Vol. 10, No. 1, 46-55, 2011

Urban expansion and its impact on urban agriculture - remote sensing based change analysis of Kizinga and Mzinga Valley - Dar Es Salaam, Tanzania
Sandra Eckert

Abstract
Urban agriculture is a phenomenon that can be observed world-wide, particularly in cities of developing countries. It is contributing significantly to food security and food safety and has sustained livelihood of the urban and peri-urban low income dwellers in developing countries for many years. Population increase due to rural-urban migration and natural - formal as well as informal - urbanisation are competing with urban farming for available space and scarce water resources. A multitemporal and multisensoral urban change analysis over the period of 25 years (1982-2007) was performed in order to measure and visualise the urban expansion along the Kizinga and Mzinga valley in the south of Dar Es Salaam. Airphotos and VHR satellite data were analysed by using a combination of a composition of anisotropic textural measures and spectral information.

The study revealed that unplanned built-up area is expanding continuously, and vegetation covers and agricultural lands decline at a fast rate. The validation showed that the overall classification accuracy varied depending on the database. The extracted built-up areas were used for visual interpretation mapping purposes and served as information source for another research project. The maps visualise an urban congestion and expansion of nearly 18% of the total analysed area that had taken place in the Kizinga valley between 1982 and 2007. The same development can be observed in the less developed and more remote Mzinga valley between 1981 and 2002. Both areas underwent fast changes where land prices still tend to go up and an influx of people both from rural and urban areas continuously increase the density with the consequence of increasing multiple land use interests.

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History
Submitted: 27 Sept 2010
Revised: 11 Apr 2011
Accepted: 18 Apr 2011
Published: 17 May 2011
Responsible editor: Carsten Jürgens

Citation
Eckert S, 2011. Urban expansion and its impact on urban agriculture - remote sensing based change analysis of Kizinga and Mzinga Valley - Dar Es Salaam, Tanzania. EARSeL eProceedings, 10(1): 46-55

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EARSeL European Association of Remote Sensing Laboratories, Strasbourg, France

   
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BIS Library and Information System, Carl von Ossietzky University of Oldenburg

 

ISSN 1729-3782