Impact of the Swansea Bay Lagoon on Storm Surges in the Bristol Channel

2019 ◽  
Author(s):  
Qian Ma ◽  
Tulio Marcondes Moreira ◽  
Thomas A. A. Adcock
Keyword(s):  
Numerical Model ◽  
Storm Surges ◽  
Tidal Energy ◽  
Water Levels ◽  
Small Scale ◽  
Surrounding Area ◽  
The Past ◽  
Operating Strategies ◽  
Swansea Bay ◽  
The Impact

Abstract The proposed Swansea Bay tidal energy lagoon is an example of a relatively small-scale tidal barrage demonstrator project. A key concern with this technology is that such structures may exacerbate other environmental problems. However, such structures might also create beneficial environmental effects in some areas, such as mitigating the impact of storm surges. In this paper we model the hydrodynamics of the Swansea lagoon and surrounding area using a depth-averaged numerical model. We simulate a number of storm surge events from the past 40 years and analyse how the presence of the Swansea Lagoon (under various operating strategies) modifies the resulting water levels.

scholarly journals PRE- and POST-STORM LiDAR SURVEYS FOR ASSESSMENT OF IMPACT ON COASTAL EROSION

2019 ◽  
Vol XLII-3/W8 ◽  
pp. 261-266
Author(s):  
A.-L. Montreuil ◽  
M. Chen ◽  
A. Esquerré ◽  
R. Houthuys ◽  
R. Moelans ◽  
...  
Keyword(s):  
Management Practices ◽  
Morphological Changes ◽  
Storm Surges ◽  
High Water ◽  
Water Levels ◽  
Airborne Lidar ◽  
Coastline Change ◽  
The Mean ◽  
The Impact

<p><strong>Abstract.</strong> Sustainable management of the coastal resources requires a better understanding of the processes that drive coastline change. The coastline is a highly dynamic sea-terrestrial interface. It is affected by forcing factors such as water levels, waves, winds, and the highest and most severe changes occur during storm surges. Extreme storms are drivers responsible for rapid and sometimes dramatic changes of the coastline. The consequences of the impacts from these events entail a broad range of social, economic and natural resource considerations from threats to humans, infrastructure and habitats. This study investigates the impact of a severe storm on coastline response on a sandy multi-barred beach at the Belgian coast. Airborne LiDAR surveys acquired pre- and post-storm covering an area larger than 1 km<sup>2</sup> were analyzed and reproducible monitoring solutions adapted to assess beach morphological changes were applied. Results indicated that the coast retreated by a maximum of 14.7 m where the embryo dunes in front of the fixed dunes were vanished and the foredune undercut. Storm surge and wave attacks were probably the most energetic there. However, the response of the coastline proxies associated with the mean high water line (MHW) and dunetoe (DuneT) was spatially variable. Based on the extracted beach features, good correlations (r>0.73) were found between coastline, berm and inner intertidal bar morphology, while it was weak with the most seaward bars covered in the surveys. This highlights the role of the upper features on the beach to protect the coastline from storm erosion by reducing wave energy. The findings are of critical importance in improving our knowledge and forecasting of coastline response to storms, and also in its translation into management practices.</p>

scholarly journals Exploitation of Documented Historical Floods for Achieving Better Flood Defense

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Slobodan Kolaković ◽  
Julius Fabian ◽  
Sándor Kovács ◽  
Ljubomir Budinski ◽  
Matija Stipić
Keyword(s):  
Numerical Model ◽  
Interdisciplinary Approach ◽  
Water Levels ◽  
Flood Mitigation ◽  
Stream Network ◽  
Detention Ponds ◽  
Extreme Flood ◽  
Tisza River ◽  
Flood Elevation ◽  
The Impact

Establishing Base Flood Elevation for a stream network corresponding to a big catchment is feasible by interdisciplinary approach, involving stochastic hydrology, river hydraulics, and computer aided simulations. A numerical model calibrated by historical floods has been exploited in this study. The short presentation of the catchment of the Tisza River in this paper is followed by the overview of historical floods which hit the region in the documented period of 130 years. Several well documented historical floods provided opportunity for the calibration of the chosen numerical model. Once established, the model could be used for investigation of different extreme flood scenarios and to establish the Base Flood Elevation. The calibration has shown that the coefficient of friction in case of the Tisza River is dependent both on the actual water level and on the preceding flood events. The effect of flood plain maintenance as well as the activation of six potential detention ponds on flood mitigation has been examined. Furthermore, the expected maximum water levels have also been determined for the case if the ever observed biggest 1888 flood hit the region again. The investigated cases of flood superposition highlighted the impact of tributary Maros on flood mitigation along the Tisza River.

