博斯腾湖水位变化特征及其可能影响机制分析

应用开都河下游大山口水文站径流和博斯腾湖1956-2009年的逐月水位数据和流域内各气象站的气象数据,通过模糊聚类等统计方法,分析了博斯腾湖水位变化趋势及其可能影响因子.结果表明:博斯腾湖的水位年际变化受开都河流域径流的影响很大,当开都河流域径流量大时博湖水位较高,且开都河径流与其上、下游气温和降水关系密切.博斯腾湖水位逐年的月变化基本上可以分为5类,其中最主要的为第一类型和第二类型:第一类为递减型,特征为季节变化不明显,水位在春季较高,以后逐渐降低;第二类为递增型,特点是季节变化较第一大类明显,水位在夏末秋初的时候较高,整体呈现上升趋势.递增、递减型出现的主要原因是受上下游降水和大山口径流的影响,当上下游降水和径流偏多时水位月际变化出现递增型,反之易出现递减型.     

黄河上游和源区气候、水文的年代际变化及其对华北水资源的影响

利用我国气象观测站1951~2000年降水、气温资料以及黄河上游有关水文测站1960~2003年的径流资料,分析了黄河上游和源区气候的年代际变化及其对径流变化的影响,并分析了黄河上游径流变化对华北水资源的影响。分析结果表明:黄河上游和源区降水从20世纪90年代有所减少,气温明显上升,导致了黄河源区和上游径流量锐减。黄河上游径流的减少是90年代黄河下游流量锐减、黄河断流天数增多的重要原因,并表明了黄河上游来水量的多少是影响华北地区水资源的重要原因。     

The impact of changing environments on the runoff regimes of the arid Heihe River basin, China

This study analyzed the inter- and inner-annual variations of discharge regimes in the upper and mid reaches of the Heihe River basin. These variations then correlated with temperature and precipitation variations in the area. The differences between the runoff regimes at the upper and mid reaches were compared, and the human impacts on discharge variations in the Heihe River were discussed. The results indicate that in the upper reaches, the long-term trends and periods of discharge and precipitation correlate well. In the mid reaches, the discharge and temperature trends correlate well, and the short discharge and precipitation periods correlate well. Precipitation increases would generate more runoff in both the upper and mid reaches, but the effects of temperature increases on discharge are different in the upper and mid reaches. Temperature increases would enhance the glacial ablation processes and increase runoff in the upper reaches. However, temperature increases would increase the evaporation and decrease runoff in the mid reaches. After the 1980s, higher temperature enhanced snow and glacial melt, and increasing precipitation increased the discharge in the upper reaches. Although increasing precipitation increased some discharge, great human activities caused a notable discharge decrease in the 1990s in the mid reaches, especially during the spring to autumn when large amounts of water resources were used for irrigation. In summary, both precipitation and temperature impact the availability of water resources in the study area, and active and effective adaptation strategies should be developed to improve the efficiency of water resource exploration and to prevent the desertification processes in the arid Heihe River basin.     

全球变化下澜沧江-湄公河流域水量平衡模拟

流域水文模型是区域水资源评价的重要工具,基于普林斯顿全球气象驱动数据集和澜沧江-湄公河流域（简称：澜湄流域）八个水文站实测资料,分析了澜湄流域不同区间的水文特性,采用RCCC-WBM模型（Water Balance Model developed by Research Center for Climate Change,RCCC-WBM）开展了区间径流及水量平衡模拟研究。结果表明：1）澜湄流域不同区间气候水文差异显著,上游气温低且年内变幅大,下游气温高年内变幅小;尽管不同区间降水、径流的年内分配特征总体一致,但径流的年内分布峰值大多滞后降水峰值一个时段。2）RCCC-WBM模型能够较好地模拟出澜湄流域不同区间的径流过程,率定期和验证期的月径流模拟效率系数（Nash-Sutcliffe Efficiency,NSE）均在60%以上,总量模拟误差（Relative Error,RE）也均控制在±10%以内,模型具有较好的区域适应性。3）模拟的土壤含水量都具有先衰减后增加再衰减的年内分配特征;不同季节径流和蒸发耗散的水源不同,降水是汛期水分耗散的主要来源,而土壤含水量是非汛期径流和蒸发消耗的主要水源。     

