Proefschrift Universiteit van Amsterdam. / Met bibliogr., lit. opg. - Met samenvatting in het Nederlands.

Thesis (doctoral)--Wageningen Agricultural University, 1998. / Summary and conclusion also in Dutch. Includes bibliographical references.

Marine diamond mining as practiced on the west coast of southern Africa is considered to be a high-risk venture. Investment decisions can be eased by using simulations to model likely outcomes. This study utilised Net Present Value (NPV) to measure the impact of sampling and grade estimation decisions on a marine diamond mining project. It focused on aspects such as the accurate determination of geological conditions, the influence of the degree of error in the geostatistical estimation process, sample density and sample support size. A simulated deposit was constructed that could be sampled using various parameters to measure the sensitivity of NPV. Various scenarios and their related NPV's showed that exploration costs have a small impact on a project in comparison with other cost aspects. However, the decisions made in the exploration process do have a significant impact on the NPV of a project. Inaccuracy in recovery efficiency and mining rate prediction, lead to a decline in NPV. Misfitting the semi-variogram model had a smaller impact on the NPV than the other scenarios investigated, but the importance of reflecting the true variance of the deposit in financial terms was evident. Finding the optimal sampling density and support size do have a positive effect on NPV. It is believed that the method demonstrated in this study can be used as a guide to add value in the selection of optimal parameters when planning exploration campaigns in marine mining projects. AFRIKAANS : Mariene diamant ontginning, soos beoefen aan die weskus van suidelike Afrika, is 'n hoe risiko ondememing. Beleggings besluite kan vergemaklik word deur simulasies te gebruik om moonlike resultate te modeleer. Hierdie studie het Netto Huidige Waarde (NHW) gebruik om die impak van steekproefneming en skattings besluite op 'n mariene diamantontginning projek te meet. Aspekte soos die korrekte bepaling van geologiese kondisies, die invloed van foute in die geostatistiese skattings proses, steekproef spasieering en steekproef grootte, is ondersoek. 'n Afsetting is met 'n simulasie geskep. Steekproewe is dan geneem van die afsetting om NHW sensitiwiteit teenoor verskeie parameters te meet. Verskeie scenarios en hulle verwante NHW's het gewys dat, in vergelyking met ander kostes, eksplorasie kostes 'n klein impak op 'n projek het. In teenstelling hiermee is die impak van besluite wat geneem word in die eksplorasie fase groot. Onakkurate herwinnings effektiwiteit en ontginningstempo skattings lei tot 'n afname in NHW. Swak modelering van die semi-variogram het 'n kleiner invloed op NHW, maar die belangrikeid daarvan om die ware variansie van die afsetting te reflekteer, was duidelik in finansieele terme. Die gebruik van optimale steekproef spasieering en grootte het 'n positiewe impak op NHW. Die metode wat gedemonstreer word in hierdie studie kan gebruik word as 'n gids om optimale parameters te selekteer wanneer eksplorasie programme beplan word vir mariene diamantontginnings projekte. Copyright / Dissertation (MSc)--University of Pretoria, 2012. / Geology / unrestricted

The South African coastal and marine environment is an essential ecologic and economic asset. Its associated services and products are substantially contributing to economic growth and sustainable development of the country. However, it is internationally and nationally recognised that land-based marine pollution (LBMP) is the most important single risk to the health and sustainability of coastal and marine waters and the associated ecosystems. The regulation of LBMP at the national level is still difficult and challenging. The issue of LBMP management has only recently been introduced in South Africa with the development of the National Programme of Action to Protect Marine Environment from Land-based Activities, 2008. South Africa is only starting to consider the question of LBMP regulation. This thesis aims to conduct a critical analysis of the South African regulatory framework pertaining to LBMP in comparison to international best practice and the French regulatory framework, in order to identify the key South African challenges in this regard and to make recommendations to address them. In order to do so, this research commences by providing an analysis of LBMP and the theoretical foundations associated with LBMP regulation, as promoted by international best practice. The study identifies and assesses the main regulatory features to be considered in the development, implementation and/or assessment of a regulatory framework pertaining to LBMP. These features will form the methodological framework to conduct the comparative legal assessment between the French and South African regulatory frameworks pertaining to LBMP. This thesis then provides a detailed and thorough legal analysis of the French and South African regulatory frameworks pertaining to LBMP using the methodological framework developed using guidance from international best practice. Finally, based on lessons learnt from the comparative legal study, this study concludes with a set of recommendations for the South African context. / Thesis (LL.D.)--North-West University, Potchefstroom Campus, 2011.

