Palaeoflood simulation of the <scp>K</scp>amo River basin using a grid‐cell distributed rainfall run‐off model

Abstract

Abstract Land‐use change and human activities have dramatic implications for water resources, especially through impacts on hydrology and water quality. We characterise the impact of land‐use change on floods through the reconstruction of palaeoflood events and the estimation of discharge during extreme rainfall events under the historical environment using the grid‐ C ell D istributed R ainfall R un‐off M odel V ersion 3 ( CDRMV3 ). Historical land use maps were digitised using the Palaeoland‐Use Reconstruction ( PLUR ) programme as the input data for CDRMV3 . Palaeoflood simulations show the delay and the reduction of the peak discharge under 1902 land use in the K amo River basin because of increases in coverage of forest and paddy fields compared with 1976 land use. Lower discharge and earlier peak discharge time are estimated under historical land use and compared with conditions under present land use. The results of the palaeoflood simulations under extreme rainfall events create a better understanding of palaeoenvironmental conditions and their potential impact on flood management while suggesting important implications for resource management under land use and climate change.