Impact of climate change on the spatiotemporal variability of a coastal ecosystem in the Tunisian Sahel

Abstract

Wetlands are some of the most important ecosystems on Earth. Despite their importance for water and carbon cycle regulation, wildlife survival and economic value. Furthermore, wetlands are experiencing rapid degradation due to severe transformations. They have been polluted and declined dramatically as land cover has changed in many regions. Whereas, human activities along with severe climate changes have led to critical loss and degradation of these ecosystems. This study evaluates changes of Halq El Mingel wetland, Tunisia, between 2006 and 2017. Spatial and temporal dynamics of wetland changes were quantified using Landsat and Google Earth images and three radiometric indexes have been calculated; Normalized Difference Vegetation Index, Normalized Difference Water Index and Salinity Index. Results revealed that important spatial and temporal variations are detected for each index.Also, the area of wetland in Hergla city decreased significantly over the last 10 years from 1146.7 ha to 806.6 ha respectively. A notable change is the shrinkage of the wetland area during 2006-2017 period which is linked to the decline of rainfall over the years. This study proposes a methodology to monitor changes in wetland using geospatial technology and thus to support decision-making for sustainable management.