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Assessment of GIS-interpolation techniques for groundwater evaluation : a case study of the Sandveld, Western Cape, South AfricaMunch, Zahn 12 1900 (has links)
Thesis (MSc)--University of Stellenbosch, 2004 / ENGLISH ABSTRACT: The Sandveld, a potato growing area of the Western Cape is subject to significant
groundwater abstraction for both municipal and agriculture purposes. The climate is arid and
sensitive and important ecosystems in the area are showing varying degrees of impact.
Management measures are needed to ensure ongoing sustainable development of the area.
In this study, different interpolation techniques were evaluated to calculate values for
unsampled variables rainfall and groundwater elevation. Local deterministic techniques as
well as geostatistical techniques were used. It was found that geostatistical techniques,
especially with collateral information, such as topography, provided a more accurate result.
For environmental studies of this nature, Kriging is recommended as interpolation technique.
The underlying data will determine the selection of the particular type of Kriging.
Data was extracted from a customized relational database, geoMon, used for data capture,
retrieval, processing and reporting. Ease of data extraction facilitated analysis.
The interpolated grids were applied in two scenarios: Recharge calculations and quantification
as well as a new classification approach according to Resource Directed Measures (RDM).
Management classes were defined based on GIS-derived data. / AFRIKAANSE OPSOMMING: Die Sandveld, ‘n aartappelverbouingsgebied in die Wes-Kaap, ondergaan aansienlike
grondwateronttrekking vir beide munisipale sowel as landbou doeleindes. Die klimaat is dor
en droog en sensitiewe en belangrike ekosisteme in die area ondervind wisselende
impakvlakke. Bestuursmaatreëls word benodig om volhoubare ontwikkeling van die area te
verseker.
In hierdie studie is verskillende interpolasie tegnieke om onbekende waardes vir veranderlikes
gebruik in grondwater evaluasie te bereken, evalueer. Lokale deterministiese tegnieke sowel
as geostatistiese tegnieke is gebruik. Geostatistiese tegnieke, veral gebruik saam met
addisionele inligting soos topografie, bereken meer akkurate resultate. Vir omgewingsstudies
van hierdie aard, word Kriging aanbeveel as interpolasie tegniek. Eienskappe van die
onderliggende data word gebruik om die tipe Kriging aan te dui.
Data is onttrek uit ‘n gebruikersaangepaste databasis, geoMon, wat gebruik is vir
datavaslegging, onttrekking, prosessering en verslaggewing. Die gemak waarmee data
onttrek kon word het analise vergemaklik.
Geïnterpoleerde data is gebruik vir grondwateraanvullingsberekeninge en -kwantifisering
sowel as ‘n nuwe benadering tot klassifikasie volgens hulpbron gerigte maatreëls.
Bestuursklasse gebaseer op GIS-afgeleide data, is gedefinieer.
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Remote sensing of forest health : the detection and mapping of Pinus patula trees infested by Sirex noctilio.Ismail, Riyad. January 2008 (has links)
Sirex noctilio is causing considerable mortality in commercial pine forests in KwaZulu-
Natal, South Africa. The ability to remotely detect S. noctilio infestations remains
crucial for monitoring the spread of the wasp and for the effective deployment of
suppression activities. This thesis advocates the development of techniques based on
remote sensing technology to accurately detect and map S. noctilio infestations. To date,
no research has examined the potential of remote sensing technologies for the detection
and mapping of Pinus patula trees infested by S. noctilio.
In the first part of this thesis, the focus was on whether high spatial resolution
imagery could characterize S. noctilio induced stress in P. patula forests. Results
showed that, the normalized difference vegetation index derived from high spatial
resolution imagery has the potential to accurately detect and map the later stages of
S. noctilio infestations. Additionally, operational guidelines for the optimal spatial
resolutions that are suitable for detecting and mapping varying levels of sustained
S. noctilio mortality were defined. Results showed that a pixel size of 2.3 m is
recommended to detect high (11-15%) infestation levels, and a pixel size of 1.75 m is
recommended for detecting low to medium infestation levels (1-10%).
In the second part of this thesis, the focus was on the ability of high spectral
resolution (hyperspectral) data to discriminate between healthy trees and the early
stages of S. noctilio infestation. Results showed that specific wavelengths located in the
visible and near infrared region have the greatest potential for discriminating between
healthy trees and the early stages of S. noctilio infestation. The researcher also evaluated
the robustness and accuracy of various machine learning algorithms in identifying
spectral parameters that allowed for the successful detection of S. noctilio infestations.
