共查询到20条相似文献，搜索用时 15 毫秒
1.
L. S. Kuchment A. N. Gel’fan V. N. Demidov P. Yu. Romanov 《Russian Meteorology and Hydrology》2011,36(9):630-637
A technique is proposed of precomputing the snowmelt runoff hydrograph on the basis of physical and mathematical models of
river runoff formation, available standard data of surface hydrometeorological measurements, and satellite measurements of
Earth’s surface conditions. The computations were carried out for two regions including the basins of the Vyatka and Don rivers.
It is demonstrated that, in spite of the possible errors and gaps depending on meteorological conditions, the satellite snow
cover measurements can be an important addition to the surface measurements for simulating a spatial picture of the runoff
formation. The use of physical and mathematical models of the runoff formation enables to reduce the errors of satellite snow
cover data and to ensure the spatiotemporal continuity of its monitoring. 相似文献
2.
Arctic environments are generally believed to be highly sensitive to human-induced climatic change. In this paper, we explore the impacts on the hydrological system of the sub-arctic Tana Basin in Northernmost Finland and Norway. In contrast with previous studies, attention is not only given to river discharge, but also to the spatial patterns in snow coverage and evapotranspiration. We used a distributed water balance model that was coupled to a regional climate model in order to calculate a scenario of climate change by the end of this century. Three different model experiments were performed, adopting different approaches to using the climate model output in the hydrological model runs. The results were largely consistent, indicating a much shorter snow season and, accordingly, decreased sublimation, an increase in evapotranspiration, and a shift in the annual runoff peak. As the snow-free season is extended, the amount of solar radiation that is received during this period increases significantly. The results also show important local differences in the hydrological response to climate change. For example, in the scenario runs, the snow season was more than 30 days shorter at higher elevations, but in some of the river valleys, this was up to 70 days. 相似文献
3.
Jaak Jaagus 《Climatic change》1997,36(1-2):65-77
The paper deals with problems of temporal and spatial variability of snow cover duration, of correlation between snow cover and winter mean air temperature patterns and of the impact of climate change on the snow cover pattern in Estonia. Snow cover fields are presented in form of IDRISI raster images. Snow cover duration measured at ca 100 stations and observation points have been interpolated into raster cells. On the base of time series of raster images, a map of mean territorial distribution of snow cover duration is calculated. Estonia is characterized by a great spatial variability of snow cover mostly caused by the influence of the Baltic Sea. General regularities of snow cover pattern are determined. A 104-year time series of spatial mean values of snow cover duration is composed and analyzed. A decreasing trend and periodical fluctuations have detected. Standardized principal component analysis is used for the time series of IDRISI raster images. It enables to study the influence of different factors on the formation of snow cover fields and territorial extent of coherent fluctuations. Correlation between snow cover duration and winter mean air temperature fields is analyzed. A spatial regression model is created for estimation of the influence of climate change on snow cover pattern in Estonia. Using incremental climate change scenarios (2 °C, 4 °C and 6 °C of warming in winter) mean decrease of snow cover duration in different regions in Estonia is calculated. According to results of model calculation, the highest decrease of snow cover duration will be take place on islands and in the coastal region of West Estonia. A permanent snow cover may not form at all. In the areas with maximum snow cover duration in North-East and South-East Estonia, that decrease should be much lower. 相似文献
4.
基于1961-2006年全疆32个测站的逐日积雪深度资料,使用一元线性回归和二项式滑动平均等统计方法,分析了北疆区域积雪开始时间、积雪结束时间、相对积雪期和绝对积雪期的时空变化特征。结果表明,积雪开始时间、结束时间、相对积雪期和绝对积雪期存在明显的区域差异,前3种差异主要是由地形高度变化引起的。积雪开始时间和相对积雪期各测站基本呈上升和下降趋势,积雪结束时间和绝对积雪期趋势变化的空间分布较为类似,伊犁河谷地区呈明显的下降趋势。1995年以后,积雪开始时间呈上升趋势,而积雪结束时间、相对积雪期和绝对积雪期均呈下降趋势。相关分析和合成分析表明,积雪开始时间和相对积雪期及绝对积雪期存在较好的负相关关系,可以通过积雪开始时间的早晚,大致预测相对积雪期和绝对积雪期的长短。 相似文献
5.
