芬兰Valkea-Kotinen湖5月～10月水温长期变化趋势分析

Analysis of long-term variation trend of water temperature in Valkea-Kotinen Lake from May to October in Finland

选取1990年-2017年芬兰Valkea-Kotinen湖5月～10月不同深度水温现场观测数据,重点考察每年5月～10月整个无冰期不同深度实测最高水温和各月不同深度实测平均水温这两个指标;对历年最高水温和各月平均水温时间序列,统计计算出Kendall秩次相关检验统计量.检验分析结果表明,Valkea-Kotinen湖无冰期水体表层0 m～1 m水温和5月、10月水温总体呈上升趋势,反应到具体冰现象上就是冰期缩短,而表层以下水温呈不显著下降趋势.这与现场实际现象和目前很多地区的湖泊因气候变暖导致的湖水温度提高的趋势相符合.

In this paper,the field observation data of water temperature at different depths from May to October in Valkea-Kotinen Lake in Finland from 1990 to 2017 are selected,and the two indexes of the measured maximum water temperature at different depths and the measured average water temperature at different depths during the whole ice-free period from may to October were emphatically analyzed; The Kendalltrend rank correlation test statistics were calculated for the time series of the highest water temperature and the monthly average water temperature. The results of test and analysis show that the water temperature below the surface layer of Valkea-Kotinen Lake during the non-glacial period showed no significant downward trend,but the surface water temperature of Valkea-Kotinen Lake showed an overall upward trend in May and October. The rising trend,reflected in the specific ice phenomenon,is the shortening of the ice age. This conclusion is consistent with the current trend of global warming caused by greenhouse effect in many areas.