1954-1993年间窟野河径流量变化趋势及其影响因素分析

采用窟野河温家川站1954-1993年的水文资料和降水量资料,应用多种统计分析方法,系统分析了窟野河径流的年内分配及年际变化规律及其影响因素。研究表明:窟野河流域径流年内分配极不均匀,主要集中于7-9月。径流的年际变化剧烈,且呈减少趋势,1980年代以后基本处于枯水时段,与降水量的变化趋势基本一致。从多年平均值来看,温家川站1973-1979年平均年径流量较前期减少24.6%,20世纪80年代以来径流量锐减,年均径流量较1973年以前减少38.6%。在各项水土保持措施中,造林对径流量的影响最大。通过降水-径流双累积曲线的分析表明,径流变化趋势在1973年发生系统性向右偏转,说明径流量变化受降水量和人类活动共同影响。     

煤矿开采对窟野河地表径流影响的水文模拟

为了探明煤炭开采与窟野河河川径流减少甚至断流之间的关系,利用窟野河控制性水文站——温家川站1953—2010年逐日流量资料及相关水文气象资料,在对其径流变化特性进行分析的基础上,通过黄河月水量平衡模型模拟定量评价煤矿开采对地表径流的影响。结果表明:1953年以来,窟野河流域实测径流量以1979年和1999年为转折点总体上呈现阶段性减少趋势;人类活动对径流减少影响的比例由1979—1998年的39.44%快速上升到1999—2010年的56.50%,其中,煤矿开采对径流的影响量年均值在1999—2010年间达到29.69 mm,约2.58亿m3/a,成为影响窟野河地表径流减少的主导因素。     

窟野河流域径流演变及其驱动因素分析

以黄土高原典型流域窟野河流域为对象,采用有序聚类方法,诊断了近60 a来实测径流演变的阶段性特征,在此基础上,分析了不同阶段实测径流与气候要素之间的响应关系,初步揭示了径流演变的驱动机制。结果表明：近60 a来窟野河流域实测径流量以1980年和1998年为分割点总体呈现阶段性减少趋势,其中,1999年以来减少尤其明显。不同阶段的年降水、径流关系有一定差异,相比而言,汛期（6-10月份）的月降水量与径流量具有相对较好的相关关系;非汛期（11-5月份）的月降水径流关系点群散乱,在月平均气温低于5℃时,月径流量与月平均气温具有较好的正相关性。窟野河流域汛期产流受高强度降水支配,人类活动对河川径流演变的影响有增大趋势。     

1956-2016年拉萨河径流量变化及影响因素分析

通过分析拉萨河径流量的演变规律和突变情况,开展降水和人类活动对径流量变化的成因分析,为拉萨河流域水资源管理与利用提供科学依据。基于1956-2016年的径流和降水数据,利用Mann-Kendall趋势分析、累积距平-滑动t检验法和降水－径流双累积曲线法,统计分析拉萨河径流序列的趋势性和突变性,计算降水与人类活动对拉萨河汛期6-9月径流量变化的贡献率。结果表明： 1956-2016年拉萨河径流量年际变化波动较大,其中1995和2005年为径流量突变年份。以1956-1994年为基准期,通过双累积曲线法定量分析表明1995-2004年人类活动对汛期径流量变化的贡献率小于50%,而2005-2016年人类活动的贡献率增大至70%以上,即人类活动成为汛期径流量改变的主要影响因素,且下游河道人类活动的影响程度更大,主要原因是新建的直孔和旁多水库调控了下游河段的流量过程。     

近50a来窟野河流域水文情势变化研究

对窟野河流域1966—2012年降水量、径流量以及降水—径流量关系的变化趋势进行了分析,通过建立SIMHYD模型,研究了气候变化和人类活动对窟野河流域径流的影响程度。结果表明:近50 a来流域径流量呈显著减少趋势;降水量虽然没有明显变化,但是1999年以后降雨强度减小;1998年后流域产流条件发生了很大变化;近几十年来,人类活动是窟野河流域径流量减少的主要因素。     

