Mechanisms behind the uneven increases in early, mid- and late winter streamflow across four Arctic river basins

2022 ◽  
pp. 127425
Author(s):  
Shiqi Liu ◽  
Ping Wang ◽  
Jingjie Yu ◽  
Tianye Wang ◽  
Hongyan Cai ◽  
...  
Keyword(s):  
2019 ◽  
Vol 13 (6) ◽  
pp. 1635-1659 ◽  
Author(s):  
Olga Makarieva ◽  
Nataliia Nesterova ◽  
David Andrew Post ◽  
Artem Sherstyukov ◽  
Lyudmila Lebedeva

Abstract. Large Arctic river basins experience substantial variability in climatic, landscape, and permafrost conditions. However, the processes behind the observed changes at the scale of these basins are relatively poorly understood. While most studies have been focused on the “Big 6” Arctic rivers – the Ob', Yenisey, Lena, Mackenzie, Yukon, and Kolyma – few or no assessments exist for small and medium-sized river basins, such as the Yana and Indigirka River basins. Here, we provide a detailed analysis of streamflow data from 22 hydrological gauges in the Yana and Indigirka River basins with a period of observation ranging from 35 to 79 years up to 2015. These river basins are fully located in the zone of continuous permafrost. Our analysis reveals statistically significant (p<0.05) positive trends in the monthly streamflow time series during the autumn–winter period for most of the gauges. The streamflow increases in a stepwise pattern (post-1981) for 17 out of 22 gauges in September (average trend value for the period of record is 58 % or 9.8 mm) and 15 out of 22 gauges in October (61 % or 2.0 mm). The positive trends are seen in 9 out of 19 rivers that do not freeze in November (54 %, 0.4 mm) and 6 out of 17 rivers that do not freeze in December (95 %, 0.15 mm). Precipitation is shown to decrease in late winter by up to 15 mm over the observational period. Additionally, about 10 mm of precipitation that used to fall as snow at the beginning of winter now falls as rain. Despite the decrease in winter precipitation, no decrease in streamflow has been observed during the spring freshet in May and June in the last 50 years (from 1966); moreover, five gauges show an increase of 86 % or 12.2 mm in spring floods via an abrupt change in 1987–1993. The changes in spring freshet start date are identified for 10 gauges; the earlier onset in May varies from 4 to 10 d over the observational period. We conclude that warmer temperatures due to climate change are impacting the hydrological regime of these rivers via changes in precipitation type (rain replacing snow). Other factors, such as the melting of permafrost, glaciers, and aufeis or changes in groundwater conditions, are likely to contribute as well; however, no direct observations of these changes are available. The changes in streamflow can have a significant impact on the ecology of the zone of continuous permafrost, while the increasing freshwater fluxes to the Arctic Ocean can impact the Arctic thermohaline circulation.


2011 ◽  
Vol 15 (6) ◽  
pp. 1819-1833 ◽  
Author(s):  
M. Renner ◽  
C. Bernhofer

Abstract. Recently, climatological studies report observational evidence of changes in the timing of the seasons, such as earlier timing of the annual cycle of surface temperature, earlier snow melt and earlier onset of the phenological spring season. Also hydrological studies report earlier timing and changes in monthly streamflows. From a water resources management perspective, there is a need to quantitatively describe the variability in the timing of hydrological regimes and to understand how climatic changes control the seasonal water budget of river basins. Here, the timing of hydrological regimes from 1930–2009 was investigated in a network of 27 river gauges in Saxony/Germany through a timing measure derived by harmonic function approximation of annual periods of runoff ratio series. The timing measure proofed to be robust and equally applicable to both mainly pluvial river basins and snow melt dominated regimes. We found that the timing of runoff ratio is highly variable, but markedly coherent across the basins analysed. Differences in average timing are largely explained by basin elevation. Also the magnitude of low frequent changes in the seasonal timing of streamflow and the sensitivity to the changes in the timing of temperature increase with basin elevation. This sensitivity is in turn related to snow storage and release, whereby snow cover dynamics in late winter explain a large part of the low- and high-frequency variability. A trend analysis based on cumulative anomalies revealed a common structural break around the year 1988. While the timing of temperature shifted earlier by 4 days, accompanied by a temperature increase of 1 K, the timing of runoff ratio within higher basins shifted towards occurring earlier about 1 to 3 weeks. This accelerated and distinct change indicates, that impacts of climate change on the water cycle may be strongest in higher, snow melt dominated basins.


Author(s):  
V.K. Khilchevskyi ◽  

In contrast to the hydrological and hydrochemical zoning, hydrographic and water management zoning of Ukraine (2016) was created on a basin basis, taking into account the boundaries of river basins, and not physiographic zoning. The main function of hydrographic and water management zoning is water management. Primary is hydrographic zoning, and water management - based on it. The description of modern hydrographic zoning of the territory of Ukraine, approved in 2016 by the Verkhovna Rada of Ukraine and included in the Water Code of Ukraine is given. Hydrographic zoning is carried out for the development and implementation of river basin management plans. On the territory of Ukraine nine areas of river basins are allocated: Dnipro; Dnister; Danube; Southern Bug; Don; Vistula; rivers of the Crimea; rivers of the Black Sea coast; rivers of the Azov Sea coast 13 sub-basins are allocated in four river basins district. The water management zoning is described - the division of hydrographic units into water management areas, which is carried out for the development of water management balances. In the regions of the river basins in the territory of Ukraine allocated 132 water management areas, 59 of which are located in the Dnipro basin. About 9,000 bodies of surface water allocated for monitoring in Ukraine. Approved zoning is the implementation of the provisions of the EU Water Framework Directive 2000/60 / EC in the management of water resources in Ukraine. Modern hydrographic and water management zoning of the territory of Ukraine approximates the management of water resources of the state to European requirements.


