汾河流域径流减少因素的定量解析

分析汾河流域 1981—2015 年气候、植被和人类取用水的演变特征。结果表明,流域年降水和净辐射分别呈 不显著（p>0.05）增加和减少趋势,叶面积指数显著（p<0.05）增加,人为取用水量波动增加,实测年径流显著（p<0.05） 减少。基于分布式水文模型和因素去趋势方法定量解析降水、净辐射、温度、叶面积指数以及取用水对汾河年径 流减少的贡献。结果表明,取用水的增加是导致汾河径流减少的主要原因,其次为温度、叶面积指数和净辐射的 变化。在上述 4 个因素无趋势情景下,实测年平均径流将分别增加 27.4%、14.4%,13.7% 和 2.1%。降水增加缓解 了年径流的减少。在年降水无趋势的情景下,实测年平均径流将减少 5.3%。上述研究结果可为汾河流域的水资 源管理和规划提供参考。     

近50年来额济纳三角洲气象要素变化对蒸发皿蒸发量的影响

识别蒸发皿蒸发量与气象要素的关系是认识气候变化对水循环影响的重要基础。根据额济纳旗气象站1961年-2001年的常规气象数据,建立了额济纳三角洲地区蒸发皿蒸发量与相关气象要素关系的Penpan模型,并据此估算了2002年-2011年的蒸发皿蒸发量,延展了蒸发皿蒸发量的时间序列,进而分析了1961年-2011年研究区蒸发皿蒸发量和相关气象要素的变化趋势及其相互关系。研究结果表明:(1)1961年-2011年期间,额济纳三角洲蒸发皿蒸发量呈下降趋势(气候倾向率为年-215.5mm/10a),而平均气温呈上升趋势,风速、总辐射、相对湿度则均呈下降趋势;(2)总体上,蒸发皿蒸发量对各气象因子的敏感程度从大到小依次为风速、相对湿度、太阳总辐射、平均气温;1961年-2011年,蒸发皿蒸发量对风速、相对湿度的敏感性呈下降趋势,对太阳总辐射、平均气温的敏感性呈上升趋势;(3)风速变化对蒸发皿蒸发量变化的贡献度最大,其次是相对湿度、平均气温、总辐射。     

干旱区平原水库模拟蒸发量试验研究

干旱区平原水库水面蒸发是平原水库水量损失的重要组成部分,由于水库面积大,采用常规蒸发皿测定的蒸发量与水库实际蒸发量特征不相符。为了准确模拟干旱区平原水库蒸发量,开展了模拟水库的小面积水域蒸发试验,通过水位测针测量蒸发池的蒸发量,并与蒸发皿蒸发量进行比较。试验结果表明,在实际蒸发量中,蒸发池的蒸发量波动较大,蒸发皿蒸发速率比水面蒸发速率高9.1%。蒸发皿蒸发量与水面蒸发量的比值呈现先下降后上升的趋势;蒸发池水面蒸发量主要受到温度、净辐射、风速、饱和水汽压差影响;蒸发皿水体容量小,与蒸发池相比水体热容量较小,因此与大气交换更加快速,受净辐射和气温日较差影响较大。     

南宁站蒸发皿蒸发变化特性及成因分析

基于南宁气象站1954-2012年气象数据,采用距平法、Mann-Kendall检验法、突变分析法及相关分析法等方法分析了蒸发皿蒸发的变化趋势以及蒸发皿蒸发与其他气象要素（降水、气温、日照时数、风速、相对湿度等）的相关性,识别影响蒸发皿蒸发变化的主导因素。结果表明：1954-2001年期间,蒸发皿蒸发主要呈现下降趋势;日照时数与蒸发皿蒸发的相关性最高,其次为风速和相对湿度,说明影响南宁站蒸发皿蒸发变化的主要因素是日照时数、风速及相对湿度。     

新疆地区气象要素变化对潜在蒸散发量的影响

基于乌鲁木齐站和喀什站1954—2008年气象资料,运用P-M法计算了各站点的潜在蒸散发量,运用Mann-Kendall非参数统计检验法统计分析了两站气象要素的变化趋势,并分析了各气象要素与潜在蒸散发量的相关性。结果表明:①1954—2008年,喀什站气温和相对湿度呈显著上升趋势,风速呈显著下降趋势,乌鲁木齐站气温呈显著上升趋势,风速和日照时数呈显著下降趋势;②气象要素的变化趋势不具有规律性,不同季节的变化趋势不同;③气温、风速、日照时数与潜在蒸散发量均呈正相关关系,相对湿度与潜在蒸散发量呈负相关关系,气温和相对湿度是乌鲁木齐站潜在蒸散发量的主要影响因素,气温和风速则是喀什站潜在蒸散发量的主要影响因素。     

