Investigating the Relationship between Precipitable Water Vapor and Rainfall Data during Flood Events: A GNSS-Based Study in Thailand

Abstract

This research investigates the correlation between Precipitable Water Vapor (PWV), derived from Global Navigation Satellite System (GNSS) measurements, and rainfall during flood events in Chanthaburi, Surat Thani, and Songkhla, Thailand. Utilizing GPS-PWV and meteorological data collected from 2007 to 2016, the study reveals a significant increase in average PWV during flood events at CHAN, SRTN, and SOKA stations, suggesting its potential as an anticipatory indicator for impending rainfall. The robust correlation between PWV and rainfall patterns underscores the pivotal role of meteorological parameters in shaping PWV distribution. Categorized by flood events, consistent correlations were observed, with Case 1 (2009) showing correlation coefficients of 0.78 for CHAN, Case 2 (2010) displaying correlation coefficients of 0.70 for SRTN and 0.27 for SOKA, and Case 3 (2011) exhibiting correlation coefficients of 0.64 for SRTN and 0.71 for SOKA. These findings contribute valuable insights for precipitation forecasting and flood management, emphasizing the utility of PWV as a reliable tool. Future studies incorporating an expanded network of GNSS CORS stations aim to refine PWV distribution understanding for enhanced monitoring and prediction of precipitation events in the region.