基于MODIS数据的青藏高原地表温度的时空变化特征分析

Temporal and Spatial Variations of Land Surface Temperature over the Qinghai-Xizang Plateau Based on MODIS Data

随着全球气候变化,青藏高原地表呈现出增温的趋势,这会引发一系列灾害事件的发生。本研究利用2003—2017年中国地表温度数据集(MOD11C1和MYD11C1),通过趋势分析法、M-K趋势检验法等,系统分析了青藏高原地表温度的时空分布特征。分析结果表明:青藏高原2003—2017年平均地表温度为0.88℃,整体表现为由东南向西北递减的趋势。从四季分布来看,整个研究区内四个季节的地表温度平均值由高到低排列为:夏季、春季、秋季、冬季,分别为9.57、1.53、1.51和-9.13℃;研究时段内青藏高原年平均地表温度呈波动上升趋势,平均每10年上升0.41℃;四季的地表温度变化趋势表现为春季降温、夏秋冬三季升温的特点,且秋季的地表升温幅度最大,达到0.70℃/10 a;此外,地表温度随海拔高度的变化特征表现为:青藏高原地区海拔每升100 m,年平均地表温度下降0.36℃。研究结果以期为青藏高原灾害风险评估研究提供参考。

Based on China's land surface temperature data sets(MOD11C1 and MYD11C1)from 2003 to 2017,the temporal and spatial distribution characteristics of land surface temperature over the Qinghai-Xizang Plateau were systematically analyzed by means of climate tendency rate method,trend analysis method,cumulative anomaly method and M-K trend test method.The results show that the average land surface temperature over the Qinghai-Xizang Plateau during 2003 and 2017 was 0.88℃,decreasing from southeast to northwest.The annual average land surface temperature over the Qinghai-Xizang Plateau showed a fluctuating and rising trend,with an average increase of 0.412℃ every 10 years.From the perspective of four seasons distribution,the average land surface temperature of the four seasons in the whole study area was in the order of summer,spring,autumn,and winter from high to low,with values of 9.57,1.53,1.51 and -9.13℃,respectively.It shows that the temperature drops in spring and rises in summer,autumn and winter,and the surface temperature rises the fastest in autumn,reaching 0.70℃/10a.