This paper presents scattering power decomposition images of fully polarimetric synthetic aperture radar (SAR) data for disaster monitoring. Utilization of fully polarimetric data can derive full color images with red-green-blue color coding, red for the double-bounce power, green for the volume scattering power, and blue for the surface scattering power, for which each color brightness corresponds to the magnitude. Since disaster events cause the changes of each scattering power, it becomes straightforward for everyone to recognize the changes of the color in the polarimetric decomposed images provided time series data sets are made available. After applying the four-component scattering power decomposition to fully polarimetric image data sets acquired with the Advanced Land Observing Satellite (ALOS) Phased-Array-type L-band SAR (PALSAR), several images are presented for natural disaster monitoring of volcanic activity, snow accumulation, landslides, and tsunami effects caused by great earthquakes. It is seen in the polarimetric decomposition images that the surface scattering power becomes predominant in most disaster areas compared to those in normal situations.