scholarly journals Influences of tidal energy advection on the surface energy balance in a mangrove forest

2012 ◽  
Vol 9 (8) ◽  
pp. 11739-11765 ◽  
Author(s):  
J. G. Barr ◽  
J. D. Fuentes ◽  
M. S. DeLonge ◽  
T. L. O'Halloran ◽  
D. Barr ◽  
...  
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Mangrove Forest ◽  
Surface Energy Balance ◽  
Energy Transport ◽  
Tidal Energy ◽  
Water Levels ◽  
Energy Output ◽  
Tidal Flows ◽  
The Impact

Abstract. Mangrove forests are ecosystems susceptible to changing water levels and temperatures due to climate change as well as perturbations resulting from tropical storms. Numerical models can be used to project mangrove forest responses to regional and global environmental changes, and the reliability of these models depends on surface energy balance closure. However, for tidal ecosystems, the surface energy balance is complex because the energy transport associated with tidal activity remains poorly understood. This study aimed to quantify impacts of tidal flows on energy dynamics within a mangrove ecosystem. To address the research objective, an intensive study was conducted in a mangrove forest located along the Shark River in the Everglades National Park, FL. Forest-atmosphere energy exchanges were quantified with an eddy covariance system deployed on a flux tower. The lateral energy transport associated with tidal activity was calculated based on a coupled mass and energy balance approach. The mass balance included tidal flows and accumulation of water on the forest floor. The energy balance included temporal changes in enthalpy, resulting from tidal flows and temperature changes in the water column. By serving as a net sink or a source of available energy, tidal flows reduced the impact of high radiational loads on the mangrove forest. Including tidal energy advection in the surface energy balance improved the 30-min daytime energy closure from 73% to 82% over the study period. Also, the cumulative sum of energy output improved from 79% to 91% of energy input during the study period. Results indicated that tidal inundation provides an important mechanism for heat removal and that tidal exchange should be considered in surface energy budgets of coastal ecosystems. Results also demonstrated the importance of including tidal energy advection in mangrove biophysical models that are used for predicting ecosystem response to changing climate and regional freshwater management practices.

scholarly journals Oceanographic, ecological, and socio-economic impacts of an unusual summer storm in the Mackenzie Estuary

2020 ◽  
Vol 6 (2) ◽  
pp. 62-76 ◽  
Author(s):  
Kevin C. Scharffenberg ◽  
Dustin Whalen ◽  
Shannon A. MacPhee ◽  
Marianne Marcoux ◽  
John Iacozza ◽  
...  
Keyword(s):  
Habitat Use ◽  
Marine Mammals ◽  
Storm Surges ◽  
Open Water ◽  
Water Levels ◽  
Environmental Drivers ◽  
Mackenzie Delta ◽  
Arctic Ecosystems ◽  
Significant Drop ◽  
The Impact

With increased warming and open water due to climate change, the frequency and intensity of storm surges is expected to increase. Although studies have shown that strong storms can negatively impact Arctic ecosystems, the impact of storms on Arctic marine mammals is relatively unknown. In July 2016, an unusually large storm occurred in the Mackenzie Delta while instrumented seabed moorings equipped with hydrophones and oceanographic sensors were in place to study environmental drivers of beluga habitat use during their summer aggregation. The storm lasted up to 88 h, with maximum wind speeds reaching 60 km/h; historical wind data from Tuktoyaktuk revealed a storm of similar duration has not occurred in July in at least the past 28 years. This provided a unique opportunity to study the impacts of large storms on oceanographic conditions, beluga habitat use, and the traditional subsistence hunt that occurs annually in the delta. The storm resulted in increased water levels and localized flooding as well as a significant drop in water temperature (∼10 °C) and caused belugas to leave the area for 5 days. Although belugas returned after the storm ended, the subsistence hunt was halted resulting in the lowest beluga harvest between 1978 and 2017.

Demand and supply side changes in the Santa Cruz, Bolivia, milk sector 1985 – 2002: impact on small-scale producers and poor consumers

2004 ◽  
Vol 33 ◽  
pp. 315-321
Author(s):  
J. Rushton ◽  
N. Duran ◽  
S. Anderson
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Small Scale ◽  
Supply Side ◽  
Santa Cruz ◽  
Demand And Supply ◽  
The Past ◽  
Country Study ◽  
The Impact ◽  
The City

