浅析土石坝测压管水位影响因素

简要介绍了土石坝测压管的结构，施工，讨论了土石坝测压管水位监测的常见问题，并提出了一些简单的处理方法，可供设计单位，水库管理单位参考。     

测压管清污器的制作及使用方法

黄河下游的引黄间大都为涵洞式水闸，为了解涵闸底部渗压和两侧渗流情况，必须通过测压管进行渗压观测。但由于一些设置位置比较暴露的测压管经常遭到堵塞损坏，因而很有必要研制出一套合理的清污设备，以保证测压管正常工作。针对测压管内的杂物种类，研制了3种不同的设备，即泥土清除设备、乱石清除设备和杂草清除设备。泥土清除设备由供水和清污两部分组成，该设备适用于测压管深度小于5m的情况，其工作原理为：利用供水设备提供高速水流，把管内泥＿上翻起，泥浆顺测压管自然流出，以达到清除泥土的目的，设备装置见图1。图中＃40钢管长…     

水工结构的渗流监测

本文对水工结构渗流监测中所出现的一些问题进行理论分析,利用稳态轮替法建立了描述测压管水位变化规律的数学模型,讨论了模型在各种不同输入时的响应,进而分析了测压管水位滞后现象.分析证明:上下游水位变化时,测压管水位取极值的时刻为无偏差时刻.拟定了分析测压管水位动态的电算程序.对测压管灵敏度给予明确定义,提出现场测定灵敏度的方法.在第二部分研究了渗流区域边界条件发生变化对测压管折算水头的影响,从而指出如何根据折算水头的变化,推断边界条件的变化.专门讨论了地基发生冒水翻砂现象对折算水头的影响.     

宝珠寺水电站测压管工况浅析

坝基扬压力是影响大坝稳定的重要因素，有必要了解测压管的工作状况是否正常。通过对宝珠寺水电站测压管日常观测数据和注水（或抽水）试验资料的分析，发现测压管不能完全正常工作，在对大部分测压管进行结构改进和简单处理后，对比其前后观测数据可以说明经处理测压管的效果和性能有了较大改善。由于基础资料不完善，难以全面判别其性能和效果。分析原因的同时提出了相应的建议和措施。     

土工织物在土坝渗流观测中的应用

土坝渗流观测的方法，目前国内普遍采用测压管来进行观测。传统的测压管，通常是采用棕皮和麻布作滤水材料，这种测压管存在着成本高、寿命短、施工麻烦、过滤性能差和易造成人为错误等问题。针对这些问题，我们进行了新的研究，用土工织物代替棕皮、麻布，作为测压管的反...     

测压管若干问题的讨论

讨论渗流监测中测压管的设计与施工的某些问题，认为测压管进水段的长度应根据具体工程、部位和监测内容而定，不必硬性规定；测压管的管径大小不会产生管内水位对周围岩土中地下水位的滞后，不会影响监测成果；测压管中水位对库水位的滞后，取决于渗径和岩土的渗透性能，与测压管的管径无关。     

测压管若干问题的讨论

讨论渗流监测中测压管的设计与施工的某些问题，认为测压管进水段的长度应根据具体工程、部位和监测内容而定，不必硬性规定；测压管的管径大小不会产生管内水位对周围岩土中地下水位的滞后，不会影响监测成果；测压管中水位对库水位的滞后，取决于渗径和岩土的渗透性能，与测压管的管径无关。     

测压管清淤方法简介

测压管是水库、闸涵观测的重要设施，根据观测目的不同，在工程的不同位置均设置了各种测压管，工程投入运用后，根据测压管实际观测水位，了解分析水工建筑物在渗透水压力作用下的工作状态．为工程管理运用提供可靠依据。因此，测压管观测是分析工程是否正常的重要手段之一。但在施工、管理和运用过程中，由于施工及人为等原因，容易造成测压管的淤塞．不仅影响了工程的正常观测．而且易酿成事故，造成不可弥补的损失。     