Seasonal variations of oceanic conditions near the southeastern coast of Sakhalin Island

Seasonal variations of hydrological conditions in the area adjoining the southeastern coast of Sakhalin Island are described based on the analysis of monthly mean temperature and salinity obtained over standard oceanic sections Makarov-Cape Georgii and Cape Svobodny-the sea and from nine oceanic surveys. The Poronai River runoff that promotes the formation of a warm surface layer with low salinity largely influences the water area of Terpeniya Bay in the northern part of the area studied. In spring, these waters primarily spread southward along the coast; in summer, they flow southeastward, forming a weak vortex structure at 144° E. In the fall, major changes occur below 20 m, where waters of the cold intermediate layer are replaced by warmer waters (4–6°C) of low salinity connected with the Amur River runoff. The destruction of the CIL core near the shelf edge at depths of about 100 m resulting from the fall intensification of the East Sakhalin Current is pronounced in the southern, abyssal part of the region. The coastal area is covered by waters with salinity below 32‰ connected with the Amur River runoff. The volume of low-salinity waters coming through the Cape Svobodny-the sea section into the southern part of the Sea of Okhotsk is estimated at 3000 km³ taking into account instrumental measurements of flow rates.     

Relations of lower atmosphere wind dynamics to synoptic conditions and weather phenomena

Nonperiodic vertical and temporal variations in wind direction in the lower 500-meter air layer related to synoptic conditions are studied using the long-term data of acoustic remote sensing by the MODOS sodar at Moscow State University. Average values of wind shear to the right (clockwise) with time as a result of the passage of atmospheric fronts are 55° for cold fronts, 40° for warm fronts, and 45° for occlusion fronts. In some cases the clockwise wind shear may reach 180° per 30 minutes and 720° per several hours. The wind shear to the left with time is usually observed if the northern periphery of anticyclones or the ridge axis pass by. It takes more time than the clockwise wind shear does. Dramatic variations in wind direction with height including synchronous opposite air flows at different heights are observed in the zones of fronts, axes of ridges and troughs (if they are inclined), and cols. The vertical wind shear may reach 250° in the lower 300-meter air layer. Thunderstorms in Moscow are usually accompanied by the average wind speed increase by 1 m/s during 30-40 minutes after their beginning.     

Peculiarities of seasonal variations of atmospheric aerosol concentration in the surface air of Moscow environs

The seasonal variations of the concentration of particles of different sizes in the atmospheric surface layer are studied on the basis of the data of daily measurements of atmospheric aerosol characteristics in the town of Dolgoprudny (20 km from the center of Moscow) carried out in 2006–2009. It is revealed that the steady variations of monthly mean aerosol concentration are observed within the particle diameter interval of 0.02–1 μm. The annual course of concentration of these particles has two maxima, in February-March and in September–October, and one minimum in June. The concentrations of particles with the size of 0.01–0.02 μm defined by the general atmospheric background and the concentrations of particles of >1 μm associated with the local sources do not have clearly pronounced seasonal variations. It is shown that the regularities of the annual concentration variations of particles with the size of 0.02–1 μm are mainly explained by the sign and value of the lapse rate in the layer up to 925 hPa that indicates the prevalence of the vertical mixing in the processes of aerosol scattering in the surface layer as compared with the horizontal transfer.     

Variations in climatic and hydrological parameters in the Selenga River basin in the Russian Federation

The variations in average annual surface air temperature, precipitation, and runoff in the Selenga River basin (within Russia) are analyzed. It is demonstrated that the considerable increase in average annual temperature of surface air layers occurred in the 1980s-1990s. The decrease in peak water discharge in the rivers and the increase in the frequency of low-water periods were revealed in the forest-steppe and steppe zones of the Selenga River basin in 2001-2010. In the southwestern mountain regions (the Dzhida River basin) the river runoff increased during that period.     

