黄河源区水源涵养有关问题探讨

黄河源区是黄河流域重要产水区和水源涵养区,在气候变化和人类活动双重胁迫下,黄河源区各类型生态系统发生了显著变化,影响了源区水源涵养功能。在总结前人研究的基础上,阐述了水源涵养的概念和内涵,系统梳理了黄河源区水源涵养主体的变化过程,论述了水源涵养功能对水源涵养主体变化的响应特征,分析了黄河源区未来水源涵养能力演变所面临的形势,并基于此提出了黄河源区水源涵养能力提升的对策与建议。可为黄河源区水源涵养相关研究的进一步开展及其水源涵养能力提升提供支撑。     

基于流域水循环视角的黄河水源涵养区水源涵养量评价方法

【目的】水资源是黄河流域经济社会发展的刚性约束，科学评估水源涵养区的水源涵养量，对流域生态环境保护与高质量发展具有重要意义。【方法】针对当前水源涵养量评价存在的不足，从流域水循环角度出发，辨识了多要素对水源涵养功能的影响机制，提出了契合黄河流域特点的水源涵养量评价目标、原则与方法。在此基础上，构建了以分布式水文模型为核心的评价工具，对黄河水源涵养区的水源涵养量进行了评价。【结果】主要研究结论如下：(1)植被的水源涵养功能体现在汛期调蓄洪水、坦化洪水过程，在枯水期增加基流和水资源供给量；土壤的蓄水能力/调节库容即其水源涵养能力，与土壤层厚度、有效蓄水量成正比，并且在一定时期内存在多个“蓄满—释放—再蓄满”过程；含水层的调蓄能力即其水源涵养能力，与含水层厚度、储水/释水能力成正比；不同资源开发利用方式对水循环过程施加影响，进而将这种影响传递到水源上。(2)黄河水源涵养区水源评价，应以提升全流域水安全综合保障能力为目标，统筹全流域生态安全、防洪安全以及供水与能源安全需求；应同时考虑平水时段的“滞留”、汛期时段的“调峰”、枯水时段的“产水”三项功能。(3)黄河水源涵养区1960—2018年多年...     

黄河源区径流演变研究进展

黄河源区是黄河流域重要的产流区和水源涵养区,年径流量占黄河流域径流量的三分之一左右,对流域水资源安全具有重要意义。总结了近20 a发表的有关黄河源区径流演变特征及其影响因素的相关文献,对研究成果进行了系统梳理、总结和对比。各研究成果在黄河源区径流整体变化趋势上具有一致性,近几十年黄河源区径流总体呈下降趋势,且存在丰枯交替的演变特征,径流年内分配不均,存在不同时间尺度的周期性变化,未来一定时期黄河源区径流仍将有所下降。但在径流演变驱动机制方面存在一定的分歧,气温和蒸发对径流变化的影响机制仍不明确,未来径流变化的定量预测仍存在差异。基于此,未来应注重开展黄河源区径流演变驱动机制、空间特征及未来趋势等方面的研究,为黄河源区水源涵养能力提升提供支撑。     

若尔盖湿地年径流序列趋势识别研究

若尔盖湿地是黄河上游重要水源涵养地,由于沙化、退化等一系列生态问题对湿地水源涵养能力产生了严重破坏。本文采用Mann-Kendall检验法、Spearman秩次相关检验法和线形趋势回归检验法对若尔盖湿地黑河和白河流域进行趋势识别研究,利用大水和唐克年径流资料进行分析,结果表明若尔盖湿地的年径流存在较强的减小趋势。     

黄河河源区水沙特征与组成的初步分析

黄河源区控制站唐乃亥站多年平均年径流量 2 0 0亿m3 ,占黄河流域年径流量 5 80亿m3 的 34 5 % ,占青海境内黄河干流年径流量的 91 0 %。唐乃亥以上不仅是黄河河源区 ,也是黄河水量的主要供给地和水源涵养区之一。利用黄河源区干流主要测站黄河沿、吉迈、玛曲、唐乃亥站自建站至 2 0 0 2年实测径流量和输沙量资料 ,初步分析了黄河源区水沙特征、组成及来源。     

黄河河源区水沙特性及来源分析

黄河源区控制站唐乃亥站多年平均年径流量200亿m^3，占黄河流域年径流量580亿m^3的35．2％，占青海境内黄河干流年径流量的91．0％。唐乃亥以上不仅是黄河河源区，也是黄河水量的主要供给地和水源涵养区之一。利用黄河源区干流主要测站（黄河沿、吉迈、玛曲、唐乃亥站）建站至2002年实测径流量和输沙量资料，初步分析了唐乃亥站水沙特性及来源。     