测压管清淤方法简介

测压管是水库、闸涵观测的重要设施，根据观测目的不同，在工程的不同位置均设置了各种测压管，工程投入运用后，根据测压管实际观测水位，了解分析水工建筑物在渗透水压力作用下的工作状态，为工程管理运用提供可靠依据。因此，测压管观测是分析工程是否正常的重要手段之一。但在施工、管理和运用过程中，由于施工及人为等原因，容易造成测压管的淤塞，不仅影响了工程的正常观测，而巨易酿成事故，造成不可弥补的损失。经过10余年的研究试验，总结出一套测压管清淤方法，通过在王决、西大洋、岗南、陡河、磐若院、上关等20多座大中型水库以…     

测压管掏堵工具研制与应用

测压管是观测水库水位变化的重要设施，解决测压管堵塞的问题尤为重要根据实际情况，作者研制了一套测压管堵塞的掏堵工具。本文详细介绍了捣堵工具的构造、掏堵方法和应用实例。实践证明该套工具具有构造简单、使用方便、合理的特点，在应用中取得了最佳效果。     

长江中游四大家鱼发江生态水文因子分析及生态水文目标确定

基于长江中游四大家鱼发江量历次调查数据,采用宜昌站作为长江中游水文情势变化分析的控制站,基于其1900~2004年共105年的日径流资料,采用每年5~6月涨水过程数、总涨水日数、平均每次涨水过程日数等3项生态水文指标,分析了四大家鱼发江量与3项生态水文因子的变化关系,认为产卵场所处江段每年5~6月的总涨水日数是决定家鱼苗发江量多寡的一个重要环境因子。根据IHA方法,对宜昌站105年来的生态水文指标分析表明,长江宜昌站生态水文过程的改变并不明显,5~6月总涨水日数变化趋势不显著,显示长江中游影响四大家鱼苗发江量的生态流量过程改变不明显,与前人得出的葛洲坝枢纽修建后四大家鱼的产卵条件和卵苗江汛规律没有变化这一认识一致。但是,随着三峡水库的运行,下游河道的生态环境流量过程会有较大改变,本文建议三峡水库的调控以保障长江中游每年5~6月的总涨水日数维持在22.1±7.2范围内为生态水文目标,即可从生态环境流量过程方面补偿水利工程对中游四大家鱼鱼苗发江量的影响。     

Seminar on Water and Energy,Stockholm, Sweden,August 21, 2005

Abstract

In Europe the implementation of the Water Framework Directive (WFD) will have major implications for water resources management. Part of the Directive requires Member States to implement a comprehensive system of controls (licences) on the allocation and abstraction (withdrawal) of surface and groundwater resources. This paper describes the development of a procedure to help assess and set abstraction licences for agricultural irrigation. The methodology is described with reference to Scotland, a country with limited abstraction control previously and where irrigation is supplemental to rainfall. The methodology combines spatial climatic information using a Geographical Information System (GIS) with data derived from a water balance computer model. The procedure enables the volumetric irrigation demand in a ‘design’ dry year for a given site to be estimated, taking into account local variations in climate, soil type, land use and irrigation practices. The approach provides a scientifically robust framework to allow the regulatory authority to assess the ‘reasonable’ water requirements of individual irrigators and hence develop allocations to satisfy the range of competing demands (e.g. agriculture, industry, and environment) on water resources. The methodology is applicable in other temperate countries where water abstraction controls are required and where appropriate datasets are available. The application of the procedure and its methodological limitations are described.     

Stakeholder-driven,enquiry-driven,or stakeholder-relevant,enquiry-driven science?

