104 research outputs found
A space-time hybrid hourly rainfall model for derived flood frequency analysis
For derived flood frequency analysis based on hydrological modelling long continuous precipitation time series with high temporal resolution are needed. Often, the observation network with recording rainfall gauges is poor, especially regarding the limited length of the available rainfall time series. Stochastic precipitation synthesis is a good alternative either to extend or to regionalise rainfall series to provide adequate input for long-term rainfall-runoff modelling with subsequent estimation of design floods. Here, a new two step procedure for stochastic synthesis of continuous hourly space-time rainfall is proposed and tested for the extension of short observed precipitation time series. First, a single-site alternating renewal model is presented to simulate independent hourly precipitation time series for several locations. The alternating renewal model describes wet spell durations, dry spell durations and wet spell intensities using univariate frequency distributions separately for two seasons. The dependence between wet spell intensity and duration is accounted for by 2-copulas. For disaggregation of the wet spells into hourly intensities a predefined profile is used. In the second step a multi-site resampling procedure is applied on the synthetic point rainfall event series to reproduce the spatial dependence structure of rainfall. Resampling is carried out successively on all synthetic event series using simulated annealing with an objective function considering three bivariate spatial rainfall characteristics. In a case study synthetic precipitation is generated for some locations with short observation records in two mesoscale catchments of the Bode river basin located in northern Germany. The synthetic rainfall data are then applied for derived flood frequency analysis using the hydrological model HEC-HMS. The results show good performance in reproducing average and extreme rainfall characteristics as well as in reproducing observed flood frequencies. The presented model has the potential to be used for ungauged locations through regionalisation of the model parameters.BMBF/FKZ:033068
Modeling human-water-systems: towards a comprehensive and spatially distributed assessment of co-evolutions for river basins in Central Europe
In the context of river basin and flood risk management there is a growing
need to improve the understanding of and the feedbacks between the driving
forces âclimate and socio-economyâ and water systems. We make use of a
variety of data resources to illustrate interrelationships between different
constituents of the human-water-systems. Taking water storage for energy
production as an example we present a first analysis on the co-evolution of
socio-economic and hydrological indicators. The findings will serve as for
the development of conceptual, but fully coupled socio-hydrological models
for selected sectors and regions. These models will be used to generate
integrated scenarios of the climate and socio-economic change
Could an open-source clinical trial data-management system be what we have all been looking for?
The authors argue that research organizations and funders should combine efforts to produce an open-source solution for trial data management
Recommended from our members
Management of unfavorable locoregional prostate carcinoma with radiation and androgen ablation
Recommended from our members
Serum prostate-specific antigen, clinical stage, pathologic grade, and the incidence of nodal metastases in prostate cancer
- âŠ