利用1989年和1998年NOAA气象卫星资料，提取植被、积雪等信息，分析了十年来祁连山自然保护区植被空间分布状况及其变化特征，研究了祁连山积雪年变化和1989与1998年年代变化特征，结果表明:祁连山保护区主体部分十年来植被退化严重，且退化植被以灌木林和草为主；祁连山区积雪年变化基本特点是呈双峰形，但不同流域积雪的年变化存在一定差异。1998年各流域旬平均积雪面积均较1989年减小，自西向东减小幅度逐渐增大，党河流域减小2.17%，西营河流域减小10.05%。1998年和1989年春季积雪面积相差不大，但冬季积雪明显少于1989年。由于1998年气温明显偏高，使得山区积雪融化速度加快，1998年积雪面积随时间变化振幅加大。 相似文献
6.
A global atmospheric model is used to calculate the monthly river flow for nine of the world's major high latitude rivers for the present climate and for a doubled CO2 climate. The model has a horizontal resolution of 4° × 5°, but the model's runoff from each grid box is quartered and added to the appropriate river drainage basin on a 2° × 2.5° resolution. A routing scheme is used to move runoff from a grid box to its neighboring downstream grid box and ultimately to the mouth of the river. In a model simulation in which atmospheric carbon dioxide is doubled, mean annual precipitation and river flow increase for all of these rivers, increased outflow at the river mouths begins earlier in the spring, and the maximum outflow occurs approximately one month sooner due to an earlier snow melt season. In the doubled CO2 climate, snow mass decreases for the Yukon and Mackenzie rivers in North America and for rivers in northwestern Asia, but snow mass increases for rivers in northeastern Asia. 相似文献
7.
青藏高原冬春雪深分布与中国夏季降水的关系 总被引：2，自引：0，他引：2
利用SSMR和SSM／I卫星遥感雪深反演资料,通过与高原测站雪深观测资料的对比分析,揭示了高原雪深的时空分布特征,在此基础上对积雪异常年中国夏季降水异常和大气环流进行了对比分析。结果表明,卫星遥感雪深资料可较真实反映出高原积雪的状况,并可反映出高原西部积雪的变化;高原冬、春季积雪EOF分解第1模态具有相同的空间分布,反映了高原冬、春季积雪分布具有相当的一致性,而春季积雪的第2模态则反映高原积雪的东西差异;冬、春季雪深EOF第1模态的时间序列与中国夏季降水的相关分析表明,大致以长江为界,我国东部地区呈现出南涝北旱的分布模态,春季高原东（西）部多（少）雪与东（西）部少（多）雪年的夏季,我国东部降水表现出长江以南（北）地区为大范围的降水偏多（少）。 相似文献
8.
C. D. Groot Zwaaftink M. Diebold S. Horender J. Overney G. Lieberherr M. B. Parlange M. Lehning 《Boundary-Layer Meteorology》2014,153(1):117-139
Observations of drifting snow on small scales have shown that, in spite of nearly steady winds, the snow mass flux can strongly fluctuate in time and space. Most drifting snow models, however, are not able to describe drifting snow accurately over short time periods or on small spatial scales as they rely on mean flow fields and assume equilibrium saltation. In an attempt to gain understanding of the temporal and spatial variability of drifting snow on small scales, we propose to use a model combination of flow fields from large-eddy simulations (LES) and a Lagrangian stochastic model to calculate snow particle trajectories and so infer snow mass fluxes. Model results show that, if particle aerodynamic entrainment is driven by the shear stress retrieved from the LES, we can obtain a snow mass flux varying in space and time. The obtained fluctuating snow mass flux is qualitatively compared to field and wind-tunnel measurements. The comparison shows that the model results capture the intermittent behaviour of observed drifting snow mass flux yet differences between modelled turbulent structures and those likely to be found in the field complicate quantitative comparisons. Results of a model experiment show that the surface shear-stress distribution and its influence on aerodynamic entrainment appear to be key factors in explaining the intermittency of drifting snow. 相似文献
9.
