Mapping field photographs to textured surface meshes directly on mobile devices

Funded by Research Council of Norway. Grant Number: 234111/E30Peer reviewedPublisher PD

The Influence of Filmic Representations on Narratives of Place and Tourist Destination Image : Johannesburg, South Africa.

Dissertation (MSocSci (Heritage and Cultural Tourism))--University of Pretoria, 2022.The purpose of this study is to investigate the influence of popular media representations, specifically film and television, on narratives of place and tourist destination image. The argument is based on the premise that popular media representations of potential tourist destinations, through wide dissemination and use, construct and sustain specific expectations and perceptions in potential tourists. This may ultimately influence motivational indicators for travel to or deterrents from travel to a specific destination. The dissertation reflects on various aspects in films, at destinations, and inherent to audiences that can have an influence on location filming, film tourism and filmic destination marketing. It further explores certain infrastructural arrangements that make location filming, film tourism and filmic destination possible. These aspects are first examined through international examples, then related to a South African context and finally to specific filmic representations of Johannesburg in the Marvel Cinematic Universe and by Director Neill Blomkamp between 2009 and 2018.Historical and Heritage StudiesMSocSci (Heritage and Cultural Tourism)Unrestricte

Developing tools and models for evaluating geospatial data integration of official and VGI data sources

PhD ThesisIn recent years, systems have been developed which enable users to produce, share and update information on the web effectively and freely as User Generated Content (UGC) data (including Volunteered Geographic Information (VGI)). Data quality assessment is a major concern for supporting the accurate and efficient spatial data integration required if VGI is to be used alongside official, formal, usually governmental datasets. This thesis aims to develop tools and models for the purpose of assessing such integration possibilities. Initially, in order to undertake this task, geometrical similarity of formal and informal data was examined. Geometrical analyses were performed by developing specific programme interfaces to assess the positional, linear and polygon shape similarity among reference field survey data (FS); official datasets such as data from Ordnance Survey (OS), UK and General Directorate for Survey (GDS), Iraq agencies; and VGI information such as OpenStreetMap (OSM) datasets. A discussion of the design and implementation of these tools and interfaces is presented. A methodology has been developed to assess such positional and shape similarity by applying different metrics and standard indices such as the National Standard for Spatial Data Accuracy (NSSDA) for positional quality; techniques such as buffering overlays for linear similarity; and application of moments invariant for polygon shape similarity evaluations. The results suggested that difficulties exist for any geometrical integration of OSM data with both bench mark FS and formal datasets, but that formal data is very close to reference datasets. An investigation was carried out into contributing factors such as data sources, feature types and number of data collectors that may affect the geometrical quality of OSM data and consequently affect the integration process of OSM datasets with FS, OS and GDS. Factorial designs were undertaken in this study in order to develop and implement an experiment to discover the effect of these factors individually and the interaction between each of them. The analysis found that data source is the most significant factor that affects the geometrical quality of OSM datasets, and that there are interactions among all these factors at different levels of interaction. This work also investigated the possibility of integrating feature classification of official datasets such as data from OS and GDS geospatial data agencies, and informal datasets such as OSM information. In this context, two different models were developed. The first set of analysis included the evaluation of semantic integration of corresponding feature classifications of compared datasets. The second model was concerned with assessing the ability of XML schema matching of feature classifications of tested datasets. This initially involved a tokenization process in order to split up into single words classifications that were composed of multiple words. Subsequently, encoding feature classifications as XML schema trees was undertaken. The semantic similarity, data type similarity and structural similarity were measured between the nodes of compared schema trees. Once these three similarities had been computed, a weighted combination technique has been adopted in order to obtain the overall similarity. The findings of both sets of analysis were not encouraging as far as the possibility of effectively integrating feature classifications of VGI datasets, such as OSM information, and formal datasets, such as OS and GDS datasets, is concerned.Ministry of Higher Education and Scientific Research, Republic of Iraq

