Risk of gully erosion: methods and examples of estimates

Author(s):  
Aleksey Sidorchuk ◽  
Andrei Entin

<p>Risk of damage of buildings and infrastructure by gully erosion can be estimated on the net of flowlines or by evaluation of depths of gullies with erosion model, or by calculation of some simplified measures of erosion rate, which are correlated with such calculated gullies depths and/or with the measurements of gully erosion. The most exact approach is based on calculation of the transformation of longitudinal profiles of linear erosion features along all flowlines on DEM with GULTEM model. The model includes calculation of gully erosion and thermoerosion, gully bank widening and collapsing. This requires detailed meteorological, hydrological, morphological and lithological information and includes model calibration on the measurement data. The simplified methods are based on the calculation of critical runoff depth at which linear erosion of the soil begins for each point on the catchment. The total sediment yield at each point by all flows above critical or difference between the maximum runoff depth and its critical value is calculated within such approach. This requires much less hydrological, morphological and lithological information, but takes into account only initial conditions on the catchment. Calculations of the risk of gully erosion were performed on the net of flowlines for the gas fields on the Yamal Peninsula with existing and designed structures and buildings. Comparison of the results of evaluating the gully erosion potential by the simplified methods with the data of calculations of gully erosion using the detailed dynamic model and field measurements showed their satisfactory agreement. This confirms the possibility of using express-methods for a quick assessment of the scope of using territories for development with the following detailed calculations with the use of GULTEM on certain areas of construction for evaluation of the risks of landscape and infrastructure disturbance.</p><p><strong>Funding: </strong>This research was funded by RFBR grant 18-05-60147 "Extreme hydrometeorological phenomena in the Kara Sea and the Arctic coast".</p><p> </p>

2019 ◽  
Vol 12 (1) ◽  
pp. 260 ◽  
Author(s):  
Aleksey Sidorchuk

The Yamal Peninsula occupies the northern part of the West Siberian Plain in Russia. This territory has rapidly developed due to the exploitation of several gas fields. At the same time, the Yamal Peninsula is one of the most severely gullied landscapes in the Arctic. The potential risk of damage to the environment or structures and the cost of such damages are very high there. The erosion potential is the cumulative erosion by runoff above critical, calculated for each point at a catchment. Calculations take into account the geomorphic, lithological, and vegetation cover thresholds, realized in the form of critical runoff depth of erosion initiation. It also takes into account action of all flows between the critical and maximum runoff. The calculations for several gullied catchments on the Yamal Peninsula show the uneven distribution of erosion potential level with the maximum of gully erosion on the steep banks of the river valleys and on gully heads with bare soil. The area with potential erosion in these catchments varies within the range of 17–33%. The erosion on the Yamal Peninsula is mainly of natural origin. It occurs on steep slopes and at the heads of gullies. These landforms are not used for exploitation camps and settlements. Nevertheless, the linear structures, such as railways, roads and pipelines, can cross these unstable landforms with the risk of damage. Erosion potential increases at the spots with bare soil, which appear due to both construction work and natural processes, such as slumping.


Author(s):  
Nataliya Belova ◽  
Nataliya Belova ◽  
Alisa Baranskaya ◽  
Alisa Baranskaya ◽  
Osip Kokin ◽  
...  

The coasts of Baydaratskaya Bay are composed by loose frozen sediments. At Yamal Peninsula accumulative coasts are predominant at the site where pipeline crosses the coast, while thermoabrasional coast are prevail at the Ural coast crossing site. Coastal dynamics monitoring on both sites is conducted using field and remote methods starting from the end of 1980s. As a result of construction in the coastal zone the relief morphology was disturbed, both lithodynamics and thermal regime of the permafrost within the areas of several km around the sites where gas pipeline crosses coastline was changed. At Yamal coast massive removal of deposits from the beach and tideflat took place. The morphology of barrier beach, which previously was a natural wave energy dissipater, was disturbed. This promoted inland penetration of storm surges and permafrost degradation under the barrier beach. At Ural coast the topsoil was disrupted by construction trucks, which affected thermal regime of the upper part of permafrost and lead to active layer deepening. Thermoerosion and thermoabrasion processes have activated on coasts, especially at areas with icy sediments, ice wedges and massive ice beds. Construction of cofferdams resulted in overlapping of sediments transit on both coasts and caused sediment deficit on nearby nearshore zone areas. The result of technogenic disturbances was widespread coastal erosion activation, which catastrophic scale is facilitated by climate warming in the Arctic.


