Modelling the climate change impact on the largest White Sea estuarine areas

Author(s):  
Evgeniya Panchenko ◽  
Andrei Alabyan ◽  
Inna Krylenko ◽  
Serafima Lebedeva

<p>Possible sea level rise and changes in hydrological regime of rivers are the major threats to estuarine systems. The sensibility of hydrodynamic regime of the Northern Dvina delta and the Onega estuary under various scenarios of climate change has been investigated. Hydrodynamic models HEC-RAS (USA, US Army Corps of Engineers Hydrologic Engineering Center) and STREAM_2D (Russia, authors V.Belikov et.al.) were used for analysis of estuarine flow regime (variations of water levels, discharges and flow velocities throughout tidal cycles). Input runoff changes were simulated for different climate scenarios using ECOMAG model (Russia, author Yu.Motovilov) based on data of global climate models (GSM) of CMIP5 project for the White Sea region.</p><p>ECOMAG modelling has demonstrated that the maximum river discharges averaged for 30-year period 2036 – 2065 can reduce for about 20 – 27% for the Onega and 15 – 20% for the Northern Dvina river compared against the historical period 1971 – 2000.Averaged minimum river discharges can reduce for about 33 – 45% for the Onega and 30 – 40% for the Northern Dvina.</p><p>The White Sea level rise by 0.27 m in average (with inter-model variation from 0.20 to 0.38 m) can took place by the middle of the XXI century according to input data of GSM models. The 12 scenarios of estuarine hydrodynamic changes were simulated for the both rivers based on combining river runoff changes and sea level elevation.</p><p>In general, the expected flow changes are negative for the local industry and population. According to modelling results for ‘high runoff/spring tide’ scenarios the flooding area in the Northern Dvina delta will increase by 13-20% depending on the intensity of sea level rise. In the low water seasons the distance from the river mouth to the upper boundary of the reach, where reverse currents can be observed, will move upstream by 8 - 36 km depending of sea/river conditions due to decrease in minimum river runoff. It may adversely effect on shipping conditions at the city of Arkhangelsk and on brackish water intrusion up-to industrial and communal water intakes.</p><p>The reverse currents also will intensify in the Onega estuary (tidal flow velocities increase for 11 – 19%) that leads to the change of the sediment regime and can significantly deteriorate the navigation conditions at the seaport of the Onega town. The problem of the intensification of salt intrusion can arise there as well.</p><p>The research was supported by the Russian Foundation for Basic Research (Projects No. 18- 05-60021 in development of the scenarios; No. 19-35-90032 in providing hydrodynamic modelling of the Onega; Project No. 19-35-60032 in providing hydrodynamic modelling of the Northern Dvina).</p>

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Benjamin H. Strauss ◽  
Philip M. Orton ◽  
Klaus Bittermann ◽  
Maya K. Buchanan ◽  
Daniel M. Gilford ◽  
...  

AbstractIn 2012, Hurricane Sandy hit the East Coast of the United States, creating widespread coastal flooding and over $60 billion in reported economic damage. The potential influence of climate change on the storm itself has been debated, but sea level rise driven by anthropogenic climate change more clearly contributed to damages. To quantify this effect, here we simulate water levels and damage both as they occurred and as they would have occurred across a range of lower sea levels corresponding to different estimates of attributable sea level rise. We find that approximately $8.1B ($4.7B–$14.0B, 5th–95th percentiles) of Sandy’s damages are attributable to climate-mediated anthropogenic sea level rise, as is extension of the flood area to affect 71 (40–131) thousand additional people. The same general approach demonstrated here may be applied to impact assessments for other past and future coastal storms.


Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 545
Author(s):  
Alexis K. Mills ◽  
Peter Ruggiero ◽  
John P. Bolte ◽  
Katherine A. Serafin ◽  
Eva Lipiec

Coastal communities face heightened risk to coastal flooding and erosion hazards due to sea-level rise, changing storminess patterns, and evolving human development pressures. Incorporating uncertainty associated with both climate change and the range of possible adaptation measures is essential for projecting the evolving exposure to coastal flooding and erosion, as well as associated community vulnerability through time. A spatially explicit agent-based modeling platform, that provides a scenario-based framework for examining interactions between human and natural systems across a landscape, was used in Tillamook County, OR (USA) to explore strategies that may reduce exposure to coastal hazards within the context of climate change. Probabilistic simulations of extreme water levels were used to assess the impacts of variable projections of sea-level rise and storminess both as individual climate drivers and under a range of integrated climate change scenarios through the end of the century. Additionally, policy drivers, modeled both as individual management decisions and as policies integrated within adaptation scenarios, captured variability in possible human response to increased hazards risk. The relative contribution of variability and uncertainty from both climate change and policy decisions was quantified using three stakeholder relevant landscape performance metrics related to flooding, erosion, and recreational beach accessibility. In general, policy decisions introduced greater variability and uncertainty to the impacts of coastal hazards than climate change uncertainty. Quantifying uncertainty across a suite of coproduced performance metrics can help determine the relative impact of management decisions on the adaptive capacity of communities under future climate scenarios.


