Green Coastal Protection and Flood Defence Options for Western Indian Ocean Countries

Date
2022-11
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: Traditionally engineers have resorted to hard or grey infrastructure to defend vulnerable coastlines against the forces of coastal processes. However, there is growing interest and awareness in more sustainable or soft coastal defence approaches that work with the forces generated by coastal processes to achieve the same levels of coastal protection and gain the benefits of ecosystem services that hard infrastructure does not offer. Countries bordering and within the Western Indian Ocean have a large collective coastal population of about sixty million people. These countries are also among the most under-resourced and most at risk to the effects of climate change and sea-level rise in the world. This study intended to investigate and propose green coastal protection infrastructure options that could be adopted in countries in the Western Indian Ocean. A literature review was completed to understand the spectrum of coastal protection infrastructure including grey or hard infrastructure, eco-friendly infrastructure, hybrid infrastructure, and green or soft infrastructure. The advantages and disadvantages of each coastal protection type were discussed. Furthermore, the study explored a few examples of each coastal protection type. Literature was also sourced on ways to quantitatively evaluate the vulnerability of coastlines in the Western Indian Ocean using variables that are easily obtainable for countries that may not have detailed coastal surveys or historical records of coastal data. Finally, quantitative comparative evaluation methods of coastal infrastructure were investigated to account for the ecosystem services provided by soft infrastructure which are often ignored in traditional evaluation approaches. The information from the literature review informed the proposal of green and hybrid infrastructure strategies that could be adopted in countries in the Western Indian Ocean. Case studies were conducted in three Western Indian Ocean Countries to illustrate how green coastal infrastructure can be incorporated into coastal defence strategies. The case studies investigated were Mon Choisy, Albion, and Case Noyale in Mauritius, Ponta Gea and Praia Nova in Beria, Mozambique, and Richards Bay in South Africa.
AFRIKAANS OPSOMMING: In die verlede het ingenieurs meestal teruggeval op grys of harde infrastruktuur om kwesbare kuslyne te beskerm teen kusprosesse. Daar is egter toenemende belangstelling in en bewustheid van meer volhoubare of sagte kusbeskermingsbenaderings wat saamwerk met die kusprosesse en wat dieselfde vlakke van beskerming kan bied as tradisionele metodes, asook die voordele van ekosisteme kan benut. Lande in die Westelike Indiese Oseaan het ‘n groot kusbevolking van gesamentlik om en by sestig miljoen mense. Hierdie lande het ook ‘n aansienlike tekort aan hulpbronne en is onder die wat mees blootgestel is aan die risiko van klimaatverandering soos wat seevlakke wêreldwyd styg. Hierdie studie het ondersoek ingestel na, en groen kus beskermings opsies voorgestel, wat deur lande in die Westelike Indiese Oseaan benut kan word. ‘n Literatuuroorsig is voltooi om die omvang van kusbeskermings infrastruktuur, insluitend grys of harde infrastruktuur, eko-vriendelike infrastruktuur, gemengde infrastruktuur en groen of sagte infrastruktuur te kan verstaan. Die voordele en nadele van die verskillende benaderings word bespreek. Daar word ook voorbeelde van verskeie kusbeskermings tipes ondersoek. ‘n Literatuuroorsig is ook gebruik om maniere te kry om die kwesbaarheid van kuslyne van die Westelike Indiese Oseaan kwantitatief te kan evalueer, deur middel van algemeen beskikbare veranderlikes wat maklik verkrygbaar is vir lande wat ‘n tekort het aan gedetailleerde kusopnames of historiese data. Laastens is kwantitatiewe vergelykende evaluerings-metodes ondersoek om die nut van ekosisteem dienste gebied deur sagte infrastruktuur te bepaal, wat andersins dikwels deur bestaande evaluerings-metodes misgekyk word. Die inligting voortspruitend uit die literatuuroorsig het aanleiding gegee tot voorstelle vir infrastruktuur strategieë wat deur lande in die Wes-Indiese Oseaan aangewend kan word. Gevallestudies is uitgevoer in drie Wes-Indiese Oseaan lande om te wys hoe groen kusinfrastruktuur in kusbeskermingsstrategieë opgeneem kan word. Die gevallestudies wat ondersoek is sluit in Mon Choisy, Albion, en Case Noyale in Mauritius, Ponta Gea en Praia Nova in Beira, Mosambiek, en Richardsbaai in Suid Afrika.
Description
Thesis (MEng) -- Stellembosch University, 2022.
Keywords
Sustainable engineering, Coastal engineering, Sea level, Coastal ecology, Ecosystem services, Coastal Vulnerability Index, Breakwaters, UCTD
Citation