2021 ◽  
Author(s):  
Xinping Xu ◽  
Shengping He ◽  
Yongqi Gao ◽  
Botao Zhou ◽  
Huijun Wang

AbstractPrevious modelling and observational studies have shown discrepancies in the interannual relationship of winter surface air temperature (SAT) between Arctic and East Asia, stimulating the debate about whether Arctic change can influence midlatitude climate. This study uses two sets of coordinated experiments (EXP1 and EXP2) from six different atmospheric general circulation models. Both EXP1 and EXP2 consist of 130 ensemble members, each of which in EXP1 (EXP2) was forced by the same observed daily varying sea ice and daily varying (daily climatological) sea surface temperature (SST) for 1982–2014 but with different atmospheric initial conditions. Large spread exists among ensemble members in simulating the Arctic–East Asian SAT relationship. Only a fraction of ensemble members can reproduce the observed deep Arctic warming–cold continent pattern which extends from surface to upper troposphere, implying the important role of atmospheric internal variability. The mechanisms of deep Arctic warming and shallow Arctic warming are further distinguished. Arctic warming aloft is caused primarily by poleward moisture transport, which in conjunction with the surface warming coupled with sea ice melting constitutes the surface-amplified deep Arctic warming throughout the troposphere. These processes associated with the deep Arctic warming may be related to the forcing of remote SST when there is favorable atmospheric circulation such as Rossby wave train propagating from the North Atlantic into the Arctic.


2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Anna K. Liljedahl ◽  
Ina Timling ◽  
Gerald V. Frost ◽  
Ronald P. Daanen

AbstractShrub expansion has been observed across the Arctic in recent decades along with warming air temperatures, but tundra shrub expansion has been most pronounced in protected landscape positions such as floodplains, streambanks, water tracks, and gullies. Here we show through field measurements and laboratory analyses how stream hydrology, permafrost, and soil microbial communities differed between streams in late summer with and without tall shrubs. Our goal was to assess the causes and consequences of tall shrub expansion in Arctic riparian ecosystems. Our results from Toolik Alaska, show greater canopy height and density, and distinctive plant and soil microbial communities along stream sections that lose water into unfrozen ground (talik) compared to gaining sections underlain by shallow permafrost. Leaf Area Index is linearly related to the change in streamflow per unit stream length, with the densest canopies coinciding with increasingly losing stream sections. Considering climate change and the circumpolar scale of riparian shrub expansion, we suggest that permafrost thaw and the resulting talik formation and shift in streamflow regime are occurring across the Low Arctic.


2021 ◽  
Vol 55 (3) ◽  
pp. 87-98
Author(s):  
S.V. Kvasovets ◽  
◽  
A.V. Ivanov ◽  
Yu.A. Bubeev ◽  
◽  
...  

The paper introduces the principles of an adjoint ideomotion method (AIM) for psychophysiological diagnostics based on a client – server distributed system within which information is communicated and measurement data filed with the help of commonly used smartphones. The authors discuss the issues of remote diagnostics automation and unification, application areas, and practical uses. Comparison of the results of questioning and AIM evidenced for advantages of the latter in respect to small populations and revealing symptoms undetectable by standard questionnaires.


2017 ◽  
Vol 14 (12) ◽  
pp. 3129-3155 ◽  
Author(s):  
Hakase Hayashida ◽  
Nadja Steiner ◽  
Adam Monahan ◽  
Virginie Galindo ◽  
Martine Lizotte ◽  
...  

Abstract. Sea ice represents an additional oceanic source of the climatically active gas dimethyl sulfide (DMS) for the Arctic atmosphere. To what extent this source contributes to the dynamics of summertime Arctic clouds is, however, not known due to scarcity of field measurements. In this study, we developed a coupled sea ice–ocean ecosystem–sulfur cycle model to investigate the potential impact of bottom-ice DMS and its precursor dimethylsulfoniopropionate (DMSP) on the oceanic production and emissions of DMS in the Arctic. The results of the 1-D model simulation were compared with field data collected during May and June of 2010 in Resolute Passage. Our results reproduced the accumulation of DMS and DMSP in the bottom ice during the development of an ice algal bloom. The release of these sulfur species took place predominantly during the earlier phase of the melt period, resulting in an increase of DMS and DMSP in the underlying water column prior to the onset of an under-ice phytoplankton bloom. Production and removal rates of processes considered in the model are analyzed to identify the processes dominating the budgets of DMS and DMSP both in the bottom ice and the underlying water column. When openings in the ice were taken into account, the simulated sea–air DMS flux during the melt period was dominated by episodic spikes of up to 8.1 µmol m−2 d−1. Further model simulations were conducted to assess the effects of the incorporation of sea-ice biogeochemistry on DMS production and emissions, as well as the sensitivity of our results to changes of uncertain model parameters of the sea-ice sulfur cycle. The results highlight the importance of taking into account both the sea-ice sulfur cycle and ecosystem in the flux estimates of oceanic DMS near the ice margins and identify key uncertainties in processes and rates that should be better constrained by new observations.


2013 ◽  
Vol 10 (1) ◽  
pp. 357-370 ◽  
Author(s):  
J. M. Holding ◽  
C. M. Duarte ◽  
J. M. Arrieta ◽  
R. Vaquer-Sunyer ◽  
A. Coello-Camba ◽  
...  