2017 ◽  
Author(s):  
Aiqing Feng ◽  
Jiangbo Gao ◽  
Shaohong Wu ◽  
Yanzhong Li ◽  
Xiliu Yue

Abstract. Extreme water levels, caused by the joint occurrence of storm surges and high tides, always lead to super floods along coastlines. Given the ongoing climate change, this study explored the risk of future sea-level rise on the extreme inundation by combining P-III model and losses assessment model. Taking Rongcheng as a case study, the integrated risk of extreme water levels was assessed for 2050 and 2100 under three Representative Concentration Pathways (RCP) scenarios of 2.6, 4.5, and 8.5. Results indicated that the increase in total direct losses would reach an average of 60 % in 2100 as a 0.82 m sea-level rise under RCP 8.5. In addition, affected population would be increased by 4.95 % to 13.87 % and GDP (Gross Domestic Product) would be increased by 3.66 % to 10.95 % in 2050 while the augment of affected population and GDP in 2100 would be as twice as in 2050. Residential land and farmland would be under greater flooding risk in terms of the higher exposure and losses than other land-use types. Moreover, this study indicated that sea-level rise shortened the recurrence period of extreme water levels significantly and extreme events would become common. Consequently, the increase in frequency and possible losses of extreme flood events suggested that sea-level rise was very likely to exacerbate the extreme risk of coastal zone in future.


Geosciences ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 76 ◽  
Author(s):  
David Didier ◽  
Marion Bandet ◽  
Pascal Bernatchez ◽  
Dany Dumont

Coastal management often relies on large-scale flood mapping to produce sea level rise assessments where the storm-related surge is considered as the most important hazard. Nearshore dynamics and overland flow are also key parameters in coastal flood mapping, but increase the model complexity. Avoiding flood propagation processes using a static flood mapping is less computer-intensive, but generally leads to overestimation of the flood zone, especially in defended urban backshore. For low-lying communities, sea level rise poses a certain threat, but its consequences are not only due to a static water level. In this paper, the numerical process-based model XBeach is used in 2D hydrodynamic mode (surfbeat) to reproduce an observed historical flood in Maria (eastern Canada). The main goal is to assess the impacts of a future storm of the same magnitude in the horizon 2100 according to an increase in sea level rise. The model is first validated from in situ observations of waves and water levels observed on the lower foreshore. Based on field observations of a flood extent in 2010, the simulated flooded area was also validated given a good fit (59%) with the actual observed flood. Results indicate that the 2010 storm-induced surge generated overwash processes on multiple areas and net landward sediment transport and accumulation (washover lobes). The flood was caused by relatively small nearshore waves (Hs < 1 m), but despite small water depth (>1.2 m), high flow velocities occurred in the main street (U > 2 m/s) prior to draining in the salt marsh. The impact of sea level rise on the low-lying coastal community of Maria could induce a larger flood area in 2100, deeper floodwater, and higher flow velocities, resulting in higher hazard for the population.


2013 ◽  
Vol 6 (2) ◽  
pp. 81-87 ◽  
Author(s):  
T. L. A. Driessen ◽  
M. van Ledden

Abstract. The objective of this paper was to describe the impact of climate change on the Mississippi River flood hazard in the New Orleans area. This city has a unique flood risk management challenge, heavily influenced by climate change, since it faces flood hazards from multiple geographical locations (e.g. Lake Pontchartrain and Mississippi River) and multiple sources (hurricane, river, rainfall). Also the low elevation and significant subsidence rate of the Greater New Orleans area poses a high risk and challenges the water management of this urban area. Its vulnerability to flooding became dramatically apparent during Hurricane Katrina in 2005 with huge economic losses and a large number of casualties. A SOBEK Rural 1DFLOW model was set up to simulate the general hydrodynamics. This model included the two important spillways that are operated during high flow conditions. A weighted multi-criteria calibration procedure was performed to calibrate the model for high flows. Validation for floods in 2011 indicated a reasonable performance for high flows and clearly demonstrated the influence of the spillways. 32 different scenarios were defined which included the relatively large sea level rise and the changing discharge regime that is expected due to climate change. The impact of these scenarios on the water levels near New Orleans were analysed by the hydrodynamic model. Results showed that during high flows New Orleans will not be affected by varying discharge regimes, since the presence of the spillways ensures a constant discharge through the city. In contrary, sea level rise is expected to push water levels upwards. The effect of sea level rise will be noticeable even more than 470 km upstream. Climate change impacts necessitate a more frequent use of the spillways and opening strategies that are based on stages.


