无棱镜技术在电厂施工土方量测量中的应用

随着全站仪在测量中的广泛应用,测量的精度有了很大的提高.特别是无棱镜技术的发展,改变了以往的测量手段和方法,提高了工作的效率.土方量测量是施工过程中不可避免的,为此本文介绍无棱镜测量技术在洛河电厂施工过程中测量土方量的应用情况,通过对比实验,我们对无棱镜测量技术工作效率和成果精度以及适用条件进行分析.     

Using Sequential Self-Calibration Method to Identify Conductivity Distribution: Conditioning on Tracer Test data

An iterative inverse method, the sequential self-calibration method, is developed for mapping spatial distribution of a hydraulic conductivity field by conditioning on nonreactive tracer breakthrough curves. A streamline-based, semi-analytical simulator is adopted to simulate solute transport in a heterogeneous aquifer. The simulation is used as the forward modeling step. In this study, the hydraulic conductivity is assumed to be a deterministic or random variable. Within the framework of the streamline-based simulator, the efficient semi-analytical method is used to calculate sensitivity coefficients of the solute concentration with respect to the hydraulic conductivity variation. The calculated sensitivities account for spatial correlations between the solute concentration and parameters. The performance of the inverse method is assessed by two synthetic tracer tests conducted in an aquifer with a distinct spatial pattern of heterogeneity. The study results indicate that the developed iterative inverse method is able to identify and reproduce the large-scale heterogeneity pattern of the aquifer given appropriate observation wells in these synthetic cases.     

Interpreting tracer breakthrough tailing in a conduit-dominated karstic aquifer

Breakthrough tailing has been observed during dye-tracing recovery tests in the Norville aquifer system (chalk), France. Karst-conduit flow and transport parameters were assessed using two different interpretative methods: the linear graphical method and the Chatwin method (implemented in the Qtracer2 program). The linear graphical method was used to model the observed tailing effects, which was explained by a second smaller delayed breakthrough curve. By comparing the results of tracer-test interpretation for the two methods, it was possible to relate the area of this second curve to the importance of turbulent flow in spring discharge. The more turbulent the flow, the less important the contribution of the second breakthrough curve and the tailing effect. The observed tailing could possibly be controlled by hydrodynamics to a greater extent than usually expected, the tailing effects being mostly attributed to diffusion phenomena. Tailing effects were expected to increase with discharge and the piezometric level, which would have resulted in overpressure in conduits, fissure flooding, etc. Instead, breakthrough tailing tended to disappear with increasing aquifer discharge, which would support the hypothesis of there being mostly hydrodynamic-controlled tailing effects instead of matrix- or fissure-diffusion.An erratum to this article can be found at     

ADVANCES IN MEASURING TECHNIQUES OF BED LOAD

I.m~UCrIONBedloadisthesedimentwhichmovesalongtheriverbedintheformofrolling,slidingandsaltation.BedloadmaycreatemanyproblemsintheoperationandmaintenanceofnavigationchannelandinthedevelOPmentofhydroelectricity.Dataofbedloaddischargearealsorequiredinthedesignofreservoir,inwhichtheinflowbedloadareallactuallytrapped.Thewaysofbedloadmotionaredifferentfordifferentsizes.Thus,itisextremelydifficulttodeterminethebedloaddischargeaccurately.Manyequationshavebeenproposedtocalculatethebedloaddischarge.H…     

滑坡监测的新方法——PMP测量方法

文章从国内外滑坡灾害、滑坡灾害的危害及现有滑坡监测方法等方面，论述了滑坡灾害带来的危害性，从而验证了滑坡监测的重要性。但目前现行的滑坡监测手段各有不足之处。针对这种情况，提出了新的测量方法改进其不足之处。位相测量剖面术的测量原理是将LCD投影仪安装于滑坡体上，在滑坡体外稳定地带放置监测系统，CCD光束中心垂直于滑坡体位移方向，监测系统由望远镜头和CCD组成，CCD输出的视频信号进入计算机。通过软件对图像进行处理，绘制出滑坡整体的三维面貌，并计算出滑动的距离，从而有效的观测滑坡体的运动过程。     

丝绸之路经济带甘肃黄金段找矿勘查新进展

丝绸之路经济带已成为国家战略,赋于了上合组织新的内涵,也给地质工作者提出了新的要求。甘肃是古丝绸之路的锁匙之地,是丝绸之路经济带上的“黄金路段”。2014年甘肃省提出利用拥有古丝绸之路贯穿境内1600 km的战略通道优势,打造丝绸之路经济带的黄金段,使其成为向西开放的战略平台、经贸物流的区域中心、产业合作的示范基地、人才交流的桥梁纽带。本文就甘肃省矿产资源优势、找矿勘查新进展及向西走出去提出建议。     