黄河流域夏季分区面雨量预报研究 总被引：6，自引：0，他引：6
介绍黄河流域分区夏季面雨量预报的研究成果，精心挑选51个具有较好代表性的测站对黄河流域夏季降水的时空演变特征进行分析，使用K均值动态聚类对黄河流域的夏季降水进行了客观分区，并计算出各流域夏季面雨量。通过对黄河流域夏季雨量与500hPa环流，海温、OLR、中纬阻高，高原积雪，欧亚积雪等重要影响因子的关系分析，结合黄河流域夏季面雨量年降和年代际演变特征的分析，研究出黄河流域分区夏季面雨量预测的基本方法和模型，并通过客观化的数学方法建立黄河流域夏季面雨量预测系统，预测系统十年回报的结果显示出具有较的预测技巧。 相似文献
10.
Soil wetness, in both its global distribution and the seasonal change, has been mainly estimated by the water balance approach
using the bucket model which regards the soil wetness as soil moisture. The soil moisture data of Mintz and Serafini is one
of the representatives examples, however, this method has problems since it does not incorporate the effects of flooding,
snow accumulation on the ground, and so on. In this study, we use the Amazon and Volga river basin to carry out a case study
to evaluate these problems. In the Amazon river basin, the annual range of the entire terrestrial water storage, about 400 mm,
can be mainly explained by the rising and falling of the water level, and flooding around river channels, although soil moisture
data of Mintz and Serafini is almost constant throughout the year. In the Volga river basin, snow accumulates on the ground
producing 80 mm of water equivalent during winter, however the soil moisture data of Mintz and Serafini is almost saturated
in winter.
Received: 30 October 1996 / Accepted: 4 June 1997 相似文献
11.
Assessing the Impacts of Eurasian Snow Conditions on Climate Predictability with a Global Climate Model 总被引：1，自引：0，他引：1 
下载免费PDF全文
下载免费PDF全文 CHEN Hong 《大气和海洋科学快报》2010,3(6):336-341
On the basis of two ensemble experiments conducted by a general atmospheric circulation model (Institute of Atmospheric Physics nine-level atmospheric general circulation model coupled with land surface model, hereinafter referred to as IAP9L_CoLM), the impacts of realistic Eurasian snow conditions on summer climate predictability were investigated. The predictive skill of sea level pressures (SLP) and middle and upper tropospheric geopotential heights at mid-high latitudes of Eurasia was enhanced when improved Eurasian snow conditions were introduced into the model. Furthermore, the model skill in reproducing the interannual variation and spatial distribution of the surface air temperature (SAT) anomalies over China was improved by applying realistic (prescribed) Eurasian snow conditions. The predictive skill of the summer precipitation in China was low; however, when realistic snow conditions were employed, the predictability increased, illustrating the effectiveness of the application of realistic Eurasian snow conditions. Overall, the results of the present study suggested that Eurasian snow conditions have a significant effect on dynamical seasonal prediction in China. When Eurasian snow conditions in the global climate model (GCM) can be more realistically represented, the predictability of summer climate over China increases. 相似文献
12.
V. Yu. Abakumova 《Russian Meteorology and Hydrology》2013,38(8):575-583
Catchments of first-order streams in the Chita River basin in Zabaikal’skii krai are studied in order to reveal the spatial structure of conditions influencing the river network formation. The river network construction was carried out using the TAS GIS (Terrain Analysis System Geographic Information System) software and SRTM (Shuttle Radar Topographic Mission) digital terrain model. The comparison of the TAS river network with the river network of topographic maps enables to reveal the distribution of conditions of river network formation for the territory of the basin as well as the type and degree of their impact on the surface runoff. The obtained data enabled to group the basin streams according to these conditions and to reveal favorable and unfavorable areas for the first-order stream initiation. 相似文献
13.
