Fig. 4: Comparison in flood duration in 1931 and 1998.
From: Flood modeling prior to the instrumental era reveals limited magnitude of 1931 Yangtze flood
Flood duration (unit: days) in a year of each spatial unit (color blocks in a, b) is identified as the number of days with the standardized discharge index (Sdi) above 1.28 (90% quantile of daily discharges over 1982–2000). a and b show the spatial distribution of flood duration in 1931 and 1998, respectively. The red polygons divide the Yangtze River Watershed into 11 sub-catchments (Mu, Mm, Ml, Jsu, Jsl, M, J, W, H, D, P), each composed of a subset of the 279 units. The mean (m) and standard deviation (std) were calculated based on the flood duration of all 279 units over 1982–2000. c displays the flood duration in 1931 (the blue) and 1998 (the orange) in the 11 sub-catchments of the Yangtze River Watershed. Yup, Ymd, and All indicate the upstream, mid-downstream, and entire watershed. The horizontal black lines (whiskers) show the flood duration start and end. The left and right bounds of the boxes are the first and third quartiles. The red bar in the middle shows the average.
