Land use/cover changes and vulnerability to flooding in the harts catchment, South Africa

Abstract

The purpose of this study was to determine the hydrological impacts of land use/land cover (LULC) change in the Harts River catchment from 1990 to 2010 using an integration of remote sensing, Geographic Information System and statistical methods. Hydrological data of rainfall and river discharge were statistically analysed to reveal the changes and trends from 1990 to 2010. Changes in year-to-year relationships between precipitation and discharge suggested that discharge was relatively higher in the second half than in the first half of the study period. In fact, a weak correlation of 0.39 was found between precipitation and river discharge. The positive trend in discharge in the Harts River coincided with major changes in land cover over the study area. The LULC changes showed a decrease of vegetation cover from 758345 ha in 1990 to 736879ha in 2008, while barren land increased from 226670 ha in 1990 to 324322 ha in 2008 (an increase of 97652 ha). The coupIing of surface observations, remote sensing, and statistical analysis demonstrated the impact of changes in LULC on peak river discharge and hence flooding behaviour on the Harts River catchment.