The South African coastal and marine environment is an essential ecologic and economic asset. Its associated services and products are substantially contributing to economic growth and sustainable development of the country. However, it is internationally and nationally recognised that land-based marine pollution (LBMP) is the most important single risk to the health and sustainability of coastal and marine waters and the associated ecosystems. The regulation of LBMP at the national level is still difficult and challenging. The issue of LBMP management has only recently been introduced in South Africa with the development of the National Programme of Action to Protect Marine Environment from Land-based Activities, 2008. South Africa is only starting to consider the question of LBMP regulation. This thesis aims to conduct a critical analysis of the South African regulatory framework pertaining to LBMP in comparison to international best practice and the French regulatory framework, in order to identify the key South African challenges in this regard and to make recommendations to address them. In order to do so, this research commences by providing an analysis of LBMP and the theoretical foundations associated with LBMP regulation, as promoted by international best practice. The study identifies and assesses the main regulatory features to be considered in the development, implementation and/or assessment of a regulatory framework pertaining to LBMP. These features will form the methodological framework to conduct the comparative legal assessment between the French and South African regulatory frameworks pertaining to LBMP. This thesis then provides a detailed and thorough legal analysis of the French and South African regulatory frameworks pertaining to LBMP using the methodological framework developed using guidance from international best practice. Finally, based on lessons learnt from the comparative legal study, this study concludes with a set of recommendations for the South African context. / Thesis (LL.D.)--North-West University, Potchefstroom Campus, 2011.

Abstract in English, Afrikaans and Sesotho / Scuba diving is a popular marine recreational activity along the eastern and southern coast of Africa. This region is characterised as the East African Marine Ecoregion (EAME) and is known for its richness in marine fauna and flora, including some of the Indian Ocean‟s most diverse and abundant coral reef ecosystems, making it a popular destination for scuba divers. The future of the scuba diving industry has come under threat as a result of environmental, social, political and economic impacts, and there is a need to better understand how these external risks impact on scuba diving tourism businesses in the EAME. Empirical evidence suggests that external risks, both international and domestic, have an effect on the tourism industry as a whole. However, limited research has been conducted on the impact of such external risks on the dive tourism industry specifically. Existing research has also focused extensively on environmental risks rather than on how external risks of a political, economic and social nature affect dive operator sustainability in the EAME. Most studies have also focused on the demand side (divers) as opposed to the supply side (dive operators). In addition, as dive tourists have greater flexibility to change their destination should risks arise, this threatens the success of dive operators in higher risk areas. To address these problems, the primary objective of the research undertaken sought to comprehensively identify the impact of external risks (environmental, economic, social and political) on dive operators in four countries within the EAME from a supply-side perspective. In order to achieve the primary objective, the following secondary objectives were achieved: 1. Identified scuba diving tourism operators in the EAME and their scope of operation. 2. Determined the external risks most relevant to dive operators in the EAME and assessed their level of impact. 3. Compared the individual external risks experienced by each of the countries in the EAME (Kenya, Tanzania, Mozambique and South Africa) using a cross-case analysis. 