19 March, 2021
Determining sediment discharge out of hyperarid watersheds is a greater challenge.
Dr. Judith Lekach and Prof. Yehouda Enzel analyzed the decades-long (>50 years) hydrologic and sedimentologic dataset of Nahal Yael, an experimental, well-instrumented, hyperarid (25–30 mm year−1) watershed in southern Israel, which was initiated in 1965 by the late Prof. Asher Schick. They show that in this watershed the sediment yield can be predicted by the total flood energy, represented by flood-integrated stream power. Then they determined the long-term frequency-magnitude of sediment exported out of this hyperarid basin, probably representing other hyperarid watersheds.
They concluded that, at the decadal scale, moderate floods are the most effective in terms of total sediment transport.
Lekach, J., Enzel, Y., in press. Flood-duration integrated stream power and frequency magnitude of >50-year-long sediment discharge out of a hyperarid watershed. Earth Surface Processes and Landforms. https://onlinelibrary.wiley.com/doi/10.1002/esp.5104