Historical spatial change in the Gauteng City-Region

March 2013This Occasional Paper is one of two that GCRO has commissioned specifically to deepen our understanding of the past of the GCR. Both focus on aspects of the region’s spatial past, and ought to be read together. This paper by Brian Mubiwa and Harold Annegarn explores the historical spatial evolution of the GCR. It examines key spatial changes that have shaped the region over a century and provides a remarkable picture, based on satellite imagery, of regional spatial growth in the last two decades. The companion paper by Alan Mabin asks the different but related question of how the idea of a city-region found expression in various statutory planning frameworks over the course of the last century, and how embryonic city-region concepts influenced spatial decisions and developments.written by Brian Mubiwa, Harold Annegarn (Department of Geography, Environmental Management and Energy Studies, University of Johannesbur

Influence of meteorologyparameters on pulmonary Tuberculosis morbidity in two Eco-climatic zones in Nigeria

Weinvestigated the influence of weather parameters on the morbidity pattern of pulmonary tuberculosis (PTB) in the rain-forest (Ile-Ife)and guinea savanna (Ilorin) zonesof Nigeria. Retrospective clinic data on PTB (1996- 2006) were collected from major hospitals in the zones while weather data (1996-2006) were collected from the Nigerian Meteorological agency. The highest reported cases of PTB were found in age-group 20-29 at Ile-Ife (19%) and Ilorin (27%).Gender distribution showed more casesamong malesinthetwo zones. More PTB cases were reported during wet season I and II at Ile-Ife while at Ilorin, wet season I and short dry season had higher concentration of cases. Periods of high PTB reporting at Ile-Ife associated with low ambient temperature, high relative humidity and wind speed. At Ilorin, periods of high PTB cases were characterised by low temperature and wind speed. Early onset of rains in the forest zone was linked with high PTB reporting during intense rainy period, characterised by high wind speed while high cases reporting was in the later phase of rains with low wind speed in the savanna zone. Intervention strategies for PTB control should therefore be sensitive to seasonal characteristics of locations for optimum outcomes. Keywords: Tuberculosis, eco-health, respiratory diseases, weather parameters, associative analysi

SMME development through productive use of domestic energy resources

Productive energy services are often overlooked in domestic energy access programs; yet people cannot raise their welfare except by engaging in economic activities. Household energy demand(s) should be viewed in two components, that is, residential and productive energy services. Although the South African government prioritised electricity distribution after independence, this programme was framed in terms of domestic residential use. Thus, the supplied electrical power was limited to low amperage current, adequate only for household lighting and electronics. Intrinsically, the National Electrification Programme and the Free Basic Electricity Programme [1]) that have substantially increased electricity access in the last decade, did little to spur Small, Medium and Micro Enterprises [SMME] growth in urban penumbras and rural localities. Yet, perambulates in these areas indicate that people are engaged in enterprises that yearn for cleaner, reliable, and cost-effective energy inputs. Commercial cooking is a prevalent business in the low-income settlements, which is powered mostly by basic fuels and low efficiency combustion technologies. Although SMMEs contribute about a quarter of gross capital formation, they have a major potential in employment creation, especially within the current context of negative jobs growth in government and large enterprise sectors. This paper argues that SMME growth can be consolidated and accelerated through provision of safe, affordable and efficient energy technologies. Evidence for this claim is based on a quantitative survey that was carried out among street vendors in Alexandra Township, Johannesburg. Discussions were held with the business owners on alternative fuels and modalities for transitioning the informal business sector to use of clean energy resources. The entrepreneurs cite energy poverty and poor premises as the biggest constraints to their businesses

Trade-offs between community preference, energy and environmental performance; and passive and active surveillance as a deterrence to crime in government assisted human settlements.

