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A method of spatial calibration and verification of regional numerical physically based models of river runoff formation, incorporating runoff formation processes in the main river channel and its tributaries, was used to obtain a statistical estimate of the quality of river runoff calculation by conventional and alternative criteria focused on runoff reproduction in different phases of water regime and the characteristics of its variations. The analysis of the simulation quality of the annual and mean monthly river runoff (average runoff, standard deviation, and the coefficient of variation) at the near-mouth gages over the historical period with boundary conditions represented by data of global climate models showed the results to be satisfactory. This allows the proposed combination of climate and hydrological models to be used to study physically based regional variations of water regime under different physiographic and climatic conditions in the examined river basins with flood runoff regime (the Amur R.) and the predominant snowmelt runoff during spring flood (the Lena R.). 相似文献
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The main features of the structure and water regime of the mouth area of the Senegal River and their changes caused by river regulation in its upper reaches and within its delta area are considered. Data on water and sediment runoff of the Senegal River and their variations along the river are specified. River runoff was found to dramatically decrease in recent decades because of a drought. Zoning of river mouth area was carried out, and morphological processes in its estuary, in particular, the formation of a new outlet of the river into the ocean with the formation of a lagoon, are described. 相似文献
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The hydroclimatic conditions of water runoff formation and the hydrography of Parana and Uruguay river basins in the South America are considered. A survey of the recent studies of the hydrological regime of these rivers is given. Observation data are used to evaluate the long-term average values of water runoff and suspended sediment yield in the Parana and Uruguay and their variations along the rivers. Characteristics of many-year runoff variations in the rivers were evaluated. A climate-induced increase was identified in the Parana and Uruguay water runoff, and the corresponding present-day trends in river runoff variations in both rivers were evaluated. The total water runoff and suspended sediment yield of the Parana and Uruguay into La Plata estuary were calculated. Water balance of the drainage basin of La Plata estuary was characterized. 相似文献
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The natural conditions and the anthropogenic factors governing the formation of the environmental-hydrochemical situation in the rivers of the upper part of Ural R. basin are analyzed. Pollution transport is partially taking place under the conditions of hampered water exchange, caused by the structure of river channels and runoff regulation. The study confirms the uneven distribution of heavy metal concentrations in river water in different seasons, which is mostly due to differences in river runoff characteristics. The long duration and the high intensity of anthropogenic impact have considerably weakened the stability of river systems. 相似文献
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西太湖湖滨典型河网区与太湖水量的交换 总被引：1，自引：1，他引：0
以西太湖湖滨典型河网区——宜兴大浦河网区为研究区域,对于该典型河网区与太湖之间的水量交换情况进行了系统的计算研究．考虑降雨因素的影响,采用考虑下垫面分类的产汇流模型,对各计算年内(2002年(基准年)．1998年(丰水年),1995年(平水年),1994年(枯水年))典型河网区及其西部山地区域的降雨径流过程进行了产汇流模拟．建立起适合该河网区域的非稳态河网水量模型,结合径流计算结果,对各年内典型河网区内水流的动态变化进行了计算模拟,对典型河网区与太湖水体的水量交换情况进行系统研究,分别对顺流与逆流情况下交换水量的年内分布与年际变化规律进行了分析． 相似文献
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Specific features of the water balance of river deltas located in different geographic zones are discussed. Variations in the mean long-term water runoff in river deltas are estimated. As revealed, the river water runoff increases in the deltas located in subarctic, subequatorial, and equatorial regions, where precipitation exceeds evaporation, while the river water runoff decreases in deltas located in the temperate zone, subtropics, and tropics, where evaporation exceeds precipitation. It is noted that increase in water runoff is typical of the river deltas of the world as a whole. 相似文献
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ECOMAG software complex was adapted to simulate river runoff in the Amur basin using data from global databases (relief, soils, landscapes). The results of model calibration and verification were used to give a statistical estimate of the efficiency of river runoff calculation over a long period based on standard data of meteorological and water management monitoring. The results of calculations using the developed runoff formation model were used in the space and time analysis of the formation conditions of 2013 flood in the Amur basin. 相似文献
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Three stages were identified in the development of meandering rivers and the formation of floodplains with natural levees
in Northern Eurasia: the development of rivers with size larger than that of the modern ones; the development of rivers smaller
than the modern ones; and the development of rivers of the present-day morphodynamic type. Small oxbows of the second stage
are widespread in the floodplains of lowland rivers in Northern Eurasia. The largest amount of floodplain segments with such
oxbows can be seen in the forest zone, mostly in the coniferous forests of northeastern European Russia. The available radiocarbon
datings show that river channel were significantly decreasing in size and the steepness of meanders was increasing during
the Atlantic period of the Holocene. Data on changes in the size of river channels were used to evaluate the ratios between
paleo- and modern discharges and to construct a map of difference between runoff depths in the Holocene optimum and in the