There is currently debate within the international hydrological community on whether hydrological science should give priority to providing measurements, knowledge, and understanding pre-determined as being needed by stakeholders, or priority to more basic enquiry-driven science that will stimulate the continued health and growth of hydrology as an important Earth science discipline. Two recent major international initiatives in hydrology reflect these two perspectives. One, the Hydrology for the Environment, Life, and Policy (HELP) program, is primarily fostered by UNESCO-IHP and is focused on stimulating the stakeholder-driven hydrological science required in specific catchments that have become members of a global network. The second, the decade on Prediction in Ungauged Basins (PUB), which is appropriately managed by IAHS, is primarily driven by scientific enquiry and is focused on creating new scientific methods and understanding, albeit with practical application ultimately in mind. This paper summarizes the nature, origins, growth, and progress of these two international programs but also describes the subtly different approach that has been adopted by the U.S. National Science Foundation's (NSF's) Center for Sustainability of semi-Arid Hydrology and Riparian Areas (SAHRA). NSF is a federal agency whose primary goal is to ‘enable the future’ by stimulating novel science. Because SAHRA is a federally-funded entity supported by an agency with this goal, the Center clearly cannot operate in stakeholder-driven, response mode in competition with the already effective private U.S. consultancy industry. Nonetheless, SAHRA's mission is to create knowledge and build understanding that will enhance the prospects of sustainable water management in semi-arid regions, especially the southwestern U.S. To resolve this apparent conflict, SAHRA looks ahead to future stakeholder needs and builds its research agenda around selected critical stakeholder-relevant questions that require substantial and sustained investment in basic, multidisciplinary, enquiry-driven science. This paper describes SAHRA's approach and reports on associated research and outreach activities.     

Survival,Growth, and Movement of Subadult Humpback Chub,Gila Cypha,in the Little Colorado River,Arizona

Ecologists estimate vital rates, such as growth and survival, to better understand population dynamics and identify sensitive life history parameters for species or populations of concern. Here, we assess spatiotemporal variation in growth, movement, density, and survival of subadult humpback chub living in the Little Colorado River, Grand Canyon, AZ from 2001–2002 and 2009–2013. We divided the Little Colorado River into three reaches and used a multistate mark‐recapture model to determine rates of movement and differences in survival and density between sites for different cohorts. Additionally, site‐specific and year‐specific effects on growth were evaluated using a linear model. Results indicate that summer growth was higher for upstream sites compared with downstream sites. In contrast, there was not a consistent spatial pattern across years in winter growth; however, river‐wide winter growth was negatively related to the duration of floods from 1 October to 15 May. Apparent survival was estimated to be lower at the most downstream site compared with the upstream sites; however, this could be because in part of increased emigration into the Colorado River at downstream sites. Furthermore, the 2010 cohort (i.e. fish that are age 1 in 2010) exhibited high apparent survival relative to other years. Movement between reaches varied with year, and some years exhibited preferential upstream displacement. Improving understanding of spatiotemporal effects on age 1 humpback chub survival can help inform current management efforts to translocate humpback chub into new locations and give us a better understanding of the factors that may limit this tributary's carrying capacity for humpback chub. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.     

淮河治理与河湖江海的关系

根据淮河近千年演变记录、近百年实测的河床演变资料以及治淮的经验教训,论述黄河夺淮使淮河中下游发生本质性变化,加重了洪涝灾害和治理的难度,治淮不仅要研究淮河自身,还应研究和处理淮河与黄河、洪泽湖、长江和大海的关系。认为保留洪泽湖一定的蓄水功能,实施河湖分开,扩大入海通道,消除洪泽湖作为中游侵蚀基准面的负面效应,利用疏浚和溯源冲刷调整淮河中游河床纵剖面等措施,是提高已有治淮工程防洪标准、减轻洪涝灾害的治本方向。     

Growth,Reproduction, Mortality,Distribution, and Biomass of Freshwater Drum in Lake Erie

