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The integration of extreme historical floods in contemporary flood protection contributes towards improved risk management and safer handling of floods in the future. As a case study within the "Xfloods" project at the University of Freiburg (Germany), the discharges of the extreme flood in 1824 in the Neckar River basin (Baden-Württemberg/southwest Germany) were reconstructed using historical data. Quantitative and qualitative historical sources were applied to model the regional atmospheric circulation pattern, the weather conditions and the precipitation distribution associated with the event. Discharges were simulated using the water-balance model LARSIM (Large Area Runoff Simulation Model), the operational flood forecasting model in Baden-Württemberg. The developed methodology shows potential for wider use in assessing extreme historical floods and for application to contemporary flood management.Reconstitution hydro-météorologique de la crue 1824 dans le bassin du Neckar (sud-ouest de l'Allemagne) Résumé L'intégration des crues historiques dans la prévention actuelle des risques d'inondation contribue à établir une meilleure estimation des risques et à faire un traitement plus sûr des futures crues. La crue extrême de 1824 dans le bassin du Neckar (Bade-Wurtemberg/sud-ouest de l'Allemagne) a été reconstituée en exploitant les informations des sources historiques en tant qu'étude de cas pour le projet "Xfloods" mené à l'Université de Freiburg (Allemagne). Des sources historiques quantitatives et qualitatives ont été utilisées pour modéliser la circulation atmosphérique à grande échelle spatiale, ainsi que la situation météorologique et la distribution des précipitations qui ont causé cet événement. Les écoulements ont été alors simulés en utilisant le modèle hydrologique LARSIM, qui est le modèle opérationnel de la prédiction des crues au Bade-Wurtemberg. La méthode développée montre un potentiel pour une utilisation plus importante en vue d'évaluer les crues historiques extrêmes et pour son application à la gestion contemporaine des risques d'inondation.

We present a 1-km 2 gridded German dataset of hourly surface climate variables covering the period 1995 to 2012. The dataset comprises 12 variables including temperature, dew point, cloud cover, wind speed and direction, global and direct shortwave radiation, down-and up-welling longwave radiation, sea level pressure, relative humidity and vapour pressure. This dataset was constructed statistically from station data, satellite observations and model data. It is outstanding in terms of spatial and temporal resolution and in the number of climate variables. For each variable, we employed the most suitable gridding method and combined the best of several information sources, including station records, satellite-derived data and data from a regional climate model. A module to estimate urban heat island intensity was integrated for air and dew point temperature. Owing to the low density of available synop stations, the gridded dataset does not capture all variations that may occur at a resolution of 1 km 2 . This applies to areas of complex terrain (all the variables), and in particular to wind speed and the radiation parameters. To achieve maximum precision, we used all observational information when it was available. This, however, leads to inhomogeneities in station network density and affects the long-term consistency of the dataset. A first climate analysis for Germany was conducted.

Abstract. This paper presents a hydrometeorological reconstruction of the flood triggering meteorological situation and the simulation of discharges of the flood event of December 1882 in the Neckar catchment in Baden-Württemberg (southwest Germany). The course of the 1882 flood event in the Neckar catchment in southwest Germany and the weather conditions which led to this flood were reconstructed by evaluating the information from various historical sources. From these historical data, daily input data sets were derived for run-off modeling. For the determination of the precipitation pattern at the end of December 1882, the sparse historical data were modified by using a similar modern day precipitation pattern with a higher station density. The results of this run-off simulation are compared with contemporary historical data and also with 1-D hydraulic simulations using the HEC-RAS model.

Abstract. This paper presents a case study on the estimation of peak discharges of extreme flood events during the 19th century of the Neckar River located in south-western Germany. It was carried out as part of the BMBF (German Federal Ministry of Education and Research) research project RIMAX (Risk Management of Extreme Flood Events). The discharge estimations were made for the 1824 and 1882 flood events, and are based on historical cross profiles. The 1-D model Hydrologic Engineering Centers River Analysis System (HEC-RAS) was applied with different roughness coefficients to determine these estimations. The results are compared (i) with contemporary historical calculations for the 1824 and 1882 flood events and (ii) in the case of the flood event in 1824, with the discharge simulation by the water balance model LARSIM (Large Area Runoff Simulation Model). These calculations are matched by the HEC-RAS simulation based on the standard roughness coefficients.