Classification of Estuarine Wetlands in Yemen Using Local and Catchment Descriptors

• Published in: Estuaries and coasts 2021-11, Vol.44 (7), p.1946-1974
• Main Authors: Al-Mahfadi, Afrah Saad, Dakki, Mohamed, Alaoui, Altaf, Ben Hichou, Badr
• Format: Article
• Language: English
• Subjects: Algorithms; Arid regions; Arid zones; Brackishwater environment; Catchment area; Catchment areas; Classification; Coastal Sciences; Conservation; Data; Developing countries; Earth and Environmental Science; Ecology; Environment; Environmental Management; Estuaries; Estuarine dynamics; Estuarine ecosystems; Freshwater & Marine Ecology; Geographical information systems; Human populations; Hydrodynamics; Hydrology; LDCs; Orography; Quaternary; Remote sensing; Satellites; Water and Health; Water demand; Watersheds; Wetlands
• ISSN: 1559-2723; 1559-2731
• DOI: 10.1007/s12237-020-00887-x

A high number of wetlands were irreversibly lost in arid regions, mainly because their conservation raises the great conflict between maintaining wetland hydrology and satisfying water needs of the human population. In Yemen, as an arid developing country, the poor knowledge on wetlands is another challenge that faces their conservation. The present paper contributes to this knowledge by providing a preliminary classification of estuarine ecosystems in Yemen, using satellite data, which provide us with 15 physiographical descriptors of both estuaries, their catchment areas and sea waters. These data were extracted with GIS tools and treated with modern classification algorithms. Their treatment revealed six different types of estuaries, which are distinguished by three categories of descriptors (size and rock nature of both estuary and watershed and sea exposition). These categories confirm the significant influence of the watershed characteristics in shaping estuaries, whose influence has mainly been established during the pluvial Quaternary episodes. The sea characteristics (hydrodynamics and orography) are crucial in estuary classification; yet, despite the great effort deployed to get pertinent data, it was still difficult to find satellite descriptors of these two features. Therefore, the remote sensing has actually some limits in providing sea data for estuarine classification, which will be no longer exceeded with the increasing number of significant satellite data. Finally, we remind that the raw and compiled data gathered in this study constitute a preliminary inventory of the 451 Yemen estuaries, which is very useful for their knowledge and management.