TY  - JOUR
A1  - Olen, Stephanie M.
A1  - Bookhagen, Bodo
T1  - Applications of SAR interferometric coherence time series
BT  - satiotemporal dynamics of geomorphic transitions in the South-Central Andes
JF  - Journal of geophysical research : Earth surface
N2  - Sediment transport domains in mountain landscapes are characterized by fundamentally different processes and rates depending on several factors, including geology, climate, and biota. Accurately identifying where transitions between transport domains occur is an important step to quantify the past, present, and future contribution of varying erosion and sedimentation processes and enhance our predictive capabilities. We propose a new methodology based on time series of synthetic aperture radar (SAR) interferometric coherence images to map sediment transport regimes across arid and semiarid landscapes. Using 4 years of Sentinel-1 data, we analyze sediment transport regimes for the south-central Andes in northwestern Argentina characterized by steep topographic and climatic gradients. We observe seasonally low coherence during the regional wet season, particularly on hillslopes and in alluvial channels. The spatial distribution of coherence is compared to drainage areas extracted from digital topography to identify two distinct transitions within watersheds: (a) a hillslope-to-fluvial and (b) a fluvial-to-alluvial transition. While transitions within a given basin can be well-constrained, the relative role of each sediment transport domain varies widely over the climatic and topographic gradients. In semiarid regions, we observe larger relative contributions from hillslopes compared to arid regions. Across regional gradients, the range of coherence within basins positively correlates to previously published millennial catchment-wide erosion rates and to topographic metrics used to indicate long-term uplift. Our study suggests that a dense time series of interferometric coherence can be used as a proxy for surface sediment movement and landscape stability in vegetation-free settings at event to decadal timescales.
KW  - Copernicus
KW  - SAR
KW  - critical infrastructure resilience
KW  - early warning
KW  - landslides
Y1  - 2020
U6  - https://doi.org/10.1029/2019JF005141
SN  - 2169-9003
SN  - 2169-9011
VL  - 125
IS  - 3
PB  - American Geophysical Union
CY  - Washington
ER  -