Integrated Study of Flash Floods in Wadi Basins Considering Sedimentation and Climate Change: An International Collaboration Project

Abstract

Recently, Wadi flash floods (WFFs) have happened frequently in arid environments, resulting in great damage the society and the environment. In Oman, severe WFFs have occurred repeatedly within the last 10 years causing a huge impact on human lives and properties. This paper aims at introducing the framework of an international collaboration project between Japan and Oman for WFF management considering sediment dynamics and climate changes. Four research groups were established: climate change (G1), rainfall-runoff modeling (G2), sediment yield and transport (G3), and sedimentation and infiltration processes (G4). Several field investigations were conducted since 2017 until now. The detailed field survey to assess the deposited sediment in a dry reservoir by using sediment bars, and infiltration test, as well as drone survey were addressed. Some of the preliminary results and findings from the field investigation is discussed. The results show there is an adverse impact of sedimentation clogging on the infiltration process at the reservoirs. Based on the historical rainfall data analysis, there is a systematic increasing trend of the annual average precipitation with remarkable cycles over the MENA region and Oman. The knowledge obtained from this project is expected to be valuable to understanding sediment dynamics at Wadi basins.