Results showed that the random forest algorithm simplified the process by identifying
the minimum number of spectral parameters that provided the best overall accuracies.
In the final part of this thesis spatial modelling techniques were used to
proactively identify pine forests that are highly susceptible to S. noctilio infestations.
For the first time the random forest algorithm was used in conjunction with geographic
information systems for mapping pine forests that are susceptible to S. noctilio
infestations. Overall, there is a high probability of S. noctilio infestation for the majority
(63%) of pine forest plantations located in Mpumalanga, South Africa. Compared to
previous studies, the random forest model identified highly susceptible pine forests at a
more regional scale and provided an understanding of localized variations of
environmental conditions in relation to the distribution of the wasps. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.
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A land suitability evaluation for improved subsistence agriculture using GIS : the case study of Nkwezela, KwaZulu-Natal, South Africa.January 2007 (has links)
Rural farmers in the Nkwezela Area, with an average family size of 10 people, face a
number of problems. The crops that are predominantly cultivated in the area, for
subsistence (maize, dry beans, sorghum, potatoes, cabbages and turnips) have very low
yields compared to the potential yield of the land. Natural resources in the area are
increasingly deteriorating. In addition, arable land has shown remarkable signs of soil
erosion that may lead to loss of soil fertility.
This study evaluates the current land suitability for subsistence agriculture in Nkwezela
based on climatic, soil, topographic and crop requirement data collected from different
sources. The spatial parameters of the land resources were digitally encoded into a GIS
database to create thematic layers of the land resources which was then compared to the
crop requirement data of the selected crops grown in Nkwezela namely, maize, sorghum,
dry beans, potatoes, cabbages and turnips. A GIS was used to overlay the thematic layers
of the resources to select areas that satisfied the crop requirements of the selected crops.
The results of the analysis of the land evaluation in the study area showed that the very hot
summers, very cold winters together with the high clay content in the soils are the two
limiting factors in Nkwezela. The land suitability maps indicate that sorghum is highly
suitable in the area with dry beans and maize being relatively suitable. Cabbages are the
least the least adapted crop with potatoes and turnips being not suitable due to the high
temperatures during the growing season and the very cold winters.
In conclusion Nkwezela is in a high rainfall area that is suitable for subsistence agriculture
where warm season crops like dry beans, maize and sorghum are used for daily
consumption by the community and can be cultivated in a sustainable manner. In addition
the correct farming methods, procedures, liming and fertiliser requirements must be
implemented, adhered to and maintained in order to improve crop yields in a sustainable
manner and to encourage subsistence agriculture by the community. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.
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Late quaternary palaeoenvironments of the Mfabeni Peatland, Northern KwaZulu-Natal.Finch, Jemma M. January 2005 (has links)
To assist in developing a more precise understanding of past climatic changes in southern Africa, further pollen analytical research is required. In the past, pollen sites in the subregion have been restricted to swampy areas such as permanent springs and peat deposits. While such sites are often rare as a consequence of the aridity of the country, rich polliniferous deposits can be found in the peatlands surrounding coastal lakes in the Maputaland Coastal Plain. The Mfabeni peatland, situated on the eastern
shores of St. Lucia, contains relatively old sediments dating back to >45000 years bp at a depth of 7.80m. A multi-proxy approach, comprising radiocarbon, stable carbon isotope (513C) and palynological analysis, was applied in the investigation of Late Quaternary climatic conditions and vegetation changes along the Maputaland Coastal Plain. A single 10 m sediment core, dating back to >45000 years bp, was extracted
from the Mfabeni Peatland. A detailed fossil pollen analysis of Mfabeni sediments indicated the existence of extensive Podocarpus-abundant coastal forests before ca. 44500 years bp. The onset of wetter local conditions after this time is inferred from forest retreat and the development of swampy conditions, which prevailed until ca. 25000 Cal years BP. Conditions during the Last Glacial Maximum (LGM; 18000 years BP) are inferred to have been generally colder and drier, as evidenced by forest retreat and replacement of swampy reed/sedge communities by dry grassland. A significant depletion in 813C values at ca. 18200 Cal years BP indicates the dominance of C3 vegetation during the LGM, reflecting considerably colder conditions. This is in agreement with palaeoenvironmental indications from elsewhere in the Transvaalian Ecozone, although conditions at Mfabeni were more moderated in their manifestation, which can be attributed to the proximity of this site to the ocean. Cool, relatively moist conditions are inferred for the Holocene Altithermal (ca. 8000-6000 years BP), as evidenced by forest growth and expansion during this time. Warm, dry conditions are inferred for the Late Holocene, with the establishment of grassland/savanna type vegetation in the area after ca. 2000 Cal