The paper analyses the trade-offs between big streetfacing windows in the historical context of passive surveillance; and passive solar design in government assisted human settlements. It challenges the assertion that these are two mutually exclusive specifications. It introduces the concept of cost optimisation with regards to community stakeholder management and assertion of historical preferences in the face of new sustainable human settlement guidelines including health, safety and energy efficiency standards

Evaluating land cover change and its impact on hydrological regime in Upper Shire River Catchment, Malawi

A study was conducted to investigate hydrological impacts of land cover changes in the degradation of the hydrological on flow regimes of the Upper Shire river, Malawi. Remote sensing techniques were used to inventory temporal changes of land cover changes in the catchment. Hydrological data were analyzed to reveal the alterations ecosystems, and water resources for an informed decision on proper catchment planning and management and trends for two periods; 1989 and 2002. The study revealed significant changes in magnitude and direction that have occurred in the catchment between 1989 and 2002, mainly in areas of human habitation. Trends in land cover change in the Upper Shire river catchment depict land cover transition from woodlands to mostly cultivated/ grazing and built-up areas. The land cover mapping showed that 23% of the land was covered by agricultural land in 1989. Subsistence agricultural area has increased by 18%, occupying 41% of the study area in 2002. The effects of the derived land cover changes on river flow in the Upper Shire river were investigated using the semi distributed soil and water assessment tool (SWAT) model. River flows were found to be highly variable and sensitive to land cover changes. Simulation results show that 2002 land cover data produces higher flow peaks and faster travel times compared to the 1989 land cover data. The changes detected indicate the effects of land use pressure in the catchment. The study highlights the importance of considering effects of land use and land cover changes on ecosystems, and water resources for an informed decision on proper catchment planning and management

The potential and prospects of improved cookstoves (ICS) in Zimbabwe

In Zimbabwe, alternatives to grid electricity are being sought in the light of limited electricity supply and under-performance of major electricity generation plants following the economic meltdown affecting the country since the mid-1990s, triggered by the Economic Structural Adjustment Programme (ESAP), and more recently due to political instability. Extensive black-outs routinely up to 12 hours per day and even for several days are common in some areas. Consequently, the majority of households continue to rely substantially on wood fuel to meet their basic daily energy needs. Yet the provision of modern energy services and technologies to these households does not seem to be a priority for national energy policy makers. Although improved cookstoves (ICS) are in greater use in rural areas than urban settlements of Zimbabwe, their potential remains largely unexploited. This research aims to highlight the marked potential and current prospects of improved cookstoves in rural and urban communities of Zimbabwe. Ultimately, this research will better inform policy makers, government, academia and the public about cookstove technologies with reduced fuel use, reduced energy costs, and user friendly capacity to improve health in rural and urban communities

A policy review of synergies and trade-offs in South African climate change mitigation and air pollution control strategies

Climate change mitigation and air quality management are mostly addressed separately in South African legal acts and policies. This approach is not always coherent, especially in the context of other serious issues South Africa is facing, suh as poverty alleviation. Policies implemented to mitigate climate change might increase negative health affects due to unanticipated outcomes (e.g. increased local air pollution), and these indirect consequences must therefore be taken into account when devising mitigation strategies. However, greenhouse gas mitigation policies can also have co-benefits and positive impacts on local air pollution. An evidence-based approach that takes into account greenhouse gas emissions, ambient air pollutants, economic factors (affordability, cost optimisation), social factors (poverty alleviations, public health benefits), and political acceptability is needed tackle these challenges. A proposal is made that use of an integrated climate/air pollution techno-economic optimising model, such as the Greenhouse Gas and Air Pollution Synergies (GAINS) model, may provide a rational decision support tool to guide policy makers into effective strategies for combined Climate Change and Air Quality mitigation measures

Potential of bio-fuel geysers : characterisation and performance evaluation of the Shiza Manzi bio-fuel geyser

Please refer to full text to view abstrac

Influence of coal properties on the performance of fixed-bed coal-burning braziers

Abstract: Informal fixed-bed coal-burning braziers are used extensively in low-income communities of South Africa for space-heating and cooking needs. An investigation was carried out on the effects of coal moisture content and coal quality on the thermal and emissions performance of domestic coal-burning braziers in three field-procured braziers (with three different air ventilation rates), using the bottom- lit updraft (BLUD) and top-lit updraft (TLUD) ignition methods. Results showed that an increase in coal moisture content (from 2.4 wt.% to 8.6 wt.%) led to 18% and 30% decreases in fire-power when using the TLUD and BLUD methods, respectively. The combustion efficiency increased by 25% with an increase in moisture content. Measured carbon monoxide (CO) emission factors increased with an increase in moisture content, while carbon dioxide (CO2) emission factors remained unchanged. The use of A-grade coal resulted in a 49% increase in PM emissions compared with D-grade coal at high ventilation rates, despite no statistically significant differences (p > 0.05) in CO and CO2 emission factors produced between coal grades