present and assess changes in water runoff volume. The discharges in the basins of the Vyatka and middle Irtysh accounted
for as little as 40–50% of their current values. North, east, and west from those basins, the ratio of ancient and present-day
discharges increases. During the Holocene optimum, water runoff from the northern megaslope of the East European Plain was
∼180 km3/year, which is 30% less than the present runoff from the same drainage area. The annual runoff in Volga basin was ∼134 km3, which is almost half as large as the present value. The runoff in Don and Dnieper basins during the Holocene optimum was
40% less, and that in the Ob and Irtysh basin was 30% less than the present one. If we accept the hypothesis that the Holocene
optimum was a climate analogue of global anthropogenic warming of the mid-XXI century, the obtained estimates of the state
of water resources in Northern Eurasia acquire great prognostic importance. 相似文献
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The mean annual water runoff and the amount and dynamics of the discharge of the organochlorine pesticides into seas by large rivers of Russia in 1981–2000 are estimated. The main factors governing the formation of the organochlorine pesticide runoff within the river basins located in different physico-geographic conditions are revealed. 相似文献
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R. G. Dzhamalov I. S. Zektser G. N. Krichevets T. I. Safronova L. F. Sotnikova Yu. V. Gromova 《Water Resources》2008,35(1):15-22
Quantitative relationships between groundwater runoff and other water balance components are obtained. These relationships enable the prediction of changes in groundwater nourishment in different natural-geographic zones on the Earth because of global climatic changes and intense anthropogenic impact on the water regime of different areas. Groundwater runoff values (natural groundwater resources) in individual river basins are estimated. Digital maps (grid-models) of the space and time distribution of water balance elements (based on GIS-technology) are constructed for major river basins in European Russia, and river runoff is calculated in each grid node in river basins with a step of 0.1° in geographic coordinates. The values of major water balance components, thus related with one another, serve as the basis for their spatial and temporal analysis and cartographic representation. The proposed method was tested against data on Volga basin where long-term observational data on water balance elements are available in a number of hydrometric sections. 相似文献
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The water balance of four different rainforest types in the Wet Tropics region of north Queensland is inferred from measurements of canopy hydrological components undertaken for periods between 391 to 657 days. These measurements of rainfall, cloud interception, stem-flow, throughfall, canopy interception and transpiration have revealed considerable differences in the canopy water balance of different locations as a result of forest structural differences, altitude, exposure and climate. Cloud interception is a significant extra input of water to forests at high altitude sites (>1000 m) and varies between 7 and 29% of the total water input. At coastal and lower montane rainforests annual total evaporation is consistently around 50% of the total water input, but in upper montane cloud forest this drops dramatically to only 13% of the water input. At all sites actual evaporation is greater than potential evaporation for most of the year and on an annual basis exceeds potential by between 2 and 53%. The source of this additional energy is uncertain, but is likely to come from advection. Annual interception at all the rainforest sites was greater than annual transpiration, with transpiration dominating in the dry season and interception dominating in the wet season. All of the rainforests have a large annual net water balance to sustain runoff and recharge. Towards the end of the dry season runoff and recharge can cease in coastal lowland and lower mountain forests and they may have to draw on soil moisture and/or ground water at this time. In contrast, upper montane cloud forests have a positive net water balance throughout the year and are therefore an important source of dry season river flows. Furthermore, their exceptionally large annual runoff (∼6500 mm year−1) is a major source of downstream water. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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The effect of forests on annual water yield is an unresolved central issue in forest hydrology despite years of study. There has been a particular shortage of research in the mountains of arid inland river basins. In the present study, we examined the effects of forests on hydrology using data on precipitation, evaporation, canopy interception, transpiration, and runoff from 1994 to 2008 for the Pailugou catchment of northwestern China's Qilian Mountains. We modelled the water balance to assess the contribution of different vegetation types to annual water yield. In our study area, Picea crassifolia forest covered 38·5% of the catchment area, but contributed little to annual water yield. For an annual average precipitation of 407·1 mm (from 2003 to 2008) at an elevation of 2700 m, the runoff depth from the forest was 11·6 mm, accounting for only 3·5% of total annual water yield of the catchment. For an annual average precipitation of 374·1 mm (from 1994 to 2002), the runoff depth from the forest was ? 14·3 mm (i.e. 5·9% of total annual water yield of the catchment was consumed to sustain tree growth). This has significant implications, because forests are increasingly being planted in the Qilian Mountains, and this may decrease the downstream water supply. Thus, the relationship between the forest and water yield must be better understood to permit the establishment of an appropriate regional level of forest cover. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
14.
