The application of remote sensing in drought monitoring : a case study of KwaZulu-Natal, South Africa.

Abstract

Drought is a severe natural disaster which occurs across wide spatial boundaries and inconsistent temporal patterns. The slow onset and gradual formation of drought highlights the importance of early detection, allowing for appropriate time in implementing relief and mitigation procedures. The vague extensiveness of drought raises concern on the ability for site specific ground based weather stations to assess the full extent of a drought occurrence. This problem is further compounded in developing nations, such as South Africa, where weather stations suffer from missing historical records and are poorly distributed across harsh inaccessible rural areas. Remote sensing seeks to resolve this problem through the high resolution, near real-time and multitemporal spatial coverage it possesses. Based on that premise, this study sought to evaluate the evolution of remote sensing on drought monitoring and subsequently conduct a remote sensing drought assessment, to determine the accuracy and potential for future drought occurrences. The scope of this study was to firstly to evaluate the evolution and progress of remoting sensing approaches in drought monitoring, which was completed as a systematic literature review. Secondly, a drought assessment was conducted in KwaZulu-Natal, South Africa. Focusing on the ability of the Normalized Difference Vegetation Index (NDVI) to observe any trends of vegetation drought over the past 16 years, confirmed through rainfall data. Findings from this study concluded the following. Firstly, there has been substantial growth in research papers pertaining to remote sensing on drought; particularly over the past decade. Secondly, developing nations have limited resources available and should consider the advantages possessed by remote sensing. Thirdly, remote sensing results complimented climate conditions recorded over the past 16 years. Fourthly, future studies should look to include additional indices to strengthen the broadband NDVI, which was affected by the saturation of vegetation biomass.