Browsing by Author "Bousemma, Safa Bel Fekih"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Impact of climate change on the spatiotemporal variability of a coastal ecosystem in the Tunisian Sahel
    (جامعة الوادي - university of el oued, 2021-12-15) Bousemma, Safa Bel Fekih; Chaabane, Balkis; Allouchea, Khebour Faiza; Bel Haj Salah, Raya
    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
  • No Thumbnail Available
    Item
    Mapping and monitoring of Large-Sfax wetlands (center-east of Tunisia) using radiometric indexes and GIS tools
    (جامعة الوادي - university of el oued, 2021-12-02) Chaabane, Balkis; Bousemma, Safa Bel Fekih; Allouche, Faiza Khebour
    Wetlands are characterized by temporary alterations in their structure and composition, and by multifunctionality. Therefore, identifying the boundaries of these zones is essential for appropriate characterization. In this context, this applied research work focuses on the wetlands of Large Sfax in the eastern center of Tunisia. The adopted methodology is based on a combined approach based on multivariate analysis and multi-dates analysis for the identification and the spatial delimitation of wetlands in the study area. The radiometric indexes of humidity NDWI, vegetation NDVI and brightness IB were calculated for the years 2003 and 2015 by using satellite imagery coming from Landsat ETM+7 and Landsat OLI 8. The classification maps of the calculated indexes enabled the identification and spectral delimitation of the wetlands of the study area. The multi-dates analysis was based on the visual interpretation of the panchromatic aerial photographs and the Google Earth snippets for the update of the results. This allowed the spatial delineation and the monitoring of marine, inland, and artificial wetlands in the study area. The importance of using the combined approach is that it allows a better characterization of wetlands