Temporal Design Rainfall Patterns in Bang Poo Industrial Estate

Abstract

Bang Poo industrial estate is in Samut Prakan province near the Chao Phraya River mount. In recent years, the Bang Poo industrial estate has faced with flooding damage in the industrial estate on several times. This was caused by the inadequate drainage system which was unable to handle continuous heavy rainfall events. According to the observed rainfall stations in the industrial estate on 20-21 June 2016, there was a total rainfall of 340 millimeters in 2 days leading to flooding within the industrial estate, especially in low-lying free zones. This study aimed to investigate the temporal distribution rainfall patterns in Bang Poo Industrial Estate using three rainfall design analysis methods based on rainfall data from surrounding stations: the Triangular method, the Alternating Block Method, and the Chicago method. The different 6-hour rainfall patterns from various analysis methods were investigated to understand the limitations and the appropriateness of each method based on the availability of the rainfall data. The result comparing with actual 15-minute interval rainfall data from the Automatic Weather System of Thai Meteorological Department (TMD) show that both the Alternating Block and Chicago methods produced design rainfall patterns closely resembling the actual rainfall. The Alternating Block Method provided the most similar distribution to the real rainfall pattern with a MAPE of 42.62%. The findings of this study could be applied to the design and improvement of drainage systems, as well as the flood preparation related to different temporal rainfall distribution patterns. This information is beneficial for mitigating the impact of future flood events in the Bang Poo industrial estate. It may be a guideline for other areas that have only the daily rainfall data.