青藏高原冬春季雪盖对东亚夏季大气环流影响的研究 总被引：17，自引：7，他引：17
通过分析青藏高原积雪的基本特征，指出高原冬春季雪盖在东亚夏季气候形成与异常中的重要作用，同时分别总结了高原冬春季积雪对东亚夏季大气环流影响的诊断研究和数值试验进展，提出了高原冬春季雪盖对气候影响的可能机制。 相似文献
14.
River discharge and freshwater runoff to the Barents Sea under present and future climate conditions
River discharge forms a major freshwater input into the Arctic Ocean, and as such it has the potential to influence the oceanic
circulation. As the hydrology of Arctic river basins is dominated by cryospheric processes such as snow accumulation and snowmelt,
it may also be highly sensitive to a change in climate. Estimating the water balance of these river basins is therefore important,
but it is complicated by the sparseness of observations and the large uncertainties related to the measurement of snowfalls.
This study aims at simulating the water balance of the Barents Sea drainage basin in Northern Europe under present and future
climate conditions. We used a regional climate model to drive a large-scale hydrological model of the area. Using simulated
precipitation derived from a climate model led to an overestimation of the annual discharge in most river basins, but not
in all. Under the B2 scenario of climate change, the model simulated a 25% increase in freshwater runoff, which is proportionally
larger than the projected precipitation increase. As the snow season is 30–50 day shorter, the spring discharge peak is shifted
by about 2–3 weeks, but the hydrological regime of the rivers remains dominated by snowmelt. 相似文献
15.
Over recent years, many numerical studies have suggested that the land surface hydrology contributes to atmospheric variability
and predictability on a wide range of scales. Conversely, land surface models (LSMs) have been also used to study the hydrological
impacts of seasonal climate anomalies and of global warming. Validating these models at the global scale is therefore a crucial
task, which requires off-line simulations driven by realistic atmospheric fluxes to avoid the systematic biases commonly found
in the atmospheric models. The present study is aimed at validating a new land surface hydrology within the ISBA LSM. Global
simulations are conducted at a 1° by 1° horizontal resolution using 3-hourly atmospheric forcings provided by the Global Soil
Wetness Project. Compared to the original scheme, the new hydrology includes a comprehensive and consistent set of sub-grid
parametrizations in order to account for spatial heterogeneities of topography, vegetation, and precipitation within each
grid cell. The simulated runoff is converted into river discharge using the total runoff integrating pathways (TRIP) river
routing model (RRM), and compared with available monthly observations at 80 gauging stations distributed over the world’s
largest river basins. The simulated discharges are also compared with parallel global simulations from five alternative LSMs.
Globally, the new sub-grid hydrology performs better than the original ISBA scheme. Nevertheless, the improvement is not so
clear in the high-latitude river basins (i.e. Ob, MacKenzie), which can be explained by a too late snow melt in the ISBA model.
Over specific basins (i.e. Parana, Niger), the quality of the simulated discharge is also limited by the TRIP RRM, which does
not account for the occurrence of seasonal floodplains and for their significant impact on the basin-scale water budget. 相似文献
16.
