Introduction
The four presentations suggest solutions for alleviating flooding and preserving the Great Barrier Reef.
In the first presentation, solutions to protect the Great Barrier Reef, which is endangered from rising acidity levels due to methane extraction, were given while the second, third and fourth presentations focused on the measures to manage the effects of flash flooding in Penzance, the floods of river Erewash and the tidal and fluvial flooding in Pwllheli, North Wales, respectively.
This paper critically evaluates the suggested solutions to determine the best two solutions and two others, which can be improved.
The Best Two Solutions
The solution provided for conserving the Great Barrier Reef is a good approach for ensuring that the reef remains healthy and thriving in the future. An inclusive legislation is suggested, which, among other things, authorizes the minimum drilling depths, restricts mining around the Great Barrier Reef and encourages the use of the carbon sequestration technique through tax exemptions.
In my view, this solution stands out as the best since, currently, there is no piece of legislation (in international) that provides guidelines on deep sea methane mining or mining near the Great Barrier Reef.
In my view, the other best solution in the presentations is the storm drains to control river Erewash flooding. In my view, the other best solution in the presentations is the storm drains to control river Erewash flooding. They have many advantages over flood barriers and deep basins. They are cheap to build, they protect homes from flood waters and they enhance road safety.
Solutions that Need Improvement
In order for the solution to prevent tidal and fluvial flooding in Pwllheli and the integrated urban draining (IUD) to prevent flash flooding in Penzance and achieve their desired goals, some improvements need to be made.
Channelization and levees can help avert flooding of the downstream rivers. Also, upstream storage can serve as a cheap alternative to river diversion.
The second solution, the integrated urban draining (IUD) in Penzance, also needs some adjustments. Besides getting the community to work together, alleviating flood risks and implementing IUD, it would be important to conduct spatial planning, engage the stakeholders and assess the social/health issues before implementing this solution.
Analysis of the Solutions
The diversion of Rhyd Hir and Penrhos via the dunes at the Golf Club along with raising A499 and building a culvert under is a viable solution for managing the fluvial flooding risk in Pwllheli. It seeks to put in place defenses, monitor developments along the rivers and enhancing the resilience of built structures like A499.
However, the current defenses have declined significantly. The Abererch frontage’s dune crest has declined significantly to about 2m in width, which puts the affected regions at risk of flooding (Warburton, Holden & Mills 2004).
Moreover, in the west, there is a large part of the dune (Traeth Crugan frontage) remains undefended and may lead to floods in a single storm. Therefore, the proposed solution should also focus on strengthening the dunes to counter tidal and fluvial flooding. Also, raising awareness and promoting proper land use and development planning will help alleviate fluvial flooding.
The integrated urban draining (IUD) will allow different stakeholders to collaborate in flood risk management. However, the proposed solution did not outline the IUDM stakeholders and their roles and responsibilities in the partnerships. The IUD can benefit from modeling tools, which estimate the flood water risk (Griffiths 2010).
Pilot modeling projects in Penzance can help predict floods volumes caused by urban development and climate change. The other proposed solution for managing Erewash flooding is the use of storm drains. Compared to the other solutions to control flood water (flood barriers and deepening/new basins), storm drains offer several advantages over the other solutions.
They are safer, do not need to be repeated, do not overflow, are cheaper (cost £300,793 less) and integrate flood basins at the edges. They help drain run-off water and alleviate flooding. If rain water is not drained away, it builds up and causes flooding. Storm drains direct rainwater to a water reservoir. This helps reduce the amount of water runoff, which help alleviate flooding.
The solution for the Great Barrier Reef’s affected growth (an inclusive legislation) has the potential of protecting the Reef from the effects of climate change. Carbon emissions have a greater impact on coral reefs, including the Reef, as they increase the ocean temperature. Thus, to protect the Reef’s future, an effective action should involve measures that reduce carbon dioxide (CO2) gas emissions.
The suggested solution promises to protect the Reef from the effects of global warming, acidity and widespread ocean floor disturbances. The carbon sequestration approach will reduce the amount of CO2 emissions and reduce ocean acidity.
This will protect the organisms growing around the Reef. Deep sea mining causes ocean floor disturbances, which affect the growth of corals. Thus, the solution is to regulate deep sea mining, prohibit mining around the Reef and encourage carbon sequestration.
Alternative Proposal
The diversion of Rhyd Hir and Penrhos has the potential of alleviating flooding at Pwllheli. A better alternative would be to increase the upstream storage of water for river Rhyd Hir. This will create a wetland habitat that will enhance the management of the river flows (Hill et al. 2010).
This site should be located before A499. A risk management approach will be integrated to create awareness and reduce the effects of flooding to the people. It is projected that the sea level will rise to over 2m by the next century (Hough et al. 2010).
For Wales and Pwllheli, this implies “a 1: 10 year flood risk for every 1m sea level rise” (McInnes 2008, p. 67). The proposed alternative will involve the following approaches: enhancing the understanding of Pwllheli floods (fluvial floods), advance planning and responsive actions.
Besides public awareness, enhancing the resilience of infrastructural facilities would help in flood risk management. The current flood defenses including the dune protection, the tidal gates and the fluvial defenses should be evaluated to determine their capacity to prevent flooding (Johnson et al. 2010).
Coastal defenses at Traeth Crugan and Traeth Abererch along with diversion of river Penrhos (Moore et al. 2010) is another viable solution. Also, policies and legislations to guide development are important in flood risk management. The level of the levees at North Quay and Cob should be raised or reinforced at different areas along the river. This along with sustainable drainage systems will keep the rivers from overflowing.
References
Griffiths, J 2010, ‘Land Surface Evaluation for Engineering Practice’, Geological Society Special Publication vol. 18, no. 1, pp. 189-192.
Hill, A, Evans, T, Fish, P, &Thomas, S 2010, Deepwater Angola: geohazard mitigation. 2nd International Symposium on Frontiers in Offshore Geotechnics, Perth, Western Australia.
Hough, G, Green, J, Moore, R, Fish, P, & Mills, A 2010, Geomorphological mapping of seabed for geohazard risk assessment, ICE, Brighton.
Johnson, R, Warburton, J, Mills, A, & Winter, C 2010, ‘Evaluating the significance of event and post-event sediment dynamics in a first order tributary using multiple sediment budgets’, Geogrfiska Annaler vol. 92, no. 2, pp. 189-209.
McInnes, R 2008, Proceedings of the 2007 International Conference on Coastal Management, ICE, London
Moore, R, Rogers, J, Woodget, A, & Baptiste, A 2010, ‘Climate change impact on cliff instability and erosion in the UK’, Proceedings of the EA Conference of River and Coastal Engineers, vol. 7, no. 9, pp. 201-210.
Warburton, J, Holden, J, Mills, A 2004, ‘Hydrological controls on surficial mass movements in peat’, Earth Science Reviews, vol. 67, no. 3, pp. 139-156.