利用GPS资料预报局地降雨初步成果

Preliminary Result for Local Precipitation Forecast Using GPS Data

利用2015年5-7月浙江连续运行参考站(Continuously Operating Reference Station,CORS)和2013—2014年香港卫星定位参考站网(Satellite Positioning Reference Station Network,SatRef)的GPS观测数据对大气可降水量(Precipitable Water Vapor,PWV)的变化与地表相对湿度(Surface Relative Humidity,SRH)、局部实际降水量之间的关系进行分析。实验发现,PWV与局地降水成正相关关系;降水事件多数出现在PWV上升至最大值以及PWV迅速下降的时间段内;在有降水发生时,SRH的变化趋势与PWV变化趋势基本一致。此外,PWV增量的大小与每小时降水量的峰值关系很大,且在有大雨发生是尤为明显。根据上述发现,提出了基于单站GPS观测资料合理预报局地降水的方法;该方法能够预报出80%以上的降水事件和90%以上的大雨事件,这对降水事件的短期预报具有十分重要的意义。

The relationship between Precipitable Water Vapor（ PWV）, Surface Relative Humidity（SRH） and local precipita- tion is analyzed using data both from Continuously Operating Reference Station（CORS） of Zhejiang province from May- to Ju- ly 2015 and Satellite Positioning Reference Station Network（SatRef） from 2013 to 2014. The result shows that PWV is posi- tively correlated with the local precipitation. In most cases, the events of precipitation occurred during the period of PWV up to a maxinmnl and sharp decline, in which the trend of SRH is basically identical with PWV＇ s. In addition, the incremental of PWV has a great relationship with hourly precipitation peak, especially obvious when the severe rain event occurs. Ac- cording to the findings, a method to forecast the local precipitation reasonably is proposed based on the data from single GPS station. This method are able to forecast more than 80% of total rain events and more than 90% of severe rain events,which is very- important to the short-term forecast of precipitation events.