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The subject of the present paper is the flood situation in the German part of the Elbe river. For this, no (international) agreement could be reached till now. Problems occur due to missing, non-plausible or uncertain flow data and due to non-stationary hydrological conditions in the basin caused by climatological variability and human impact (diking and installation of reservoirs). Regarding this complex hydrological situation a systematic procedure consisting of existing hydrological tools was developed. In a harmonised and complementary structure this procedure mainly includes the consistency analysis of flow data, statistical analyses of the flow process, especially flood statistics and their regionalisation, stochastic simulations of the flow process in the basin and flow routing. Therewith a stepwise increasingly reliable, representative, detailed and funded knowledge of the flow process may be achieved. Till now complete longitudinal sections of statistical flood parameters along the German part of the watercourse were determined for a sufficiently long period (1964–1995) best reflecting the present situation. Moreover, approximative flood statistics could be derived for a longer period (1936–1995), which may be regarded as representative for the variable hydrological conditions during the 20th century.In addition to this fundamental study the tools were applied in order to contribute to a decision support with respect to the presently discussed measures of dike shifting. The analyses revealed that a significant impact of these measures—even the impact of all measures together—on flood peaks may be achieved only if control systems at the sites of the retention spaces are used.Finally, the paper considers options of a further utilisation of the hydrological analysis results by the definition of interfaces to other disciplines. [Copyright &y& Elsevier]

Summary: The Mekong River Basin in South East Asia has experienced in recent decades large inter-annual variations between large floods and severe droughts. The general perception is that climate variability has increased in the region. In this paper our aim was to examine the role of El Niño-Southern Oscillation (ENSO) on these recent climate variations. To achieve our aim, we analysed the influence of ENSO on precipitation (over period 1981–2005) and discharge (1910–2008) by using spatial GIS analyses and statistical methods, such as linear correlations, spectral analysis and stochastic regression models. We found that the Mekong’s hydrology was significantly influenced by ENSO, particularly in the decay year of ENSO events. The influence was strongest in the southern parts of the basin. The precipitation and discharge decreased (increased) during El Niño (La Niña) and the annual flood period was shorter (longer) during El Niño (La Niña). We found also decadal variations in the ENSO-discharge relationship. Our findings indicate high potential for developing prediction methods for ENSO induced hydrological anomalies. These findings may significantly improve the possibility of preparing for extreme hydrological events, either drought or exceptional floods, and thus potentially improve water resources management in the basin. [ABSTRACT FROM AUTHOR]