Remote Sensing Assessment of Isimangaliso Wetland Change Dynamics from 1987 – 2017 in KwaZulu Natal Province South Africa

Keywords: Geospatial analysis, wetland change detection, threats, Isimangaliso
Abstract Type: Paper Abstract

Abstract

Wetlands have experienced multiple natural and anthropogenic threats leading to ecosystem services loss and uncertainty about livelihood formation across many parts of the globe. Consequently, the benefits of wetlands, in general, get compromised and therefore, call for constant monitoring to advance just-in-time measures to restore these fragile environments. To this, the current study explored and appraised the Isimangaliso Wetland (IW) in the KwaZulu-Natal Province of South Africa using Landsat imageries (1997 -2017) and a geospatial hybrid approach in ArcGIS 10.2 platform. In 1987 and 2017, the Normalized Difference Water Index (NDWI) results showed that wetland spatial extent was 655.416 Km2 and 429.489 Km 2 respectively which denotes a shift. The result also revealed that the area’s natural landscapes have experienced changes in the last three decades (i.e., dense vegetation – 14%, sparse vegetation – 23% and water body - 1% have increment) between 1987 and 2017. While wetland features (marshland and quag) experienced a drastic decrease of about 38%. The analyses revealed the significant threat to IW extinction which could be attributed to natural or human stressors. The overall classification accuracy of 97.55% and the Kappa coefficient of 0.941. This wetland depletion might significantly negatively impact human well-being, flora and fauna and diminish its ecological and world heritage status. Consequently, the study reveals the need to restore and conserve the IW to ensure sustainable ecosystem functioning and development among others, especially in a changing climate.