MONSOON AND TROPICAL CYCLONE CHANGES DURING 1981-2013 IN COASTAL AREA THE UPPER GULF OF THAILAND

Abstract

This study of meteorological variables those affected coastal area changes on the upper Gulf of Thailand, revealed that factors affected coastal erosion by north-eastern and south-western monsoons, which had important role for weather condition control in monsoon system blowing areas, related to changes of winds, rain and ocean currents in the Gulf of Thailand. The objectives of this research were studies of changing trend of monsoons and tropical cyclones during 1981-2013 in coastal area on the upper Gulf of Thailand and effects of relationship between changes of monsoons and tropical cyclones, which affected to coastal erosion on the upper part of the Gulf of Thailand. By using historical data from six stations of meteorology department around studied area and statistical processing with graphical plotting of changes compared to aerial satellite images of coastal erosion. The study of changing trend of monsoons from the six stations showed obvious change at Phetchaburi station. Wind blowing directions during having north eastern monsoon changed from south eastern direction and south-western monsoon changed to south-eastern and southern directions and during having north eastern monsoon conformed to increasing coastal erosion areas. Aerial satellite images showed increasing coastal change when compared to coastal erosion data from department of Marine and Coastal Resources 49.75 kilometers in Phetchaburi province, 34.69 kilometers in Samut Prakan province and 33.45 kilometers in Samut Songkhram province. For changing trend of tropical cyclones, there was no change in moving direction of the cyclones. There were low opportunities for typhoons to pass through studied area so that there was low coastal erosion from typhoons. During study tropical storm, named “Yvette 2004” affected coastal erosion in the studied area, which could be obviously seen on aerial satellite images