4. Assessed the perception of dive operators regarding whether external risks would influence a dive tourists decision to travel to the dive operators area of operation in the EAME ii The study consisted of two phases. Phase 1 comprised structured interviews with a select group of dive operators to gain insight into the external risks most prevalent in the scuba diving industry, as well as to assist in developing a quantitative structured survey (Phase 2), which was subsequently completed by dive operators in Kenya, Tanzania, Mozambique and South Africa. Data was imported into SPSS for quantitative statistical analysis. From the primary data collected, the major findings from this study determined that current economic and political risks have the greatest impact on dive operators in the EAME, and this trend is expected to continue. Environmental degradation of coral reefs, while not seen as a threat at present, constitutes a key threat for the near future. The greatest influences expressed in terms of risk categories impacting on dive tourism are domestic economic risks, international economic risks, domestic political risks and international political risks. A cross-case analysis conducted on the four countries concluded that external risks have varying effects within the different countries. Finally, the results indicated that external risks significantly influence a dive tourist's decision to travel to the EAME. By identifying and assessing the external risks that have an impact on dive operators in the EAME, this research contributes to knowledge on the dive tourism industry in the EAME, as well as dive tourism further afield and the wider field of tourism management. The study's findings create awareness of the effect that external risks have on dive operators in the region. A conceptual framework was developed which encompasses external risks in the scuba diving industry. Risk radars, risk maps and colour-coded tables were further outputs this study which can assist businesses, society and economies in responding to current and future threats and crises in a more informative and intuitive way. This can be achieved by implementing risk management strategies to mitigate or reduce exposure to external risks; strengthening stakeholder involvement along the tourism value chain; and stressing the need for government involvement towards the protection of the environment and promotion of small business growth in the region. Future research can include a wider view of the marine tourism industry and other areas of the Blue Economy. / Skubaduik is 'n gewilde mariene ontspanningsaktiwiteit langs die oos- en suidkus van Afrika. Hierdie streek staan bekend as die Oos-Afrika Mariene Ekostreek (East African Marine Ecoregion, EAME) en is bekend vir sy rykheid aan mariene fauna en flora, insluitende sommige van die Indiese Oseaan se mees diverse en welige koraalrif-ekostelsels, wat dit 'n gewilde bestemming vir skubaduikers maak. Die toekoms van die skubaduikbedryf word bedreig weens die impak van omgewings-, sosiale, politieke en ekonomiese gebeure, en daar is 'n behoefte om beter te verstaan hoe hierdie eksterne risiko's skubaduiktoerisme-besighede in die EAME beïnvloed. Empiriese bewyse suggereer dat eksterne risiko's, internasionaal sowel as plaaslik, 'n invloed op die toerismebedryf as 'n geheel het. Beperkte navorsing is egter gedoen oor die impak van sulke eksterne risiko's op spesifiek die duiktoerisme-bedryf. Bestaande navorsing het ook uitvoerig gefokus op omgewingsrisiko's eerder as hoe eksterne risiko's van 'n politieke, ekonomiese en sosiale aard duik-operateur-volhoubaarheid in die EAME beïnvloed. Die meeste studies het ook gefokus op die aanvraagkant (duikers) in teenstelling met die aanbodkant (duik-operateurs). Verder, omdat duiktoeriste meer buigsaamheid het om hulle bestemming te verander indien risiko's voorkom, bedreig dit die sukses van duik-operateurs in hoë-risiko-gebiede. Om hierdie probleme te hanteer is die primêre doel van die navorsing wat gedoen is om op omvattende wyse die impak van eksterne risiko's (omgewing, ekonomies, sosiaal en polities) op duik-operateurs in vier lande in die EAME te identifiseer uit 'n aanbodkant-perspektief. Om die primêre doelwit te behaal, is die volgende sekondêre doelwitte bereik: 1. Skubaduik-toerisme-operateurs in die EAME en hulle operasionele omvang is geïdentifiseer. 