Contribution of satellite imagery towards sustainable urbanisation, human settlement planning and management; South Africa case study

摘要

The success of Sustainable Development Goals is highly dependent on effective monitoring of set targets and indicators, and also on the quality of data and information used to formulate solutions that respond to economic, social and environmental challenges. Geospatial technologies play an important role in understanding and monitoring of land cover and land use change which is critical in achieving SDG 11 and related goals. In this study, we assessed the ratio to land consumption rate to population growth rate (LCRPGR) of four cities in South Africa using Landsat and SPOT 2&5 satellite images and census data collected in 1996,2001 and 2011. The assessment shows that Johannesburg, South-Africa's largest city recorded a decline in the ratio of LCRPGR between 2001 and 2011, which was recorded at 0.5742, down from 0.8509 recorded during the period 1996 - 2001. A similar trend was observed in Tshwane, whose ratio almost halved, from 1.0482 recorded in the 1996 - 2001 period to 0.5451 between 2001 and 2011. In contrast, between 1996 and 2001, the LCRPGR ratios for secondary cities, Polokwane and Rustenburg, were 0.5249 and 0.4826, which increased to 0.6705 and 0.6163 during the 2001 -2011 period respectively. These values indicate that, with the exception of Tshwane whose LCRPGR value for 1996 - 2001 was greater than one, the rate of land consumption remained relatively lower than the population growth rate throughout the 1996 - 2011 period. The primary cities experienced a decrease in their rates of urban sprawl between the periods 1996 - 2001 and 2001 - 2011 period, while the secondary cities recorded increasing urban sprawl between the periods. In addition to ratio of LCRPGR, we also assessed the land consumption per capita of the four cities, which is measured as the amount of built-up area per person. In Tshwane, the high LCRPGR recorded over the 1996 - 2001 period resulted in an increase in the land consumption per capita from 237m~2 to 250m~2, a value that dropped