Is the rate of extremely climate-intensifying rainfall for Bangkok severely propagating into flooding?

ABSTRACT The present paper assesses whether the extremely climate-intensifying rate (i.e., 14%/°C) for maximum rainfall in Bangkok is severely propagating into flooding. The impact evaluation involves the development of a flooding assessment method for a drainage system (DS) representative of the capital and the application of the developed procedure to assess the interested effect of the DS on its flooding. Considering the DS of Thammasat University (DS-TU) as the typical DS for the city, the popular storm water management model (SWMM) is then used for developing the dynamic simulation method against the most critical flooding condition of the DS-TU. Applying this SWMM for impact assessment of the intense rainfall rate has indicated that the rising temperature in excess of 2 °C would cause the gradient to severely propagate into the flooding because of the rapid increase in its associated peak, volume and duration properties. The propagated flooding has been shown to be further escalated, as a result of the clogging in the DS-TU. The clogging height that exceeded the 30% threshold of the full openings would intensify the volume and duration properties increasingly.