Sustainable utilisation of Table Mountain Group aquifers

Philosophiae Doctor - PhDThe Table Mountain Group (TMG) Formation is the lowest member of the Cape Supergroup which consists of sediments deposited from early Ordovician to early Carboniferous times, approximately between 500 and 340 million years ago. The Table Mountain Group (TMG) aquifer system is exposed along the west and south coasts of South Africa. It is a regional fractured rock aquifer that has become a major source of bulk water supply to meet the agricultural and urban water requirements of the Western and Eastern Cape Provinces of South Africa. The TMG aquifer system comprises of an approximately 4000 m thick sequence of quartz arenite and minor shale layers deposited in a shallow, but extensive, predominantly eastwest striking asin, changing to a northwest orientation at the west coast. The medium to coarse grain size and relative purity of some of the quartz arenites, together with their well indurated nature and fracturing due to folding and faulting in the fold belt, enhance both the quality of the groundwater and its exploitation potential for agricultural and domestic water supply purposes and its hot springs for recreation. The region is also home to some unique and indigenous floral species (fynbos) of worldwide importance. These and other groundwater dependent vegetation are found on the series of mountains, mountain slopes and valleys in the Cape Peninsula. The hydrogeology of the TMG consists of intermontane and coastal domains which have different properties but are interconnected. The former is characterized by direct recharge from rain and snow melt, deep groundwater circulation with hot springs and low conductivity groundwater. The coastal domain is characterized by shallow groundwater occurrence usually with moderate to poor quality, indirect recharge from rainfall of shallow circulation and where springs occur they are usually cold. The sustainable utilization of the TMG aquifer addressed the issues of the groundwater flow dynamics, recharge and discharge to and from the aquifer; challenges of climate change and climate variability and their potential impact on the aquifer system. The concept of safe yield, recharge and the capture principle and the integration of sustainable yield provided the basis for sustainable utilization with the adaptive management approach. Methodology used included the evaluation of recharge methods and estimates in the TMG aquifer and a GIS based water balance recharge estimation. The evaluation of natural discharges and artificial abstractions from the TMG aquifer system as well as its potential for future development. The Mann-Kendal trend analysis was used to test historical and present records of temperature and rainfall for significant trends as indication for climate variability and change. The determination of variability index of rainfall and standard precipitation index were additional analyses to investigate variability. The use of a case study from the Klein (Little) Karoo Rural Water Supply Scheme (KKRWSS) within the TMG study area was a test case to assess the sustainable utilization of TMG aquifers. Results show that recharge varies in time and space between 1% and 55% of MAP as a result of different hydrostratigraphic units of the TMG based on geology, hydrology, climate, soil, vegetation and landuse patterns however, the average recharge is from 1% to 5% of MAP. The TMG receives recharge mainly through its 37,000 km2 of outcrop largely exposed on mountainous terrain. Natural discharges from the TMG include 11 thermal and numerous cold spring discharges, baseflow to streams and reservoirs, and seepage to the ocean. Results from this study also show increasing temperature trend over the years while rainfall trend generally remain unchanged in the study area. Rainfall variability persists hence the potential for floodsand droughts in the region remain. Global and Regional Models predict about 10% to 25% reduction in rainfall and increase in variability in future. Impacts of his change in climate will affect the different types of aquifers in various ways. Increase in temperature and reduction in rainfall will increase evapotranspiration, reduce surface flows and eventually reduce shallow aquifer resources. Coastal aquifers risk upsurge in salinisation from sea level rise and increase in abstractions from dwindling surface water resources. While floods increase the risk of contamination to shallow aquifers droughts put pressure on all aquifers especially deep aquifers which are considered to be more reliable due to the fact that they are far removed from surface conditions. Future population growth and increase in freshwater demand will put more pressure on groundwater. Recharge to groundwater have been over-estimated in certain areas in the past leading to high abstraction rates from boreholes causing extensive groundwater storage depletion evident by high decline in groundwater levels in these areas and hampering sustainable management of the aquifer resources. Over-abstraction have resulted in loss of stream flow and baseflow reduction to streams during summer, complete loss of springs and reduction of flow to others. Flow to wetlands, riparian vegetation, and sometimes loss and shifts in dependent ecosystems have also resulted from over-abstraction. Sustainability has spatial and temporal implications due to changing climate and demand. The study recommends adaptive management practices in which several factors are considered in managing groundwater together with surface water resources in order to maintain ecological and environmental integrity. The KKRWSS and other groundwater supply schemes in the Western and Eastern Cape Provinces demonstrate the huge potential of the TMG to provide freshwatersupply for domestic and irrigation water needs however, the huge decline in groundwater levels due to over-abstraction in the KKRWSS and other groundwater schemes underscores the need for sustainable utilization of the TMG groundwater resources for present and future generations with minimal impacts on the quality, dependent hydrological and ecosystems as well as the environment.South Afric

