ABSTRACT

The Devon Ice Cap (DIC) is one of the largest ice masses in the Canadian Arctic. Each summer, extensive supraglacial river networks develop on the DIC surface and route large volumes of meltwater from ice caps to the ocean. Mapping their extent and understanding their temporal evolution are important for validating runoff routing and melt volumes predicted by regional climate models (RCMs). We use 10 m Sentinel-2 images captured on 28 July and 10/11 August 2016 to map supraglacial rivers across the entire DIC (12,100 km²). Both dendritic and parallel supraglacial drainage patterns are found, with a total length of 44,941 km and a mean drainage density (D_d ) of 3.71 km⁻¹. As the melt season progresses, D_d increases and supraglacial rivers form at progressively higher elevations. There is a positive correlation between RCM-derived surface runoff and satellite-mapped D_d , suggesting that supraglacial drainage density is primarily controlled by surface runoff.

摘要

德文郡冰盖（DIC）是加拿大北极地区最大的冰块之一。每年夏天，DIC表面都会形成大量的冰川上河网，并将大量的融水从冰盖引到海洋。绘制它们的范围并了解它们的时间演变对于验证径流路径和区域气候模型（RCM）预测的融雪量很重要。我们使用2016年7月28日和8月10/11日捕获的10 m Sentinel-2图像来绘制整个DIC（12,100 km ²）的冰川河。均发现树突状和平行的滩上排水模式，总长度为44,941 km，平均排水密度（D _d ）为3.71 km ^-1。随着融化季节的发展，D _d 河流的增加和冰川河在逐渐升高的高度形成。RCM衍生的地表径流与卫星测绘的D _d 之间存在正相关关系，这表明冰川流域排水密度主要受地表径流控制。