汾河水库控制流域径流突变及其驱动因素分析

针对目前汾河入黄径流锐减的问题,基于汾河水库控制流域1960-2013年54年的径流资料,采用MannKendall法和滑动T法相结合对径流时间序列进行突变检验,探究了流域径流阶段性变化规律,并建立双累积曲线模型定量计算了驱动因素降水和人类活动对径流减少的影响量。结果表明:(1)汾河水库控制流域内静乐站和上静游站径流均呈现减少趋势;(2)流域内静乐站径流序列突变年份为1979年,上静游站为1982年;(3)人类活动是该流域径流减少的主要因素,占径流减少总影响量的84.48%,静乐站和上静游站的降水对径流影响率分别为15.62%和14.95%,人类活动的影响率分别为84.38%和85.05%。     

降水变化和人类活动对浏阳河流域径流的影响

定量评估降水变化和人类活动对浏阳河流域径流的影响,有助于更合理地利用流域水资源。采用线性拟合、滑动平均和累积距平等方法分析了1969—2013年浏阳河流域径流和降水的演变规律及其相关关系,应用累积斜率变化率比较法定量估算了不同时期降水变化和人类活动对径流量变化的贡献率。结果表明:浏阳河流域降水量表现为增加趋势,上升率为3 mm/(10 a);年径流量表现为下降趋势,下降率为2.7 (m³·s^-1)/(10 a);降水和径流在1988年和1999年均发生显著性突变,经历了“减少—增多—减少”的交替变换。与基准期1969—1988年相比,1989—1998年和1999—2013年这2个时期的降水量变化对径流量变化贡献率依次为56.8%,7.62%,而人类活动对径流量的贡献率依次为43.2%,92.38%,可见人类活动已成为影响浏阳河流域径流变化的主要因素。     

抚河临水流域径流量变化及其对降雨的响应

利用抚河临水流域1979—2008年降水和径流数据,采用累积距平法、M-K非参数检验、小波分析以及累积量斜率变化率法,分析了临水流域径流量变化特征及趋势,并定量分析降水和人类活动对临水流域径流变化的影响程度。结果表明临水流域径流量年内变化为单峰型曲线,径流量的季节差异较大;年径流量呈下降趋势,但变化趋势都不明显;径流量变化的突变年份为1984年和2002年;年径流量存在7 a和14 a周期变化,其中14 a周期振荡最显著;相对于基准期AR(1979—1984),BR(1984—2002)和CR(2003—2008)时期降雨对径流的降水变化对径流变化的贡献率分别为75.5%和59.92%,贡献率均在59%以上,说明降雨是导致临水流域年径流量减少的主导因素。随着社会经济的发展,人类活动对径流变化的影响也逐渐显现出来。     

赣江上游潋水流域径流变化特征及其驱动力分析

基于赣江上游潋水流域东村水文站1980～2010年的逐月、逐年降水和径流数据,结合M-K趋势检验、累积距平法和双累积曲线法系统分析了潋水流域降水量和径流量的年内分布特征、年际变化趋势及其突变点以及流域径流量变化的主要驱动因子.结果 表明:潋水流域多年平均降水量和径流量分别为1604.8mm和6.53×108m3,降水量和径流量在年内均呈单峰型,主要集中在3～8月,分别占年降水总量和年径流总量的72.43％和75.93％;受人类活动的影响,虽然流域降水量在年际间呈不显著的波动增加趋势,但径流量呈不显著的波动减小趋势,且径流量在1984、1991和2002年发生突变;径流的年际变化受降水和人类活动的共同影响,降水的影响由59.05％下降到45.45％,人类活动的影响又由40.95％增加到了54.55％,表明水土流失治理初期流域径流变化主要受降水的影响,而随着植被的恢复,人类活动的影响越来越大.研究结果可为赣江上游流域水土流失的治理及水资源的合理利用提供理论和实践依据.     

河南省卫河流域降水径流演变规律分析

根据河南省卫河流域1956-2012年的降水、径流资料,运用Mann-Kendall法、径流差积曲线、双累积曲线法对降水、径流的年际变化趋势、突变特征及相关性进行了分析。结果表明:河南省卫河流域的降水量和径流量在1956-2012年期间呈现递减的变化趋势,径流量的下降趋势较降水更为明显;期间降水量发生多次突变,径流量在1978年发生一次突变,两者的变化过程并不完全同步;降雨径流关系的突变发生于1979、1980年前后,1980年前后的降水径流关系存在较大差异。     

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.     

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.     

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.     

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．     

Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.     

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。