| Thermal inertia approach is the major method to use remote sensing data to monitor drought and has produced positive effects in its use in north China. Shaanxi province straddles over three climatic zones from south to north and has complicated landforms. The paper uses NOAA/AVHRR data to calculate real thermal inertia, apparent thermal inertia and brightness-temperature difference on NOAA/AVHRR channel 4, and then deduce their relation models with relative soil moisture as well as discuss the effects of the landforms and vegetation coverage of Shaanxi province on the relation between apparent thermal inertia and soil moisture. The results reveal that the model depending on apparent thermal inertia and relative soil humidity can be used to monitor drought in the monitoring services by remote sensing. Considering a landform, vegetation and soil types, the correlativity between apparent thermal inertia and relative soil humidity become better as the underlying surface become more uniformed, but the effects of vegetation coverage on temperature on ground surface need be further studied. |