Estimation of probable maximum precipitation at three provinces in Northeast Vietnam using historical data and future climate change scenarios

Abstract

Study regionIn this study, three provinces in Northeast Vietnam including Bac Kan, Thai Nguyen, and Tuyen Quang are examined to determine the precipitation variation characteristics. Study focusThe average yearly temperature during the last two decades in Northeast Vietnam has increased by 0.72 °C when compared to the period 1962–1990. The Clausius Clapeyron (CC) relation indicates that a warmer atmosphere can result in higher moisture-holding capacity; hence, there is the possibility of increased extreme rainfall with respect to the rise in temperature. We evaluate the relationship between the average 24-hour temperature and rainfall extremes using the binning method. The estimation of the 24-hour probable maximum precipitation (PMP) is then implemented based on the moisture maximization and Hershfield statistical methods. New hydrological insights for the regionThe 99.9th percentiles of 24-hour precipitation are close to the super CC scaling up to peak points of 22.6–25.6 °C and decrease at higher temperatures. The Hershfield method produces 24-hour PMP results ranging from 232 mm to 895 mm. PMP outputs using the moisture maximization method based on the 100-year dew point are higher than those results generated from the statistical method except for Chiem Hoa station. Considering possible changes in future relative humidity under a warming climate from GCMs and RCM projections for two RCP scenarios, RCP 8.5 indicates the possible rise in probable extreme precipitation.