基于GIS的浙江省积雪遥感监测与评估研究 总被引：1，自引：0，他引：1
针对2008年初浙江省遭受的持续性大范围低温雨雪冰冻天气,利用MODIS数据,综合运用遥感和地理信息系统技术对积雪的发生、发展和消融特征进行深入研究,在探讨云和积雪区分关键技术的基础上,建立积雪指数模型提取积雪专题信息,对积雪覆盖进行动态监测,同时利用DEM分地区分析各海拔高度带的积雪覆盖情况,探讨其消融变化特征,最后用雪灾前后△NDVI的方法结合地面实地调查,对林区进行灾情初步评估。研究结果表明,积雪的消融大致呈负指数减少趋势,起初各海拔高度带积雪覆盖比例呈中间多两头少的特征,即海拔300～900 m的中等海拔高度上积雪覆盖率较高,达70%以上,在300 m以下及900 m以上海拔高度带积雪覆盖率为50%左右,随着积雪的慢慢消融,各高程带间的积雪面积差逐渐减小,消融速度较之前明显减缓,表现出较稳定的下降趋势后再继续融化的特点,至2月16日,积雪覆盖比例与高程带呈正向一致性,即海拔越高,积雪覆盖越大,2月17日海拔500 m以下积雪已基本消融,20日700 m以下积雪基本消融,至2月29,全省基本无积雪。林区受灾的严重程度主要与积雪覆盖时间及林区海拔高度有关。利用遥感和地理信息系统技术在南方开展雪情分析、动态监测及灾后评估工作,对地方防灾减灾具有重要的指导意义。 相似文献
17.
亚洲季风模拟试验中青藏高原积雪强迫问题的讨论 总被引：10，自引：3，他引：10
青藏高原积雪对亚洲季风和东亚，南亚时旱涝灾害的影响，百余年来一直为中外气候学家所瞩目。近几年来用大气环流模式进行数值试验已成为该研究领域的主要手段，但是由于假设的积雪强迫不同，模拟结果很不一致。作者概据美国宇航局ＳＭＭＲ微波逐候积雪深度１０年的观测结果，提出了一个真实的青藏高原积雪强迫试验方案。 相似文献
18.
黑河流域生态环境气象卫星遥感监测研究 总被引：13，自引：6，他引：13
根据甘肃降水资料和农业气象资料得出1989年和1998年为相似年景，利用1989年和1998年NOAA气象卫星AVHRR晴空资料，判识出黑河流域植被，积雪和水体，并根据相应的计算方法得出植被指数，积雪面积和水体面积，对10年来黑河上游地区的植被和积雪，中游地区绿洲植被和下游地区植被和湖泊变化进行分析。结果表明，10年来黑河上游和下游地区植被在退化，中游地区绿洲面积增加，植被指数增高；1989年与1998年黑河上游山区积雪面积变化特征一致，但1998积雪融化明显快于1989年；下游湖泊面积1998年较1989年严重退缩。 相似文献
19.
该文首先回顾了有关中国冬季积雪的研究进展,包括中国冬季积雪的空间分布气候特征以及季节、年际和年代际变化,中国冬季降雪特征,气象因子对中国冬季积雪水量平衡的影响,外强迫和大气环流系统在积雪形成中的作用等。冬春季欧亚大陆积雪对同期和后期中国气候影响的相关研究说明与欧亚大陆积雪异常相关联的中国气候异常以及积雪通过改变土壤湿度、表面温度和辐射分布,引起大气环流异常,进而对中国气候产生影响的物理过程。应用美国环境预测中心 (NCEP) 第2版气候预测系统 (CFSv2) 的回报试验结果,对CFSv2在欧亚大陆积雪变化及其与中国气候关系的可预报性方面的分析表明,CFSv2能够较好地回报出春季欧亚积雪的年际和年代际变异及其与中国夏季降水之间的联系。文章最后提出了在积雪及其气候效应研究方面一些有待解决的问题。 相似文献
20.
Yu. G. Motovilov 《Russian Meteorology and Hydrology》2017,42(2):121-128
The potential of the model approach to the construction of mean annual fields (maps) of specific runoff for large territories from meteorological data is demonstrated for the Lena River basin. The ECOMAG (ECOlogical Model for Applied Geophysics), the physically based distributed model of river runoff formation is used to simulate hydrological parameters. Methodological aspects of calibration of the spatial fields of model parameters are discussed. The results of runoff hydrograph calculations are compared with the data of hydrometric observations at 12 gaging stations for the period of 1966-2009. The field of mean annual specific runoff in the Lena River batin computed with the ECOMAG model is compared with the map of specific runoff constructed from the data on water discharge in the river network. The comparative analysis of consistency between the fields is provided, and the possible sources of errors are considered. 相似文献