GIS and remote sensing-based integrated modelling of climate and land use change impacts on groundwater quality: Cape Flats Aquifer, South Africa

Philosophiae Doctor - PhDThe need to ensure groundwater security is vital, particularly in urban areas. Assessing the impact of land use and climate variables on groundwater quality can help improve sustainable management. The vulnerability mapping of groundwater contamination identifies high-risk areas. Using models and technologies that forecast the distribution of contamination risk over time and place can help prioritize groundwater monitoring. Based on such needs, the Cape Flats aquifer in Cape Town, South Africa, was chosen as the case study for assessing the potential for groundwater contamination risk in urban and coastal hydrogeological settings. The Cape Flats aquifer has been highlighted as an alternate water supply source to augment current supply sources in Cape Town. However, the shallow aquifer is under pressure from agricultural and industrial activities and long-term climate variables, among other factors

Understanding and modelling of surface and groundwater interactions

The connections between surface water and groundwater systems remain poorly understood in many catchments throughout the world and yet they are fundamental to effectively managing water resources. Managing water resources in an integrated manner is not straightforward, particularly if both resources are being utilised, and especially in those regions that suffer problems of data scarcity. This study explores some of the principle issues associated with understanding and practically modelling surface and groundwater interactions. In South Africa, there remains much controversy over the most appropriate type of integrated model to be used and the way forward in terms of the development of the discipline; part of the disagreement stems from the fact that we cannot validate models adequately. This is largely due to traditional forms of model testing having limited power as it is difficult to differentiate between the uncertainties within different model structures, different sets of alternative parameter values and in the input data used to run the model. While model structural uncertainties are important to consider, the uncertainty from input data error together with parameter estimation error are often more significant to the overall residual error, and essential to consider if we want to achieve reliable predictions for water resource decisions. While new philosophies and theories on modelling and results validation have been developed (Beven, 2002; Gupta et al., 2008), in many cases models are not only still being validated and compared using sparse and uncertain datasets, but also expected to produce reliable predictions based on the flawed data. The approach in this study is focused on fundamental understanding of hydrological systems rather than calibration based modelling and promotes the use of all the available 'hard' and 'soft' data together with thoughtful conceptual examination of the processes occurring in an environment to ensure as far as possible that a model is generating sensible results by simulating the correct processes. The first part of the thesis focuses on characterising the 'typical' interaction environments found in South Africa. It was found that many traditional perceptual models are not necessarily applicable to South African conditions, largely due to the relative importance of unsaturated zone processes and the complexity of the dominantly fractured rock environments. The interaction environments were categorised into four main 'types' of environment. These include karst, primary, fractured rock (secondary), and alluvial environments. Processes critical to Integrated Water Resource Management (IWRM) were defined within each interaction type as a guideline to setting a model up to realistically represent the dominant processes in the respective settings. The second part of the thesis addressed the application and evaluation of the modified Pitman model (Hughes, 2004), which allows for surface and groundwater interaction behaviour at the catchment scale to be simulated. The issue is whether, given the different sources of uncertainty in the modelling process, we can differentiate one conceptual flow path from another in trying to refine the understanding and consequently have more faith in model predictions. Seven example catchments were selected from around South Africa to assess whether reliable integrated assessments can be carried out given the existing data. Specific catchment perceptual models were used to identify the critical processes occurring in each setting and the Pitman model was assessed on whether it could represent them (structural uncertainty). The available knowledge of specific environments or catchments was then examined in an attempt