[1] Precipitation downscaling improves the coarse resolution and poor representation of precipitation in global climate models and helps end users to assess the likely hydrological impacts of climate change. This paper integrates perspectives from meteorologists, climatologists, statisticians, and hydrologists to identify generic end user (in particular, impact modeler) needs and to discuss downscaling capabilities and gaps. End users need a reliable representation of precipitation intensities and temporal and spatial variability, as well as physical consistency, independent of region and season. In addition to presenting dynamical downscaling, we review perfect prognosis statistical downscaling, model output statistics, and weather generators, focusing on recent developments to improve the representation of spacetime variability. Furthermore, evaluation techniques to assess downscaling skill are presented. Downscaling adds considerable value to projections from global climate models. Remaining gaps are uncertainties arising from sparse data; representation of extreme summer precipitation, subdaily precipitation, and full precipitation fields on fine scales; capturing changes in small-scale processes and their feedback on large scales; and errors inherited from the driving global climate model.

BACKGROUND. State predictions for terrestrial systems are usually performed by means of numerical process models, which consider all compartments. However, it is unclear to what extent system heterogeneity must be considered for a particular set of conditions and for different types of model predictions.Numerical process models of the terrestrial system usually consider three vertically stacked mediarepresenting the subsurface, including ground and surface water; vegetation; and atmosphere-that are typically coded in three separate compartment models. These compartment models interact at their

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Slum dwellers are often exposed to natural hazards. While their high vulnerability seems to leave them unprotected to face these hazards, current research points to the fact that slum dwellers in particular are able to deal with crises remarkably well due to their high social capital. Using the example of extreme floods in the megacity Dhaka, we study the structure of social capital in slum dwellings by focusing on the question how this form of capital enables the management of these events. Three characteristics seem to be crucial for this: first, trusting relationships between the people, which allows for a quick and unbureaucratic way to receive financial aid in form of small credits. In addition, the multifaceted and redundant structures of social capital, which allow numerous people to ask for help from people in varying positions. The final characteristic consists of the various possibilities to resume work immediately after a flood event. However, while the social capital in Dhaka allows slum dwellers to overcome the crisis, it does not enable a long-term development. For the slum dwellers it is not sufficient to utilize social capital alone in order to become resilient in a comprehensive way. Zusammenfassung: Slum-�ewohner sind h�ufi g Naturgefahren ausgesetzt. �inerseits sind sie solchen �reignissen auf-Slum-�ewohner sind h�ufig Naturgefahren ausgesetzt. �inerseits sind sie solchen �reignissen aufgrund ihrer hohen Vulnerabilit�t scheinbar schutzlos ausgeliefert, andererseits deuten aktuelle Forschungen darauf hin, dass gerade Slum-�ewohner über ein hohes Maß an Sozialkapital verfügen und mit Krisen erstaunlich gut umgehen können. Anhand des �eispiels von schweren Überschwemmungen in der Megastadt Dhaka untersucht dieser �eitrag, wie das Sozialkapital der Haushalte in Slums strukturiert ist. Im Vordergrund steht dabei die Frage, wie diese Kapitalform es ermöglicht, trotz der Vulnerabilit�t erhebliche Krisen zu bew�ltigen. Drei �igenschaften scheinen dafür zentral zu sein: �rstens das allgemeine Vertrauen zwischen den Menschen, das es ermöglicht, rasch und unkompliziert an kleine Kredite zu kommen. Zweitens, die vielf�ltigen und redundanten Strukturen des Sozialkapitals, wodurch bei vielen Personen in unterschiedlichen Positionen Hilfe angefragt werden kann. Drittens, die verschiedenen Möglichkeiten gleich nach der Überschwemmung wieder rasch eine Arbeit aufnehmen zu können. Allerdings ermöglicht das Sozialkapital nur ein Überwinden der Krise, aber keine langfristige �ntwicklung der Haushalte. In einem umfassenden Sinne resilient werden die Haushalte in den Slums von Dhaka durch die Nutzung von Sozialkapital kaum.

Climate change is expected to impact flooding in many highly populated coastal regions, including Dhaka (Bangladesh), which is currently among the fastest growing cities in the world. In the past, high mortality counts have been associated with extreme flood events. We first analyzed daily water levels of the past 100 years in order to detect potential shifts in extremes. A distributed lag non-linear model was then used to examine the connection between water levels and mortality. Results indicate that for the period of 2003–2007, which entails two major flood events in 2004 and 2007, high water levels do not lead to a significant increase in relative mortality, which indicates a good level of adaptation and capacity to cope with flooding. However, following low water levels, an increase in mortality could be found. As our trend analysis of past water levels shows that minimum water levels have decreased during the past 100 years, action should be taken to ensure that the exposed population is also well-adapted to drought.