Inland wetland time-series digital change detection based on SAVI and NDWI indecies: Wadi El-Rayan lakes, Egypt

Abstract

Water resource scarcity and climate change impacts are putting pressure on Egyptian government to achieve the water, energy and food security nexus in order to find optimized choices compromising between environmental ecosystems and the society. Despite of being considered as an ecological restoration success, Wadi El-Rayan (WR) wetlands is becoming a depleted ecosystem due to water resources vulnerability. The primary objective of this study is to apply remote sensing (RS) data and GIS methods to the various components of the WR wetland ecosystem, including vegetation, water and soil, and to assess their recent status over the previous three decades. Four multi-temporal/multi-spectral Landsat were analyzed, including TM (1990, 1999 and 2010) and OLI-TIRS (2019). Vegetation and water indices were employed to extract the vegetation, water and soil features in order to assess the change scenarios. The results showed that open soil increased significantly during the study period, particularly during the past ten years, with a concomitant decrease in the vegetation and water body areas. The study therefore indicates that the protection of the existing wetland resources for sustainable use for the next generation must be urgently considered.