years BP. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
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Local economic development and local government : a case study of the Ingwe Municipality.Gardyne, Samantha Lee. January 2005 (has links)
On a global scale, the challenges of confronting poverty and inequality continue to dominate the development agenda. The ability of local economic development to empower local people has earned favour with national governments and development theorists. The imperative facing South Africa to achieve a more equitable and sustainable economy is essentially the challenge to adopt and implement a development approach that will reduce poverty and inequality to the greatest extent. It is within this context that the South African government has sought to incorporate local economic development into their economic development framework, predominantly through the decentralisation of development control and planning to the local government level. This dissertation seeks to examine the potential for South African local government to have a positive impact on economic development through fulfilling the roles and responsibilities provided in the government's mandate for developmental local government. The analysis focuses on the local economic development strategy adopted by the Ingwe Municipality, with specific attention given to the diversification of their economy through the tourism sector. The dissertation seeks to identify key lessons and contributions for local economic development that Ingwe has to offer, as well as providing recommendations for the Ingwe municipality's benefit. An extensive range of research methodologies, including interviews, questionnaires, secondary data analysis and literature reviews, were employed in this study. Analysis and evaluation of the Ingwe Municipality's local economic development strategy was achieved using the Sustainable Livelihoods Framework and the guidelines set out by Nel (1999). This dissertation revealed the potential that does exist within local government to play a developmental role. The Ingwe experience illustrates the benefits gained when local leadership and vision is extended on behalf of the local communities. Through the acquisition of funds and the formation of public and private partnerships, the Ingwe Municipality has created an economic environment conducive to further economic growth through the avenue of tourism. While success cannot be guaranteed, the Ingwe Municipality is evidence of the potential that does and can exist within local government to embark on innovative pro-poor development initiatives. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.
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Field spectroscopy of plant water content in Eucalyptus grandis forest stands in KwaZulu-Natal, South AfricaJanuary 2008 (has links)
The measurement of plant water content is essential to assess stress and
disturbance in forest plantations. Traditional techniques to assess plant water
content are costly, time consuming and spatially restrictive. Remote sensing
techniques offer the alternative of a non destructive and instantaneous method of
assessing plant water content over large spatial scales where ground
measurements would be impossible on a regular basis. The aim of this research
was to assess the relationship between plant water content and reflectance data in
Eucalyptus grandis forest stands in KwaZulu-Natal, South Africa. Field reflectance
and first derivative reflectance data were correlated with plant water content. The
first derivative reflectance performed better than the field reflectance data in
estimating plant water content with high correlations in the visible and mid-infrared
portions of the electromagnetic spectrum. Several reflectance indices were also
tested to evaluate their effectiveness in estimating plant water content and were
compared to the red edge position. The red edge position calculated from the first
derivative reflectance and from the linear four-point interpolation method performed
better than all the water indices tested. It was therefore concluded that the red
edge position can be used in association with other water indices as a stable
spectral parameter to estimate plant water content on hyperspectral data. The
South African satellite SumbandilaSat is due for launch in the near future and it is
essential to test the utility of this satellite in estimating plant water content, a study
which has not been done before. The field reflectance data from this study was
resampled to the SumbandilaSat band settings and was put into a neural network
to test its potential in estimating plant water content. The integrated approach
involving neural networks and the resampled field spectral data successfully
predicted plant water content with a correlation coefficient of 0.74 and a root mean
square error (RMSE) of 1.41 on an independent test dataset outperforming the
traditional multiple regression method of estimation. The potential of the
SumbandilaSat wavebands to estimate plant water content was tested using a
sensitivity analysis. The results from the sensitivity analysis indicated that the xanthophyll, blue and near infrared wavebands are the three most important
wavebands used by the neural network in estimating plant water content. It was
therefore concluded that these three bands of the SumbandilaSat are essential for
plant water estimation. In general this study showed the potential of up-scaling field
spectral data to the SumbandilaSat, the second South African satellite scheduled
for launch in the near future. / Thesis (M.Sc.) - University of KwaZulu-Natal, Pietermaritzburg, 2008.
