Detecting changes in surface water area of Lake Kyoga sub-basin using remotely sensed imagery in a changing climate

Abstract

Detection of changes in Earth surface features, for example lakes, is important for understanding the relationships between human and natural phenomena in order to manage better the increasingly scarce natural resources. This work presents a procedure of using Modified Normalised Difference Water Index (MNDWI) to detect fluctuations of Lake surface-water area and relate it to a changing climate. The study used radiometrically and geometrically rectified Landsat images for 1986, 1995 and 2010 encompassing the Kyoga Basin lakes of Uganda, in order to investigate the changes in surface-water area between the respective years. The Standard Precipitation Index (SPI) and Drought Severity Index (DSI) are applied to show the relationship between variability of surface-water area and climate parameters. The present analysis reveals that surface-water area fluctuation is linked to rainfall variability. In particular, Lake Kyoga sub-basin lakes experienced an increase in surface-water area in 2010 compared to 1986. This work has important implications to water resources management for Lake Kyoga and could be vital to water resource managers across Ugandan lakes.