Challenges of Sustainable Land Management in Siwa Oasis: The Waterlogging Problem in the Newly Reclaimed Desert Land

Abstract

Accurate and frequent information about waterlogging problems is very necessary for the sustainable land management. The objectives of this research are to detect and mapping the vegetated and waterlogged areas in a newly reclaimed desert land in Siwa oasis, using remote sensing data and techniques; and suggest a future plan to solve the waterlogging problem. The Normalized Difference Vegetation Index (NDVI) and the Modified Normalized Difference Water Index (MNDWI) algorithms were applied on four Landsat images (2009, 2012, 2015 and 2018) to detect and map the vegetation and waterlogging states, respectively. The results of NDVI revealed that the cultivated land was increased by 2.3 times in nine years (2009-2018) due to private land reclamation process. The results of MNDWI indicated that the waterlogged area was increased remarkably by 21 times during nine years, where it increased remarkably from 19 ha in 2009 to 393 ha in 2018. The development of the waterlogged areas was most likely due to the increase in the surface water level of Lake Aghormy North of the study area, as well as the trapping of the agricultural drainage water and well-water overflow between the sand dune formations. This study recommended a strategy to solve the waterlogging problem, which include the establishment of a surface drainage network covering the study area. This network should be connected with a main drain at the Northern border of the study area. This strategy will enhance the drainage conditions and solve the waterlogging problem in the area.