中国典型山地冰川平衡线的影响因素分析

中国典型山地无现代冰川作用区冰川平衡线高度的确定对于过去环境变化研究具有重要的科学意义。选取青藏高原边缘17个山体的28个气象站气温与降水数据,采用确定的最大降水带与经验曲线关系法 (简称MPC,下同)、确定的最大降水带与统计公式法 (MPF) 和实际气象站降水与经验公式法 (WPF),恢复了17个山地的现代理论冰川平衡线高度,并对比了三种方法的适用性;综合分析了三种方法的原理、参数选取、计算过程以及误差来源;详细讨论了冰川平衡线处气温与降水关系式、气象站的海拔高度、气温垂直递减率、降水梯度对计算现代冰川平衡线的影响。提出了无现代冰川区的现代理论冰川平衡线计算的综合因子法 (ZYZ)。

Theoretical glacial equilibrium line altitudes and their influencing factors in the typical mountains of China

It is important to reconstruct the past environmental changes for unglaciated area in the typical mountains of the Tibetan Plateau and in eastern China by using modern theoretical equilibrium line altitudes (ELAs). Based on the data from 28 meteorological stations of 17 typical mountains, the ELAs were calculated by the methods of Maximum Precipitation Zoneand Empirical Curve (MPC), Maximum Precipitation Zone and Empirical Formula (MPF) and Meteorological Precipitation and Empirical Formula (WPF). Research results show that, MPF is better than WPF through the comparison of the applicability between these two methods in the study areas. The results also indicate that the factors affecting the ELAs are precipitation, temperature, altitude of the meteorological stations and lapse rate of temperature. Based on the in-depth analysis of the principle, parameter selection, computational process and error sources, the authors put forward a newly improved method for calculating modern theoretical ELAs.