Application of Landsat-7 satellite data and a DEM for the quantification of thermokarst-affected terrain types in the periglacial Lena–Anabar coastal lowland
Application of Landsat-7 satellite data and a DEM for the quantification of thermokarst-affected terrain types in the periglacial Lena–Anabar coastal lowland
复制标题
应用 Landsat-7 卫星数据和 DEM 对冰缘勒拿-阿纳巴尔沿海低地受热岩溶影响的地形类型进行量化
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
T. Malthus
中科院分区：
文献类型：
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作者：
G. Grosse;Lutz Schirrmeister;T. Malthus
大规模的永久冻土退化，主要是通过全新世热岩溶活动的影响，广泛的北极永久冻土为主的低地。现今在北极的大多数冰缘低地都可以观察到热岩溶作用的影响。由于冻土退化是全球气候变化的一个重要影响因素，因此有必要发展有效的方法来量化其过去和现在的规模。我们开发了一个程序的量化的冰缘低地地形类型的退化功能为重点，并将其应用到角Mamontov Klyk地区在西部拉普捷夫海地区。我们的地形分类方法是基于地理空间数据集的组合，包括应用于Landsat-7 ETM+数据和数字高程数据的监督最大似然分类。提取了13个最终地形表面类，随后根据与热岩溶和富冰矿床退化的相关性进行了表征。据估计，78%的调查区域受到永久冻土退化的影响。总体分类准确率为79%。沿海平原上的热岩溶发育并不均匀，从南到北，热岩溶相关区域的覆盖面越来越密集。这一以区域为重点的程序可以扩展到其他地区，以提供目前缺乏全球规模的永久冻土数据集的高度详细的冰缘地形测绘能力。
Extensive parts of Arctic permafrost-dominated lowlands were affected by large-scale permafrost degradation, mainly through Holocene thermokarst activity. The effect of thermokarst is nowadays observed in most periglacial lowlands of the Arctic. Since permafrost degradation is a consequence as well as a signifi cant factor of global climate change, it is necessary to develop effi cient methods for the quantifi cation of its past and current magnitude. We developed a procedure for the quantifi cation of periglacial lowland terrain types with a focus on degradation features and applied it to the Cape Mamontov Klyk area in the western Laptev Sea region. Our terrain classifi cation approach was based on a combination of geospatial datasets, including a supervised maximum likelihood classifi cation applied to Landsat-7 ETM+ data and digital elevation data. Thirteen fi nal terrain surface classes were extracted and subsequently characterized in terms of relevance to thermokarst and degradation of ice-rich deposits. 78% of the investigated area was estimated to be affected by permafrost degradation. The overall classifi cation accuracy was 79%. Thermokarst did not develop evenly on the coastal plain, as indicated by the increasingly dense coverage of thermokarst-related areas from south to north. This regionally focused procedure can be extended to other areas to provide the highly detailed periglacial terrain mapping capabilities currently lacking in global-scale permafrost datasets.