川东平行岭谷地表温度时空分布驱动机制分析

Analysis of Driving Mechanism of Temporal and Spatial Distribution of Surface Temperature in Parallel Ridge Valley of East Sichuan

川东平行岭谷是我国一种特殊的地理单元,探讨该区域在不同因素影响下地表温度的变化规律,可以了解当地水热时空分布特征。文章选取三个时期的Landsat-8数据反演地表温度,结合地形和土地覆盖数据对该区域地表温度时空分布特征进行驱动力分析。结果发现,不同季节地表温度都表现出随高程和坡度的增加而降低,北坡温度低于南坡温度的特征。山岭区域海拔高、地物均一、植被覆盖高、地表温度较低;槽谷区地势平坦、海拔较低、人工地表分布广、地表温度总体较高。对比不同季节,夏季地表温度差异较春冬两季表现更为显著。地表温度空间分布呈现破碎化,喀斯特地物石漠化等因素影响加剧了这种趋势。本研究可以为川东平行岭谷的陆表过程监测与模拟提供参考依据。

The parallel ridge valley of east Sichuan(PRVES)is a kind of special geographic unit in China.The exploration of the variation law of the land surface temperature(LST)under the influence of different factors in this region can help us to understand the local spatio-temporal distribution of hydrothermal energy.In this paper,three different periods of Landsat-8 remote sensing images are selected to retrieve the LST.A driving force analysis is performed on the spatio-temporal distribution characteristics of the LST in conjunction with the topographic and land cover data.The results show that the LST has the same seasonal trend as the three topographic factors,which are elevation,slope and aspect in the PRVES.The LST decreases with increasing elevation and slope,and it is higher on the north slope than on the south slope.The mountain region has higher elevation,more homogeneous surface cover types,thicker vegetation coverage and lower LST.The trough valley area is flat,with relatively lower elevation,wider artificial surface distribution and higher LST.Compared with the change of LST in different seasons,the difference of LST between the mountain range and the trough valley in summer is more pronounced than that in spring and winter.The spatial distribution of LST in the PRVES presents fragmented,and factors such as bare surface rocks caused by karst further aggravate this trend.This study can afford references for land surface process monitoring and simulation in the PRVES.