楼兰消失之迷初探——兼论罗布泊变化

Discussion on the disappearing of Loulan City and the change of Lop Nor

楼兰消失的原因多被解释为与人类活动有关或与自然灾害有关。以木扎尔特冰川为例,通过以往不同时期对冰川的记载与现在冰川情况的对比分析,发现冰川长度在逐步缩短,雪线呈现相应的升高趋势;从不同时期冰碛物分布情况推测出天山及周围山地冰川在第四纪以来曾有过四次冰期发生。各次冰期时间长短有别,冰川规模不一,但都影响到罗布泊湖的存在和消失。第四次冰期活动则对楼兰的存废产生直接影响,然而前三次的冰期活动对楼兰有无影响及其是否存在仍待进一步研究。

The reasons resulting the disappearing of Loulan were generally concluded as two aspects.One is human activities and the other is environments variation.This paper took the Muzarte glacier as a sample,analyzed the dynamics of the glacier during the past three centuries by comparing the current glacier and recordation on previous glacier.The result showed that the length of glacier decreasing with the increasing of snow line.The also were comparing the dynamics of the glacier moraine distribution in Tianshan Mountain and adjacent area at different times.The analysis of glacier moraine presented that there were four times ice age since the quaternary glaciations.Although,the duration and range of the four glacier ages were different,they all influenced the disappearing of Lop Nor-lake;especially the fourth glacier age was closely related to the disappearing of Loulan.Are anterior three glacier ages contributing on the disappearing of Loulan? Further investigations are needed.Based on the above results,the paper concluded that the major reason that lead to the disappearing of Loulan is the glacier retreating and the decrease of melt water runoff.