During the past three decades worldwide dairy policies have been implemented to promote the consumption of milk and milk products in urban areas and the production from rural areas close to big cities (Alderman et al., 1987). Bolivia and the city of Santa Cruz de la Sierra have been influenced by these worldwide directives and this current study examines the impact of policies on the demand and supply side of the sector, but with particular emphasis on smallholder milk producers and poor urban consumers. The current research is part of a multi-country study on the supply, demand and impact of dairy and other policies over a 10 to 15 year period (1985 to 2000) of the milk sectors of Santa Cruz, Bolivia; Nairobi, Kenya; and Kathmandu, Nepal.

scholarly journals Model Sensitivity during Extreme Positive and Negative Surges in the Río de la Plata Estuary: Highlighting the Need for an Appropriate Hindcast/Forecast System

2020 ◽  
Vol 35 (3) ◽  
pp. 1097-1112 ◽  
Author(s):  
Matías G. Dinápoli ◽  
Claudia G. Simionato ◽  
Diego Moreira
Keyword(s):  
Water Level ◽  
Surface Pressure ◽  
Numerical Solutions ◽  
Storm Surges ◽  
Water Levels ◽  
Wind Forcing ◽  
Rio De La Plata ◽  
Río De La Plata ◽  
La Plata ◽  
The Impact

Abstract The large and fast-flowing Río de la Plata (RdP) estuary is affected by extreme storm surges (above ±2 m with respect to tidal datum), which have large impacts on the millions of inhabitants and for navigation. In this work the Coastal and Regional Ocean Community Model (CROCO) numerical model was modified and implemented as a set of regional one-way nested 2D applications for the hindcast/forecast of water level in the RdP. A sensitivity analysis (SA) was carried out to determine the impact on the numerical solutions of the uncertainties in the different modeling parameter forcings and to highlight the need for the construction of a modeling system that provides meaningful information to the potential users. The SA included the friction coefficients, the wind speed and direction, the atmospheric surface pressure, and the continental discharge. Water level is most sensitive to uncertainties in the wind forcing; even small changes in this input can create large errors in the water level forecast/hindcast. Forcing with different analyses’ wind products yielded differences of up to 50% in the peak water levels. Results also showed that the modeling system requires a reasonable adjustment of the bottom friction parameters; that it is important to include the atmospheric surface pressure forcing; and that, from the point of view of water level forecast, it is not necessary to couple a hydrological model in spite of the enormous runoff of this estuary. Given the strong sensitivity to errors in the wind forcing, we believe it is important to provide estimates of uncertainty together with hindcast/forecast water level for these predictions to be of greatest quality and practical applicability.

scholarly journals Exploring the experiences of domestic abuse survivors working in the field of domestic abuse support: assisting recovery or re-victimisation revisited?

2020 ◽  
Vol 4 (1) ◽  
pp. 73-87
Author(s):  
Beverley Gilbert
Keyword(s):  
Women Survivors ◽  
Support Services ◽  
Vicarious Trauma ◽  
Domestic Abuse ◽  
Qualitative Interviews ◽  
Small Scale ◽  
Abuse Survivors ◽  
The Past ◽  
The Impact ◽  
The Voice

Women’s domestic abuse support services have developed over the past decades with the inclusion of women surviving abuse as practitioners themselves (Mullender and Hague, 2001; Slattery and Goodman, 2009; Bemiller and Williams, 2011). Following a literature review of this area, women ‘survivor support workers’ or ‘peer support/mentors’ have rarely been given the opportunity to articulate what it is that they are gaining personally and the impact in undertaking this emotionally challenging work. This small-scale study considers the voice of women survivors working in the field of domestic abuse support work, affording them the opportunity to explore the benefits and the costs to them as survivors of domestic abuse when working in this practice area. Twelve women ‘survivor support workers’ from five distinct English organisations took part in this research. Qualitative interviews were then analysed thematically within a feminist paradigm. Findings indicate that there are both highly positive aspects for survivors of abuse working in the domestic abuse sector, and equally, that there are areas of risk where re-victimisation and vicarious trauma could occur.

Integrated agriculture-aquaculture production systems in southern Malawi.

2020 ◽  
Author(s):  
Daniel Jamu
Keyword(s):  
Environmental Sustainability ◽  
Production Systems ◽  
Household Food Security ◽  
Small Scale ◽  
Annual Household Income ◽  
The Past ◽  
Household Food ◽  
Integrated Agriculture ◽  
The Impact ◽  
Aquaculture Production

Abstract Southern Malawi is characterized by the Rift valley and the Shire Highlands, which are dominated by the Zomba and Mulanje plateaux, and the Kirk Range. These mountainous areas are a source of various rivers and streams, which support small-scale integrated agriculture-aquaculture systems (IAA). The IAA systems were introduced to Malawi in 1986 by the WorldFish Center when a range of IAA technologies were developed and disseminated to farmers. The most common IAA system consists of fishponds, vegetables, fish, rice and irrigated maize. This system is practised by over 2,000 farmers in southern Malawi. The number of farmers practising this system has grown by 25% per year over the past 5 years because of the impact that this system has on household food security, income and environmental sustainability. Farmers practising IAA achieve yields of over 1,500 kg ha-1 yr-1 extrapolated from 450 m2 ponds compared with 900 kg ha-1 yr-1 for non-integrated farms and twice as much annual household income (US$ 270) than non-IAA farms.

