at Wood Point and another site suggest that plant transpiration drove changes in water storage at those sites. Significantly greater differences in elevation with lower plant cover in the third marsh suggests that evaporation drove changes in water storage there. Surface elevation change due to ET should be of greatest concern to SET users in temperate regions where there are large changes in plant biomass and variable temperatures. Variation due to plant transpiration could be reduced if yearly monitoring is scheduled before the start of the growing season.     

西气东输管道工程中卫黄河穿越隧道场地工程地质条件评价

西气东输工程中卫黄河穿越隧道长1197.77m,高4.3m,宽5.6m。隧道入口高于黄河水位28m,出口高于黄河水位45m。隧道顶板高程为1130m。位于黄河水下100m。隧道场地围岩为寒武系磨盘井组灰绿色、银灰色浅变质中厚层细粒长石石英砂岩、千枚状板岩、绢云母化千枚岩。围岩为弱风化Ⅲ～Ⅳ类岩石。透水率为4～67Lu,纵波波速为500～3300m.s-1。BQ为300～400。变形模量为6.11～9.22GPa。泊松比（）0.14～0.24。内摩擦角（）为42.1～44.7。地下水为基岩裂隙水。含水层为寒武系浅变质岩,受大气降水渗入补给,单井涌水量为1.0～50m3.d-1。隧道轴线穿越区岩体较完整较破碎,未有全新活动断层。隧道位置选择和开挖深度设计是可行的。施工和长期运营是安全的。     

Contrasting Decadal-Scale Changes in Elevation and Vegetation in Two Long Island Sound Salt Marshes

Northeastern US salt marshes face multiple co-stressors, including accelerating rates of relative sea level rise (RSLR), elevated nutrient inputs, and low sediment supplies. In order to evaluate how marsh surface elevations respond to such factors, we used surface elevation tables (SETs) and surface elevation pins to measure changes in marsh surface elevation in two eastern Long Island Sound salt marshes, Barn Island and Mamacoke marshes. We compare marsh elevation change at these two systems with recent rates of RSLR and find evidence of differences between the two sites; Barn Island is maintaining its historic rate of elevation gain (2.3?±?0.24 mm year^?1 from 2003 to 2013) and is no longer keeping pace with RSLR, while Mamacoke shows evidence of a recent increase in rates (4.2?±?0.52 mm year^?1 from 1994 to 2014) to maintain its elevation relative to sea level. In addition to data on short-term elevation responses at these marshes, both sites have unusually long and detailed data on historic vegetation species composition extending back more than half a century. Over this study period, vegetation patterns track elevation change relative to sea levels, with the Barn Island plant community shifting towards those plants that are found at lower elevations and the Mamacoke vegetation patterns showing little change in plant composition. We hypothesize that the apparent contrasting trend in marsh elevation at the sites is due to differences in sediment availability, salinity, and elevation capital. Together, these two systems provide critical insight into the relationships between marsh elevation, high marsh plant community, and changing hydroperiods. Our results highlight that not all marshes in Southern New England may be responding to accelerated rates of RSLR in the same manner.     

利用钻孔注水试验测试爆区周边岩体损伤场的可行性研究

穿孔爆破是露天矿开采的主要模式,爆破产生的冲击效应将导致周边岩体出现不同程度的损伤破裂,影响台阶边坡的稳定性。提出一种利用钻孔注水试验评价爆破周边岩体等效损伤场的方法,通过向若干钻孔内注满水,记录不同时间的水位,绘制水位随时间的变化曲线,并最终获得不同位置的损伤程度及损伤深度。采用相对损伤因子定量化表征爆破对岩体的损伤程度,通过水位-时间曲线中速降段与平缓段的交界点反映岩体的损伤深度及损伤距离。通过试验发现,爆破引起的周边岩体损伤范围一般在20 m之内,引起的最大损伤深度在12 m以内;铁矿的抗爆能力高于灰岩,相同位置铁矿的相对损伤因子比灰岩的小7.5%左右,铁矿的最大损伤距离及最大损伤深度均比灰岩的小4～6 m;某些情况下注水后水位会快速降至某一特定高程,然后保持不变,表明该高程出现了贯通性导水带,可通过窥视仪等设备进行观察校核。     

基于DEM的水位变幅带内稳定坡角的自动提取

天然河道的平均枯水位、水位变幅带和平均洪水位, 分别与水库运行期低水位、调节水位(即水位变动带)、最高设计洪水位存在可类比性.因此, 通过获取现今天然河道的平均枯水位以下、水位变幅带以及平均洪水位以上3带内不同岩土体的稳定坡角, 这对水库蓄水后回水区内塌岸预测具有重要意义.基于高分辨率航空影像数据, 目视解译得到天然河道的水位变幅带范围, 采用GIS组件开发模式, 应用高分辨率DEM(digital elevation model)作为高程源数据, 实现了水位变幅带内稳定坡角的提取, 该方法具有自动化程度高、获取速度快和范围广的特点.同时, 可通过折算的方法获得水下稳定坡角度, 水上稳定坡角的获取则可按类似的方法实现, 与传统的测量或统计方法相比, 大大减少了野外工作量, 即使人类无法涉足的区域, 也能获取详细的信息, 并能一次性获得足够多的样本数据, 便于不同岩土体稳定坡角的对比与统计分析, 可为水库回水区塌岸预测提供更可靠的数据参考.      

雄安至北京大兴国际机场快线起步区地下段结构抗浮设防水位取值研究

抗浮设防水位直接影响到地下结构的安全与建设费用,在地下结构建设中至关重要,因此,科学合理地确定地下结构的抗浮设防水位具有巨大的社会意义和经济价值。本文以“雄安新区至北京大大兴国际机场快线地下工程段”为研究对象,系统分析了研究区水文地质条件以及地下水位年内年际动态变化规律,利用数值模拟法和类比预测法确定了地下结构抗浮设防水位标高建议值。结果表明,该场地区域浅层地下水水位埋深一般为5.0～20.0m,地下水水位标高一般为–10.0～1.0m。近五年场地浅层地下水水位标高一般为–5～–10 m,埋深一般为3.0～15.0 m,地下水位逐年升高,回升速率约1.0 m/a。地下结构抗浮设防水位标高取值建议取使用期抗浮设防水位采用数值模拟法预测结果。该成果服务了“雄安新区至北京大兴国际机场快线(R1线)”项目场地抗浮设计,为雄安新区重大工程建设项目的抗浮安全设计提供了示范。