Long-term changes of river runoff in the Transbaikal region during wet and dry periods

2013 ◽  
Vol 450 (2) ◽  
pp. 676-678 ◽  
Author(s):  
V. A. Obyazov
2021 ◽  
pp. 98-104
Author(s):  
G. KH. ISMAIYLOV ◽  
◽  
N. V. MURASCHENKOVA ◽  
I. G. ISMAIYLOVA

The results of the analysis and assessment of long-term changes in the qualitative characteristics of the Oka River runoff are presented. To analyze the temporal dynamics of the variability of the average annual and maximum concentrations of pollutants in the runoff of the Oka River, we used long-term observational data on typical pollutants for the period 1984-2019. The assessment of the state of the quality of surface waters of the Oka River was carried out according to the values of the concentrations of pollutants in the upper, middle and lower reaches of the river. The dynamics of the main pollutants of the following indicators is considered: ammonium nitrogen, oil products, copper and zinc compounds and easily oxidized organic substances. It was found that in the upper reaches of the river (according to observations of the Oka – Orel city) the main pollutants are ammonium nitrogen and copper compounds, the average annual concentrations of which respectively increased to 9 values. A similar situation was observed downstream of the river (the Oka River – Kaluga city). As a result of the analysis, it was revealed that more noticeable changes in the concentration of pollutants are observed in the section of the river from the city of Murom to the city of Dzerzhinsk. Near the city of Murom, the content of oil products in the water sharply increases. From the beginning of the study period (1984) and until 1995, the average annual concentration varied from 5 to 30 values, and the maximum concentration in the year in creased to 87 values. After 2000, the content of oil products in water dropped sharply and the average annual value did not exceed 3 values, and the maximum concentration was 4-6 values. The paper analyzes the frequency of cases of exceeding the maximum permissible concentrations of pollutants in the Oka River in the mouth of the river. There was a high repeatability of the content of copper compounds in water, which varied from 70 to 88%. The frequency of cases of excess of easily oxidized organic matter in the mouth of the Oka River varied from 64 to 74%. Relatively low, although stable, the repeatability of the content of oil products in water remained, which ranged from 23 to 42%.


2020 ◽  
Vol 24 (4) ◽  
pp. 1721-1740 ◽  
Author(s):  
Erwin Rottler ◽  
Till Francke ◽  
Gerd Bürger ◽  
Axel Bronstert

Abstract. Recent climatic changes have the potential to severely alter river runoff, particularly in snow-dominated river basins. Effects of changing snow covers superimpose with changes in precipitation and anthropogenic modifications of the watershed and river network. In the attempt to identify and disentangle long-term effects of different mechanisms, we employ a set of analytical tools to extract long-term changes in river runoff at high resolution. We combine quantile sampling with moving average trend statistics and empirical mode decomposition and apply these tools to discharge data recorded along rivers with nival, pluvial and mixed flow regimes as well as temperature and precipitation data covering the time frame 1869–2016. With a focus on central Europe, we analyse the long-term impact of snow cover and precipitation changes along with their interaction with reservoir constructions. Our results show that runoff seasonality of snow-dominated rivers decreases. Runoff increases in winter and spring, while discharge decreases in summer and at the beginning of autumn. We attribute this redistribution of annual flow mainly to reservoir constructions in the Alpine ridge. During the course of the last century, large fractions of the Alpine rivers were dammed to produce hydropower. In recent decades, runoff changes induced by reservoir constructions seem to overlap with changes in snow cover. We suggest that Alpine signals propagate downstream and affect runoff far outside the Alpine area in river segments with mixed flow regimes. Furthermore, our results hint at more (intense) rainfall in recent decades. Detected increases in high discharge can be traced back to corresponding changes in precipitation.


