TY - JOUR
T1 - The rate and extent of wind-gap migration regulated by tributary confluences and avulsions
AU - Shelef, Eitan
AU - Goren, Liran
N1 - Funding Information:
Financial support. This research has been supported by the National Science Foundation (grant no. 1946253) and the United States–Israel Binational Science Foundation (grant no. 2019656).
Funding Information:
Acknowledgements. This research was supported by grant no. 2019656 from the United States–Israel Binational Science Foundation (BSF) and by grant no. 1946253 from the United States National Science Foundation (NSF-Geomorphology and Land-use Dynamics). We thank Onn Cruvi, Elhanan Harel, Tianyue Qu, Philip Prince, and Sean Gallen for valuable discussions. We also thank Helen Beeson and Fiona Clubb for insightful and constructive reviews that greatly improved this paper. TanDEM-X data were kindly provided by the German Aerospace Center (DLR) (project ID: DEM_GEOL1399).
Publisher Copyright:
© Copyright:
PY - 2021/7/7
Y1 - 2021/7/7
N2 - The location of drainage divides sets the distribution of discharge, erosion, and sediment flux between neighboring basins and may shift through time in response to changing tectonic and climatic conditions. Major divides commonly coincide with ridgelines, where the drainage area is small and increases gradually downstream. In such settings, divide migration is attributed to slope imbalance across the divide that induces erosion rate gradients. However, in some tectonically affected regions, low-relief divides, which are also called wind gaps, abound in elongated valleys whose drainage area distribution is set by the topology of large, potentially avulsing side tributaries. In this geometry, distinct dynamics and rates of along-valley wind-gap migration are expected, but this process remains largely unexplored. Inspired by field observations, we investigate along-valley wind-gap migration by simulating the evolution of synthetic and natural landscapes, and we show that confluences with large side tributaries influence migration rate and extent. Such confluences facilitate stable wind-gap locations that deviate from intuitive expectations based on symmetry considerations. Avulsions of side tributaries can perturb stable wind-gap positions, and avulsion frequency governs the velocity of wind-gap migration. Overall, our results suggest that tributaries and their avulsions may play a critical role in setting the rate and extent of wind-gap migration along valleys and thus the timescale of landscape adjustment to tectonic and climatic changes across some of the tectonically most affected regions of Earth, where wind gaps are common.
AB - The location of drainage divides sets the distribution of discharge, erosion, and sediment flux between neighboring basins and may shift through time in response to changing tectonic and climatic conditions. Major divides commonly coincide with ridgelines, where the drainage area is small and increases gradually downstream. In such settings, divide migration is attributed to slope imbalance across the divide that induces erosion rate gradients. However, in some tectonically affected regions, low-relief divides, which are also called wind gaps, abound in elongated valleys whose drainage area distribution is set by the topology of large, potentially avulsing side tributaries. In this geometry, distinct dynamics and rates of along-valley wind-gap migration are expected, but this process remains largely unexplored. Inspired by field observations, we investigate along-valley wind-gap migration by simulating the evolution of synthetic and natural landscapes, and we show that confluences with large side tributaries influence migration rate and extent. Such confluences facilitate stable wind-gap locations that deviate from intuitive expectations based on symmetry considerations. Avulsions of side tributaries can perturb stable wind-gap positions, and avulsion frequency governs the velocity of wind-gap migration. Overall, our results suggest that tributaries and their avulsions may play a critical role in setting the rate and extent of wind-gap migration along valleys and thus the timescale of landscape adjustment to tectonic and climatic changes across some of the tectonically most affected regions of Earth, where wind gaps are common.
UR - http://www.scopus.com/inward/record.url?scp=85109391054&partnerID=8YFLogxK
U2 - 10.5194/esurf-9-687-2021
DO - 10.5194/esurf-9-687-2021
M3 - Article
AN - SCOPUS:85109391054
SN - 2196-6311
VL - 9
SP - 687
EP - 700
JO - Earth Surface Dynamics
JF - Earth Surface Dynamics
IS - 4
ER -