Table of Contents

Runoff hydrographs of Ahr tributaries

Author: Van Oproy Kurt

The objectif is to make a realistic hydrograph for Altenahr based on its tributaries. Therefore, the watersheds of the important tributaries of the Ahr were delineated seperately, selecting only the tributaries of the Ahr upstream from Altenahr. For each watersheds a runoff calculation was performed, and the discharge values were transposed to an Excel file.
The first combined results gave a reaction profile for the discharge at Altenahr that started 1.5 hours earlier than the observed flow.

The measure stations of the Ahr

Official version

Some facts and reference points about the flood, collected from the media:

Video of houses of the Uberdorfstrasse 2 and 4 in Insul, where the height of floodwave - shown in the video - was at least 1.5 - 2 meters above the street level.

Video interview with local Christof Pätz in Altenburg:

Factual version

The plot 'MidAhr(Fr)' contains the aggregated flowrate, which is based on the precipitation of the nearest location with pluvio data I could find, for places like Freilingen, Barweiler, ...

The first bump suggests that there is some kind of hidden or unknown storage in the flow path. This could make the torrent even more raging in nature.

Several surface runoff hydrographs

The first set is representing the Sahrbach catchmant surface runoff.

The runoff values were calculated for these tributaries:

we merge the individual hydrographs.

Summation of the discharges of the streams upstream of Altenahr