2. Die eksterne risiko's wat die relevantste vir duik-operateurs in die EAME is, is bepaal en hulle vlak van impak is geassesseer. 3. Die individuele eksterne risiko's wat deur elkeen van die lande in die EAME (Kenia, Tanzanië, Mosambiek en Suid-Afrika) ervaar is, is vergelyk deur die gebruik van 'n kruisgeval-analise. 4. Die persepsie van duik-operateurs wat betref of eksterne risiko's 'n duiktoeris se besluit sal beïnvloed om na die duik-operateur se operasionele gebied in die EAME te reis, is geassesseer. Die studie het uit twee fases bestaan. Fase 1 het gestruktureerde onderhoude met 'n geselekteerde groep duik-operateurs behels om insig te kry in die eksterne risiko's wat die algemeenste in die skubaduikbedryf voorkom, en om te help om 'n kwantitatiewe gestruktureerde peiling (fase 2) te ontwikkel, wat gevolglik deur duik-operateurs in Kenia, Tanzanië, Mosambiek en Suid-Afrika voltooi is. Data is ingevoer in SPSS vir kwantitatiewe statistiese analise. Uit die primêre data wat ingesamel is, het die belangrikste bevindings van hierdie studie bepaal dat die huidige ekonomiese en politieke risiko's die grootste impak op duik-operateurs in die EAME het, en daar word verwag dat hierdie tendens sal voortduur. Die omgewingsagteruitgang van koraalriwwe, hoewel dit nie tans as 'n bedreiging beskou word nie, is 'n sleutelbedreiging vir die nabye toekoms. Die grootste invloede wat uitgedruk is as risiko-kategorieë wat 'n invloed op duiktoerisme het, is plaaslike ekonomiese risiko's, internasionale ekonomiese risiko's, plaaslike politieke risiko's en internasionale politieke risiko's. 'n Kruisgeval-analise wat op die vier lande uitgevoer is, het bevind dat eksterne risiko's wisselende uitwerkings binne die verskillende lande het. Laastens het die resultate aangedui dat eksterne risiko's 'n duiktoeris se besluit om na die EAME te reis, aansienlik beïnvloed. Deur die eksterne risiko's te identifiseer en te assesseer wat 'n impak op duik-operateurs in die EAME het, dra hierdie navorsing by tot kennis oor die duiktoerismebedryf in die EAME, asook duiktoerisme verder weg en die wyer veld van toerismebestuur. Die studie se bevindings skep 'n bewustheid van die uitwerking wat eksterne risiko's op duik-operateurs in die streek het. 'n Konseptuele raamwerk is ontwikkel wat eksterne risiko's in die skubaduikbedryf omvat. Risiko-radars, risiko-kaarte en tabelle wat volgens kleur gekodeer is, was verdere uitsette van hierdie studie wat besighede, die gemeenskap en ekonomieë kan help om te reageer op huidige en toekomstige bedreigings en krisisse op 'n meer ingeligte en intuïtiewe manier. Dit kan bereik word deur risikobestuurstrategieë te implementeer om blootstelling aan eksterne risiko's te mitigeer of te verminder; belanghebberbetrokkenheid op die toerismewaardeketting te versterk; en om die behoefte vir regeringsbetrokkenheid by die insluit. / Ho sesa tlasa metsi a lewatle ke mosebetsi o tsebahalang haholo wa boithabiso ba lewatle haufi le mabopo a ka botjhabela le borwa ba Afrika. Sebaka sena se kgethollwa e le lefatshe la bophelo ba mawatle a Afrika Botjhabela (EAME) mme se tsejwa ka leruo la sona la diphoofolo tsa lewatle le dimela, ho kenyelletsa le tse ding tsa diphedi tse fapaneng tsa lewatle la Indian, e leng se etsang hore e be sebaka se tumeng bakeng sa batho ba sesang tlasa lewatle. Bokamoso ba indasteri ya ho tola tlasa lewatle bo kotsing ka lebaka la tshusumetso ya tikoloho, kahisano, dipolotiki le moruo, mme ho na le tlhokahalo ya ho utlwisisa hantle hore dikotsi tsena tsa kantle di ama jwang dikgwebo tsa bothori bo amanang le ho sesa tlasa lewatle EAME (Mabatoweng a Afrika Botjhabela a diphedi tsa mawatle). Bopaki bo hlakileng bo fana ka maikutlo a hore dikotsi tsa kantle, tsa matjhaba le tsa lehae, di na le tshwaetso indastering ya bohahlauli ka kakaretso. Leha ho le jwalo, dipatlisiso tse fokolang di ile tsa etswa mabapi le sefutho sa dikotsi tse jwalo tsa kantle indastering ea bohahlaudi