Article

The Woodhead dam on Table Mountain, Cape Town, South Africa

February 2011
Proceedings of the Institution of Civil Engineers - Engineering History and Heritage 164(1):27-33

February 2011
164(1):27-33

DOI:10.1680/ehah.9.00041

Authors:

The Woodhead dam was constructed between 1893 and 1897 on the ‘Back Table’ of the well-known landmark Table Mountain overlooking the city of Cape Town. At that time it was the main source of water supply to the city and was the largest dam of any consequence in southern Africa. It is still operational and, in 2008, was awarded international civil engineering landmark status by the American Society of Civil Engineers. This paper describes: the background to the water supply problems to Cape Town that led to construction of the dam; some details of the careers of John Gamble, the engineer who located the dam, and Scottish engineer Thomas Stewart, who became the first consulting engineer in South Africa; Stewart's design and construction of the dam, located on a mountain top with very difficult access; and brief details of subsequent measures taken to provide water to Cape Town.

ResearchGate has not been able to resolve any citations for this publication.

ResearchGate has not been able to resolve any references for this publication.

Article

Full-text available

Mountain resources and conflict instigating issues, Ethiopia

Teshome Soromessa

Degradation of natural resources is more a result of social conflicts, which have not been recognized, than of bio-physical conditions and actions on the environment, and hence there is a low rate of success in most of the projects set up to arrest environmental degradation. Unless it is recognized to what extent environmental degradation is a result of conflicts over resources utilities, the ... [Show full abstract] community will keep battling with the wrong issues and fail to make progress on the environmental resource management front. According to Carpenter and Kennedy (1988) environmental disputes are considered as a sub-sector of public disputes which come in all shape and sizes. These disputes could be between communities, or between community and decision makers or planners, or within a community. The underlying factor is that environmental conflicts are normally based on human needs and at the local level they tend to be over the allocation, distribution and management of natural resources (Kraybill, 1995). Goldblatt (1995) indicated how the conflicts that ensued in Kogelberg (South Africa), over a future dam, which threatened a special biodiversity park, reflected a clash of interests between one sector of the community and another. Conflicts are also recorded to have occurred between the 'would be' beneficiaries of the land and the government planners, since the communities were not in agreement with the resource management rules laid down by government. This further emphasized the intrinsic value of the land as seen by Goldblatt (1995), as well as the lack of proper negotiations over natural resources. In describing the relationship between development, environment and conflict, Friedman (1994) discusses negotiated development as opposed to development that is imposed on a community. Kraybill (1995) describes development as a process that raises expectations and brings change to a society, which always results in conflicts and disagreements, either within the community or between communities, or between the communities and the planners. The actual cause might be that the community needs to be involved, recognized and /or acknowledged in the development that is taking place. Therefore, if the planner does not address such a need, a seed of bitter conflict would be sown. In order to avoid conflicts that are a result of environmental problems, sustainable development might be the answer. The phenomenon that environmentally caused conflicts tends to erupt in poor countries, which are not in a position to implement sustainable development. It is necessary to note here that development can cause negative environmental impacts, which can lead to conflicts, and the conflicts could result in a further environmental degradation and the cycle continues.

Article

Full-text available

HIGH RESOLUTION LANDCOVER MODELLING WITH PLÉIADES IMAGERY AND DEM DATA IN SUPPORT OF FINE SCALE LAND...

November 2017 · The International Archives of the Photogrammetry Remote Sensing and Spatial Information Sciences

In the evaluation of air-borne thermal infrared imaging sensors, the use of simulated spectral infrared scenery is a cost-effective way to provide input to the sensor. The benefit of simulated scenes includes control over parameters governing the spectral and related thermal behaviour of the terrain as well as atmospheric conditions. Such scenes need to have a high degree of radiometric and ... [Show full abstract] geometric accuracy, as well as high resolution to account for small objects having different spectral and associated thermal properties. In support of this, innovative use of tri-stereo, ultra-high resolution Pléiades satellite imagery is being used to generated high detail, small scale quantitative terrain surface data to compliment comparable optical data in order to produce detailed urban and rural landscape datasets representative of different landscape features, within which spectrally defined characteristics can be subsequently matched to thermal signatures. Pléiades tri-stereo mode, acquired from the same orbit during the same pass, is particularly favourable for reaching the required metric accuracy because images are radiometrically and geometrically very homogeneous, which allows a very good radiometric matching for relief computation. The tri-stereo approach reduces noise and allows significantly enhanced relief description in landscapes where simple stereo imaging cannot see features, such as in dense urban areas or valley bottoms in steep, mountainous areas. This paper describes the datasets that have been generated for DENEL over the Hartebeespoort Dam region, west of Pretoria, South Africa. The final terrain datasets are generated by integrated modelling of both height and spectral surface characteristics within an object-based modelling environment. This approach provides an operational framework for rapid and highly accurate mapping of building and vegetation structure of wide areas, as is required in support of the evaluation of thermal imaging sensors.