Multi-annual flood mapping using multi-sensor satellite data in the Iishana Sub-Basin (Namibia/Angola)

Abstract

In this study a remote sensing approach based on multi-sensor satellite data for the creation of different hydrological products is presented. It includes different methods for deriving general water masks from optical multi-spectral remote sensing data and sensors using synthetic aperture radar (SAR), as well as their joint processing. Result layers are calculated for the maximum flood extent, the relative frequencies of flood observations and the total flood duration for all three study years (10/2007 - 09/2008, 10/2008 - 09/2009, 10/2016 – 09/2017). Since the study combines already validated methods, quality layers provide information about the confidence of the results. Further analyses such as the aggregation of the annual results allow insights into the complex surface water dynamics in the transnational study area of the Iishana Zone (Namibia/Angola).