ba ho sesa ka ho kgetheha. Dipatlisiso tse teng di boetse di tsepamisitse maikutlo haholo ka dikotsi tsa tikoloho di sa shebe hore na dikotsi tsa kantle tsa dipolotiki, tsa moruo le tsa kahisano di ama jwang ho tsitsisa tshebetso ho EAME. Diphuputso tse ngata di boetse di tsepame lehlakoreng la tlhokahalo (disesi) ho fapana le lehlakore la diphallelo (batho ba sesang). Ho phaella moo, jwalo ka ha disesi tsa bahahlaudi di ena le maemo a mangata a ho fetola dibaka tsa bona ha ho hlaha dikotsi, sena se senya katleho ya disesi dibakeng tse nang le dikotsi tse ngatanyana. Ho rarolla mathata ana, sepheo se ka sehloohong sa dipatlisiso tse entsweng di ile tsa leka ho lemoha ka ho hlaka sefutho sa dikotsi tsa kantle (tikoloho, moruo, kahisano le dipolotiki) ho disesi dinaheng tse nne tse ka hare ho EAME ho tloha lehlakoreng la phepelo. E le ho finyella sepheo se ka sehloohong, dipheo tse latelang di ile tsa fihlellwa: 1. Ho kgetholla basebeletsi ba bahahlaudi ba ho sesa lebatoweng la EAME le tsela ya tshebetso ya bona. 2. Ho etsa qeto ya dikotsi tse ka ntle tsa bohlokwa ho tsamaisa ba disesi ho EAME le ho hlahloba boemo ba tsona ba tshusumetso. 3. Ho bapiswa dikotsi tse ka ntle tsa naha ka nngwe ho EAME (Kenya, Tanzania, Mozambique le Afrika Borwa) ho sebedisa dintlha tsa ho hlahloba diketsahalo. 4. Hlahloba maikutlo a disesi mabapi le hore na dikotsi tse ka ntle di tla susumetsa qeto ya bahahlaudi ba ho etela sebakeng seo ba sebetsang ho sona ho EAME Thuto e ne e ena le mekgahlelo e mmedi. Mokgahlelo wa 1 o ne o ena le dipuisano tse hlophisitsweng le sehlopha se kgethilweng sa basebetsi ba disesi ho utlwisisa dikotsi tse ka ntle tse atileng haholo indastering ya ho sesa, le ho thusa ho ntlafatsa tlhahlobo e entsweng ka bongata (Phase 2), e ileng ya qetella e phethilwe ke basebetsi ba disesi Kenya, Tanzania, Mozambique le Afrika Borwa. Lesedi le ile la kenngwa ka SPSS bakeng sa tlhahlobo ya dipalopalo. Ho tswa leseding la motheho le bokelletsweng, diphuputso tse kgolo tsa thuto ena di bontshitse hore dikotsi tsa moraorao tsa moruo le tsa lipolotiki di na le tshusumetso e kgolo ho ba sebetsang e le basebetsi ba disesi EAME, mme mokgwa ona o lebeletswe hore o tswele pele. Ho senyeha ha tikoloho ya dimela/diphedi tsa lewatle, ha ho sa nkuweng e le tshoso hona jwale, ke tshoso e ka sehloohong bakeng sa nako e tlang. Tshusumetso e matla ka ho fetisisa e hlalositsweng ka mekgahlelo ya dikotsi tse amang tsela ya ho etela dibaka tsa bohahlaudi ke dikotsi tsa moruo wa lehae, dikotsi tsa matjhaba tsa moruo, dikotsi tsa dipolotiki tsa lehae le dikotsi tsa matjhaba tsa dipolotiki. Phuputso e entsweng dinaheng tse nne e qetile ka hore dikotsi tsa ka ntle di na le diphello tse fapaneng dinaheng tse fapaneng. Qetellong, diphello di bontshitse hore dikotsi tsa ka ntle di susumetsa haholo qeto ya mohahlaudi wa ya sesang tlasa lewatle ho etela EAME. Ka ho kgetholla le ho hlahloba dikotsi tse ka ntle tse nang le tshwaetso basebetsing ba disesi EAME, dipatlisiso tsena di tlatsetsa tsebong lefapheng la bohahlaudi ba ho ho sesa tlasa lewatle dibakeng tsa EAME, ha mmoho le bahahlaudi ba ho sesa ka ho phatlalla tsamaisong ya bohahlaudi. Diphuputso tsa thuto di etsa hore ho be le tlhokomediso ya phello ya ka moo dikotsi tse ka ntle di nang le kameho disesing sebakeng seo. Ho na le moralo o ileng wa etswa o kenyeletsang dikotsi tsa kantle indastering ya ho sesa tlasa lewatle. Diwaelese tse nkgellang dikotsi, dimmapa tsa dikotsi le ditafole tse nang le mebala di ne di boetse di hlahisa thuto ena e ka thusang dikgwebo, setjhaba le moruo ho arabela dikotsing tsa moraorao le tsa nakong e tlang ka ditsela tse rutang le tse nang le tsebo. Sena se ka fihlellwa ka ho kenya tshebetsong maano a tsamaiso ya kotsi bakeng sa ho fokotsa ho pepeseha dikotsing tsa kantle; ho matlafatsa tshebetsong ya bankaseabo motjheng wa bohlokwa wa bohahlaudi; le ho totobatsa tlhokahalo ya ho nka seabo ha mmuso ho sireletsa tikoloho le tshehetso ya kgolo ya dikgwebo tse nyenyane sebakeng seo. Phuputso ya nako e tlang e ka kenyelletsa pono e pharaletseng ya indasteri ya bahahlaudi ba lewatle le dibaka tse ding tsa Blue Economy. / Environmental Sciences / M. Com. (Tourism Management)