Trend Analysis on 100 Years of Rainfall Data

In 1999, the digitization of a unique rainfall series of 100 years was completed, which was an ideal opportunity to search for trends in the rainfall. Large variations in rainfall extremes over the century have been observed. For small aggregation levels there is a small decrease in extreme rainfall events over the century. For large aggregation levels, between a few days and a few months, there is a more explicit increase in extreme rainfall. Because the rainfall on the seasonal aggregation level is only slightly increased, this increase for aggregation levels between a few days and a few months can only occur due to larger clustering. However, the final conclusion is that these trends are not significant.