Extreme events in the past and future - A comparative assessment for the Hai He river and the Poyang lake basins

• Applicant: Dr. Christian Ohlwein
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management
• Term: from 2010 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 162142802

The impact of future climate change on land-use and water resource management is strongly dependent on the related changes in weather extremes. The future can only be assessed by the use of global climate models, which currently lack the necessary spatial resolution to represent such events. Moreover, global climate models are not able to incorporate all processes leading to extremes because of their low resolution. Thus downscaling of such runs is necessary, and only dynamical downscaling with high-resolution regional models is able to catch the necessary non-linear processes and process chains leading to extremes. The goal of this joint proposal is to provide estimates including their uncertainties of the behaviour of extreme weather events impacting land-use and water management for the 21st century for two climatically very different catchments, namely the Hai He river and the Poyang lake basins. To this goal we will first analyse the past of extreme events in both regions on the basis of observations and reanalysis data sets using state of the art extreme value statistics. Dynamical downscaling of global climate runs will be performed in order to evaluate the future of extreme events in the catchments. This necessitates first an evaluation of simulations of the current climate and its extremes by comparison with observations on a statistical basis. This will enable us to use the most appropriate regional climate model and to select the parametrisation setup most suitable for both regions, which might be different. While the Chinese partners will provide the observation data sets and perform the dynamical downscaling of global climate runs, the German partners will install the dynamical downscaling procedure at the Chinese partner institute, and generate the statistics of extremes both from observations and the simulations. The evaluation towards trends and uncertainties will be performed in close cooperation.

• DFG Programme: Research Grants
• International Connection: China
• Participating Persons: Professor Dr. Clemens Simmer; Professor Dr. Jiang Tong