Using thermal UAV imagery to model distributed debris thicknesses and sub-debris melt rates on debris-covered glaciers
Using thermal UAV imagery to model distributed debris thicknesses and sub-debris melt rates on debris-covered glaciers
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DOI：
10.1017/jog.2022.116
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发表时间：
2022-12
影响因子：
3.4
通讯作者：
Rosie R. Bisset;P. Nienow;D. Goldberg;O. Wigmore;R. Loayza-Muro;J. Wadham;M. Macdonald;R. Bingham
中科院分区：
文献类型：
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作者：
Rosie R. Bisset;P. Nienow;D. Goldberg;O. Wigmore;R. Loayza-Muro;J. Wadham;M. Macdonald;R. Bingham
摘要冰上碎屑覆盖调节了世界各地山区许多冰川的融化速度，从而改变了下游水资源的可用性和质量。然而，由于缺乏提供高精度、空间连续的碎片厚度测量的技术，冰上碎片的影响在冰川学模型中往往没有得到很好的反映。在这里，我们使用高分辨率无人机热成像，结合当地气象数据、可见无人机图像和垂直剖面的碎片温度时间序列，模拟秘鲁科迪莱拉·布兰卡冰川部分冰川上碎片厚度的空间分布。基于我们的结果，我们模拟了2019年期间3个月内的每日亚碎片融化速率。我们证明，通过有效地校准辐射热成像，并考虑到无人机调查期间气象变量的时间和空间变化，热无人机数据可以更准确地表示碎片覆盖的冰川上碎片厚度和亚碎片融化的高度不均匀的模式。此外，我们的结果表明，平均亚碎片融化速率几乎是从卫星获取的碎片厚度模拟的平均融化速率的三倍，这突显了进一步获取高精度碎片厚度数据的重要性，目的是研究冰川规模的融化过程，校准区域融化模型，并提高径流预测的准确性。
Abstract Supraglacial debris cover regulates the melt rates of many glaciers in mountainous regions around the world, thereby modifying the availability and quality of downstream water resources. However, the influence of supraglacial debris is often poorly represented within glaciological models, due to the absence of a technique to provide high-precision, spatially continuous measurements of debris thickness. Here, we use high-resolution UAV-derived thermal imagery, in conjunction with local meteorological data, visible UAV imagery and vertically profiled debris temperature time series, to model the spatially distributed debris thickness across a portion of Llaca Glacier in the Cordillera Blanca of Peru. Based on our results, we simulate daily sub-debris melt rates over a 3-month period during 2019. We demonstrate that, by effectively calibrating the radiometric thermal imagery and accounting for temporal and spatial variations in meteorological variables during UAV surveys, thermal UAV data can be used to more precisely represent the highly heterogeneous patterns of debris thickness and sub-debris melt on debris-covered glaciers. Additionally, our results indicate a mean sub-debris melt rate nearly three times greater than the mean melt rate simulated from satellite-derived debris thicknesses, emphasising the importance of acquiring further high-precision debris thickness data for the purposes of investigating glacier-scale melt processes, calibrating regional melt models and improving the accuracy of runoff predictions.