The presently applied remote sensing algorithms and approaches to monitor soil surface fluxes are reviewed at the beginning of this paper, and the bottleneck of the estimation of soil sur-face fluxes lies in the depen...The presently applied remote sensing algorithms and approaches to monitor soil surface fluxes are reviewed at the beginning of this paper, and the bottleneck of the estimation of soil sur-face fluxes lies in the dependence on non remotely sensed parameters (NRSP). A soil surface evaporation model based on differential thermal inertia, only using remotely sensed information, has thus been proposed after many experiments. The key of the model is to derive soil moisture availability by differential thermal inertia rather than local soil parameters such as soil properties and type. Bowen ratio is estimated by means of soil moisture availability instead of NRSP, such as temperature and wind velocity. Net radiation flux and apparent thermal inertia have been used for soil heat flux parameterization, therefore, the objective of evaporation (latent heat flux) inversion for bare soil only by remotely sensed information can be realized. Two NOAA-AVHRR five-band images, taken at Shapotou northwest of China when soil surface temperature approximated to the highest and lowest of the region, were applied in combination with the ground surface information measured synchronously. The distribution of soil evaporation in Shapotou could be determined. Model verification has been performed between the measured soil surface evaporation and the corresponding calculated value of the images, and the result has proved model to be feasible. Fi-nally, the possible errors and further modifications when applying model to fulling vegetation can-opy have been discussed.展开更多
基金This work was supported by theKey Project of the National Natural Science Foundation of China(Grant No.49890330)the National Basic Research Project(Grant No.2000077900)the Knowledge Innovation Project,Chinese Academy of Sciences(Grant Nos.CXIOG-C00-05-02,CXIOG-E01-01,04).
文摘The presently applied remote sensing algorithms and approaches to monitor soil surface fluxes are reviewed at the beginning of this paper, and the bottleneck of the estimation of soil sur-face fluxes lies in the dependence on non remotely sensed parameters (NRSP). A soil surface evaporation model based on differential thermal inertia, only using remotely sensed information, has thus been proposed after many experiments. The key of the model is to derive soil moisture availability by differential thermal inertia rather than local soil parameters such as soil properties and type. Bowen ratio is estimated by means of soil moisture availability instead of NRSP, such as temperature and wind velocity. Net radiation flux and apparent thermal inertia have been used for soil heat flux parameterization, therefore, the objective of evaporation (latent heat flux) inversion for bare soil only by remotely sensed information can be realized. Two NOAA-AVHRR five-band images, taken at Shapotou northwest of China when soil surface temperature approximated to the highest and lowest of the region, were applied in combination with the ground surface information measured synchronously. The distribution of soil evaporation in Shapotou could be determined. Model verification has been performed between the measured soil surface evaporation and the corresponding calculated value of the images, and the result has proved model to be feasible. Fi-nally, the possible errors and further modifications when applying model to fulling vegetation can-opy have been discussed.
