Investigation on the Variance of Sand Beach Size and Sand Particle Distribution Due to Typhoon Rainfall and downslope wind - case of Kenting National Park

The Kenting National Park is located in Hengchun area of southern Taiwan and its main duties are conservation of land area plants and marine ecology. There are many beaches in the park where are the important places to tourism and conservation studies. Two particular weather conditions, rainstorm in summer and downslope wind in winter (also called as Luo-shan wind season), may be the reasons for the variance of the Park's beach. To explore the effect on beach size and sand particle distribution due to rainstorm and the downslope wind, thirteen topographic survey and sand sieve analysis from 2010 March to December are carried out at least once a month for Nan Wan, Shiau Wan, Feng Chuei Sha, and Yu Tsuen Park beaches in National Park. By using the results of the survey and sand sieve analysis, the sand volume and particle size distribution of each beach are calculated for further study. This study shows that the downslpope wind makes beach size bigger and sand particle size becomes more fine than before because of terrain effect. Wind and typhoon rainstorm significantly affect the beach's sand volume and sand particle-size due to the fact that the rain washing the beach's surface and let the fine particles into the sea or coarse sand into the beach from the sea.