Large scale quantification of aquifer storage and volumes from the Peninsula and Skurweberg Formations in the southwestern Cape

The Western Cape Province of South Africa is a relatively water-scarce area as a result of the Mediterranean climate experienced. Due to the increased usage of groundwater, and the requirement to know how much water is available for use, it is imperative as a 1st step to establish an initial estimate of groundwater in storage. The storage capacity, namely, the total available storage of the different aquifers, and the storage yield of the fractured quartzitic Peninsula and Skurweberg Formation aquifers of the Table Mountain Group (TMG), are calculated with a spreadsheet and Geographic Information System (GIS) model. This model is based on the aquifer geometry and estimated values (based on measured data) for porosity and specific storage (calculated using the classic Jacob relation). The aquifer geometry is calculated from 1:50 000 and 1:250 000 geological contacts, faults and major fractures, with dips and aquifer formation thickness calculated through structural geology 1st principles using a Digital Elevation Model (DEM). Balanced geological cross-sections constructed through the model areas provide an important check for the aquifer top and bottom surface depth values produced by the GIS model. The storage modelling undertaken here forms part of the City of Cape Town TMG Aquifer Feasibility Study and Pilot Project, with modelling focusing on the 3 main groundwater target areas at Theewaterskloof (Nuweberg), Wemmershoek and Kogelberg-Steenbras. In the storage models, the Peninsula and Skurweberg Formation aquifers have confined pore volumes ranging from approximately 29 bn. to 173 bn. m3 and 4 bn. to 26 bn. m3, respectively (based on using different porosity values ranging from 2.5% to 15%). Using an average head decline of 1 m across the confined aquifer areas across all 3 groundwater exploration areas, and confined pore volumes based on a porosity of 5%, 6.9 Mm3 and 1.1 Mm3 of groundwater, from the Peninsula and Skurweberg Formation aquifers, respectively, is available. The aquifer storage model intentionally makes use of low, geologically reasonable values for porosity and aquifer compressibility, so as to provide minimum large-scale 1st  estimates of potential yields; however, when new data become available these initial porosity and compressibility assumptions will probably be revised upward. The storage yield approach is also very conservative, as it does not take into account the annual replenishment of the aquifer, and constitutes the yield potential during drought conditions (zero recharge) from the confined portion of the aquifer only. The yield model therefore provides a quantitative perspective on the common public and decision-maker perception that groundwater abstraction from the deep confined Peninsula Formation aquifer will significantly dewater the system, with (often unspecified) adverse ecological consequences. Even where the regionally-averaged decline in hydraulic head approaches 20 m, the volume released by aquifer compression generally remains in the order of 0.24% of the total volume in slow circulation within the deep groundwater flow system. A vastly greater volume of groundwater is essentially non-extractable by any practical and/or economical means.Keywords: Table Mountain Group, Peninsula Formation, Skurweberg Formation, hydrogeology, aquifer, storage modelling, storage yiel

Earth Observation Strategies For Degradation Monitoring In South Africa With The Sentinels - Results From The Spaces II Saldi-Project

The overarching goal of SALDi (South African Land Degradation MonItor) is to implement novel, adaptive, and sustainable tools for assessing land degradation in multi-use landscapes in South Africa. This presentationdemonstrates results from hyper-temporal Sentinel-1 and -2 timeseries concerning woody cover mapping in complex savanna systems, invasive slangbos bushencroachment in grassland areas and regional soil moisture retrievals. Validation has been performed by cross-comparisons, field trips and permanently installed soil moisture networks

Motives for resource integration in value co-creation in a multi-stakeholder service ecosystem

The study contributes to the body of knowledge on motives that drive multiple stakeholders to participate in resource integration processes for value co-creation. The research objectives of why and how multiple stakeholders co-created values were explored through the context of a case of an Intergovernmental Organisation. An exploratory qualitative research methodology was employed to meet these objectives. The study engaged a diverse set of participants from public government, private, academic and NGO sectors, by utilising semi-structured interview approach. The participants further belonged to four GEO Work Plan activities, that were used for within case analysis. The findings of the exploratory research reveal the interdependency between intrinsic and extrinsic motivation with key motivation themes centred on relationships, learning and identity and voice. The research provides insights for managers in recognizing that psychological traits such as motivation are unique to each stakeholder, hence managers would benefit from obtaining insights into the different motivation drivers and assigned importance by the stakeholder, and to leverage these to improve stakeholder engagement and positioning their value proposition.Mini Dissertation (MBA)--University of Pretoria, 2021.zl22Gordon Institute of Business Science (GIBS)MBAUnrestricte

Spatial decision support system for hydrogeological studies in Table Mountain Group Aquifers, Western Cape Province, South Africa