to resolve the parameter uncertainty present within each catchment and ensure the subsequent model setup was correctly representing the process understanding as far as possible. The confidence in the quantitative results inevitably varied with the amount and quality of the data available. While the model was deemed to be robust based on the behavioural results obtained in the majority of the case studies, in many cases a quantitative validation of the outputs was just not possible based on the available data. In these cases, the model was judged on its ability to represent the conceptualisation of the processes occurring in the catchments. While the lack of appropriate data means there will always be considerable uncertainty surrounding model validation, it can be argued that improved process understanding in an environment can be used to validate model outcomes to a degree, by assessing whether a model is getting the right results for the right reasons. Many water resource decisions are still made without adequate account being taken of the uncertainties inherent in assessing the response of hydrological systems. Certainly, with all the possible sources of uncertainty in a data scarce country such as South Africa, pure calibration based modelling is unlikely to produce reliable information for water resource managers as it can produce the right results for the wrong reasons. Thus it becomes essential to incorporate conceptual thinking into the modelling process, so that at the very least we are able to conclude that a model generates estimates that are consistent with, and reflect, our understanding (however limited) of the catchment processes. It is fairly clear that achieving the optimum model of a hydrological system may be fraught with difficulty, if not impossible. This makes it very difficult from a practitioner's point of view to decide which model and uncertainty estimation method to use. According to Beven (2009), this may be a transitional problem and in the future it may become clearer as we learn more about how to estimate the uncertainties associated with hydrological systems. Until then, a better understanding of the fundamental and most critical hydrogeological processes should be used to critically test and improve model predictions as far as possible. A major focus of the study was to identify whether the modified Pitman model could provide a practical tool for water resource managers by reliably determining the available water resource. The incorporation of surface and groundwater interaction routines seems to have resulted in a more robust and realistic model of basin hydrology. The overall conclusion is that the model, although simplified, is capable of representing the catchment scale processes that occur under most South African conditions

Mapping and assessment of ecosystem services to improve resource management and human wellbeing in data-scarce peri-urban ecosystems

The ecosystem service (ES) approach acknowledges the fundamental interactions between biodiversity, ecosystems, natural resources and human wellbeing, while substantiating both tangible and intangible benefits of ecosystems to humans. Reflecting on the challenges of rapid population growth and land use changes in Africa’s urban areas on the one hand, and the opportunities provided by the ES approach on the other hand, the thesis adopts suitable ES mapping and assessment methodologies, frameworks and tools. Focus is directed to the emerging peri-urban ecosystems with complex social and ecological (socio-ecological) interactions, and with limited data and expertise. This focus helps to identify the socio-ecological problems of peri-urban ecosystems and the plausible solutions in developing countries. Chapter 1 introduces crucial definitions, concepts and frameworks for ES mapping and assessment. Results show, first, that there is an increase in ES studies between the year 2005 and 2014 in Africa, and they are heterogeneously distributed across the continent. Second, based on a peri-urban case study in Nairobi Kenya, rapid conversions of grassland and forestland into settlements over time have caused a decline in the potential for regulating ES in the area. Third, cultural ES (intangible benefits from the peri-urban ecosystem) positively influence human wellbeing and could improve resource policy of the area. Fourth, the gap between the potential and demand for provisioning ES is increasing over time, hence proposing an adaptive policy against the socio-ecological dynamics in the peri-urban areas. In conclusion, the thesis recommends that the adoption of the ES approach in research could guide proactive measures, hence averting future pressures on the socio-ecological processes and thus enhancing the status of the biodiversity and ecosystems, optimizing natural resource use and improving human wellbeing in the study area