2013 ◽  
Vol 25 (1-2) ◽  
pp. 136-148
Author(s):  
I. V. Gryb

The concept of an explosion in freshwater ecosystems as a result of the release of accumulated energy, accompanied by the destruction of the steady climax successions of hydrocenoses is presented. The typification of local explosions as well as methods for assessing their risk during the development of river basins are shown. The change in atmospheric circulation, impaired phases of the hydrological regime of rivers, increasing the average temperature of the planet, including in Polesie to 0,6 ºC, deforestation leads to concentration and release of huge amounts of unmanaged terrestrial energy, which manifests itself in the form of disasters and emergencies. Hydroecological explosion is formed as a result of multifactorial external influence (natural and anthropogenic) on the water body in a certain period of time. Moreover, its level at wastewater discharge depends on the mass of recycled impurities and behaved processing capacity of the reservoir, and the mass of dumped on biocides and the possibility of the water flow to their dilution and to the utilization of non-toxic concentrations. In all these cases the preservation of "centers of life" in the tributaries of the first order – local fish reproduction areas contributed to ecosystem recovery, and the entire ecosystem has evolved from equilibrium to non-equilibrium with further restructuring after the explosion and environmental transition to a new trophic level. It means that hydroecological explosion can be researched as the logical course of development of living matter in abiotic environmental conditions, ending abruptly with the formation of new species composition cenoses and new bio-productivity. The buffer capacity of the water environment is reduced due to re-development and anthropic transformation of geobiocenoses of river basins, which leads to a weakening of life resistance. This applies particularly to the southern industrial regions of Ukraine, located in the arid zone that is even more relevant in the context of increased average temperature due to the greenhouse effect, as well as to Polesie (Western, Central and Chernihiv), had been exposed to large-scale drainage of 60-80th years, which contributed to the degradation of peatlands and fitostroma. Imposing the western trace of emissions from the Chernobyl accident to these areas had created the conditions of prolonged hydroecological explosion in an intense process of aging water bodies, especially lakes, change in species composition of fish fauna and the occurrence of neoplasms at the organismal level. Under these conditions, for the existence of man and the environment the vitaukta should be strengthened, i.e. buffer resistance and capacitance the aquatic environment, bioefficiency on the one hand and balanced using the energy deposited - on the other. This will restore the functioning of ecosystems "channel-floodplain", "riverbed-lake", reducing the energy load on the aquatic environment. Hydroecological explosions of natural origin can not be considered a pathology – it is a jump process of natural selection of species of biota. Another thing, if they are of anthropogenic origin and if the magnitude of such an impact is on the power of geological factors. Hydroecological explosions can be regarded as a manifestation of environmental wars that consciously or unconsciously, human society is waging against themselves and their kind in the river basins, so prevention of entropy increase in the aquatic environment and the prevention of hydroecological explosions is a matter of human survival. While the man - is not the final link in the development of living matter, it can develop without him, as matter is eternal, and the forms of its existence are different.


2014 ◽  
Vol 25 (1-2) ◽  
pp. 61-68 ◽  
Author(s):  
V. I. Monchenko ◽  
L. P. Gaponova ◽  
V. R. Alekseev

Crossbreeding experiments were used to estimate cryptic species in water bodies of Ukraine and Russia because the most useful criterion in species independence is reproductive isolation. The problem of cryptic species in the genus Eucyclops was examined using interpopulation crosses of populations collected from Baltic Sea basin (pond of Strelka river basin) and Black Sea basin (water-reservoires of Dnieper, Dniester and Danube rivers basins). The results of reciprocal crosses in Eucyclops serrulatus-group are shown that E. serrulatus from different populations but from water bodies belonging to the same river basin crossed each others successfully. The interpopulation crosses of E. serrulatus populations collected from different river basins (Dnipro, Danube and Dniester river basins) were sterile. In this group of experiments we assigned evidence of sterility to four categories: 1) incomplete copulation or absence of copulation; 2) nonviable eggs; 3) absence of egg membranes or egg sacs 4) empty egg membranes. These crossbreeding studies suggest the presence of cryptic species in the E. serrulatus inhabiting ecologically different populations in many parts of its range. The same crossbreeding experiments were carries out between Eucyclops serrulatus and morphological similar species – Eucyclops macruroides from Baltic and Black Sea basins. The reciprocal crossings between these two species were sterile. Thus taxonomic heterogeneity among species of genus Eucyclops lower in E. macruroides than in E. serrulatus. The interpopulation crosses of E. macruroides populations collected from distant part of range were fertile. These crossbreeding studies suggest that E. macruroides species complex was evaluated as more stable than E. serrulatus species complex.


10.1596/28574 ◽  
2017 ◽  
Author(s):  
Satya Priya ◽  
William Young ◽  
Thomas Hopson ◽  
Ankit Avasthi

2017 ◽  
Author(s):  
Tales Carvalho-Resende

The Environmental Water Stress in Transboundary River Basins indicator focuses on the water quantity aspect and considers hydrological alterations from monthly dynamics of the natural flow regime due to anthropogenic water uses and dam operations. For more information, visit: http://twap-rivers.org/ Basin Stress Surface water Transboundary


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