Rainfall generator for the Meuse basin : description of simulations with and without a memory term and uncertainty analysis

The rainfall generator has been developed to generate long synthetic sequences of daily precipitation and temperature for the Meuse basin [see e.g. Leander and Buishand (2004), Leander et al. (2005), and Buishand and Leander (2011)] using the nearest-neighbour resampling (NNR) technique. These sequences have been used for discharge simulations with the semi-distributed HBV model (Aalders et al., 2004; Leander et al., 2005) to estimate the design discharge for flood protection works in the Netherlands. For the non-tidal embanked part of the river, the 1250-year return level of the discharge at Borgharen (near the city of Maastricht) is presently used as design discharge. An important source of uncertainty of this design discharge is the length of the historical records used for resampling. In order to study the sensitivity of the 1250-year return level to the choice of the historical data, several 20,000-year simulations were conducted with various 33-year subsets of the 1930-1998 period as well as a 20,000-year simulation based on the whole 1930-1998 period (Leander and Buishand, 2008).