黄河源区季节冻土最大冻结深度估算方法

Estimation Method for Maximum Frozen Depth of Seasonal Frozen Soil in Source Region of the Yellow River

鉴于黄河源区实测季节冻土最大冻结深度资料极其匮乏,基于1996～2008年黄河源区及其周边气象站点季节冻土数据,分析了季节冻土最大冻结深度与负积温的关系及时空变化规律,建立了最大冻结深度估算公式,对气温空间插值并由最大负积温和高程估算季节冻土最大冻结深度。结果表明,在季节冻土的迅速发展期,冻结下界深度与负积温呈线性相关;最大冻结深度和最大负积温相关性显著;最大负积温可反映季节冻土随时间的变化趋势;黄河源区仅阿尼玛卿山及其周边存在山地多年冻土,季节冻土最大冻结深度由西北向东南方向递减;气温较高年份中东部地区最大冻结深度明显变小,最大冻结深度小的地区对气候变暖更加敏感;1996～2007年间,最大冻结深度随时间推移呈减小趋势。

There is little observed data of seasonal frozen soil in the source region of the Yellow River. Based on the observed data of frozen soil from meteorological stations which locate around the source region of the Yellow River in the period of 1996-2008, the relationship between accumulated negative temperature and maximum frozen depth, spatial and temporal variation of maximum frozen depth are analyzed. And empirical equation is established to simulate the maximum frozen depth. Air temperature is spatially interpolated and maximum frozen depth is estimated by maximum accumulated negative temperature and elevation. The results show that in the period of the seasonal frozen soil developing rapidly, there is a linear relationship between the accumulated negative temperature and frozen depth; the maximum accumulated negative temperature has significant linear correlation with the maximum frozen depth; maximum accumulated negative temperature reflects the temporal variation of maximum frozen depth; permafrost only exists around the Animaqing moun tain; the maximum frozen depth decreases from the northwest to southeast in the source region of the Yellow River; max- imum frozen depth decreases obviously in the east part of the study region in hot years; the region with less frozen depth becomes more sensitive to warmer temperature; the maximum frozen denth aPPears downtrend in the period of 1996-2007.