Since modifications of climate values impact the hydrological processes as well as the water regime, the Conference of Rhine Ministers charged the ICPR in 2007 to draft a scenario study for the flow regime of the Rhine.
The ICPR has immediately started work on this issue in its newly set up expert group KLIMA and has, in a first approach, commissioned a <link file:3023 _blank download den einer>bibliographical evaluation entitled: <link file:3023 _blank download den einer>„Analysis of the state of knowledge on climate changes so far and of the impact of climate change on the water regime in the Rhine watershed". Its recently presented results are an important element for further work. Investigations of the air temperature monitoring data already result in statements for the Rhine watershed. During the past 100 years, considerably higher air temperatures have been registered in winter. The rise in air temperature during the summer is less important. On this basis, the mean annual rise in temperature in the Rhine watershed is calculated to about +0,5°C to + 1,2°C. As a result of the rise in temperature, increased precipitation and less snow storage in winter, the monthly average flow regime values in the winter half year in the entire Rhine watershed are higher than what they used to be. Parallel to this development, the maximum runoff is rising. The result is a transfer of runoff from summer to winter while the annual average runoff remains constant.
Further ongoing work concerns the support and follow-up of the drafting of a scenario study with reliable results for the flow regime of the Rhine. In a next step, and based on these results, adjustment strategies will be drafted within the ICPR.