Spatio‐Temporal Variation in High‐Centre Polygons and Ice‐Wedge Melt Ponds, Tuktoyaktuk Coastlands, Northwest Territories
Spatio‐Temporal Variation in High‐Centre Polygons and Ice‐Wedge Melt Ponds, Tuktoyaktuk Coastlands, Northwest Territories
复制标题
西北地区图克托亚克图克海岸高中心多边形和冰楔融化池的时空变化
DOI：
--
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
S. Kokelj
中科院分区：
文献类型：
--
作者：
Audrey Steedman;T. Lantz;S. Kokelj
高中心多边形地形是北极景观的一个普遍特征，由于其高的地面冰含量，对地面温度的增加很敏感。了解高中心多边形地形的分布和敏感性的空间变化对于预测景观变化非常重要。在加拿大西北地区的Tuktoyaktuk海岸地区，过去40年来，永久冻土的年平均地面温度上升了1至2°C，高中心多边形地形约占陆地景观的10%。为了调查影响冰楔分布和潜在退化的因素，我们绘制了高中心多边形地形和冰楔融化池，并使用2004年的航空照片记录了人为干扰下与冰楔相关的热岩溶。利用1972年的航空照片评估了历史上融化池的分布。多边形地形的密度（高达37%）在研究区域的北方明显高于南部，那里更丰富的湖泊沉积物和较低的地面温度有利于冰楔的发展。较大比例的融化池面积（0.68%），增加池塘面积（高达3.74%）和更高频率的主要热岩溶活动后，人为的表面干扰（54%）表明，在研究区的北方的高中心多边形地形比南部更容易退化。版权所有© 2016约翰威利父子有限公司.
High‐centred polygonal terrain is a widespread feature of Arctic landscapes that is sensitive to increasing ground temperatures because of its high ground‐ice content. Understanding spatial variation in the distribution and sensitivity of high‐centred polygonal terrain is important for predicting landscape change. In the Tuktoyaktuk Coastlands, Northwest Territories, Canada, mean annual ground temperatures in permafrost have increased between 1 and 2°C over the last 40 years and high‐centred polygonal terrain comprises about 10 per cent of the terrestrial landscape. To investigate factors affecting the distribution and potential degradation of ice wedges, we mapped high‐centred polygonal terrain and ice‐wedge melt ponds, and documented ice wedge related thermokarst at anthropogenic disturbances using 2004 aerial photographs. Historical melt pond distribution was assessed using 1972 aerial photographs. The density of polygonal terrain (up to 37%) was significantly higher in the northern than the southern part of the study area, where more abundant lacustrine sediments and lower ground temperatures have favoured ice‐wedge development. Larger proportional melt pond area (0.68%), increases in pond area (up to 3.74%) and a higher frequency of major thermokarst activity following anthropogenic surface disturbance (54%) suggest that high‐centred polygonal terrain in the northern part of the study area is more susceptible to degradation than in the southern part. Copyright © 2016 John Wiley & Sons, Ltd.