Land degradation and settlement intensification in Umhlathuze Municipality

Xulu, Sifiso (2014-04)

Thesis (MSc)--Stellenbosch University, 2014.

Thesis

ENGLISH ABSTRACT: The multifaceted land degradation problem and its associated manifold impacts have attracted research from different disciplines, resulting in varying definitions of the concept. However, most researchers agree that human intervention that deteriorates the state of the environment is the central element. Among the anthropogenic activities that exacerbate land degradation, land cover has been singled out as the salient element. Rapid and unplanned land cover changes are primary manifestations of this problem. UMhlathuze Municipality, the study area which has superior biodiversity richness, is one of fastest growing municipalities in South Africa and is the locale of significant land modifications in recent decades because of a variety of industrial and residential developments. Using Landsat TM imagery acquired for 1984, 1996 and 2004, this study mapped and quantified land cover change and manifestations of land degradation in the uMhlathuze Municipality in conjunction with settlement intensification computed from orthophotographs acquired for 1984 and 2004. Census population statistics were analysed as a reflection of population dynamics and further to gauge related causes of land cover change. Geographical information technology (GIT) was applied as an analytical tool. The results revealed the anthropogenic influences that led to changes in land cover over the 20- year period between 1984 and 2004. The dominant natural cover classes in 1984 declined continuously and human-dominated land categories had increased sharply by 2004. Much of grasslands, forest and wetlands were converted to monotypical agroforestry (sugar cane and forestry plantations), built-up settlement and mining. These changes engendered complete loss of biodiversity (floral and migration of fauna). Bare ground, signifying land degradation, was noticeable although it exhibited a fluctuating trend which could be attributable to differences between the various imagery used. Along with population growth, the area of settlements increased over the study period and spatially sprawled from urban areas. Settlements showed a fairly stable spatial configuration over the 20-year period, but became magnified in medium- and high-density areas. Grassland and wetlands occurring around Richards Bay, as well as indigenous forest near Port Durnford, were identified as critically threatened ecosystems. The proposed industrial development zone and port expansion were recognized as having adverse ecological implications for wetlands. The study concluded that significant land cover changes occurred in the form of natural land cover giving way to monotypical agroforestry, built-up settlements and mining - all to the detriment of pristine natural habitat.

AFRIKAANSE OPSOMMING: Die veelvlakkige probleem van omgewingsdegradasie en die gepaardgaande veelsoortige impakte lok navorsing uit verskillende dissiplines, wat lei tot verskillende definisies van die konsep. Tog is die meeste navorsers dit eens dat menslike invloede die sentrale element is wat die toestand van die omgewing verswak. Van die vele menslike aktiwiteite is grondgebruikverandering uitgesonder as die belangrikste beïnvloeder van agteruitgang van die omgewing. Veral vinnige en onbeplande grondgebruikveranderinge verteenwoordig die primêre manifestasies van hierdie probleem. UMhlathuze Munisipaliteit, die studiegebied met 'n hoë biodiversiteitsrykdom, is een van die vinnigste groeiende munisipaliteite in Suid-Afrika, waar 'n verskeidenheid nywerheids- en residensiële ontwikkelings beduidende grondgebruikverandering oor die afgelope dekades dryf. Met behulp van Landsat TM beelde van 1984, 1996 en 2004, is hierdie studiegebied gekarteer en oppervlaktes gekwantifiseer om grondgebruikverandering en verwante manifestasies van die agteruitgang van landbedekking in die uMhlathuze Munisipaliteit te konstateer. Tesame hiermee is die verdigting van nedersettings ook met behulp van ortofoto’s van 1984 en 2004 aangeteken. Bevolkingsensusstatistieke is ontleed as weerspieëling van die gepaardgaande bevolkingsdinamika en om moontlike oorsake van verandering in grondbedekking te bepaal. Vir hierdie doel is geografiese inligtingstegnologie (GIT ) as analitiese instrument toegepas. Die resultate toon antropogeniese invloede lei tot veranderinge in grondbedekking oor die tydperk van 20 jaar tussen 1984 en 2004. Die dominante natuurlike dekkingsklasse in 1984 het voortdurend verminder en menslik-gedomineerde kategorieë het teen 2004 skerp gestyg. Baie van die grasvelde, woude en vleilande is daadwerklik omskep tot monotipiese agro-bosbou (suikerrieten bosbouplantasies), beboude nedersetting en mynbou. Hierdie veranderinge behels 'n volledige verlies van biodiversiteit (plantegroei en migrasie van fauna). Kaalgrond, wat dui op die agteruitgang van grondbedekking, was ook opvallend, hoewel dit 'n wisselende tendens toon wat ook kan wees as gevolg van die verskille tussen die beeldmateriaal wat gebruik is. Saam met die groei van die bevolking is bevind dat nedersettings oor die studieperiode toegeneem het en in tipiese spreipatrone weg van die stedelike gebiede uitbrei. Nedersettings het 'n redelik stabiele ruimtelike liggingsopset oor die tydperk van 20 jaar getoon, maar het in medium- en hoë- digtheid gebiedeverdeel. Die voorkoms van grasveld en vleiland rondom Richardsbaai, asook inheemse woud naby Port Durnford, is geïdentifiseer as krities-bedreigde ekosisteme. Die voorgestelde nywerheidsontwikkelingsone en hawe-uitbreiding is geïdentifiseer as ontwikkelings met nadelige ekologiese implikasies vir vleilande. Daar is dus tot die gevolgtrekking gekom dat beduidende voortgaande grondbedekkingveranderinge in die gebied voorkom, waarin natuurlike landdekking transformeer tot monotipiese agrobosbou, beboude nedersettings en mynbou - alles tot nadeel van die ongerepte natuurlike habitat.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/86208
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