Detecting land use and land cover change for the past 28-years using multi-temporal Landsat satellite images in the Jukskei River catchment, Gauteng, South Africa.

Abstract

Jukskei River catchment is one of the urban catchments in the central part of Gauteng province covering  a large part of City of Johannesburg Metropolitan Municipality and small part of Tshwane and Ekurhuleni Metropolitan Municipalities that has witnessed tremendous LULC change over time. Jukskei River catchment is one of the fastest growing catchment in terms of population and change in land use/cover (LULC) over time. Therefore, it is very important to detect the nature and extent of these change in order to identify the direction and future expansion of LULC within the catchment. To accomplish that,  multi-temporal satellite remotely sensed data acquired from Landsat-5 Multispectral Scanner System (MSS) 1987, Landsat-5 Thematic Mapper (TM) 2001 and Landsat-8 Operational Land imager (OLI) 2015 were used to detect LULC change in Jukskei River catchment. The Jukskei River catchment was classified into four major LULC classes including: Built-up area, bare surface, sparse vegetation and intact vegetation. The analysis of the results revealed that for the past 28 years (i.e. 1987-2015), built-up and bare surface areas have increased 56.2% (42713.1 ha) and 8.2% (6225.1 ha) while intact and sparse vegetation have decreased by 9.8% (7455.0 ha) and 25.8% (19659.6 ha), respectively. The overall accuracies for 1987, 2001, and 2015, were 85.9%, 87.5%, and 92.5% respectively, with KIA of 81.3%, 83.3%, and 90% which indicates the accuracy of classified images with the reference images.  The results revealed by this study can be used for decision-making activities and policy development regarding land use management within the catchment.