A. V. Frolov 《Water Resources》2011,38(5):583-592
A model of long-term river runoff variations is proposed. The model is based on a difference stochastic equation of water
balance on a watershed. Precipitation and evaporation on the watershed are simulated by stochastic, dependent, non-Gaussian
Markov processes. Long-term river runoff variations are described by a component of three-dimensional non-Gaussian Markov
process. It is shown that the autocorrelation and skewness coefficients for river runoff can be negative. The proposed model
can be used to assess the effect of climate-induced variations in precipitation and evaporation regimes in a watershed on
long-term river runoff variations. 相似文献
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Seasonal variations in water temperature in Selenga Shallow Waters is studied. The contributions of the regimes of waves, river runoff, thermal fronts, and thermobars to the formation of physical structures are assessed. 相似文献
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Based on the methods of O.I. Krestovskii and recent information on the forestry of European Russia, the article offers the assessment of the impact of transformations in the structure of forests in the recent decades on the river runoff and evaporation. The accompanying changes in the runoff are shown to be relatively insignificant; however, in the XXI century they may become more significant and manifest themselves not only at the local but also at the regional level. 相似文献
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The current features of the space and time variations of river runoff in Kamchatka Krai have been considered. Two relatively long cycles have been shown to exist in water runoff variations in the major portion of the examined rivers. The renewable water resources were increasing until 1970–1980, while in the following years (up to 2010), they were gradually decreasing. Current data on river runoff were used to prove the existence of three zonal types of water regime in Kamchatka Krai; five azonal types of annual runoff distribution are characterized. One of them (nearly uniform annual distribution caused by the predominance of groundwater recharge) has been theoretically predicted in the classification proposed by M.I. L’vovich, though without factual confirmation. The specific features of water regime of rivers whose basins lie on the slopes of active volcanoes are considered for the first time. This type of regime typically shows alternating periods of the presence and absence of surface runoff in river channels, corresponding to the inflow of snowmelt or rainfall runoff at high level of subsoil water (when channel deposits are fully saturated with water) or at its low position (when moisture is deficient). 相似文献
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Methods for the analysis of the formation of river water chemistry based on mixing models are discussed. An analytical solution for a mixing model of four recharge sources is given along with the results of its adaptation based on the materials of hydrochemical and hydrological observations over 2013 and 2014 in drainage basins in Primorski Krai. The analysis and calculations revealed four components of river recharge in these years: rainwater, two types of subsoil water, and groundwater, the latter forming the base runoff. The estimates of the mixing model with four sources and its tests showed a high quality of modeling. 相似文献
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The geological and hydrogeological structure of a diamond deposit is considered. Forecasts of the technogenic regime of groundwater and changes in river runoff based on modeling are given. The conditions for the compensation of river runoff losses due to the rational discharge of drainage water are determined. The conditions of salt-water dilution by fresh drainage water are evaluated. The tasks and principles of hydrogeological monitoring are formulated. 相似文献