Rainfall erosivity and extreme precipitation in the Netherlands

Abstract

In order to assess the rainfall erosivity of the Netherlands, several parameters which describe distribution, concentration, and variability of precipitation were used (the annual amount of precipitation, the precipitation concentration index and the modified Fournier index), as well as eleven extreme precipitation indices (maximuml -day precipitation amount, maximum 5-day precipitation amount, simple daily intensity index, number of heavy precipitation days, number of very heavy precipitation days, number of days above 25 mm, consecutive dry days, consecutive wet days, very wet days, extremely wet days, and annual total wet-day precipitation). The precipitation data for calculating the above mentioned parameters is obtained from the Royal Netherlands Meteorological Institute for the period 1957-2016. Based on statistical analysis and the calculated values, the results have been presented with the Geographic Information System (GIS) to point out the most vulnerable parts of the Netherlands with regard to pluvial erosion. This study presents the first results of combined rainfall erosivity and extreme precipitation indices for the investigated area. Trend analysis implies a shift from being largely in the low erosivity class to being completely in the moderate erosivity class in the future, thus indicating an increase in rainfall erosivity. Furthermore, the observed precipitation extremes suggest that both the amount and the intensity of precipitation are increasing. The results of this study suggest that the climate conditions in the Netherlands are changing, and that this change might have a negative influence on the rainfall erosivity of the country.