1961—2013年黄河三角洲气候变化趋势研究

利用黄河三角洲地区11个气象站点1961—2013年间的气候数据,对该地区近53 a来的气候变化趋势及其特征进行了分析。结果表明:黄河三角洲地区气温整体呈上升趋势,气温倾向率为0.3℃/10 a;降水量、蒸发量、风速、相对湿度均呈波动减少趋势,气候倾向率分别为-12.6 mm/10 a、-69.4 mm/10 a、(-0.26 m/s)/10 a、-0.58%/10 a;黄河三角洲地区在20世纪60—70年代表现出明显的冷湿特征,80年代表现出过渡性的气候特征,90年代以来气候表现出明显的暖干特征;四季气温均呈波动上升趋势,其中冬季气温升幅最大,为0.34℃/10 a,夏季气温升温幅度最小;降水量在春季呈增加趋势,增加速率为0.54 mm/10 a,其他季节呈下降趋势,夏季下降最多;各季节蒸发量、风速和相对湿度均呈波动下降趋势;黄河三角洲地区6—8月气温高、降水丰富、蒸发旺盛、相对湿度大,风速较小。     

不同蒸发模型在辽宁中部平原区域蒸发计算中的应用对比

结合P-M和双源蒸发模型,以辽宁中部平原区为例,结合实测蒸发皿蒸发对比分析不同蒸发模型对辽中平原区蒸发计算精度和适用性,并分析区域气象要素变化和蒸发皿蒸发的相关性。结果表明:P-M模型在年、月、季尺度的计算精度均好于双源蒸发模型,更适用性辽宁中部平原区蒸发计算。相对湿度和风速与蒸发相关性最高,按相关性排序:相对湿度风速气温太阳净辐射。     

近59年广西气象要素时空变化特征分析

基于广西25个气象台站1958-2016年的气象资料,采用Daniel趋势检验法、Lee-Heghinan变异检验法、Morlet小波分析法、R/S分析法和克里金插值等方法,对广西年日照时数、年平均风速、年降水量、年平均相对湿度和年平均气温的时空变化进行了分析。结果表明:近59年广西年日照时数、年平均风速和年平均相对湿度呈减小趋势,年降水量和年平均气温表现出微弱增加趋势;各气象要素分别在1979年、1974年、2011年、2002年和1997年发生变异;各气象要素均表现出多时间尺度耦合的复杂特性,第一主周期分别为22a、29a、31a、26a和13a;各气象要素的Hurst指数均大于0.5,说明未来变化趋势将继续与过去变化趋势保持一致;在空间上,广西年日照时数由西北向东南递减,年平均风速、年降水量、年平均相对湿度和年平均气温由北向南递增。     

滦河流域主要气象要素及径流变化趋势分析

以滦河流域5个气象站1957 -2008年的气象资料和4个水文站1956-2000年的天然径流资料为基础,采用Mann - Kendall非参数趋势检验法、累计距平法、滑动平均法等方法,分析了流域内气温、日照时数、降水量、相对湿度等主要气象要素以及径流量的变化趋势.结果表明:绝大部分气象站点的年均气温都表现出显著上升趋势,Kendall倾向度为0.28 ～0.43℃/10a;年日照时数均呈显著减少趋势,Kendall倾向度为3.32～8.21 h/a;降水量均呈减少趋势,但不显著,夏季降水量的减少趋势最为显著;相对湿度除承德气象站有显著增大趋势外,其他站点均呈现下降趋势,其中乐亭站达到显著下降水平;径流量均呈不显著减少趋势,潘家口水库水文站年入库径流量的Kendall倾向度为-1799万m3/a.     

川中丘陵区参考作物蒸发蒸腾量近60 年变化成因研究

利用FAO-56 Penman-Monteith方法计算川中丘陵区4个代表站点1954—2010共57年逐月的参考作物蒸发蒸腾量（ET0）,分析ET0和各气象因子的变化趋势,采用贡献率分析法和偏相关系数分析法研究ET0近60年变化的成因。结果表明：ET0呈下降趋势;温度呈显著上升趋势;相对湿度呈显著下降趋势;日照时数和风速呈极显著减少趋势;川中丘陵区气候在近60年来趋向暖干化。日照时数和风速减少对ET0变化的负贡献率分别为-5.403%和-2.054%;相对湿度减少和温度增加对ET0 变化的正贡献率分别为2.085%和0.562%;负贡献大于正贡献使ET0下降。因此,日照时数和风速减少是引起ET0近60年下降的主要原因。偏相关系数分析法得到的ET0变化成因与贡献率分析法得出的结论一致。     

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.     

