Jochen Seidel

Hydrometeorological reconstruction of the 1824 flood event in the Neckar River basin (southwest Germany)

Abstract 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.

Regional Determination of Historical Heavy Rain for Reconstruction of Extreme Flood Events

The reconstruction of historical extreme hydrometeorological events contributes to a validation of extreme value statistics. This can mitigate several uncertainties in the flood risk analysis, e.g. in calculating possible discharges with extreme value statistics which are based on short reference data series [4.5]. The presented case study of the extreme flood of 1824 in the Neckar catchment and their triggering precipitation patterns can take place in a recent flood risk management and can be used to validate the results in trend and extreme value analysis of hydrometeorological time series.

Cross-scale precipitation variability in a semi-arid catchment area on the western slopes of the Central Andes

AbstractSpatiotemporal precipitation patterns were investigated on the western slopes of the central Andes Mountains by applying EOF and cluster analysis as well as the Weather Research and Forecasting (WRF) Model. In the semiarid catchment area in the highlands of Lima, Peru, the precipitation is assumed to be a cross-scale interplay of large-scale dynamics, varying sea surface temperatures (SSTs), and breeze-dominated slope flows. The EOF analysis was used to encompass and elucidate the upper-level circulation patterns dominating the transport of moisture. To delineate local precipitation regimes, a partitioning cluster analysis was carried out, which additionally should illustrate local effects such as the altitudinal gradient of the Andes. The results demonstrated that especially during the transition to the dry season, synoptic-scale circulation aloft controls the precipitation (correlation coefficients between 0.6 and 0.9), whereas in the remaining seasons the slope breezes due to the altitudinal gr...