scholarly journals The management dilemma: Removing elephants to save large trees

Koedoe ◽  
2019 ◽  
Vol 61 (1) ◽  
Author(s):  
Michelle D. Henley ◽  
Robin M. Cook
Keyword(s):  
Protected Areas ◽  
Mitigation Strategies ◽  
Small Scale ◽  
Individual Tree ◽  
Advantages And Disadvantages ◽  
The Past ◽  
Large Tree ◽  
Tree Survival ◽  
Large Trees ◽  
The Impact

The loss of large trees ( 5 m in height) in Africa’s protected areas is often attributed to the impact by savanna elephants (Loxodonta africana). Concerns have been raised over large tree mortality levels in protected areas such as South Africa’s Kruger National Park (KNP) and in the past, the need to manage its elephant population in order to preserve large trees and biodiversity as a whole. Our review aims to synthesise and discuss the complexities of managing elephants’ effects on the landscape to ensure the survival of large trees, as well as the application purposes of the various lethal and non-lethal elephant mitigation strategies. We further critically evaluate past management strategies, which have solely focused on controlling elephant numbers to protect large trees. Past mitigation strategies focused on managing elephant impact by directly reducing elephant numbers. However, maintaining elephant numbers at a pre-determined carrying capacity level did not prevent the loss of large trees. Research on large tree survival in African savannas has continually exposed the complexity of the situation, as large tree survival is influenced at various demographic stages. In some cases, a coalescence of historical factors may have resulted in what could be perceived as an aesthetically appealing savanna for managers and tourists alike. Furthermore, the past high density of surface water within the KNP homogenised elephant impact on large trees by increasing the encounter rate between elephants and large trees. Our review evaluates how current mitigation strategies have shifted from purely managing elephant numbers to managing elephant distribution across impact gradients, thereby promoting heterogeneity within the system. Additionally, we discuss each mitigation strategy’s occurrence at various landscape scales and its advantages and disadvantages when used to manage impact of elephant on large trees.Conservation implications: A variety of options exist to manage the effects that elephants have on large trees. These options range from large-scale landscape manipulation solutions to small-scale individual tree protection methods. Interactions between elephants and large trees are complex, however, and conservation managers need to consider the advantages and disadvantages of each mitigation strategy to protect large trees.

scholarly journals Regrassing flood-damaged pastures

2005 ◽  
pp. 117-121
Author(s):  
M.D. Wilson ◽  
I. Valentine
Keyword(s):  
Surface Condition ◽  
Soil Surface ◽  
Water Levels ◽  
Rooting Depth ◽  
Small Scale ◽  
Structured Interviews ◽  
Drying Time ◽  
Perennial Weed ◽  
Seedbed Preparation ◽  
The Impact

On the night of February 14th 2004 the lower North Island was hit with a storm system, which would cause the biggest flood seen in the region for over 100 years. The hardest hit areas include the Manawatu, Rangitikei, Horowhenua, Wairarapa and Wanganui regions. In the summer after the event, a survey was conducted of the affected areas. Semi-structured interviews of 52 individual farmers focused on their farm operations, the impact of the flood, and their regrassing strategies. The interviews established the state of the pastures postflood including depth and texture of silt deposit; water levels and flow; duration of inundation; and soil surface condition. The regrassing strategies included seedbed preparation, sowing technique, fertilizer use and weed control. Site measurements made were: pasture cover and species content, and that soil profiles revealed rooting depth and silt depth (if not cultivated). General trends that emerged were that the more thoroughly a seedbed was prepared the lower the risk of pasture establishment failure. Nitrogen (N) applications of 75 kg/ha over the intervening period did not have a significant effect but where deep sediment was encountered two or three applications of N was reported to produce feed and start inputting organic matter (OM). The use of a roller drill increased the reliability of establishment and was essential for the establishment of pasture legumes. Double normal seeding rates (30-40 kg/ha) increased the reliability of success where the seed was broadcast. Many farmers that had no sediment reported perennial weed problems including couch, creeping buttercup and a variety of thistles. Small scale surface cultivation was reported to decrease drying time dramatically in extremely wet areas. Keywords: ground cover, pasture cultivars, pasture establishment, seedbed preparation, weeds and pests

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