This technical note is composed of two parts.
　[Part 1] It is stressed that hydrographic charts are fundamentally important data detecting the nearshore process, and that they must be stored and kept being usable at anytime. How to detect the nearshore process is shown with several examples for the cases of contour maps and digitized data, respectively. It is also shown that there are possibilities of utilizing the digitized data to predict the nearshore process empirically by computer and to monitor the sea bottom conditions.
　[Part 2] Beach topography changes around ports are studied by using the statistical analysis with digitized data, and causes of the beach topography changes are investigated. Study ports are Akita, Sakata, East Port of Niigata, Kanazawa, Taki,Fukui, Kashima, Tottori, Miyazaki and Oh-igawa.