Extended riverflow reconstructions for England and Wales, 1865-2002

Most riverflow records in the United Kingdom are relatively short, with some of the longest continuous series beginning in the late 1950s. In contrast, rainfall records are plentiful with many extending back into the early decades of the nineteenth century. Earlier works have developed a method for reconstructing riverflow data from the longer rainfall series. The work reported here extends previous reconstructions from the middle of the 1990s to 2002. The inclusion of recent very wet periods has allowed a more comprehensive validation of the reconstruction model. Comparisons of reconstructed and observed flows for 1980-2002 imply that land-use changes have had little effect on flows, at least at the monthly time step. In addition, for some catchments, the inadequacy of flow-gauging installations under such extreme flow conditions is discussed. The reconstructions could prove useful for flow naturalisation for some catchments. The wet autumn of 2000 and the ensuing hydrological extremes during 2000 and 2001 are put into the context of the full 1865-2002 flow reconstructions. For 1980-2002, there were few low flow periods. The years 1984, 1989 and especially 1995 rank in the five lowest flows since 1865 on more than one catchment, but low flows during 1870, 1887, 1921, 1933/4 and 1976 were more spatially extensive. Copyright (C) 2005 Royal Meteorological Society.