Changes in Components of the Water Balance in the Croatian Lowlands

Summary ?This paper deals with variations and trends in some components of the water balance: the soil water content; evaporation loss from the soil (from the surface and underlying layers); transpiration; ground water recharge and runoff. These components are calculated by means of the Palmer procedure. This analysis is based on data from Osijek, Croatia from this century (1900–1995). Besides the meteorological input parameters necessary for the water balance calculations, i.e. precipitation, temperature and relative humidity, the pedological characteristics of this area have also been taken into account. Fluctuations have been considered by means of the 11-year binomial filtered series and linear trends were tested by means of the Mann-Kendall rank test. For a closer look on the trends of water balance components, a progressive analysis of the time series was performed, too. The results show a significant increase in potential evapotranspiration and evapotranspiration and decrease in runoff and soil water content has occurred during the century. Received February 22, 1999/Revised August 3, 1999     

Wind regime in the lower atmosphere over Moscow from the long-term acoustic sounding data

Presented are the results of the sounding of the lower atmospheric 500-meter layer for the period of 2004–2012 carried out at the Meteorological Observatory of the Moscow State University (MSU) with the MODOS Doppler acoustic radar (sodar) produced by METEK (Germany). Discussed is the methodological basis of the sodar wind data analysis. It is demonstrated that in the air layer up to 200 m the maximum values in the annual course of the wind speed are observed more often in autumn and winter, and the minimum values, in summer; this is associated with the fact that during the cold period of the year Moscow is often located in the zones of intense gradient currents. The diurnal course of the wind speed is characterized by the daytime maximum and night-time minimum in the layer up to 40–60 m from the surface; it is poorly pronounced and characterized by the minimum in the morning in the layer of 80–120 m; and the daytime minimum and night-time maximum are observed above 140–160 m. The layer from 80 to 120 m approximately corresponds to the height of the wind rotation. The amplitude of diurnal variations of the wind speed increases from 0.3 m/s at the height of 7 m and 0.6 m/s at the height of 15 m, to 4.5 m/s at the height of 400 m; however, its secondary minimum (0.5 m/s) associated with the rotation height is registered at the altitude of 80 m. The statistical relationship between the wind speed and surface air temperature is direct during the cold season, inverse during the warm season, and is absent in April and October. The average maximum wind speed over Moscow for ten minutes in the layer up to 500 m from the surface reaches 30–35 m/s in some cases if two conditions concur: the capital is located on the periphery of vast pressure formations (usually of deep cyclones) and the local low-level jet stream is present in the wind profile.     

Present-day variations of the minimum runoff of the Volga basin rivers

Carried out is the analysis of stationarity of minimum runoff series in summer and winter for the Volga basin rivers. Two conditionally homogeneous periods are singled out within the temporal variations of these characteristics, and the date of their change varies throughout the territory of the basin. The considerable rise in air temperature in winter on the whole territory of the Volga basin is demonstrated as a result of the analysis of meteorological parameters. The relationship between runoff variations and wintertime temperature variations is proposed for predicting the minimum runoff. The distribution of minimum values of runoff is computed using this dependence and the forecast method based on the sum of distributions.     

