Journal cover Journal topic
Hydrology and Earth System Sciences An interactive open-access journal of the European Geosciences Union
Hydrol. Earth Syst. Sci., 17, 1021-1034, 2013
https://doi.org/10.5194/hess-17-1021-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
07 Mar 2013
Geomorphology-based index for detecting minimal flood stages in arid alluvial streams
E. Shamir1, L. Ben-Moshe2, A. Ronen3, T. Grodek2, Y. Enzel3, K. P. Georgakakos1,4, and E. Morin2 1Hydrologic Research Center, San Diego, California, USA
2The Hebrew University of Jerusalem, Department of Geography Mount Scopus, Jerusalem, 91905, Israel
3The Hebrew University of Jerusalem, The Fredy & Nadine Herrmann Institute of Earth Sciences, Givat Ram Jerusalem 91904, Israel
4Scripps Institution of Oceanography, University of California San Diego, La Jolla California, USA
Abstract. Identification of a geomorphic index to represent lower thresholds for minor flows in ephemeral, alluvial streams in arid environments is an essential step as a precursor for reliable flash flood hazard estimations and establishing flood warning systems. An index, termed Alluvial wadi Flood Incipient Geomorphologic Index (AFIG), is presented. Analysis of data from an extensive field survey in the arid ephemeral streams in southern and eastern Israel was conducted to investigate the AFIG and the control over its value across the region. During the survey we identified distinguishable flow marks in the lower parts of streams' banks, such as niches, vegetation line, and change in bank material, which are indicative of low flows. The cross-sectional characteristics of the AFIG were studied in relationship with contributing drainage basin characteristics such as lithology, topography, and precipitation. Drainage area and hardness of the exposed lithology (presented as a basin-wide index) are the preferred descriptors to be used in estimating a specific AFIG in unsurveyed sites. Analyses of discharge records from seven hydrometric stations indicate that the recurrence interval of the determined AFIG is equal to or more frequent than 0.5 yr.

Citation: Shamir, E., Ben-Moshe, L., Ronen, A., Grodek, T., Enzel, Y., Georgakakos, K. P., and Morin, E.: Geomorphology-based index for detecting minimal flood stages in arid alluvial streams, Hydrol. Earth Syst. Sci., 17, 1021-1034, https://doi.org/10.5194/hess-17-1021-2013, 2013.
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