精河径流与降水变化特征及响应

利用精河山口水文站近50a的气象、水文资料,采用相关分析法,对精河近50a的降水和径流的变化特征以及径流对降水的响应进行了相关性分析。结果表明:精河流域的径流对降水具有很好的响应关系,二者趋势相近。精河流域降水在20世纪70年代出现减少过程,这期间河川径流量也显著减少;80年代以后流域的降水、径流变化主要呈增加趋势。     

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。     

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;夏季径流量和降水量占到全年比例的40%左右,其他3季分配较少,春季和夏季的径流降水峰值呈现出了很强的同步性;年径流、年降水量变化的第一周期时间尺度分别为18 a、16 a,二者共同的周期尺度为6 a,在时间尺度上降水变化影响径流变化。     

近48年区域气候变化对精河地表径流的影响分析

利用精河源流区近48年的降水、气象以及径流数据,借助非参数检验、小波分析、周期性叠加趋势模型等方法分析了精河流域气候因子及年径流量的变化趋势以及气候因子对径流影响量分离。结果表明:①在未来的50年气温、降水以及径流量仍将保持原来增加的趋势。②在年际变化上,年气温、降水量和径流量均存在11、14、16年的变化周期。③利用周期性叠加趋势模型对源流来水量进行模拟和预测,1998-2008年气候变化对径流量的影响是积极的,分离出近10年气候变化对径流量的影响量知降水量变化对精河径流影响更突出。     

降水和人类活动对乌江上游径流变化的影响分析

径流量变化与气候和人类活动密切相关,其相互作用使得流域水循环发生变化,对气候变化和人类活动进行定量分析,可为流域调控水资源效率、协调农业发展等提供参考。以乌江上游为例,基于鸭池河水文站和流域内及周边共12个气象站,根据1960-2013年长时间序列实测径流与气象资料,利用Mann-Kendall法、累积距平法判断流域降水量和径流量的突变时间,用Morlet小波法对径流量进行周期变化分析,重点分析乌江上游流域降水与人类活动对径流量变化的贡献率。结果表明:1960-2013年间,径流量与降水量无显著增加趋势;径流量和降水量在此期间存在1986和2002年两个突变点,且突变特征和阶段特征同步;径流量与降水量的共振周期为18～19 a及19～20 a,流域径流量对降水量变化具有一定滞后作用,滞后时间为1～2 a;以1960-1986年为基准期,1987-2002年降水和人类活动对径流的贡献率分别为50.93%和49.70%,2003-2013年降水和人类活动对径流的贡献率分别为49.30%和50.70%。降水对径流变化的影响程度在降低,而人类活动对径流变化的作用在增大,因此,未来流域水资源管理应重视良性人类活动的构建与调控。     

南四湖流域水循环要素的时空变化特征

选取南四湖流域鱼城、孙庄等8个监测站点,利用其1952-2015年的实测水文数据,采用Mann-Kendall非参数检验和Morlet小波变换等分析方法,分析了流域降水、径流、蒸发等水循环要素变化时空特征,研究结果表明:(1)流域降水量呈现增加趋势,径流量和蒸发量呈减少趋势;各水循环要素的年际变化周期都有多种时间尺度相互嵌套,降水量和蒸发量的主周期为25a,径流量的主周期为31a;水循环要素的年内分配不均匀,降水量集中在6月-8月,径流量的峰值较降水量滞后1个月,蒸发量的最大值出现在6月份;(2)空间分布不均匀,表现为降水由东南向西北方向递减趋势,径流深的空间分布格局吻合于降水;湖东区域水循环要素的变化大于湖西区域;(3)流域水循环要素的时空变化特征受到气候变化和人类活动的共同影响。     

博尔塔拉河径流与降水的集中性及关联性分析

利用1964-2012年艾比湖流域博尔塔拉河径流、降水数据,运用非参数检验、集中度、小波分析等方法研究了博尔塔拉河年径流量与降水量的集中性及多时间尺度相关关系。研究表明:博尔塔拉河年径流量及降水量均通过Mann-Kendall趋势检验,全年增加显著。通过Mann-Whitney突变检验,径流量与降水量分别在1996年和1985年发生了显著的增多突变。博尔塔拉河径流量集中度呈不显著的增加趋势,降水量集中度呈不显著的减少趋势。博尔塔拉河径流量的集中度存在6、11和14a的周期变化,而降水量集中度存在12和18a周期显著。博尔塔拉河年径流量与降水量存在多时间尺度的显著相关关系,并以正相关为主。     

