Permafrost distribution maps are of importance for environmental assessment, climate system modeling, and practical engineering applications. The scarcity of forcing data and parameters often limits the uses of permafrost models over large areas. However, detailed data are often available in a few subregions through field investigations. In this study, we propose a novel approach for mapping permafrost distribution in a large and data‐scarce area using an empirical model with subregion permafrost maps and satellite data as inputs. The surface frost number model (FROSTNUM) was re‐inferred to include an extra soil parameter to represent the thermal and moisture conditions in soils. The optimal soil parameters were determined from the subregion maps of permafrost distribution through spatial clustering, parameter optimization, and the decision tree method. FROSTNUM was fed with satellite‐derived ground surface freezing and thawing indices to map the permafrost distribution over the study area. The proposed approach was evaluated in the Gaize area on the Qinghai–Tibet Plateau, where intensive field studies have been done. The simulated permafrost distribution is consistent with a map of permafrost distribution made from borehole observations and field surveys in Gaize. Due to excellent accuracy, the approach is effective and can be used in large areas with limited data.

中文翻译：

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使用次区域地图和卫星数据在大面积上绘制多年冻土的有效方法

多年冻土分布图对于环境评估，气候系统建模和实际工程应用非常重要。强迫数据和参数的稀缺性通常会限制大面积永久冻土模型的使用。但是，通常可以通过实地调查在一些次区域中获得详细的数据。在这项研究中，我们提出了一种新的方法，该方法可以使用以子区域多年冻土图和卫星数据为输入的经验模型来绘制大面积和数据稀缺地区的多年冻土分布。重新推断了表面霜冻数模型（FROSTNUM），以包括一个额外的土壤参数来表示土壤的热和水分条件。根据多年冻土分布的分区图，通过空间聚类，参数优化，和决策树方法。FROSTNUM被提供了卫星衍生的地面冻结和融化指数，以绘制研究区域的多年冻土分布图。在青藏高原的盖兹地区对拟议的方法进行了评估，该地区已经进行了深入的实地研究。模拟的多年冻土分布与从盖兹（Gaize）的钻孔观测和现场调查得出的多年冻土分布图一致。由于精度极高，因此该方法有效，可用于数据量有限的大区域。模拟的多年冻土分布与从盖兹（Gaize）的钻孔观测和现场调查得出的多年冻土分布图一致。由于精度极高，因此该方法有效，可用于数据量有限的大区域。模拟的多年冻土分布与从盖兹（Gaize）的钻孔观测和现场调查得出的多年冻土分布图一致。由于精度极高，因此该方法有效，可以在数据有限的大区域中使用。