Serial discontinuities in a Rocky mountain river. I. Distribution and abundance of plecoptera

Samples were taken year-round at eleven sites along the altitudinal profile (2900-1400 m a.s.l.) of the Gunnison River, a 329 km tributary of the Colorado River, to document the distribution of the Plecoptera and to evaluate responses to hypolimnial-release dams in the headwaters and middle reaches. Twenty-two species were present, with the greatest species richness occurring in an unregulated segment upstream of the middle reach dams; average nymphal biomass over the study period (175 organisms, 395 mg dry mass m^?2) was also greatest in this segment. Only four species (58 organisms, 48 mg m^?2) were present in the tailwaters of the headwater dam and values were greatly reduced (nine species; 35 organisms, 180 mg m^?2) below the middle reach dams. The stonefly community recovered ca. 80 km downstream from the last dam (15 species; 244 organisms, 250 mg m^?2), apparently in response to natural resetting of environmental conditions corresponding to those above the middle reach dams. At the most downstream site (11) only four species (four organisms, 16 mg m^?2) were present. The observed distributional pattern is a classic serial discontinuity in response to hypolimnial stream regulation in a temperate latitude river.     

地下厂房施工过程的三维非线性数值模拟分析

根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。     

Impacts of Microcystis on algal biodiversity and use of new technology to remove Microcystis and dissolved nutrients

Cyanobacteria often dominate eutrophic lakes, outcompeting green algae that are required by fish and zooplankton. This study was undertaken to ascertain the impact of the cyanobacterium, Microcystis, on algal biodiversity. Under laboratory conditions, we found that the presence of Microcystis decreased phyla richness by 58%, phyla evenness by 47%, genera richness by 66% and genera evenness by 51%. Analysis by mixed anova s demonstrated a significant interaction between treatment and time and confirmed a significant reduction in richness and evenness of phyla and genera. We also conducted a phosphate restriction assay on the algae in Mason Lake (Irvine, CA, USA) and found that the threshold needed for algal growth there was 0.02 mg L^?1 PO₄. A pilot study was then conducted to test the effectiveness of the Blue Pro? water treatment facility in removal of this colonial organism from Mason Lake, in addition to removal of dissolved nutrients required for its growth. We measured a 97% reduction in Microcystis cells, a 72% reduction in chlorophyll‐a, and a 96% reduction in phosphate after just one 10 min cycle through the unit. Our study demonstrated that removal of Microcystis colonies may allow green algae to increase in numbers. This may improve algal biodiversity, which will benefit zooplankton and fishes.     

Evaluation of freshwater mussel relocation as a conservation and management strategy

The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects.     

基于模型试验的河床砂砾石层基本特性研究

为了经济可靠地确定深厚覆盖层的基本特性参数,以大渡河双江口水电站坝基河床砂砾石层基本特性研究为工程背景,进行大尺寸模型试验,研究河床砂砾石层的旁压模量和动探击数随密度、级配以及上覆压力的变化规律。根据室内模型试验结果,结合现场旁压试验及钻孔试验成果,推断出坝址区河床砂砾石相关层位的密度,并依此进行砂砾石室内力学试验,获得设计所需力学参数。研究成果可为深厚覆盖层基本特性测试提供新的方法。     

SPATIAL AND TEMPORAL WATER QUALITY VARIABILITY IN AQUATIC HABITATS OF A CULTIVATED FLOODPLAIN

The floodplains of lowland rivers contain diverse aquatic habitats that provide valuable ecosystem services but are perturbed when intensively cultivated. Hydrologic, water chemistry and biological (fish) conditions in five aquatic habitats along the Coldwater River, Mississippi, were measured for more than 4 years: the river, two severed meanders that functioned as backwaters, a managed wetland and an ephemeral channel draining cultivated fields. Off‐channel habitats were connected to downstream regions 0.10% to 32% of the dry season and 24% to 67% of the wet season. The median temperatures for the five monitored sites ranged from 18°C to 23°C, the median total solids concentration for all sites was 135 mg L^?1, the median total phosphorus was 0.29 mg L^?1 and the median total nitrogen was 1.56 mg L^?1. Chemical and physical water quality displayed strong seasonal differences between the wet winter/spring and the dry summer/fall periods so that temporal variation consisted of gradual seasonal trends superimposed on strong diurnal variations. All off‐channel habitats exhibited periods of hypoxia and temperatures >30°C during the dry season. Between‐site gradients of water and habitat quality were strongly coupled to water depth and runoff loading. The rehabilitation of one backwater by increasing water depth and diverting agricultural runoff was associated with improved water quality and fish species richness relative to an adjacent untreated backwater. The diversion of polluted runoff and the use of water control structures to maintain greater water depth were observed to be effective management tools, but the former reduces the water supply to habitats that tend to dry up and the latter reduces connectivity. Published in 2011 by John Wiley & Sons, Ltd.     

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.     

簸箕李引黄灌区水沙分布及优化调度的经验

灌区利用水沙观测所取得的资料和试验数据，运用水沙运动力学理论，总结分析和揭示了灌区水沙分布的规律和特点。在此基础上，结合灌区的实际运行情况，围绕减少骨干渠道的淤积进行探讨、研究，进而，优化水沙调度方案。该方案实施后，骨干渠道减旅伴效果明显，取得了成功的经验。