Impact of Human Activities on the Rainfall - runoff Relation of the Rur Catchment

摘要

The Rur basin (2,300 km~2) was subject to large - scale human activities in the 20th century. Nine reservoirs were built with a total capacity of 300 Mm and open pit mining activities, which started already in the 18th century were dramatically expanded in the 1950s from 10 to 100 Mton annually. Statistical analysis of the daily areal precipitation in the second half of the 20th century has shown that the annual totals and annual extremes have increased since the end of the 1970s, while the spring has become wetter and the summer has become drier. For the same period the annual and seasonal peak discharges of the Rur were found to have increased significantly since 1979. It is concluded that the response of the peak discharge to the increased extreme rainfall events is not significantly affected by human activities. However, this conclusion does not apply to the low flow regime in the Rur, which showed an increase of the minimum summer discharge due to reservoir operation.