Thesis (MA (Geography and Environmental Studies))--University of Stellenbosch, 2007.The Western Cape province of South Africa is a water scarce area with a Mediterranean climate. The majority of rainfall occurs in the cold winter months and the area experiences hot and dry summers. Studies done to investigate various water supply and water demand management options for the City of Cape Town, concluded that the Table Mountain Group (TMG) aquifer has the potential of yielding high volumes (estimated at 70Mm3/a) of good quality water, but that further research about this source as a potential augmentation supply to the City of Cape Town was necessary before extraction could commence. The aim of the study is to develop a spatial decision support system (SDSS) to be used by a hydrogeology project team, which includes hydrogeologists, environmentalists, ecologists, engineers and other stakeholders. The Table Mountain Group Aquifer (TMGA) SDSS is meant to be a decision support tool, but should also raise awareness about the use of spatial data and information and its capabilities for earth science and other multidisciplinary applications. By means of team discussions and interviews data, spatial analysis and data manipulation requirements were determined. Based on these requirements, four spatial analysis tools were developed. The spatial tool named “Borehole Analysis” analyses stratigraphic information obtained from existing boreholes and hydrogeological point data. The tool determines what groundwater use and monitoring has been undertaken in the area of interest. The “Topographic Analysis” tool identifies any topographical (e.g. rivers) and cadastral (e.g. farm boundaries) data within a certain distance from a possible borehole site. The “Sensitive Area Analysis” tool addresses queries with respect to sensitive areas, such as wetlands, statutory protected areas and private nature reserves. The “Image Classification” tool gives the team members an opportunity to use band ratios during image interpretation. The TMGA SDSS was developed using TNTmips v70, Extensible Markup Language (XML) and Spatial Manipulation Language (SML) and can be run on TNTAtlas v70, which is a free software. The TMGA SDSS enables the team members to have equal and ready access to data acquired by other members. This was found to support intra- and interdisciplinary conversation and facilitate understanding of how the data is being (or could be) used. It also contributes to levels of confidence in decision-making and supports a holistic approach to project design and implementation. Keywords: decision-making, geographic information system (GIS), spatial decision support systems (SDSS), spatial manipulation language (SML

Spatial Data Infrastructures in Africa: A Gap Analysis

The need for spatially explicit thematic data is currently increasing in parallel to the development of observing, storing and processing capabilities. This requires an integrated data management structure in which human and institutional aspects play a key role as part of a Spatial Data Infrastructure (SDI). We focus in this study on the African continent to evaluate the status of its SDI implementation. Because assessing SDI at a continental scale in a traditional way (i.e. following methods developed for national assessments) requires financial resources and mechanisms only affordable to developed countries (e.g. European Union), alternative ways have been explored based on fourteen key SDI indicators that were validated by SDI experts in a previous study. Data was collected for each African country through the African leading SDI institution (UN Economic Commission for Africa) and through Internet searches. We found relatively weak scores of the fourteen SDI indicators for African countries compared to the rest of the World, but with notable differences within Africa. We discuss the implication of the lack of information available on the Internet to assess SDI status in Africa. We conclude that it is necessary to improve statistical information in most African countries. This requires an agreed-on geospatial data structure and organization between concerned institutions that is only achievable through a shared global vision on geospatial data governance. To this end, we suggest a few quick wins and several new mechanisms that would enhance the flow of SDI statistical information and improve data management structure in Africa

Enabling Discovery of African Geospatial Resources

In Africa, natural resources are degrading, while being at the same time essential for maintaining or improving people's livelihood. The well-being of African communities is highly correlated to changes in local ecosystem services. Their vulnerability to degradation of natural resources is extremely high and resilience against natural changes (e.g. climate variability) and socio-economic changes (e.g. fluctuations in food markets) is low. Nowadays, it is widely accepted that reversing these trends and adapting to climate change require integrated responses tackling the underlying social, economic, political and institutional drivers of unsustainable use of natural resources. Integrated approaches intrinsically ask for cooperation, exchange of information and communication to better understand complex interactions and assess environmental issues. Understanding these interactions requires collecting and integrating various data describing physical, chemical, biological and socio-economic conditions. However, two common obstacles are currently preventing the implementation of such integrated approaches: (1) difficulties to find data, and (2) difficulties to integrate data. In response to these issues, this paper presents the Africa Discovery Broker, a web-based tool that enables users working in different domains to search through and access 32442 heterogeneous African geospatial resources (e.g. remote sensing, geospatial data, socio- economic data) coming from 17 international, regional, national and research projects repositories

GEOCAB Portal: A gateway for discovering and accessing capacity building resources in Earth Observation

The discovery of and access to capacity building resources are often essential to conduct environmen- tal projects based on Earth Observation (EO) resources, whether they are Earth Observation products, methodological tools, techniques, organizations that impart training in these techniques or even projects that have shown practical achievements. Recognizing this opportunity and need, the European Commis- sion through two FP7 projects jointly with the Group on Earth Observations (GEO) teamed up with the Committee on Earth observation Satellites (CEOS). The Global Earth Observation CApacity Building (GEOCAB) portal aims at compiling all current capacity building efforts on the use of EO data for societal benefits into an easily updateable and user-friendly portal. GEOCAB offers a faceted search to improve user discovery experience with a fully interactive world map with all inventoried projects and activi- ties. This paper focuses on the conceptual framework used to implement the underlying platform. An ISO19115 metadata model associated with a terminological repository are the core elements that provide a semantic search application and an interoperable discovery service. The organization and the contribu- tion of different user communities to ensure the management and the update of the content of GEOCAB are addressed

Earth Observation Strategies For Degradation Monitoring In South Africa With The Sentinels - Results From The Spaces II Saldi-Project

The overarching goal of SALDi (South African Land Degradation MonItor) is to implement novel, adaptive, and sustainable tools for assessing land degradation in multi-use landscapes in South Africa. This presentationdemonstrates results from hyper-temporal Sentinel-1 and -2 timeseries concerning woody cover mapping in complex savanna systems, invasive slangbos bushencroachment in grassland areas and regional soil moisture retrievals. Validation has been performed by cross-comparisons, field trips and permanently installed soil moisture networks

Earth Observation Strategies For Degradation Monitoring In South Africa With The Sentinels - Results From The Spaces II Saldi-Project

The overarching goal of SALDi (South African Land Degradation MonItor) is to implement novel, adaptive, and sustainable tools for assessing land degradation in multi-use landscapes in South Africa. This presentationdemonstrates results from hyper-temporal Sentinel-1 and -2 timeseries concerning woody cover mapping in complex savanna systems, invasive slangbos bushencroachment in grassland areas and regional soil moisture retrievals. Validation has been performed by cross-comparisons, field trips and permanently installed soil moisture networks