PROBABILISTIC RUNOFF FORECASTING USING A COUPLED ATMOSPHERIC-HYDROLOGIC ENSEMBLE PREDICTION SYSTEM

A high-resolution atmospheric ensemble forecasting system, based on 51 runs of the Local Model (LM), has been used to make probabilistic runoff forecasts for a 5 day forecasting period in the alpine tributaries of the Rhine basin. The investigated cases are the spring 1999 flood, when a combination of snowmelt and heavy precipitation caused severe floods in Central Europe and the November 2002 flash flood in the Alpine Rhine area. This study focuses on the feasibility of ensemble prediction system (EPS) for runoff forecasting. Runoff predictions from the deterministic forecast are compared with those obtained from probabilistic atmospheric forecasts. For both cases, the deterministic simulations yield large forecast failures, while the hydrometeorologic EPS provides appropriate forecast guidance with proper uncertainty intervals. The use of clustering techniques showed that the clustering methodology does not reduce ensemble spread

Simulation of soil moisture and evapotranspiration in a soil profile during the 1999 MAP-Riviera Campaign

Detailed plot-scale observations of basic hydrometeorological variables represent valuable data for assessing the quality of the soil moisture module and evapotranspiration scheme in hydrological models. This study presents the validation of soil moisture and evapotranspiration (ET) simulation during the special observing period (R-SOP) of the Riviera Project (July–November 1999), a sub-project of the Mesoscale Alpine Programme (MAP). The location investigated was a sandy soil plot at the edge of a corn field. The hydrological model PREVAH was driven using three meteorological data sets: hourly data from an experimental tower in the Riviera Valley (southern Switzerland), hourly data interpolated for the Riviera site during the R-SOP period from permanent automatic stations (MeteoSwiss network) and interpolated daily data (1980–2000). The quality of the interpolated meteorological data was evaluated with respect to data collected at an experimental tower. The interpolated data proved fairly representative for the location under investigation. The hydrological simulations were compared with recorded observations of soil moisture and latent heat flux (LE). The simulation of soil moisture was accurate in case of all three meteorological data sets. The results of ET simulations with three simple parameterisations showed high correlation to LE derived using the Bowen ratio and measured through eddy correlation. The quantitative agreement between observed and simulated LE was poorer because of the presence of a fully developed wind valley system during periods of good weather. This wind system claims part of the available energy and therefore reduces the amount of energy available for LE. The 21-year simulation at daily time step shows that the R-SOP period in 1999 was warm and wet compared to the last 21 years.</p> <p style='line-height: 20px;'><b>Keywords: </b>MAP-Riviera Project, soil moisture, evapotranspiration, hydrological modelling, model evaluatio

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Seasonal Water Balance of an Alpine Catchment as Evaluated by Different Methods for Spatially Distributed Snowmelt Modelling

The application of three temperature-index based models and of one energy balance based snowmelt model was investigated. The snow models were integrated in the spatially distributed hydrological model PREVAH. In this study the hydrological simulations of the alpine catchment of the Dischmabach in Switzerland in the period 1982-2000 have been analyzed. The PREVAH model was driven by hourly interpolated meteorological data. All snowmelt approaches allowed a good simulation of the discharge regime and of the seasonal course of the snowpack. The highest model efficiency was obtained by a radiation based temperature-index approach. A simplified energy balance approach combined with the positive degree-day method showed a very similar performance to the classical positive degree-day approach. The energy balance approach ESCIMO showed a high performance variability from year to year. The dependency of the seasonal water balance with respect to altitude is also discussed in this report. The quality of the spatially distributed reproduction of periods with positive and negative water balance (snow accumulation and snowmelt) is crucial for the correct simulation of the runoff hydrograph. The analysis shows that runoff maximum in the Dischmabach catchment is caused by a superposition of the main snowmelt season in the areas between 2,1002,800 m a.s.l. and the period with maximum rainfall

Grundfragen der Planung und Entwicklung des Bedarfes an pharmazeutischen Fachkraeften der Versorgungsbetriebe fuer spezifische Erzeugnisse des Gesundheitswesens in der DDR

DB Leipzig(101) - Di 1981 B VD 33 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

The hydrological role of snow and glaciers in alpine river basins and their distributed modeling

A temperature index approach including incoming solar radiation was used as a sub-model in the gridded hydrological catchment model WaSiM-ETH to simulate the melt rate of glacierized areas. Melt water and rainfall are transformed into glacier discharge by using linear reservoir approaches. The complex WaSiM model was applied to three Swiss high-alpine river catchments with different portions of glacierized areas to simulate the discharges of the whole catchments. Gridded data sets of elevation, soil type, and land-use were used including meteorological input data from the network of MeteoSwiss. These data were spatially and temporally interpolated and modified according to exposition, slope and topographic shading. Continuous discharge simulations for the catchment areas were performed in a spatial resolution of 100 m and a temporal resolution of 1 h for the period 1981-2000 and compared with hourly discharge observations measured at the catchment outlets. To improve the calculation of glacier runoff, a seasonal varying radiation factor has been implemented in the glacier melt equation. The pronounced diurnal and seasonal fluctuations in discharge, which are typical of partly glacierized catchment areas, were simulated in a good agreement with the observed values. For the investigated catchments mean annual values of precipitation, evapotranspiration, snowmelt, runoff, and components of glacier runoff are discussed and compared in their altitudinal dependence. Further, the temporal and the spatial distribution of snowmelt and runoff generation in these glacierized catchment areas are discussed. (C) 2003 Elsevier B.V. All rights reserved

Grundfragen der Planung und Finanzierung der kulturellen und sozialen Betreuung der Werktaetigen in den sozialistischen Produktionsbetrieben der DDR

HUB(11) - 76 HB 2837, T. 1, 2 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

A comparative study in modelling runoff and its components in two mountainous catchments

In mountainous catchments the quality of runoff modelling depends strongly on the assessment of the spatial differences in the generation of the various runoff components and of the flow paths as coupled with the amount and intensity of precipitation and/or the snow melting. These catchments are also suitable for the intercomparison of different kinds of hydrological models, particularly of different approaches for the simulation of runoff generation. Two differently structured catchment models were applied on the pre-alpine Rietholzbach research catchment (3·2 km2) within the period 1981-98 and on the high-alpine Dischmabach catchment (43 km2) within the period 1981-96 for the simulation of hydrological processes and of the runoff hydrographs. The models adopted are the more physically based WaSiM-ETH model, with grid-oriented computation of the water balance elements, and the rather conceptual PREVAH model, based on hydrological response units. The simulation results and the differences resulting from the application of the two models are discussed and compared with the observed catchment discharges, with measurements of evapotranspiration, soil moisture, outflow of a lysimeter, and of groundwater levels in three access tubes. The model intercomparison indicates that the two approaches for determining runoff generation with different degrees of complexity performed with similar statistical efficiency over a period longer than 15 years. The analysis of the simulated runoff components shows that the interflow is the main runoff component and that the portion of the runoff components depends strongly on the approach used. The snowmelt model component is of decisive importance in the snowmelt season and needs to take into account the role of air temperature and radiation for simulating runoff generation in a spatially distributed manne