This paper studies the detection and removal of clouds and their shadows from remote sensing images based on the theory of image processing and analyzing,and sets up the image model and region restoring model.

The results show the maximum rainfall did not occur at areas where the cloud-top temperature was the lowest or the cloud-top temperature gradient was the largest,but occurred at about four pixels ahead of the area with the largest temperature gradient around the lowest-temperature centers of cloud clusters.

Through analysis of different phenomena in the process of rainstorm of Zichang in Norhern Shaanxi on July 4, 2002, this extra-heavy rainstorm is formed by meso-βscale strong convective cloud cluster, having the characteristics of the formation, development and disappearance of the typical convective monomer.

The formation and development of the meso-β scale convective cloud clusters resulting in rainfallwith different intensities over the middle reachers of the Yangtze River are analysed.