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Integrated conservation-development : a geographical analysis of policy and practice in northern Maputaland.January 2001 (has links)
The thesis examines the genesis and implementation of integrated conservation development and associated projects in northern Maputaland during the 1980s and 1990s. The premise upon which this study is based is that there has been a worldwide paradigmatic shift in conservation policies and practices during the 1980s and 1990s. The extent to which initiatives in Maputaland reflected these trends is examined. In formulating a conceptual and theoretical framework for the study, the developments within the discipline of geography as well as the paradigmatic shifts within the broader sphere of conservation and development thinking, are discussed. Traditionally geography focuses on the nature of the relationship between human beings and their environment. Working within this tradition, the relationship between geography and conservation policy and practice is identified and applied to South Africa. Analysis of the process of integrating conservation and development in Maputaland is informed by both the broader international debate surrounding conservation and development and by local history and place specific conditions. The key geographical concepts of process and place are viewed as interdependent factors influencing one another. Within this framework and drawing on the concept of sustainable development, the experience of implementing the new conservation paradigm in Maputaland is recorded and analysed. The case study examples are associated with Ndumo Game Reserve. Sources of data and methodologies include primary sources (published books and journals), secondary sources (unpublished reports), participant-as-observer status with conservation liaison committees and the Ndumo Environmental Education Centre, key informant and focus group interviews and Participatory Rural Appraisal with the Ndumo Environmental Education Centre Management Committee. The study indicates that the Maputaland initiative did represent a considerable paradigm shift in the conservation policies guiding the general practice of conservation in Maputaland. The conservation agency did attempt to initiate Integrated Conservation Development Projects (ICDPs) during the 1990s, but this has been a complex process, fraught with tensions and suspicions. The practise fell short of the ideals and there is a long road to be travelled before reconciliation between conservation and community development is reached. / Thesis (M.A.)-University of Natal, Pietermaritzburg, 2001.
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An investigation into estimating productivity, above ground biomass and leaf area index of Eucalyptus grandis using remotely sensed data and a process-based model.Mzinyane, Thamsanqa D. January 2007 (has links)
South Africa depends largely on afforestation programs for its timber supplies due to the great demands for fiber and wood products. This has brought discomfort to other water users who have advocated that the effects of afforestation on water resources are detrimental to the country as a whole since South Africa is known as a water scarce country. This study has undertaken to integrate a process-based model and remote sensing data to estimate water use and productivity of Eucalyptus grandis in the Zululand areas of South Africa. The remote sensing techniques and recently developed "process based model" that is 3PG-S were used to estimate water use and productivity of Eucalyptus grandis, an economically important plantation species grown in the summer rainfall areas of South Africa. The study utilized monthly Landsat Thematic Mapper datasets and climatic data as inputs into the 3PG-S model, determined the Leaf Area Index (LAI) and Specific Leaf Area (SLA) through direct (destructive sampling) and indirect measurements (LiCor- 2000) and assessed the relationships between various vegetation indices (VI's) using correlation and regression analyses. The results suggest that all the indices, except the ratio VI, correlated significantly with LiCor-determined and destructively measured LAI values with both normalized difference vegetation index (NDVI) and Ratio Vegetation Index (RVI) (r=0.86, p / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritburg, 2007.
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Estimating foliar and wood lignin concentrations, and leaf area index (LAI) of Eucalyptus clones in Zululand usig hyperspectral imagery.Mthembu, Ingrid Bongiwe. January 2006 (has links)
To produce high quality paper, lignin should be removed from the pulp.
Quantification of lignin concentrations using standard wet chemistry is
accurate but time consuming and costly, thus not appropriate for a large
number of samples. The ability of hyperspectral remote sensing to predict
foliar lignin concentrations could be utilized to estimate wood lignin
concentrations if meaningful relationships between wood and foliar chemistry
are established. LAI (leaf area index) is a useful parameter that is
incorporated into physiological models in forest assessment. Measuring LAI
over vast areas is labour intensive and expensive; therefore, LAI has been
correlated to vegetation indices using remote sensing. Broadband indices use
average spectral information over broad bandwidths; therefore details on the
characteristics of the forest canopy are compromised and averaged.