变化环境下的水源涵养能力评估研究进展

水源涵养功能属于生态学与水文学的交错领域，是近年来的研究热点。水源涵养功能包涵广泛，水源涵养能力是针对不同区域特点和具体研究对象对水源涵养功能的量化评估。将水源涵养能力定义为一个区域的最大持水能力，与区域的气候、土壤、植被等因素有关，并且由区域持或蓄的水量应能够补给地表或地下水，为区域的工农业发展提供相对稳定的水源，讨论了区域水源涵养能力的组成和影响因素，分析了变化环境下气候条件和人类活动对水源涵养能力的影响。此外，水源涵养能力表征在干旱区和湿润区有所不同。基于上述观点，总结了水源涵养能力的评估方法及其适用条件与优缺点，并在此基础上，进一步讨论了水源涵养能力评估的研究方向，以期为生态水文学发展和环境治理提供科学参考。     

玛曲行吟

正玛曲县地处青藏高原东南缘。黄河自青海流入甘肃后,环流玛曲全境四百三十三公里,玛曲因此有黄河"首曲"之称。在科学界正式认定黄河源以前,当地民众一直把首曲当作源头。源自巴颜喀拉山的黄河,在玛曲段的注增流量约占黄河源区径流量的百分之五十八。玛曲丰沛的水流,宽阔舒缓的河床,成为黄河全境主要的产流区、水源涵养地和补给地。     

黄河流域水生态现状与气候变化适应性对策

黄河源区草场和湿地严重退化,沿河不少湿地出现逆向演替现象,近30a来干流与河口地区鱼类组成与数量急剧减少.预计气候变化条件下流域水循环过程的改变将进一步加剧水生态退化的趋势.针对黄河水生态现状,结合气候变化的可能影响,围绕黄河河流生态系统良性维持的关键生境和敏感因子,提出黄河水生态系统良性维持的适应性对策:确保重点生态单元用水,实施黄河湿地生态保护和生态修复工程,加强水生态监测、水生态保护与修复基础研究等.     

水源涵养相关概念辨析及水源涵养能力计算方法

为深刻理解水源涵养相关概念,在综述国内外相关研究的基础上,对水源涵养、水源涵养功能及水源涵养能力代表性概念进行了梳理和辨析,提出了内涵明确、外延清晰的定义.分析认为,水源涵养是生态系统截留降水、贮存水分、调节径流、净化水质、维持生态的过程和现象;水源涵养功能有狭义和广义之分,狭义的水源涵养功能是针对拦蓄降水、调节径流、...     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。     

Changes in Summer Irrigated Crop Area and Water Use in Southeastern Turkey from 1993 to 2002: Implications for Current and Future Water Resources

Changes in summer irrigated cropland acreage and related water use are estimated from satellite remote sensing and ancillary data in semi-arid Southeastern Turkey where traditionally dry agricultural lands are being rapidly transformed into irrigated fields with the help of water from the Euphrates-Tigris Rivers. An image classification methodology based on thresholding of Landsat NDVI images from the peak summer period reveals that the total area of summer irrigated crops has increased three-fold (from 35,000 ha to over 100,000) in the Harran Plain between 1993 and 2002. Coupled analysis of annual irrigated crop area from remote sensing and potential evapotranspiration based estimates of irrigation water requirements for cotton indicate a corresponding increase in agricultural water use from about 370 million cubic meters to over one billion cubic meters, a volume in accordance with the state estimates. These estimates have important implications for understanding the rapid changes in current agricultural withdrawals in Southeastern Turkey and form a quantitative basis for exploring the changes in future water demands in the region. For example, expansion of irrigated lands have led to a steady decrease in potential evaporation due to increased roughness and decreased humidity deficit in the Harran Plain. Assuming that the changes in future evaporation conditions will be of similar nature, water use for irrigation is expected to decrease over 40 percent in future irrigation sites. Incorporating this decrease in overall planning of the irrigation projects currently under construction should lead to improved management, and by extension, sustainability of water resources in the region.     

浅谈优化Vray渲染在制作三维场景的应用研究

用Vray三维渲染引擎来渲染三维场景,其质量和速度是由一些影响因素和参数设置决定的,不同的参数和因素,可以得出不同的三维渲染效果.因此,分析、优化三维渲染质量和速度的影响因素,正确、合理的选择参数对提高Vray最后渲染阶段的质量和速度非常重要.     

