| By using the meteorological data and EOS-MODIS data of Dingxi region, some basic ground surface parameters in the dry-farming region in northwest China are derived, and each energy flux is estimated. Moreover, the seasonal variation of the parameters is analyzed. The results show that the percentage of each flux value in net radiation energy estimated by MODIS is close to the observed value, the absolute error being less than 10%, which means that the derived fluxes may reflect the fact of the region. The seasonal variation of soil heat flux, palpable heat flux and latent heat flux appears to be the smallest in winter, and the largest in summer and spring. The seasonal variation of these fluxes also appears to be very asymmetrical in distribution, which embodies the complex surface characters of landform and physiognomy in the region. |