Rainfall Generator for the Rhine Basin. Nearest-Neighbour Resampling of Daily Circulation Indices and Conditional Generation of Weather Variables.

摘要

The KNMI rainfall generator is a non-parametric stochastic weather generator based on nearest neighbor resampling of historical data. The weather generator produces daily values of precipitation and temperature. The latter is needed for the calculation of evaporation and snowmelt. Precipitation is generated for about 200 subcatchments. Temperature is simultaneously generated for 34 stations in the basin. With this weather generator, it is possible to generate very long time series (1000 years and more). Since new combinations of historical events are generated (resampling), much higher multi-day rainfall events occur in such long simulations than in the highest historical events. In the Netherlands, this characteristic of the weather generator will be used to determine the design discharge of the Rhine for flood protection, i.e. the discharge with a mean recurrence time of 1250 years at the point where the river enters the Netherlands.