为了研究近地表面多年冻土的空间分布规律,采用野外调查、取样方法对该问题进行研究。研究区选取在大兴安岭高纬度多年冻土地区呼中自然保护区,应用等效纬度、ASAR雷达图象和坡位分级分别代表影响多年冻土的热量、水分和地形条件,利用ERDAS软件对呼中自然保护区高纬度多年冻土分布信息进行提取,结果表明考虑热量、水分和地形条件确定的多年冻土分布土的精度为86.2%,高于单独利用等效纬度提取多年冻土的方法精度。同时,水分研究结果表明,在呼中自然保护区,土壤湿度是指示多年冻土存在的重要条件。
In order to study the near-surface permafrost distribution space, field survey and sampling method are used to study the issue. The area of Great Hingan Mountains in Northeastern China is high-latitude permafrost region. The conditions of heat, soil moisture and landform are used to predict the presence or absence of permafrost table within 1.5m below the ground surface over the area of Huzhong National Reserve by Erdas software. The input conditions of classification includes equivalent latitude, wide swath image of ASAR sensor and slope position. This classification result accuracy which is better than the classification result by equivalent latitude method is up to 86.2%. Simultaneously, the results indicate that the correlativity between soil moisture and permafrost table is good. When the soil becomes drier, the permafrost table will be deeper. Thus the condition of soil moisture in Huzhong National Reserve is an important indicator of permafrost.