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.

中文翻译：

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SAR干涉相干时间序列的应用：安第斯中南部地貌过渡的时空动力学

山区景观中的泥沙输送域的特征是，其地质过程，速率的变化完全取决于某些因素，包括地质，气候和生物区系。准确地确定运输域之间的过渡发生的位置，是量化变化的侵蚀和沉积过程的过去，现在和未来贡献并增强我们的预测能力的重要步骤。我们提出了一种基于合成孔径雷达（SAR）干涉相干图像时间序列的新方法，以绘制跨越干旱和半干旱景观的沉积物输运状况。我们使用4年的Sentinel-1数据，分析了阿根廷西北部安第斯山脉中南部的沉积物运移制度，其特征是陡峭的地形和气候梯度。我们在区域雨季观察到季节性低的连贯性，特别是在山坡和冲积河道上。将相干性的空间分布与从数字地形图中提取的流域进行比较，以识别流域内的两个截然不同的过渡：（a）山坡到河流的过渡和（b）河流到冲积的过渡。虽然可以很好地限制给定盆地内的过渡，但每个沉积物运移域的相对作用在气候和地形梯度上变化很大。在半干旱地区，与干旱地区相比，我们观察到山坡的相对贡献更大。在整个区域梯度上，盆地内的连贯范围与以前公布的千禧年集水区全侵蚀速率和用来表示长期隆升的地形指标正相关。