TY - JOUR

T1 - Role of rainstorm intensity underestimated by data-derived flood models

T2 - emerging global evidence from subsurface-dominated watersheds

AU - Chappell, Nicholas Arthur

AU - Jones, Timothy Deryck

AU - Tych, Wlodzimierz

AU - Krishnaswamy, Jagdish

PY - 2017/2

Y1 - 2017/2

N2 - Intense rainstorms are a prevalent feature of current weather. Evidence is presented showing that simulation of flood hydrographs shown to be dominated by subsurface flow requires watershed model parameterisation to vary between periods of different rainstorm intensity, in addition to varying with antecedent basin storage. The data show an emerging global relation between flood response and the intensity of rainstorms. Flood responses are quantified as watershed residence times (strictly time constants of nonlinear transfer-function models) identified directly from information contained within 15-min rainfall and streamflow observations. The emerging monotonic, curvilinear relation indicates that (subsurface) watershed residence time decreases as mean intensity rises, and is seen over a wide range of synoptic conditions from temperate and tropical climates. Projected increases in rainstorm intensity would then result in a greater likelihood of river floods in subsurface-dominated watersheds than is currently simulated by systems models omitting this additional nonlinearity.

AB - Intense rainstorms are a prevalent feature of current weather. Evidence is presented showing that simulation of flood hydrographs shown to be dominated by subsurface flow requires watershed model parameterisation to vary between periods of different rainstorm intensity, in addition to varying with antecedent basin storage. The data show an emerging global relation between flood response and the intensity of rainstorms. Flood responses are quantified as watershed residence times (strictly time constants of nonlinear transfer-function models) identified directly from information contained within 15-min rainfall and streamflow observations. The emerging monotonic, curvilinear relation indicates that (subsurface) watershed residence time decreases as mean intensity rises, and is seen over a wide range of synoptic conditions from temperate and tropical climates. Projected increases in rainstorm intensity would then result in a greater likelihood of river floods in subsurface-dominated watersheds than is currently simulated by systems models omitting this additional nonlinearity.

KW - Rainfall intensity

KW - Storm hydrograph

KW - Transfer function

KW - Flood

KW - Nonlinearity

U2 - 10.1016/j.envsoft.2016.10.009

DO - 10.1016/j.envsoft.2016.10.009

M3 - Journal article

VL - 88

SP - 1

EP - 9

JO - Environmental Modelling and Software

JF - Environmental Modelling and Software

SN - 1364-8152

ER -