Monitor and Analyzing Salinity intrusion using Salinity Intrusion Forecast System in the Chao Phraya River During Tropical Pabuk 2019

Abstract

In 2019s, Thailand has encountered Tropical Storm Pabuk. Tropical Storm Pabuk is the latest severe storm in the past two decades since Typhoon Linda in 1997. On the afternoon of 4 January 2019, the storm overcame the Pak Phanang district of Nakhon Si Thammarat, which affected the southern region of Thailand. It brought heavy rains and storm surges causing widespread along gulf of Thailand. Chao Phraya River Mouth is another place that has been influenced by the wind waves from the tropical storm Pabuk resulting in rising sea levels. In the Chao Phraya River, seawater salinity intrusion hits near the Metropolitan Waterworks Authority (MWA) pumping station, which provides fresh water for water supply. Hydro-Informatics Institute (HII) monitored salinity intrusion situation by 7-day salinity intrusion forecasting system in Chao Phraya River and Storm Surge Forecasting and Early Warning System in the Gulf of Thailand. The accuracy of salinity forecasting 1 day, 2 days and 3 days are 68% 55% 50%, which is still acceptable. However, the salinity intrusion forecasting system in the Chao Phraya River is very challenging. Due to the changing water management, the uncertainty of weather forecasts and storm surge forecasting have an impact on the salinity intrusion forecasting.