长江流域水分收支以及再分析资料可用性分析

首先利用实测资料定量计算了长江流域水分收支的各分量,包括降水、径流、蒸发、水汽辐合等,分析其季节循环、年际变化以及线性趋势变化。结果表明,多年平均该流域是水汽汇区,主要来自平均流输送造成的水汽辐合,而与天气过程密切相关的瞬变波则主要造成流域的水汽辐散。蒸发所占比例接近于径流,对流域水分循环十分重要。大部分要素的季节变化和年际变化都很大,只有蒸发和大气含水量的年际变化较小。降水和平均流输送造成的水汽辐合一般在6月达到年内最大,12月达到年内最小,而径流和大气含水量则一般滞后1个月于7月达到年内最大,1月降为年内最小。1958—1983年,夏半年降水略微增加,冬半年略微减少,各月实测径流为弱的增长趋势,但均不显著,年平均蒸发亦无显著的趋势变化。然后将实测资料同ECMWF及NCEP/NCAR再分析资料作进一步对比分析,以检验两套再分析资料对长江流域水分循环的描述能力。在量值上,NCEP/NCAR再分析资料中的降水、蒸发、径流均比实测偏大很多,大气含水量及由平均流输送所造成的水汽辐合则偏小很多;ECMWF再分析资料中的降水量、径流量基本上与实测接近,蒸发量偏大,大气含水量及由平均流输送所造成的水汽辐合偏小,但比NCEP/NCAR再分析资料要接近实测。另外,该两套再分析资料均可以较好地描述长江流域水分收支的季节循环和年际变化,而且同样是ECMWF再分析资料与实测资料的一致性更好。但是两套再分析资料在1958—1983年均存在十分夸张的线性趋势变化,尤其是ECMWF再分析资料。     

黄河源区径流减少的原因探讨

分析了黄河源区1960~2000年气候变化特点,对蒸发进行了估算,并分析了植被和冻土的变化,对径流在20世纪90年代后明显减少的原因进行了探讨。结果表明,黄河源区气温在20世纪80年代中期后明显增加,降水在90年代偏少,气候向暖干方向发展,但蒸发变化不大,径流减少的直接原因是降水的减少;在90年代后降水强度的减弱也可能是径流减少的重要原因;归一化植被指数(NDVI)数据显示植被在90年代后期呈现退化的趋势,冻土在80年代以后表现出的明显的退化趋势,植被冻土的退化可以使得冻结层上水位下移,土壤水向土壤下层的渗漏增加,也会造成径流的减少。     

大规模城镇化对黄淮海地区气候及水资源影响的数值试验

黄淮海地区是我国传统的农耕区,也是经济快速发展、城镇化进程快速推进的区域之一,使得该地区植被覆盖发生了明显变化。为研究城镇化对气候与水资源的影响,应用RegCM3区域气候模式,通过控制试验和敏感性试验,在保证积分时间（2001-2005年）的情况下,输出降水、蒸发、温度、湿度、土壤水分、径流、整层水汽含量等资料,利用敏感性试验和控制试验输出量的差值,来分析黄淮海地区城镇化对气候和水资源要素的影响情况。结果表明,城镇化对研究地区气候及水资源造成的影响主要表现在使局地风场减弱、降水减少、地面气温增加、空气湿度减小、水资源总量减少、土壤含水量减少和地表径流增加等方面,从而对气候和水资源造成影响。     

River Runoff Effects on the Coastal Water Transparency in the Western Black Sea

Using the data of long-term observations of the Secchi disk visibility depth and water salinity (1947-2000) and satellite monitoring of chlorophyll a concentration (1978-1986), their seasonal spatial distributions and intraannual variability in the coastal waters of the western Black Sea are considered. The estimates of seasonal variations are obtained for the coastal zone of the sea. A good agreement is demonstrated between intraannual variations in the salinity of transformed river water, chlorophyll a concentration, and transparency in the areas where these waters propagate. We studied the effects of the Danube River runoff and transformed river water on the phytoplankton development and chlorophyll a concentration which largely define water transparency.     