Predominant age-groups in the Lake Erie freshwater drum Aplodinotus grunniens population were 3, 4, and 5 as determined from gill net, trap net, bottom trawl, and midwater trawl samples. Age and growth calculations indicated that females grew faster than males. However, the length-weight relation did not differ between sexes and was described by the equation: log W = ?5.4383 + 3.1987 log L. Some males became sexually mature at age 2 and all were mature by age 6. Females matured 1 year later than males. Three sizes of eggs were present in ovaries; the average total number was 127,000 per female for 20 females over a length range of 270 to 478 mm. Seasonal analysis of the ovary-body weight ratio indicated that spawning extended from June to August. A total annual mortality rate of 49% for drum aged 4 through 11 was derived from catch-curve analysis. Freshwater drum were widely distributed throughout Lake Erie in 1977–1979, the greatest concentration being in the western basin. They moved into warm, shallow water (less than 10 m deep) during summer, and returned to deeper water in late fall. Summer biomass estimates for the western basin, based on systematic surveys with bottom trawls, were 9,545 t in 1977 and 2,333 t in 1978.     

水-能源-粮食纽带关系定量研究方法综述

在总结水-能源-粮食纽带关系研究中, 使用频率较高或潜力较大的 8 种水-能源-粮食纽带关系定量研究方法为: 水-能源-粮食纽带关系工具 2.0( WEF Nexus Tool 2.0) ; 生命周期评价( LCA) ; 可计算的一般均衡模型( CGE) ; 系统动力学模型( SD) ; 气候、土地、能源与水资源策略( CLEWS) ; 基于社会生态系统代谢的多尺度综合评价( MuSIASEM ) ; 市场配置/ 市场配置系统集成模型( MARKAL/ TIMES) 和水资源评价规划模型-长期能源替代规划系统 ( WEAP2LEAP) 。通过总结各研究方法的产生、发展及特性, 并引用案例讨论其适用范围, 分析其优缺点和在使用 时需要注意的问题。在此基础上, 对未来水2能源2粮食纽带关系定量研究方法的发展趋势进行讨论, 认为伴随可持 续发展问题关注度的上升与水-能源-粮食纽带关系内在机理的挖掘, 未来的水-能源-粮食纽带关系定量研究方法将 更加注重量化的精确性和数据的互通以及跨学科研究和多方法的耦合。本文可为水-能源-粮食纽带关系定量研究方法的选择和更新优化提供参考。     

River channel cutoff dynamics,Sacramento River,California, USA

We measured patterns of river channel migration and cutoff between 1904 and 1997 on a 160 km meandering alluvial reach of the Sacramento River by intersecting a sequential set of river channel centrelines mapped from a field survey and aerial photography. We identified approximate dates and locations of cutoffs and quantified cutoff dimensions. Twenty‐seven chute and 11 partial cutoffs occurred over this 93‐year time interval, with an average of one cutoff approximately every 2.5 years or 0.0029 cutoffs per kilometre per year. The average rate of lateral channel change was over the study period was 5.5 ± 0.6 m year^?1 (approximately 0.02 channel widths per year) due to progressive migration and cutoff combined. An average of 5% of the total channel length moved laterally via chute cutoff at a rate of 22.1 ± 3.3 m year^?1 versus 94% of channel length that moved via progressive migration at a rate of 4.7 ± 0.5 m year^?1. The remaining 1% of channel length migrated via partial cutoff at a rate of 13.0 ± 2.8 m year^?1. Although channel cutoff was less predominant mode of channel change than progressive migration in terms of channel length, an average of 20% of the total floodplain area change between successive centrelines was attributable to cutoffs. Peak cutoff frequency was concentrated temporally between 1964 and 1987 and was also spatially clustered in specific active sub‐reaches along the valley axis over the entire study period. We hypothesize that the probability of channel cutoff is a function of both channel geometry and discharge. Bends that experienced chute cutoff displayed an average sinuosity of 1.97 ± 0.1, an average radius of curvature of 2.1 ± 0.2 channel widths and an average entrance angle of 111 ± 7°, as opposed to average values for bends migrating progressively of 1.31 ± 0.01, 2.8 ± 0.1 and 66 ± 1°, respectively. The sinuosity of Sacramento River bends experiencing chute cutoff appears to have been consistently declining from 2.25 ± 0.35 channel widths in 1904 to 1.54 ± 0.23 channel widths in 1987. We hypothesize that this trend may be due in part to the influence of land‐use changes, such as the conversion of riparian forest to agriculture, on the ‘erodibility’ of bank and floodplain materials. For the post‐dam flow regime (1937 on), cutoff frequency was significantly correlated with an estimate of cumulative overbank flow. Copyright © 2010 John Wiley & Sons, Ltd.     