Moreover, the broadband indices are known to be highly affected by soil
background at low vegetation cover. The aim of this study is to determine
foliar and wood lignin concentrations of Eucalyptus clones using hyperspectral
lignin indices, and to estimate LAI of Eucalyptus clones from narrowband
vegetation indices in Zululand, South Africa
Twelve Eucalyptus compartments of ages between 6 and 9 years were
selected and 5 trees were randomly sampled from each compartment. A
Hyperion image was acquired within ten days of field sampling, SI and LAI
measurements. Leaf samples were analyzed in the laboratory using the
Klason method as per Tappi standards (Tappi, 1996-1997). Wood samples
were analyzed for lignin concentrations using a NIRS (Near Infrared
Spectroscopy) instrument. The results showed that there is no general model
for predicting wood lignin concentrations from foliar lignin concentrations in
Eucalyptus clones of ages between 6 and 9 years. Regression analysis
performed for individual compartments and on compartments grouped
according to age and SI showed that the relationship between wood and foliar
lignin concentration is site and age specific. A Hyperion image was georeferenced
and atmospherically corrected using ENVI FLAASH 4.2.
The equation to calculate lignin indices for this study was: L1R= ~n5il: A'''''y .
1750 AI680
The relationship between the lignin index and laboratory-measured foliar lignin
was significant with R2 = 0.79. This relationship was used to calculate imagepredicted
foliar lignin concentrations. Firstly, the compartment specific
equations were used to calculate predicted wood lignin concentrations from
predicted foliar lignin concentrations. The relationship between the laboratorymeasured
wood lignin concentrations and predicted wood lignin concentrations
was significant with R2 = 0.91. Secondly, the age and site-specific equations
were used to convert foliar lignin concentration to wood lignin concentrations.
The wood lignin concentrations predicted from these equations were then
compared to the laboratory-measured wood lignin concentrations using linear
regression and the R2 was 0.79 with a p-value lower than 0.001.
Two bands were used to calculate nine vegetation indices; one band from the
near infrared (NIR) region and the other from the short wave infrared (SWIR).
Correlations between the Vis and the LAI measurements were generated and
. then evaluated to determine the most effective VI for estimating LAI of
Eucalyptus plantations. All the results obtained were significant but the NU
and MNU showed possible problems of saturation. The MNDVI*SR and
SAVI*SR produced the most significant relationships with LAI with R2 values
of 0.899 and 0.897 respectively. The standard error for both correlations was
very low, at 0.080, and the p-value of 0.001.
It was concluded that the Eucalyptus wood lignin concentrations can be
predicted using hyperspectral remote sensing, hence wood and foliar lignin
concentrations can be fairly accurately mapped across compartments. LAI
significantly correlated to eight of the nine selected vegetation indices. Seven
Vis are more suitable for LAI estimations in the Eucalyptus plantations in
Zululand. The NU and MNU can only be used for LAI estimations in arid or
semi-arid areas. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
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Free basic water implementation in selected rural areas of KwaZulu- Natal and the Eastern Cape.Balfour, Alison Faye. January 2004 (has links)
Water is both a human right and a valuable commodity. Access to water for the rural poor is
an international development concern that has been highlighted by the Millennium Development Goals adopted at the Millennium Summit in 2000 in Dublin, Ireland. South Africa's Free Basic Water policy is the government's response to assuring access to water for all - especially those who cannot pay. The policy, however, is required to work within an
economic framework that promotes cost recovery and privatisation. The Free Basic Water Policy was officially implemented in July 2001. The policy was rolled out in most urban areas on or near this date. However, in rural areas it has proven much more difficult, and there are many areas that have not yet seen the implementation of Free Basic Water (FBW). This is partly due to varying financial, technical, political and logistical problems at the local and district municipality level. This research investigates the current situation in rural municipalities, looking specifically at FBW policy, institutional arrangements, operation and maintenance costs, cost per capita and affordability in relation to the Equitable Share allocations. Five case studies - compiled through interviews, document analyses, Participatory Rural Appraisal, and workshops provide a broad scale research base from which to analyse the current implementation of FBW in rural municipalities and ascertain whether this policy is affordable at this level. Water Service Authorities (WSA) are at varying levels of implementation, with few having a
fully operational policy that is reaching rural areas. A costing exercise revealed that the service delivery price of water varies, but does follow a trend. From this trend a benchmark cost per capita of R5.84/month was determined. This price, although low, is not currently affordable in some municipalities due to insufficient government grants from National Treasury. These grants are fundamental to the sustainability of FBW and the situation must be resolved if FBW is to reach its target market - the poorest of the poor. The mixed success in the implementation of Free Basic Water in rural areas of South Africa should not be taken as indicative of future trends. As the local government transition to newly devolved powers and functions is completed, the capacity at this level to resolve the challenges is more likely. Subject to the continued strength of the South African economy,
this policy could be a solution to the historical failure of service delivery to rural areas. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2004.
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