Abstract. Climate warming is especially severe in the Arctic, where the average temperature is increasing 0.4 °C per decade, two to three times higher than the global average rate. Furthermore, the Arctic has lost more than half of its summer ice extent since 1980 and predictions suggest that the Arctic will be ice free in the summer as early as 2050, which could increase the rate of warming. Predictions based on the metabolic theory of ecology assume that temperature increase will enhance metabolic rates and thus both the rate of primary production and respiration will increase. However, these predictions do not consider the specific metabolic balance of the communities. We tested, experimentally, the response of Arctic plankton communities to seawater temperature spanning from 1 °C to 10 °C. Two types of communities were tested, open-ocean Arctic communities from water collected in the Barents Sea and Atlantic influenced fjord communities from water collected in the Svalbard fjord system. Metabolic rates did indeed increase as suggested by metabolic theory, however these results suggest an experimental temperature threshold of 5 °C, beyond which the metabolism of plankton communities shifts from autotrophic to heterotrophic. This threshold is also validated by field measurements across a range of temperatures which suggested a temperature 5.4 °C beyond which Arctic plankton communities switch to heterotrophy. Barents Sea communities showed a much clearer threshold response to temperature manipulations than fjord communities.


Author(s):  
Wolfgang Beer ◽  
Peter Hirsch

Field measurements on an industrial steam turbine with a rated power output of 5.8 MW, consisting of an impulse type control wheel and a reaction part, showed a significant gap of efficiency from the design calulations. It was suspected, that this gap results from underestimation of the loss created by non-uniform inflow conditions to the reaction part due to partial admission. The experimental results and data of experiments done in the 1990s are therefore recalculated to find possible explanations. It turns out, that probably the data considered for verifcation is not complete. When taking the complete data into account, and using an averaging method, the verification calculations show, that the models used for design and recalculation of industrial steam turbines are accurate enough for industrial purposes, but a calculation model for efficiency loss due to partial admission has to be added. In this work non-uniformity between the flow passages was not observed for the test turbine. Non-uniformity of the flow in radial direction was observed for the test turbine, but was not taken into consideration here, as the whole rotor was treated integrally. Flow seperations as unsteady effects were not considered, as a steady-state investigation was conducted. The calculation models are verified by comparison with field measurement data from industrial steam turbines, by comparison with the results of a 9 MW steam driven test turbine and by recalculated results from literature. Not all verification calculations are presented in detail here.


Georesursy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 125-135
Author(s):  
Valery I. Isaev ◽  
Galina A. Lobova ◽  
Alexander N. Fomin ◽  
Valery I. Bulatov ◽  
Stanislav G. Kuzmenkov ◽  
...  

The possibilities of Geothermy as a geophysical method are studied to solve forecast and prospecting problems of Petroleum Geology of the Arctic regions and the Paleozoic of Western Siberia. Deep heat flow of Yamal fields, whose oil and gas potential is associated with the Jurassic-Cretaceous formations, and the fields of Tomsk Region, whose geological section contents deposits in the Paleozoic, is studied. The method of paleotemperature modeling was used to calculate the heat flow density from the base of a sedimentary section (by solving the inverse problem of Geothermy). The schematization and mapping of the heat flow were performed, taking into account experimental determinations of the parameter. Besides, the correlation of heat flow features with the localization of deposits was revealed. The conceptual and factual basis of research includes the tectonosedimentary history of sedimentary cover, the Mesozoic-Cenozoic climatic temperature course and the history of cryogenic processes, as well as lithologic and stratigraphic description of the section, results of well testing, thermometry and vitrinite reflectivity data of 20 deep wells of Yamal and 37 wells of Ostanino group of fields of Tomsk region. It was stated that 80 % of known Yamal deposits correlate with anomalous features of the heat flow. Bovanenkovskoe and Arkticheskoe fields are located in positive anomaly zones. 75 % of fields of Ostanino group relate to anomalous features of the heat flow. It is shown that the fields, which are characterized by existence of commercial deposits in the Paleozoic, are associated with the bright gradient zone of the heat flow. The forecast of commercial inflows in the Paleozoic for Pindzhinskoe, Mirnoe and Rybalnoe fields is given. The correlation between the intensity of naftidogenesis and the lateral inhomogeneity of the deep heat flow is characterized as a probable fundamental pattern for Western Siberia.


Author(s):  
Dmitry V. Arzyutov

This article deals with the ethnographic analysis of the history and social life of electricity among Nenets in the Yamal Peninsula. Based on historical documents and field data the author reconstructs a history of the electrification of the northern part of the peninsula. This work also includes the reflections on social and cultural meanings of electricity among Nenets in and out the tundra. Through these historical and current dynamics, the author suggests analysing the life of electricity in off-the-grid settings through the lens of transnational technological entanglements in the Arctic


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