Evaluation,prediction, and protection of water quality in Danjiangkou Reservoir,China

The water quality in the Danjiangkou Reservoir has attracted considerable attention from the Chinese public and government since the announcement of the Middle Route of the South to North Water Diversion Project(SNWDP), which commenced transferring water in 2014.Integrated research on the evaluation, prediction, and protection of water quality in the Danjiangkou Reservoir was carried out in this study in order to improve environmental management. Based on 120 water samples, wherein 17 water quality indices were measured at 20 monitoring sites, a single factor evaluation method was used to evaluate the current status of water quality. The results show that the main indices influencing the water quality in the Danjiangkou Reservoir are total phosphorus(TP), permanganate index(COD Mn), dissolved oxygen(DO), and five-day biochemical oxygen demand(BOD5), and the concentrations of TP, BOD5, ammonia nitrogen(NH3e N), COD Mn, DO, and anionic surfactant(Surfa) do not reach the specified standard levels in the tributaries. Seasonal Mann e Kendall tests indicated that the COD Mn concentration shows a highly significant increasing trend, and the TP concentration shows a significant increasing trend in the Danjiangkou Reservoir. The distribution of the main water quality indices in the Danjiangkou Reservoir was predicted using a two-dimensional water quality numerical model,and showed that the sphere of influence from the tributaries can spread across half of the Han Reservoir if the pollutants are not controlled.Cluster analysis(CA) results suggest that the Shending River is heavily polluted, that the Jianghe, Sihe, and Jianhe rivers are moderately polluted, and that they should be the focus of environmental remediation.     

Temporal patterns in phytoplankton,zooplankton and fish composition,abundance and biomass in Shirati Bay,Lake Victoria,Tanzania

Shirati Bay is among the important breeding and nursery sites for major fish species in Lake Victoria. Weekly samplings were conducted to assess the temporal patterns in phytoplankton, zooplankton and fish composition, abundance and biomass in relation to prevailing water quality parameters. The study also determined the influences of plankton dynamics and water quality on the fish catch composition and biomass. It was hypothesized that temporal patterns in the composition, abundance and biomass in the plankton in the bay are controlled by water quality parameters that, in turn, affect the composition and biomass of fish catches. The phytoplankton comprised mainly cyanophytes and bacillariophytes, while the zooplankton were dominated by copepods. The heavy rain season exhibited a significantly higher plankton abundance and biomass than the dry season. The plankton abundances in both seasons exhibited significant positive correlations with water temperature and transparency. The phytoplankton community was controlled by calanoid and cyclopoid species. At higher trophic levels, Lates niloticus juveniles, Oreochromis niloticus juveniles and haplochromines controlled Cladocera and Cyclopoid copepods, while Tilapia rendalli juveniles controlled the Rotifera. This study revealed that Cyanophyta and Bacillariophyta are the dominant phytoplankton, whereas cyclopoids dominate the zooplankton species in the bay. These dominant plankton groups are partly controlled by rainfall, water temperature and transparency. Fish biomass, zooplankton and phytoplankton exhibit a typical predator–prey inverse relationship. Thus, evaluation of the plankton composition, abundance and biomass should be mandatory during fisheries stock assessments to effectively manage the fishery resources in the bay.