寇河流域径流变化及其影响因素分析

采用线性回归分析法、Morlet小波分析法、Spearman相关法和降水-径流双累积曲线法,分析寇河流域1965-2012年间降水和径流的年际变化特征。结果表明:寇河流域降水与径流年内分配不均,降水主要集中在6-8月,径流主要集中在7-9月;年降水量和年径流量都呈增加趋势,相对降水而言,年径流序列年际变化更大一些;年降水和年径流变化的第一主周期分别为17年和15年,第二主周期均为7年;径流量变化的主要影响因素是降水,其次是下垫面变化。     

金沙江流域径流变化特征及成因

基于金沙江流域近 60?a 的降雨和径流资料,采用水量平衡法对天然径流量进行还原,利用 Mann-Kendall 法 及小波分析方法研究流域降雨量及天然径流量的变化趋势、周期及可能突变的年份,分析天然径流的变化原因, 构建天然径流量与降雨量及归一化植被指数的相关关系式。结果表明：金沙江流域降雨量和天然径流量总体呈 周期性变化,主周期均为 28?a,与此同时降雨量和径流量均呈增加趋势,降雨量每 10?a 相对增长幅度约 1.28%,天 然径流量每 10?a 相对增长幅度约 0.57%;造成两者相对变幅差异较大的原因源于流域植被覆盖面积的增加;考虑 降雨及植被的综合影响,建立的天然径流与两者共同作用下的方程相关系数为0.940,其关系式为R=0.017?7P 1.691/N ?0.923。 研究成果可为金沙江流域水电开发和综合治理提供决策参考。     

淤地坝和植被变化对渭河流域水沙情势的影响

以渭河咸阳站以上区域为研究区,利用1965年～2016年的水沙长序列实测资料,分析了不同时间尺度上水沙的变化趋势、突变点、周期特征和空间分布,探讨了覆被变化和淤地坝对流域水沙变化的影响。结果表明,径流量和输沙量下降趋势极显著,减水减沙趋势有很强的持续性;20世纪90年代是水沙突变和剧变的时期;在年内分配上输沙量比径流量更集中,沙峰较洪峰提前;水沙主要来自武山和秦安站以上流域;不同年代的降水径流关系和水沙关系发生了很大变化,径流对降水的响应逐渐减弱,输沙量递减;植被覆盖度显著增加,总体与水沙变化呈负相关,2000年后植被覆盖度与径流变化呈正相关。     

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.     

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.     

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.     

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.     

Serial discontinuities in a Rocky mountain river. II. Distribution and abundance of trichoptera

River regulation in the headwaters and middle reaches of the Gunnison River, Colorado, significantly altered distributions and abundances of Trichoptera fauna. Twenty-five species were collected from mainstream samples, with the greatest species richness occurring at an unregulated, rhithron segment above the central reach dams. At sites immediately below the three hypolimnial-release dams and a reregulation dam, species richness was reduced 35–90 per cent and abundance > 95 per cent. Net-spinning caddisflies were the dominant trichopterans at unregulated sites; Arctopsyche grandis in the upper reaches (218 organisms, 586 mg dry mass m^?2) and Hydropsyche cockerelli, H. occidentalis and Cheumatopsyche pettiti in the lower river (9041 total organisms, 6621 mg m^?2), downstream from the last dam. The observed distributional pattern of low trichopteran densities in dam tailwaters and high hydropsychid densities at sites 60–80 km below the central reach dams is a classic expression of continuum resets and adjustments in response to stream regulation as predicted by the Serial Discontinuity Concept.     

Surveying for Water Resources

Abstract

A professional Land Surveyor (Geomatician) describes the Hydrogeologists' survey requirements of a major water resources assessment for the government of The Sultanate of Oman (1992 to 1996). The need for objective specifications is stated. Specialist terms like geoid, spheroid, Mean Sea Level are explained and how to relate spheroidal levels to the geoid. Methods like traditional survey, satellite survey, and photogrammetry are introduced. The paper encourages coordinated working for the benefit of water resource assessment and recommends employment of the professional land surveyor for major studies.     

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．