Author(s):  
Yuriy Yushchenko ◽  
Olha Palanychko ◽  
Mykola Pasichnyk ◽  
Oleksandr Zakrevskyi

Research of precipitation, water balance of river basins, and the impact of precipitation on river runoff remain relevant in the context of global and regional climate change. Nowadays, many scientific research all over the world are devoted to the research of the problem of river runoff change under the influence of climatic factors. This kind of research has been developing strongly in Ukraine in recent decades. In particular, they concern the rivers of the Ukrainian Carpathians. The basin of the river Putyla to the line of the village of Putyla has an area of 181 km2. It is located in the south-eastern part of the Carpathian and characterized by a significant influence of warm rains on the formation of water runoff. The average annual runoff is characterized by rather complex patterns of change both in time and space. There are periodic, cyclical and unidirectional changes that occur under the influence of a complex system of factors. Climate is a major factor of the water change. Thus, the research of the average runoff of the Putila River has different aspects.To determine the effect of precipitation on river runoff, the method of comparing difference-integral curves of annual runoff and precipitation, as well as water-balance methods are used. Long-term changes and intra-annual distribution of precipitation, in particular rainfall, according to the observations of the meteorological station Selyatyn were analyzed. We constructed a differential integrated curve of modular coefficients of the average annual precipitation in the Putil district. It clearly reflects the cyclical changes in precipitation. Long-term changes and intra-annual distribution of water runoff in the Putyla River also were analyzed. During the observation period, periods of long-term fluctuations of the average annual precipitation were revealed. The average annual rainfall is 842.9 mm. The annual course is stable, ie the greatest amount of precipitation falls in the summer, when there are intense thunderstorms and showers, the least – in winter. Based on the data of hydrological observations, the average long-term value of water consumption according to GP Putila is 2.47 m3/s. We calculated the coefficient of variability (variation). The coefficient of variation for average costs is 0.21 (21%), and for precipitation – 0.7 (7%). The connection between precipitation and runoff was established. We have built a comprehensive schedule of annual distribution of precipitation and costs of the Putyla River for 2010. You can see that in the spring due to snowmelt there is an influx of water and there is a spring flood. It is known that 2010 in Putilsky district was full of water. The reduction of water consumption in the Putyla River in the cold period of the year with a decrease in precipitation is also observed. Graph of the dependence of the runoff of the Putyla River on precipitation in the village of Selyatyn showed a fairly clear relationship between the variable values of runoff and precipitation (the coefficient of variation is 0,66). The feeding structure of the Putyla River is mixed. The main share is occupied by rain, less - snow and groundwater. Key words: climate change, precipitation, runoff, rivers, long-term changes in runoff, intra-annual distribution of precipitation and runoff, Putyla river.


2016 ◽  
Vol 62 (4) ◽  
pp. 575-587 ◽  
Author(s):  
Weiwei Shao ◽  
Xiangdong Chen ◽  
Zuhao Zhou ◽  
Jiahong Liu ◽  
Ziqi Yan ◽  
...  

2018 ◽  
Vol 45 (S2) ◽  
pp. 99-109 ◽  
Author(s):  
I. V. Solomonova ◽  
V. P. Yushkov ◽  
S. G. Dobrovolski

Author(s):  

Long-term changes of the river runoff in Transbaikalia have been discussed. The runoff fluctuations are cyclic by character and depend upon many-year changes of atmospheric precipitations. Prolonged trends of the runoff increase or decrease have not been revealed. According to the forecast, the runoff exceeding the standard value will dominate till 2021–2023.


2019 ◽  
Author(s):  
Erwin Rottler ◽  
Till Francke ◽  
Gerd Bürger ◽  
Axel Bronstert

Abstract. Recent climatic changes have the potential to severely alter river runoff, particularly in snow-dominated river basins. Effects of changing snow covers superimpose with changes in precipitation and anthropogenic modifications of the watershed and river network. In the attempt to identify and disentangle long-term effects of different mechanisms, we employ a set of analytical tools to extract long-term changes in river runoff in high resolution. We combine quantile sampling with moving average trend statistics and empirical mode decomposition and apply these tools to discharge data recorded along rivers with nival, pluvial and mixed flow regimes as well as temperature and precipitation data covering the time frame 1869–2016. With a focus on Central Europe, we analyze the long-term impact of snow cover and precipitation changes along with their interaction with reservoir constructions. Our results show that runoff seasonality of snow-dominated rivers decreases. Runoff increases in winter and spring, while discharge decreases in summer and beginning of autumn. We attribute this redistribution of annual flow mainly to reservoir constructions in the alpine ridge. During the course of the last century, large fractions of the alpine rivers have been dammed to produce hydropower. In recent decades, runoff changes induced by reservoir constructions seem to overlap with changes in snow cover. We suggest that alpine signals propagate downstream and affect runoff far outside the alpine area in river segments with mixed flow regimes. Furthermore, our results hint at more (intense) rainfall in recent decades. Detected increases in high discharge can be traced back to corresponding changes in precipitation.


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