Author(s): Mohamed Saber; Sameh Kantoush; Mohammed Abdel-Fattah; Tetsuya Sumi; Tahani Alharrasi; Takahiro Koshiba; Yusuke Ogiso; Mahmood Almamari; Dina Elliethy; Kenji Tanaka
Linked Author(s): Tetsuya Sumi
Keywords: No Keywords
Abstract: The main water related problems of wadi system in arid regions include disasters (flash floods and drought), water resources, and lack of monitoring data. In order to overcome such challenge, an improvement of the data availability and accuracy to enhance the performance of hydrological models are needed. Thus, the present research presents a hydrochronological approach of Wadi Flash floods (WFFs) in arid regions in order to overcome the challenges of the ungauged wadi basins. The main objective is to analysis spatiotemporally long term WFFs in both recent and future time periods in order to understand the spatial and temporal varibality of rainfall in arid regions (Arab region as case study). The proposed Hydro-Chronological Integrated Approach includes three chronological stages Paleo-WFFs, Recent-WFFs, and Future-WFFs. Recent extreme WFFs were investigated from the available historical records and monitoring observations, along with field survey. A field survey was conducted on Dec. 2017 at Wadi Mijlas in Oman to investigate the sedimentation related to flash floods and the flash floods indicators along wadi channels. Wadi channel leveling, sedimentation pedon, collecting sediments samples, and detecting of flash floods marks are the main field investigations considered in this study. Satellite-based precipitation such as Global Satellite Mapping of Precipitation (GSMaP data), and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN) are analyzed to understand the recent flash floods in the whole Arab region as one of the most arid regions over the world. Four extreme flash floods cycles were identified from 1984-2017, showing an increasing trends of the total average of rainfall during. The results also show high spatial variability from one locations to the others, however occurring the temporal systematic cycles of flash floods. Future extreme WFFs will be identified using the Global Climate Models (GCM) with addressing different futurescenarios of WFFs. The present study provides long term data analysis for the extreme flash floods in arid regions in order to enhance the database for WFFs in ungagged Wadis, which consequently contribute to reduce uncertainty of hydrological models in addition to understanding the impacts of climate changes.