Abstract:

By meteorological detection net of Global Positioning System(GPS)set up in 2006 year in Hubei Province,the paper makes detection to precipitable water vapor(〖WTBX〗PWV〖WTBZ〗)during meiyu period of 2007 year,and indicates that 〖WTBX〗PWV〖WTBZ〗 detected by GPS and that calculated by radiosonde data has high consistency.By means of analysis of time series of GPS data in multistation,the paper posts change characteristic of three phases of 〖WTBX〗PWV〖WTBZ〗 during meiyu period.Before the meiyu period comes,〖WTBX〗PWV〖WTBZ〗 has a rapid rise.The length,extent and magnitude of rapid rise reflect accumulation of water vapor,it has better corresponding relationship with precipitation process during meiyu period;during meiyu period,the process that rapid rise of 〖WTBX〗PWV〖WTBZ〗 reaches the peak has concomitant obvious precipitation,after entering high fluctuation phase,the precipitation holds on,in the course of 〖WTBX〗PWV〖WTBZ〗 descends,the precipitation steps down,up to stop.In the phase,the fluctuation of time series of 〖WTBX〗PWV〖WTBZ〗 and spatial distribution have better corresponding relationship with shortterm change of precipitation during meiyu preiod;reposefully diminishing of change amplitude and average magnitude of 〖WTBX〗PWV〖WTBZ〗 reflects that the meiyu period is about to end.

Key words: Global Positioning System(GPS)/meiyu period/precipitable water vapor