Abstract
Spatio-temporal information on the sources of flooding is essential for effective flood control and for a holistic understanding of water quality dynamics. Nevertheless, monitoring such information has been extremely challenging, particularly in the case of large-scale flooding. This paper proposes to estimate the information of flood sources by using a rainfall-runoff-inundation (RRI) model and time-space accounting scheme (T-SAS). The application of the model to the Thailand floods in 2011 demonstrated that 80 % percent of the peak stream flow in mid-October was contributed by the precipitation water in the past three months, and that 35 % of downstream inundated water originated from the local precipitation over the floodplains. We also discussed the effects of dam reservoirs and upstream inundations on the water sources in the study area. The proposed approach is useful to understand the fundamental mechanism of large-scale flooding.
