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dc.contributor.advisorViljoen, M. F.
dc.contributor.advisorEaster, K. W.
dc.contributor.authorArmour, Robert Jack
dc.date.accessioned2018-09-04T07:08:00Z
dc.date.available2018-09-04T07:08:00Z
dc.date.issued2007
dc.identifier.urihttp://hdl.handle.net/11660/9207
dc.description.abstractEnglish: This thesis is the culmination of salinity economics research conducted for the South African Water Research Commission. The contribution of this thesis to science is not only in the field of Agricultural Economics. but also in other fields involved in irrigation salinisation research. It integrates the diverse mono-disciplinary spatial and temporal dimensions of the various disciplines of hydrology, agronomy, soil science and agricultural- and macro-economics, into an economic base model, to test scenarios and evaluate the economic, social and environmental sustainability of irrigated areas subject to salinisation. Problem Statement and the Study Area: Salinisation of irrigation schemes has become a problem in various schemes in South Africa. One such area that experiences salinisation problems selected for this research is the Lower Vaal and Lower Riet irrigation areas, upstream from where these two rivers converge and flow into the Orange River. By understanding the dynamics and interactions between irrigation water quality and the soil salinity status on crop yield over time, mistakes made in the past by choosing unsustainable irrigation sites and practices can be prevented in the future. Furthermore the impact of various natural or artificial (e.g. policy mechanism) scenarios on existing schemes can be more accurately modelled, leading to increased economic efficiency and sustainability of the irrigation industry, together with its primary and secondary linkages, as a whole. Aims: The overall aim of the WRC study on which this thesis is based was to develop and integrate multi-dimensional models for sustainable management of water quantity and quality in the Orange-Vaal-Riet (OVR) convergence system. More specifically the following sub-objectives had to be addressed: 1. To better understand the polluting chemical processes and interactions in and in-between the plant andsurface-, vadase zone- and ground- water, to achieve efficient and sustainable water quality management 2. To develop new economic models at both, a. Micro level, namely dynamic long term simulation models, and at b. Macro level, using a regional dynamic Input / Output model' 3. To integrate these new economic models with models from the other disciplines of: a. Hydroloqy" (incorporating a salt mass balance and flow), and b. Agronomy (crop growth in the presence of salinity model) 4. To determine and prioritise best management practices at: a. Micro level, (i.e. per hectare and irrigation block level) and at b. Regional level. 5. Through a better understanding of the multi-dimensional interactions, to enhance water use efficiency as the quantity and quality of water available for agriculture inevitably decreases 6. To develop policy guidelines to ensure social, environmental and economic sustainability 7. To achieve all these aims based on using the complex OVR convergence system as a study area, but developing a method and models that can be applied elsewhere with relative ease. This thesis however only covers the micro-economic aspect of the WRC project conducted by the author, and how it is driven by the hydrological and bio-physical processes and how it links and translates to the macroeconomic (regional) impact. Model: The economic base model of the integrated model uses hydrology and biophysical data and algorithms as inputinto the monthly time-step, per hectare Crop Enterprise Budget based, MSExcel simulation model (SMsim) to generate the base data. The resulting steehastic and spatially differentiated data set of per hectare total gross margin above specified costs data is then converted to sub-WUA, WUA, combined WUA and regional area level data for comparison and interpretation at these various levels and for input into the macro-economic regional level model (ISIM) and the index for socio-economic welfare (ISEW) for sustainability evaluation between alternative scenarios. Results: The results of this thesis inter alia show that the installation of irrigation drainage to facilitate leaching is a far better option than planting more salt tolerant crops. In the WRC project on which this thesis is based the results of a macro-economic analysis based on the micro-economic results from this thesis show that although at sub- WUA level it may not be financially feasible to install drainage in some sub-WUA areas, the secondary and regional socio-economic and environmental impacts justify the spending of government grants for drainage installation as the secondary benefits on the regional economy exceed the costs of the drains.en_ZA