中国大陆流域分区TRMM降水质量评价

根据中国境内2 257个气象站点1998-2013年逐日降水资料,结合流域分区,采用探测准确性、相关系数以及相对误差等指标,对热带降水测量（TRMM）降水精度和一致性进行系统评价。结果表明:① TRMM日降水准确性从东南沿海向西北内陆递减;② 气象站点年均降水日数显著大于TRMM年均降水日数;③ 西北片区以外气象站点降水量和TRMM降水量在月尺度和年尺度上均具有较好的相关关系;④ 各流域年均TRMM面降水量均高于气象站点面降水量,且TRMM面降水量相对误差雨季较小,枯季较大;⑤ 各流域TRMM面降水量与气象站点面降水量演变趋势基本一致,南方各流域年降水量均呈减少趋势,北方各流域年降水量均呈增加趋势,全国尺度上年降水量呈微弱的减少趋势。     

克拉美丽山南缘西段盆山耦合机制

克拉美丽山位于准噶尔盆地东部,晚古生代克拉美丽洋盆向北俯冲消亡,西伯利亚板块与准噶尔地块在该地区发生碰撞造山。目前,就石炭纪之后克拉美丽山的构造活动存在持续挤压、拉分、伸展、挤压-伸展转换多种观点,构造样式也各不相同。本文应用断层相关褶皱理论,从盆山过渡带现今构造样式入手来探讨克拉美丽山南缘西段盆山耦合机制。研究结果表明,克拉美丽山西段在石炭纪之后经历了中二叠世早期、早三叠世早期、晚三叠世末期、晚侏罗世-早白垩世、晚白垩世早期和古新世末期6 次构造隆升。前4 期相对稳定沉积,晚白垩世早期,晚古生代地层沿着下二叠统底部的泥岩层滑脱面以叠瓦状构造楔样式向南楔入,构造缩短量大于15 km,现今盆山构造样式初步形成。始新世构造楔遭受后期突破断层改造。始新世后,克拉美丽山大规模的构造活动基本停止,地层遭受剥蚀最终形成现今地质结构。     

Measuring household vulnerability to climate change—Why markets matter

Climate change and climate variability affect households in developing countries both directly through their impact on crop yields and indirectly through their impact on wages, food prices and the livelihoods of the poor. Therefore, vulnerable household groups cannot be identified without considering their position in and access to markets. I illustrate the effects – transmitted through markets – that are significant in household exposure, sensitivity and adaptive capacity to climate change by simulating productivity shocks to maize up to 2030 due to climate change in a computable general equilibrium model of Malawi. The results show that rural households with large land holdings may benefit from the adverse impact of climate change on maize yields as a result of increased maize prices. Urban poor and small-scale farmers are vulnerable to climate change due to the large portion of their incomes spent on food. Existing vulnerability measures that do not consider equilibrium effects and characterise all farmers as vulnerable may therefore be misleading.     

Partitioning of heavy metals on soil samples from column tests

In this study, column tests were used to determine the retention capability of three types of estuarine alluvia collected adjacent to landfill sites in South Wales. Selective sequential extraction (SSE) was used to study the retention mechanisms of heavy metals in the soil columns obtained from leaching experiments. Acid digestion was later used to check the validity of the SSE results. Breakthrough curves show good retention of heavy metal ions (Pb, Cu, and Zn) by all soils, where almost 99% of heavy metals were retained with the C_e/C_o values in the order of 10⁻³. The retention strength of these soils was observed to be constant up to five pore volumes (PV). This corresponds with the pH of the effluents and pore water of soil slices, which also show good buffering capacity against very acidic leachate up to 5PV. The heavy metal extraction profiles from SSE show very similar trends with the retention profiles from the leaching experiments, where heavy metals were retained mainly at the top part where the leachate entered the column. SSE indicates qualitatively that heavy metals precipitated with carbonates and amorphous materials (oxides/hydroxides) are higher than heavy metal retention via exchangeable mechanisms. The mass balance calculation gives range of deviation of 1–16% of the total soil extraction. The distribution of the heavy metals with various soil constituents are ranked in the following order: Carbonates>Amorphous oxides hydroxides>Organic matter>Exchangeable phases.