COMPARATIVE ANALYSIS OF THE INTENSITY AND DISTRIBUTION OF RAINSTROM IN ZHEJIANG PROVINCE CAUSED BY TYPHOON HAITANG AND MATSA

Study was carried out on two landfall typhoons Haitang and Matsa,which affected zhejiang province seriously.Firstly,the similarity and difference between the two typhoon-induced rainstorms were compared and it was pointed out that both of them brought strong large-scale precipitation and the maximum centers of rainfall were located at the north side of the landfall site.Making landfall on Fujian,Haitang was weaker than Matsa in intensity but surpassed it in rainfall.Then with focus on intensity,moving speed,structure of typhoon,circulation and terrain etc,the two typhoon-related rainstorms were compared and analyzed.Results show that the asymmetrical distribution of rainfall was closely related to the structure of typhoon itself,moisture transportation and mesoscale terrain.In contrast to the south side,the north side was hotter and wetter,moisture content was also more abundant.The phenomenon of more rainfall induced by Haitang was in connection with the following reasons: invading cold air leads to rainfall increase,weakened dynamic field and slower movement both benefited precipitation.For the last part,the cold characteristic of air mass over Zhejiang was also an favorable factor for raining.