2020 ◽  
Author(s):  
Simon Treu ◽  
Matthias Mengel ◽  
Katja Frieler

&lt;p&gt;Sea level rise increases extreme water levels and thus the flood losses from storm surge events. While it is still difficult to estimate the influence of climate change on single storms, the influence of anthropogenic climate change on sea level rise is evident. We here aim to quantify the fraction of damages caused by sea level rise for a set of flood events of the last decade.&amp;#160;Flood-extents and the spatial distribution of damages are reconstructed from openly available data-sources. We construct counterfactual flood extents for each event by a counterfactual sea level as it would have been in a world without climate change. As we are particularly interested in losses in poorer countries that often lack high resolution data such as LiDAR based elevation maps or tide-gauge records, our methodology is transferable between regions, building on global and open data. Depending on the study site, we detect a difference between observed and counterfactual damages though uncertainties remain high. Data availability and data detail remain a major restriction.&lt;/p&gt;


2007 ◽  
pp. 53-72 ◽  
Author(s):  
N. N. Filatov ◽  
L. E. Nazarova ◽  
Ju A. Salo ◽  
A. V. Tolstikov

2010 ◽  
Vol 1 (1) ◽  
pp. 67-86 ◽  
Author(s):  
K. Västilä ◽  
M. Kummu ◽  
C. Sangmanee ◽  
S. Chinvanno

The flood pulse is a key element characterizing the hydrology of the Mekong River and driving the high ecosystem productivity in the Lower Mekong floodplains, both in the Cambodian lowlands and the Mekong Delta in Vietnam. This paper assesses the impacts of climate change, both in terms of changed basin water balance and sea level rise, on the Lower Mekong flood pulse. The impacts were simulated by a three-dimensional hydrodynamic model using the projected changes in sea level and the Mekong mainstream discharge under the influence of climate change as boundary conditions. The model simulations projected that average and maximum water levels and flood duration increase in 2010–2049. The most consistent and notable changes occurred in the average and dry hydrological years. Sea level rise had the greatest effects in the Mekong Delta, whereas the impacts of changed basin water balance were more notable in the upper areas of the Mekong floodplains. The projected impacts were mostly opposite to those resulting from regional water infrastructure development. Higher and longer flooding could cause damage to crops, infrastructure and floodplain vegetation, and decrease the fertile land area. On the other hand, it might boost ecosystem productivity and enhance dry season water availability.


2017 ◽  
Vol 44 (1) ◽  
pp. 9 ◽  
Author(s):  
Natalie L. Waller ◽  
Ian C. Gynther ◽  
Alastair B. Freeman ◽  
Tyrone H. Lavery ◽  
Luke K.-P. Leung

Aims Sea-level rise is one of the most certain consequences of global warming and is predicted to exert significant adverse effects on wildlife in coastal habitats worldwide. Terrestrial fauna inhabiting low-lying islands are likely to suffer the greatest loss to habitat from sea-level rise and other oceanographic impacts stemming from anthropogenic climate change. Bramble Cay (Maizab Kaur), an ~4ha, low elevation sand cay located in Torres Strait, Australia, supports the only known population of the endangered Bramble Cay melomys Melomys rubicola Thomas, 1924. As a result of a decline in this population noted during previous monitoring to 2004, habitat loss due to erosion of the cay and direct mortality from storm surges were implicated as major threats to this species. This study aimed to confirm the current conservation status of the species, to seek information about the key factor or factors responsible for the population decline and to recover any remaining individuals for a captive insurance population. Methods During three survey periods (December 2011, March 2014 and August–September 2014), a total of 1170 small mammal trap-nights, 60 camera trap-nights, 5h of nocturnal searches and 5h of diurnal searches were undertaken on Bramble Cay. Key results All three survey periods failed to detect any Bramble Cay melomys. The island had experienced a recent, severe reduction in vegetation, which is the primary food resource for the Bramble Cay melomys. Herbaceous cover on the cay decreased from 2.16ha in 2004 to 0.065ha in March 2014 before recovering somewhat to 0.19ha in August–September 2014. Conclusions These results demonstrate that this rodent species has now been extirpated on Bramble Cay. The vegetation decline was probably due to ocean inundation resulting from an increased frequency and intensity of weather events producing extreme high water levels and storm surges, in turn caused by anthropogenic climate change. Implications The loss of the Bramble Cay melomys from Bramble Cay probably represents the first documented mammalian extinction due to human-induced climate change. This event highlights the immediate need to mitigate predicted impacts of sea-level rise and ocean inundation on other vulnerable species occurring on low lying islands and in susceptible coastal zones through captive breeding and reintroduction or other targeted measures.


2019 ◽  
Vol 2 (1) ◽  
pp. 1-20
Author(s):  
S.E. Grenfell ◽  
F. Fortune ◽  
M.F. Mamphoka ◽  
N. Sanderson

We investigate coastal wetland ecosystem resilience to sea level rise by modelling sea level rise trajectories and the impact on vegetation communities for a coastal wetland in South Africa. The rate of sediment accretion was modelled relative to IPCC sea level rise estimates for multiple RCP scenarios. For each scenario, inundation by neap and spring tide and the 2, 4, and 8 year recurrence interval water level was modelled over a period of 200 years. When tidal variation is considered, the rate of sediment accretion exceeds rising sea levels associated with climate change, resulting in no major changes in terms of inundation. When sea level rise scenarios were modelled in conjunction with recurrence interval water levels, flooding of the coastal wetland was much greater than current levels at 1 in 4 and 1 in 8 year events. In the long term, increases in salinity may cause a reduction in Phragmites australis cover. Very small increases in depth and frequency of inundation are likely to cause an expansion of samphire species at the expense of Juncus spp. The study suggests that for this wetland, variability in flow may be a key factor in balancing wetland resilience.


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