AN EXPERIMENTAL STUDY ON SOIL EROSION AND FLUID MOTION CAUSED BY A RAIN DROPLET ONTO A GROUND SURFACE

Abstract

Sea pollution caused by the red soil erosion has been becoming as an important social issue for Okinawa Islands, which are popular for subtropical ocean tourism. And also the establishment of an efficient countermeasure against the pollution has been required. In this research, the fundamental fluid motion of a rain droplet and the soil erosions caused by a rain droplet impact are studied experimentally. Three characteristic impact patterns of a rain droplet onto the ground surface are shown. Erosion processes in two different characteristic soil categories namely; Kunigami-margi and Shimajiri-margi that are chiefly distributed in Okinawa Islands are discussed.