Abstract: Research shows that anomalous increase of latent heat flux was discovered before several earthquakes.Basing on the Modis data,high-spectral data and ground meteorological data of the working area,we retrieved the sensible heat flux and calculated the latent heat flux from surface energy balance equation using a simplified two-layer model(dualtemperature-difference method).In this paper,we also discussed the characteristics of this model,and retrieved the latent heat flux of the area where the Longmenshan Fault goes through.Finally,we found that there were significantly high values of latent heat flux in the epicenter area of the M_S 8.0 Wenchuan earthquake and the surrounding area of Longmenshan Fault 48 hours before the earthquake,the latent heat flux on May 12 reached the maximum of 300～400W/m²,which might be the anomalous increase of latent heat flux before the M_S 8.0 Wenchuan earthquake.

Key words: remote sensing, latent heat flux, sensible heat flux, earthquake

摘要： 研究表明,在很多地震前都出现了潜热通量异常。文中基于Modis遥感数据,结合研究区(四川省汶川地区)的高光谱数据及地面观测的气象数据,利用一种简化的双层模型(双温度差分双源模型)反演显热通量,并通过地表能量平衡方程计算研究区的潜热通量。还探讨了该模型的特点,并对龙门山断裂带通过地区进行了潜热通量的遥感反演,发现在2008年5月12日汶川M_S 8.0地震前48h内,研究区内的震中地区、龙门山断裂周边地区潜热通量值出现了明显的高值,5月12日中午12时7分沿龙门山断裂带潜热通量值达到300～400W/m²,可能是汶川8.0级地震前的异常反应。

关键词: 遥感, 潜热通量, 双层模型, 地震