中国1956—2006年地表土壤冻结天数时空分布及其变化特征
王康1, 张廷军2,3,*

Spatial and Temporal Distribution and Variations in the Near-surface Soil Freezing Days across China, 1956-2006
Wang Kang1, Zhang Tingjun1,2,*
图6 中国境内土壤冻结天数的气候平均值1971#cod#x02014;2000年与冻土分布的关系 彩色底图是1971#cod#x02014;2000年近地表土壤冻结天数的离差平均值等值线；黑色虚线为多年冻土边界,红色虚线为不冻结区的边界
Fig.6 Ralationship between climatology 1971-2000 of freezing days and map of frozen ground distribution over China Background color represents the contour values of the departure of near-surface soil freezing days from the 1971-2000 mean; Black dashed line is the boundary of permafrost regions, red dashed line is the boundary between frozen and unfrozen ground regions in China