Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: In South Africa a large number of dams owned by the Department of Water Affairs (DWA) need to
be rehabilitated. This study investigated the decision process involved in the prioritisation of dams
for rehabilitation. DWA developed a risk analysis methodology for defining the risks associated with
dam safety, expressed as the combination of the probability and consequences of dam failure. These
risks are evaluated usingmultiple acceptability criteria to assess risk to human life and the economic,
social, socio-economic and environmental impacts of dam failure. In this study, the criteria used in
the decision process to evaluate the acceptability of life safety risks were evaluated by comparing
to international best practice methods, where the acceptability of risk to human life is commonly
assessed as the expected number of fatalities against life safety criteria presented as FN-criteria on
an FN-diagram.
Damrehabilitation should reduce the probability of dam failure, thereby reducing the risk to society
in terms of the expected lives lost. However, the rehabilitation works come at a cost and the level
of these investments are usually large. In addition, the rehabilitation of South African government
owned dams are financed by society and these financial resources are limited. Thus investments into
dam rehabilitation works should be worthwhile for society. Society’s Willingness to Pay (SWTP) for
safety was applied to South African dam safety to determine the acceptable level of expenditure into
life safety that is required by society.
Investments into improved safety levels are not always dictated by society, but could also be
driven by the decision maker or owner requiring an economically optimal solution for the rehabilitation.
Economic optimisation accounts for considerations additional to life safety, including economic
motivations, damage costs of dam failure as well as compensation costs for lives lost. Often
economic optimisation would govern the decision problem. Also, the DWA current evaluation does not take the cost of rehabilitation into account in any way. Thus, FN-criteria that primarily evaluates
life safety, but also incorporates a measure of economic efficiency, were suggested in this study. / AFRIKAANSE OPSOMMING: In Suid-Afrika moet ’n groot aantal dammewat deur dieDepartement vanWaterwese (DWA) besit
word gerehabiliteer word. Hierdie studie het die besluitnemingsproses ondersoekwat toegepasword
om damme te prioritiseer vir rehabilitasiewerke. DWA het ’n bestaande metodologie wat gebaseer is
op risiko-analise. Die risikos wat verband hou met damveiligheid word deur die metode bepaal en
word uitgedruk as die kombinasie van waarskynlikheid en die beraamde gevolge van damfaling.
Hierdie risikosword geëvalueer teenoor verskeie kriteriawat die aanvaarbaarheid van risikos teenoor
menselewens en die ekonomiese, sosiale, sosio-ekonomiese en omgewingsimpakte van damfalings
assesseer. In hierdie studie word die kriteria wat gebruik word in die besluitnemingsproses om die
aanvaarbaarheid van risikos teenoor menselewens te bepaal geëvalueer deur die kriteria te vergelyk
met metodes wat internasionaal as beste praktyk beskou word. Internasionaal word die aanvaarbaarheid
van risikos teenoor menselewens oor die algemeen as die verwagte aantal sterftes teenoor
lewensveiligheidskriteria FN-kriteria op ’n FN-diagram geassesseer.
Dam rehabilitasiewerke behoort die waarskynlikheid van damfaling te verminder, sodoende verminder
die risiko teenoor die samelewing in terme van verwagte sterftes. Die rehabilitasiewerke
vereis finansiële beleggings, en hierdie beleggings is gewoonlik groot. Verder word die rehabilitasie
van Suid-Afrikaanse damme wat deur DWA besit word deur samelewing gefinansier en hierdie finasiële
hulpbronne is beperk. Dus moet hierdie beleggings die moeite werd wees vir die samelewing.
Die samelewing se bereidwilligheidomte betaal ("SWTP") vir veiligheid word toegepas in Suid-
Afrikaanse damveiligheidomdie aanvaarbare vlak van beleggings vir ’n verbeterde veiligheid teenoor
menselewens wat deur die samelewing vereis word te bepaal.
Beleggings in verbeterde damveiligheidsvlakke word egter nie altyd bepaal deur die samelewing
nie,maar kan ook gedryf word deur die besluitnemer of eienaar wat ’n ekonomies optimale oplossing
vir die rehabilitatiesewerke vereis. Ekonomiese optimering neem oorwegings addisioneel tot lewensveiligheid in ag, insluitend ekonomiese motiverings, skade kostes as die dam faal, sowel as
vergoedingskostes vir die verwagte sterftes. Ekonomiese optimering beheer dikwels die besluitnemingsprobleem.
Verder neem die huidige DWA besluitnemingssproses in geen manier die kostes
van rehabilitasie in ag nie. Dus word FN-kriteria wat hoofsaaklik veiligheid teenoor menselewens
evalueer,maar wat ook ’n mate van ekonomiese doeltreffendheid insluit, voorgestel in hierdie studie.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/80288 |
| Date | 03 1900 |
| Creators | Reynolds, Sonel |
| Contributors | Viljoen, Celeste, Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | xviii, 180 p. : ill. |
| Rights | Stellenbosch University |
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