Assessment of Potential Rainfall Distribution Patterns and Their Relationship with Inundation in Tra Vinh Province, Vietnam

This study aimed to develop temporal rainfall distribution patterns of 1-day, 3-, 5-, and 7-consecutive rain days for three meteorological stations in Tra Vinh province (Cang Long, Tieu Can, and Tra Cu), using daily rainfall data from 1978 to 2017. The study follows the Vietnamese National Standards (TCVN 10406:2015:Irrigation Works – Calculation of Design Drainage Coefficients) to determine the frequency of events of various rainfall distribution drainage patterns. Thereafter, the probability method was conducted to identify rainfall pattern design according to a 10-year return period. Only Cang Long meteorological station exhibited enough single events of rainfall patterns (>10) for 3 consecutive days to determine a rainfall distribution drainage pattern, fitting in pattern type 1 and distribution types 2 and 3. However, for all distribution types of rainfall patterns, the one with the highest last-day rainfall is the most adverse pattern. Therefore, this study recommends building a 3-consecutive day design rainfall for Cang Long station of pattern type 1 and distribution type 3 for precautionary purposes.