黄河源区径流量变化特征及其影响因子研究进展

近年来黄河源区径流的锐减,对下游水资源和经济造成了一定的威胁。本文对近年来黄河源区径流量变化特征及其影响因子的研究进行了概述与总结,结果表明近年来黄河源区径流量年内单、双峰分布形式不均,年际、年代际丰枯变化频繁,最长也只有4~5年的周期,且枯水年持续时间多于丰水年。影响源区径流量的主要气候因子是降水,降水的增加使得径流量增加,温度升高,蒸发量加大,使得径流量减少,同时人为因素造成植被覆盖减少,沙漠化加剧,破坏了源区生态环境,对径流量减少也起到很大的作用;根据以往研究总结指出,应更加关注径流量年内单、双峰分配形式变化特征及高原局地热力性质和环流场(如地面感热、高原季风等)对于径流量的影响,同时还应加强分析自然和人为因子对于径流量减少的定量贡献。      

Towards closing the vertical water balance in Canadian atmospheric models: Coupling of the land surface scheme class with the distributed hydrological model watflood

Abstract

Second generation land surface schemes are the subject of much development activity among atmospheric modellers. This work is aimed at, among other things, improving the representation of the soil water balance in order to simulate, more properly, exchanges with the atmosphere and to permit the use of model output to generate streamflow for model validation. The Canadian development program is centred on CLASS, the Canadian Land Surface Scheme, developed at Environment Canada. This paper focuses on the improvement of hydrology in CLASS. This was accomplished by designing a two‐way interface to WATFLOOD, a distributed hydrologic model developed at the University of Waterloo. The two models share many features, which facilitated the coupling procedure.

The interface retains the three‐layer vertical moisture budget representation in CLASS but adds three horizontal runoff possibilities. Runoff from the surface water follows Manning's equation for overland flow. Interflow is generated from the near‐surface soil layer using a parametrization of Richard's equation and base flow is produced by Darcian flow from the bottom of layer 3. An approximation of the internal topography of grid elements is used to supply horizontal gradients for the runoff components.

Tests are in progress in four Canadian study areas. Initial results are presented for the summer of 1993 for the Saugeen River in southwestern Ontario. The new scheme produces realistic hydrographs, whereas the old scheme did not. Bare ground evaporation is reduced by about 17% as a consequence of reduced water availability in layer 1. Evapotranspiration is not affected because the rooting depth extends into layer 3, in which soil moisture does not change appreciably with the new scheme. These results suggest that the new scheme improves the representation of streamflow in WATFLOOD/CLASS and of the soil moisture budget in CLASS. Work is in progress to validate this result over basins, such as the BOREAS study watersheds, where both runoff and evapotranspiration measurements are available.     

松花江、辽河流域实测径流的变化趋势及其与降水的关系

利用松花江、辽河流域内132个降水测站1961-2000年40年的月降水资料,以及水文测站哈尔滨、江桥、铁岭1956-2000年45年的月实测径流量资料,分析松花江、辽河流域实测径流的变化趋势,并探讨夏季径流与同期降水的相关性。结果表明：松花江流域的年实测径流量呈现较微弱的下降趋势,而辽河流域年实测径流呈现显著的下降趋势;两流域径流量均存在着一致的阶段性丰枯周期变化;最显著的一次波动是夏季实测径流由20世纪60年代中后期呈现的显著下降趋势转为80年代初期的明显上升趋势;降水是影响松花江、辽河流域夏季实测径流的一个重要气候因素。初步揭示了人类活动、下垫面改变对实测径流的影响。     

GRAPES NOAH-LSM陆面模式水文过程的改进及试验研究

土壤含水量的计算影响着陆面过程的能量平衡和水量平衡,是陆面模式的核心计算要素之一。目前,GRAPES_Meso模式采用的NOAH-LSM(Noah-Land Surface Model)陆面模式既不能有效地表达径流产源面积的变动情况,也不能完整描述水文循环过程。本次试验针对以上问题对其进行了改进:(1)加入蓄水容量曲线,考虑网格内产流面积的变化及土壤含水量的不均匀性;(2)加入汇流模式,以考虑水平二维水分再分配,提高模式对径流和流量模拟能力。选取2008年8月至9月降水进行模拟试验,研究陆面水循环过程对近地面气象要素的影响。结果表明:改进后的模式模拟土壤湿度、2 m温度等近地面气象要素更接近观测值,并最终对降水量以及降水落区也产生了一定的影响。