气候变化领域集成服务门户(CCPortal): Role of discrete water recharge from supraglacial drainage systems in modeling patterns of subglacial conduits in Svalbard glaciers

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DOI	10.5194/tc-13-735-2019
	Role of discrete water recharge from supraglacial drainage systems in modeling patterns of subglacial conduits in Svalbard glaciers
	Decaux L.; Grabiec M.; Ignatiuk D.; Jania J.
发表日期	2019
ISSN	19940416
EISSN	13
起始页码	735
结束页码	752
卷号	13 期号:3 页码:735-752
英文摘要	As the behavior of subglacial water plays a determining role in glacier dynamics, it requires particular attention, especially in the context of climate warming, which is increasing ablation and generating greater amounts of meltwater. On many glaciers, water flowing from the glacier's surface is the main source of supply to the subglacial drainage system. This system is largely influenced by the supraglacial drainage system, which collects meltwater and precipitation and rapidly delivers it to discrete points in the glacier bed via moulins and crevassed areas, called water input areas (WIAs). Models of patterns of subglacial conduits mainly based on the hydrological potential gradient are still regularly performed without taking into account the supraglacial drainage system. We modeled the pattern of subglacial channels in two glaciers located in Svalbard, the land-terminating Werenskioldbreen and the tidewater Hansbreen during the 2015 melt season. We modeled a spatial and a discrete water recharge in order to compare them. First, supraglacial catchments were determined for each WIA on a high-resolution digital elevation model using the standard watershed modeling tool in ArcGIS. Then, interpolated water runoff was calculated for all the main WIAs. Our model also accounts for several water pressure conditions. For our two studied glaciers, during the ablation season 2015, 72.5 % of total runoff was provided by meltwater and 27.5 % by precipitation. Changes in supraglacial drainage on a decadal timescale are observed in contrast to its nearly stable state on an annual timescale. Nevertheless, due to the specific nature of those changes, it seems to have a low impact on the subglacial system. Therefore, our models of subglacial channel are assumed to be valid for a minimum period of two decades and depend on changes in the supraglacial drainage system. Results showed that, for Svalbard tidewater glaciers with large crevassed areas, models of subglacial channels that assume spatial water recharge may be somewhat imprecise but are far from being completely incorrect, especially for the ablation zone. On the other hand, it is important to take discrete water recharge into account in the case of land-terminating Svalbard glaciers with limited crevassed areas. In all cases, considering a discrete water recharge when modeling patterns of theoretical subglacial channels seems to produce more realistic results according to current knowledge. © Author(s) 2019.
语种	英语
WOS研究方向	Physical Geography ; Geology
scopus关键词	ablation; digital elevation model; glacial hydrology; meltwater; precipitable water; recharge; runoff; subglacial environment; timescale; watershed; Arctic; Hansbreen; Spitsbergen; Svalbard; Svalbard; Svalbard and Jan Mayen; Werenskioldbreen
来源期刊	The Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/94714
作者单位	Department of Geomorphology, Faculty of Earth Sciences, University of Silesia, 60 Bedzinska Street, Sosnowiec, 41-200, Poland
推荐引用方式 GB/T 7714	Decaux L.,Grabiec M.,Ignatiuk D.,et al. Role of discrete water recharge from supraglacial drainage systems in modeling patterns of subglacial conduits in Svalbard glaciers[J],2019,13(3):735-752.
APA	Decaux L.,Grabiec M.,Ignatiuk D.,&Jania J..(2019).Role of discrete water recharge from supraglacial drainage systems in modeling patterns of subglacial conduits in Svalbard glaciers.The Cryosphere,13(3),735-752.
MLA	Decaux L.,et al."Role of discrete water recharge from supraglacial drainage systems in modeling patterns of subglacial conduits in Svalbard glaciers".The Cryosphere 13.3(2019):735-752.