渭河源区水文气象要素演变趋势及阶段性分析

研究渭河源区水文气象要素变化特征,并进一步分析各个要素之间的相互关系,为渭河源区水资源的合理开发利用提供科学依据与技术支撑。采用坎德尔秩次相关、斯波曼秩次相关、线性趋势回归检验法对渭河源区水文气象要素变化趋势进行检验,利用M-K检验法找出各要素的突变年份,运用多元线性回归分析法分析不同阶段降雨、蒸发量对径流量的影响程度。结果表明:近30年来渭河源区年降水量与四季降水量均呈不显著减少趋势,年蒸发量与春、夏季蒸发量呈显著增加趋势,年径流量与夏季径流量呈显著减少趋势,冬季径流量呈不显著增加趋势。年降水量和年径流量均在1993年发生显著性突变,年蒸发量在1990年发生显著性突变。分析得出:1981-1993年年径流量变化主要受降水量变化影响,1994-2010年径流量变化主要受蒸发量变化影响。     

阿卡尔河流域径流对气候变化的响应分析

根据阿卡尔河流域1981-2017年逐月径流量、降水量、平均气温及蒸发量资料,运用线性趋势法、滑动平均值法、不均匀系数法及小波方差法,分析流域气候及水文特征的变化规律.结果表明:年径流量、年降水量及年蒸发量呈递减趋势,年均气温呈增加趋势;降水和径流在不同年代变化趋势一致,呈现减小-增加-减小-增加波动变化;夏季径流量和...     

气候变化和人类活动对大凌河上游流域径流的影响

通过趋势分析方法及突变点检验方法,分析大凌河流域水文气象要素的变化趋势;结合大凌河流域人类活特征及突变点分析结果,将流域径流量序列划分为"天然基准期"和"人类活动影响期"两个阶段;应用大凌河上游水文、气象、土地利用等数据建立大凌河上游水文模型,采用弹性系数法和水文模拟法定量分析大凌河上游流域气候变化和人类活动对径流的影响。结果表明:1956—2006年,大凌河流域降水量有轻微的上升趋势,而潜在蒸发量与径流量呈现显著下降趋势,导致径流量减小的主要原因为人类活动。     

武江流域气象要素变化及对径流敏感性分析

基于武江流域1959-2006年月均气象要素(降水量、气温、蒸发量、相对湿度和日照时数)及水文资料,采用Mann-Kendall法和相关分析等方法,分析了流域近50年来气象要素变化趋势及其与径流之间的关系;运用非线性回归模型计算并分析了降雨和蒸发对流域径流的敏感性。结果表明:近50年来,流域降雨量、气温呈上升趋势,而蒸发量、相对湿度、日照时数则呈下降趋势;降雨与径流有较好的线性关系且与径流关联度最大,是径流量变化的主要驱动因子;武江流域径流对降雨变化的响应较气温更为显著。     

窟野河径流突变点分析

根据窟野河流域气象和水文资料,采用Mann-Kendall趋势检验和Pettitt突变点检验相结合的方法,对该流域径流突变点进行检验,并应用Mann-Kendall趋势检验法对流域降水量、蒸发量进行趋势分析。结果表明:窟野河的年径流量在1979年和1996年发生了突变,初步分析这主要是20世纪80年代初期开始实施的水保措施和20世纪90年代后期煤炭大规模开采造成的;窟野河流域年降水量、年蒸发量从20世纪60年代开始均呈逐年减少的趋势,相对年蒸发量而言,降水量的减少速率较小,并且其变化趋势均不明显。     

冶木河流域主要水文要素时空变化分析

依据冶木河冶力关水文站近30 a的水文监测数据,采用趋势分析法、距平分析法和不均匀系数法对主要水文要素降水量、径流量和输沙量时空变化过程进行了分析,结果表明:降水量、径流量、输沙量均呈现减小的变化趋势,减小倾向率分别为226万m3/a、1.5 mm/a和0.021万t/a;输沙量的年内集中程度强于降水量,而降水量强于径流量;输沙量的年际变化明显强于径流量和降水量,而径流量的年际变化强于降水量,并呈逐渐增强的态势。     

吐鲁番及周边地区气候及径流演变特征分析

采用吐鲁番及周边地区6个典型气象站和煤窑沟、阿拉沟2个流域水文站的1960-2012年实测数据,运用Mann-Kendall非参数秩次检验法和Pettitt变点检验法,分析了该地区的气候变化和径流变化趋势。结果表明:1960-2012年,吐鲁番及周边地区的年降水量呈一定的上升趋势,但不显著,平均气温也呈上升趋势,而日照时数和平均相对湿度呈下降趋势;阿拉沟出山径流量呈明显上升趋势,而煤窑沟出山径流量上升趋势不明显;降水量、平均气温、平均相对湿度均与径流量呈正相关关系,而日照时数与径流量呈负相关关系。     

天然文岩渠流域水文气象要素变化特征分析

运用不均匀系数法、Mann-Kendall趋势检验、R/S分析、Pettitt变点检测等数理统计方法对天然文岩渠流域1970—2009年水文气象要素变化特征进行了分析。结果表明,该流域降水量、径流量、输沙量年内分配差异较大,水面蒸发量年内分配较为平均。年降水量呈不显著减少趋势,具有反持续性,在未来将呈增加趋势;年径流量、年输沙量、年蒸发量呈显著减少趋势,分别于1984年、1994年、1977年发生变异,且都具有长持续性,在未来一段时间都将呈减少趋势。     

近50a来讨赖河流域气候变化分析

根据祁连、肃南、酒泉和金塔四站的气象资料,采用Mann-Kendall法和小波分析法研究了讨赖河流域近50 a来的气候变化特征,并用相关分析法分析了气候变化对径流量的影响。结果表明:20世纪60年代中期以前流域气温总体呈下降趋势,60年代中期后气温波动升高,80年代中期以来气温升高幅度加大;流域内年降水量近50 a来呈平、枯、丰交替状态,总体上微弱增加;11、18 a分别为山区、平原代表站气温变化的主周期;山区降水量变化的主周期为11 a,平原区降水量变化的主周期则为21 a;径流量与降水量呈正相关关系,与气温呈微弱的负相关关系。     

人类活动影响下水文要素变化特征分析

利用朱庄水库流域的长系列水文资料,用数理统计的方法分析流域内的降水量、径流量和蒸发量的变化特征及变化原因。分析结果:降水量呈递减趋势,根据该流域现有资料系列分析,平均每年减少2.7mm,减少数量最大的在7、8月;径流量变化也呈递减趋势,平均每年减少0.0557亿m3。减少幅度最大出现在8月份;水面蒸发量也呈递减趋势,平均每年下降10.2mm,汛期的水面蒸发量的减少量大于非汛期。受人类活动的影响下,使水文要素的特征和变化规律发生变化,研究和分析区域的水文要素变化规律,对开发利用水资源有重要意义。     

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。     

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。     

小湾水库大坝防渗面板及其裂缝的加固处理

小湾水库大坝防渗面板整体抗渗性能差,且存在多条裂缝,通过对面板钢丝网喷涂丙乳砂浆加固处理及其裂缝修补,大坝渗漏量明显减少,且左岸上灌浆廊道内及大坝下游坝面92～93 m高程下廊道入口处原有小股射流全部消失.