固结、渗流和沉积控制方程研究

本文从两相流体动力学的守恒方程出发，考虑固相、液相的相对运动，推导了可以考虑场的不均匀性和流体压缩性的统一形式的控制方程，并对方程所基于的物理概念和相互联系进行了必要的分析。通过对方程适当形式的表达，可导出用于大、小变形固结、渗流和沉积的简化方程，显示了在不同领域的三个理论存在一定的统一性。方程推导过程并未对本构关系加以限制，适用范围较广。依据实际问题的要求，作了不同形式的简化。     

四川省及重庆市中型水电站效益分析

该文分析了四川省及重庆市几座中型水电站的调查材料表明：四川省及重庆市中型水电站不仅在川渝主网和地方电网中起着很大的作用，并具有巨大的社会效益，同时还有综合利用效益，说明修建中型水电站的优越性．     

Site modelling methods for detecting hydrologic alteration of flood frequency and flood duration in the floodplain below the carlyle dam,lower Kaskaskia River,Illinois, USA

Reports concerning the influence of dams on river hydrology vary among researchers, interest groups and government agencies. These often contradicting statements may occur because changes in hydrology caused by dams are distinct for each dam and river watershed. The objective of this research was to use site specific techniques to determine if the 1967 installation of the Carlyle Dam, lower Kaskaskia River, Illinois, altered flood frequency and duration within the forested floodplain located below the dam. Results indicated a decrease in flood duration and frequency, and a decrease in annual flood frequency variation at a site 6.4 km below the dam. Pre‐dam versus post‐dam differences in flood frequency and duration at the site 32.2 km below the dam were related to climate rather than dam effects. Although dam impacts are a concern, this research shows that distance downstream from the dam and downstream tributary and watershed characteristics should be considered before assuming that the dam has changed hydrologic parameters for portions of rivers. This research also indicates that areas of the lower Kaskaskia River may still maintain hydrologic ecological integrity, and could be targeted for restoration and adaptive management purposes. Hydrologic modelling combined with river gage and on‐site well measurement techniques presented in this study could provide detailed flood frequency and duration information for land use, sociological and geomorphological questions in focus areas within river floodplains. Copyright © 2008 John Wiley & Sons, Ltd.     

Statistical tools for thermal regime characterization at segment river scale: Case study of the Ste‐Marguerite River

Suitable thermal fish habitats are constrained by both maximum and minimum temperature tolerances. A multivariate and geostatistical approach was developed to estimate stream thermal characteristics at the river segment scale. Data from 22 temperature‐monitoring stations during summer 2007 were used to estimate monthly maximum temperature as well as thermal characteristics such as the number of events, the cumulative degree–days and the associated duration over specific temperature thresholds of 19 and 21°C. The probability of exceeding these temperature thresholds has also been interpolated. The methodology relies on the construction of a multivariate space using physiographic and hydrological characteristics of gauging stations as inputs in a canonical correlation analysis (CCA). A geostatistical interpolation technique, ordinary kriging, was subsequently used to perform interpolation in the physiographical space constructed using CCA. Results from this study were obtained for thermal characteristics estimated into two different interpolation spaces: (1) a 7 metrics space, and (2) an 8 metrics space. Cross‐validation technique has been performed and satisfactory results were obtained. Kriging thermal characteristics (magnitude and duration) into the 7 metric space for a 19°C threshold exceedance leads to best results with Relative Root Mean Square Error (RRMSE) ranging between 9.66 and 15.08%. The study shows that kriging in a multivariate space is a promising tool for water resources managers, especially in cases where risk mapping for lethal or sub‐lethal temperature thresholds may be required for a specific fish species. Copyright © 2010 John Wiley & Sons, Ltd.     

掺MgO混凝土的宏细观试验研究

利用MgO膨胀剂的延迟微膨胀效应能显著提高大体积混凝土的力学性能,产生的预压应力还能有效提高大体积混凝土抵抗温度开裂的能力,但目前对其微观机理研究不多。采用宏观与微观相结合的方式,研究了不同活性指数、不同掺量的MgO混凝土的力学性能,利用SEM/EDS微观分析手段揭示了MgO对混凝土性能影响的作用机理。试验结果表明：MgO取代部分水泥掺入混凝土中,混凝土的力学性能降低;掺量为4%~5%时,活性指数为100s的MgO混凝土的膨胀率大于活性指数为50 s的MgO混凝土;MgO混凝土的膨胀特性与Ca,Si,Mg,Al等元素的分布情况有关,掺入的MgO将改变界面区Ca,Si,Mg元素的富集特性,Ca元素和Mg元素更易于在界面区富集,导致混凝土宏观力学性能的降低。     

基于MIDAS软件探讨施工工序对深基坑稳定性的影响

基于武汉地铁名都站深基坑工程与水文地质勘察资料,建立了三维工程地质仿真计算模型。依据名都站深基坑开挖支护方案,利用有限元软件MIDAS的摩尔-库仑本构模型,对武汉地铁名都站深基坑施工过程中,不同施工工序下每步开挖之后,基坑的变形情况做仿真模拟计算,并对比分析其对基坑稳定性的影响。结果表明：基坑围护结构的变形情况与施工工序有很大的关系,施工工序越合理,上部土体变形越小,反之越大。因此,在基坑工程的施工过程中,要注重施工步骤的划分与合理安排,从而保证基坑工程的安全。研究成果为以后武汉地区基坑工程的施工设计提供了值得借鉴的经验。