Abstract
Two high magnitude rainstorm floods are simulated by a distributed rainfall-runoff model in the 1400 km2 arid catchment of Nahal Zin, Israel. Only the processes dominating arid zone flood generation (generation and spatial concentration of Hortonian overland flow on the terrain and transmission losses into the dry channel alluvium) are described. No calibration with measured flow data is performed. During one event (October 1991) almost the entire catchment was covered by high intensity rainfall as detected by rainfall radar. During another (October 1979) only one ground station in the uppermost headwaters recorded heavy precipitation, while the majority of the catchment remained dry. For this event the distributed model serves as ‘runoff-rainfall model’ to reconstruct characteristics of the rainfall. Different event characteristics directly affect parameter sensitivity and model uncertainty. Maximum model uncertainty of the diminished October 1979 peak is governed by transmission loss parameters and exceeds 300 %. During 1991 only 90 % is determined for this value and infiltration characteristics of the terrain are more relevant. Also a paleoenvironmental scenario on the hydrological effects of widespread loess deposition is highly event dependent. It may be concluded that the separate analysis of single events is crucial for the understanding of high magnitude floods in arid catchments.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.