dc.description.abstractAfrikaans: Hierdie tesis is die kulminasie van navorsing oor die ekonomie van versouting gedoen vir die Suid Afrikaanse Waternavorsingskommissie (WNK). Die bydrae van die tesis tot die wetenskap is nie net op die terrein van Landbouekonomie nie, maar ook op ander terreine betrokke by navorsing oor versouting van besproeiing. Dit integreer diverse mono-disiplinêre ruimtelike en tyds dimensies van die verskillende disiplines van hidrologie, agronomie, grondkunde en landbou- en makro-ekonomie, in 'n ekonomiese basis model, om scenarios te toets en die ekonomiese-, sosiale- en omgewingsvolhoubaarheid van besproeiingsgebiede wat deur vesouting geaffekteer word te evalueer. Probleemsteling en Ondersoekgebied: Die vesouting van verskeie besproeiingskemas het 'n problem in Suid Afrika geword. Een sodanige gebied wat versouting ervaar en wat vir die doeleindes van die navorsing gekies is, is die Benede-Vaal en -Rietrivier besproeiingsgebiede, stroomop van waar die twee riviere bymekaar kom en in die Oranjerivier vloei. Deur die dinamika en interaksies tussen besproeiingswaterkwalitiet en die grond se vesoutingstatus op gewas opbrengs oor tyd te verstaan, kan foute van die verlede soos die keuse van onvolhoubaare besproeiingsgebiede en praktyke vehoed word. Verder kan die impakte van verskeie natuurlike en kunsmatige (b.v. beleidsmeganismes) scenarios op huidige skemas meer akuraat gemodeleer word, wat kan lei tot toenemende ekonomiese doeltreffendheid van die besproeiingsindustrie, met sy primêre en sekondêre koppelinge. Doelstelling: Die oorhoofse doelstelling van die studie waarop die tesis gebaseer is was om multi-dimensionele modelle te ontwikkel en te integreer vir die volhoubare bestuur van water-kwantiteit en -kwalitiet in die Oranje-Vaal-Riet (OVR) samevloeiings. Meer spesifiek, was die volgende sub-doelstellings aangepak: 1. Om die besoedelende chemiese prosesse en interaksies tussen en binne in die plant en oppervlakte-, wortelsone- en grond- water beter te verstaan, om doeltreffende en volhoubare waterkwaliteit te bestuur 2. Om nuwe ekonomiese modele te ontwikkelop beide, a. Mikro vlak, naamlik dinamiese langtermyn simulasiemodelle, en b. Makro vlak, deur die gebruik van 'n streeksvlak dinamiese Inset / Uitsel model' 3. Om die nuwe ekonomiese modelle te integreer met modelle van die ander dissiplines, naamlik: a. Hidroloqie" (deur die inkorporering van 'n soutmassabalans en vloei), en b.Agronomie (gewasgroei in die teenwoodigheid van soute) 4. Om die beste bestuurspraktyke te bepaal en prioritiseer op: a. Mikro vlak, (d.i. per hektaar en besproeiingsblok vlak) en op b. Streek vlak 5. Deur die multi-dimensionele interaksies beter te verstaan, kan waterverbruiksdoeltreffendheid verbeter soos wat die kwantiteit en kwaliteit van die water beskikbaar vir landbou doeleindes verminder 6. Om beleidsmaatreëls te ontwikkelom sosiale-, omgewings- en ekonomiese-volhoubarheid te bevorder 7. Om die doelstellings te bereik deur die gebruik van die komplekse OVR samevloeiingstelsel as studiegebied, maar om die metodiek en modelle so te onkwikkel dat hulle met relatiewe gemak op ander gebiede toegepas kan word. Die tesis dek net die mikro-ekonomiese aspekte van die WNK projek wat deur die skrywer self nagevors is, en hoe die aspekte deur die hidrologiese en bio-fisiese prosesse gedryf word, asook die koppeling met die makroekonomiese (streeksvlak) impakte. Die Model: Die ekonomiesebasis model van die geintegreerde model gebruik hidrologiese en bio-fisiese data en algoritmes as insette op 'n maandelikse-tydskaal-per-hektaar-gewasbegroting-gebaseerde-MSExcel-simulasie-model (SMsim) om die basis data te genereer. Die stogastiese en ruimptelik gedifferensieerde uitkomsdata stel van per hektaar Totale Bruto Marge Bo Gespesifieseerde Koste (TBMBGK) word dan omgeskakel na sub- Waterverbruikersvereniging (sub-WVV), WVV, gesamentlikke WVV en streeksvlak data vir vegelyking en interpretasie op die verskillende vlakke, en as insette binne in die makro-ekonomiese streeksvlak model (ISIM) en die Indeks vir Sosio-Ekonomiese Welvaart (ISEW) om volhoubaarheid van alternatiewe scenarios te bepaal. Resultate: Die resultate van die tesis wys onder andere dat die installering van besproeiingsdreinering om loging tefasiliteer 'n heelwat beter opsie is as om meer sout-verdraagsame gewasse te plant. In die WNK verslag waarop die tesis gebaseer is, het die resultate van die makro-ekonomiese analiese wat gebaseer is op die mikro-ekonomiese resultate van die tesis gewys dat alhoewel dit op sub-WVV vlak dalk nie finansieël die moeite werd is om dreinering in sekere sub-WVV gebiede te installeer nie, dit wel op groter gebiedsvlak geregverdig kan word. Dit is omdat die voordele van die sekondêre en streeksvlak sosio-ekonomiese en omgewingsimpakte heelwat groter is as die koste van dreinering.en_ZA
dc.description.sponsorshipWater Research Commissionen_ZA
dc.description.sponsorshipDepartment of Water Affairsen_ZA
dc.description.sponsorshipUniversity of the Free Stateen_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectWater salinization -- South Africaen_ZA
dc.subjectIrrigation farming -- Economic aspects -- South Africaen_ZA
dc.subjectSoil management -- South Africaen_ZA
dc.subjectThesis (Ph.D. (Agricultural Economics))--University of the Free State, 2007en_ZA
dc.titleIntegrated modelling for sustainable management of salinity in the lower Vaal and Riet river irrigation areasen_ZA
dc.typeThesisen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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