Using Developable Land Units as an Indicator of Rate of Growth of an Urban Area

Abstract

Developable Land Units (DLU) have been used in combination with remotely sensed data as an indicator for tracking the rate of urban growth. The variables used to model this indicator(DLU) are namely available vacant land, high land value, moderate elevation and compatibility with already existing land uses. Dar-esalaam, Tanzania, is used as the case study, specifically existing land use information (1992) is used to provide data pertaining to available vacant land and neighbourhood (i.e. compatibility), elevation data used was derived from ERS (1/2) data, whereas land value is obtained from mapped landform characteristics. The modelled developable land units is combined with new developed areas from 1998 SPOT multispectral data to estimate the amount of development occurring within this period i.e. between 1992 to 1998. The advantage of remotely sensed data in providing information continuously has been exploited in this regard, thus enabling a growth rate index to be estimated based on developable land units. The results obtained show that developable land units can be used successfully for monitoring growth and not only for predominantly allocating new developments as has been the case in the past.