Hydrological modelling in the anthroposphere: predicting local runoff in a heavily modified high-alpine catchment

Johannes Wesemann,Karsten Schulz,Mathew Herrnegger

doi:10.1007/s11629-017-4587-5

Johannes Wesemann, Karsten Schulz + Show 1 more

Open Access

https://doi.org/10.1007/s11629-017-4587-5

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Abstract

Hydrological models within inflow forecasting systems for high-alpine hydropower reservoirs can provide valuable information as part of a decision support system for the improvement of hydropower production or flood retention. The information, especially concerning runoff, is however rarely available for the calibration of the hydrological models used. Therefore, a method is presented to derive local runoff from secondary information for the calibration of the model parameters of the rainfallrunoff model COSERO. Changes in water levels in reservoirs, reservoir outflows, discharge measurements at water intakes and in transport lines are thereby used to derive the local, “natural” flow for a given sub-catchment. The proposed method is applied within a research study for the ÖBB Infrastructure Railsystem division in the Stubache catchment in the central Austrian Alps. Here, the ÖBB operates the hydropower scheme “Kraftwerksgruppe Stubachtal”, which consists of 7 reservoirs and 4 hydropower stations. The hydrological model has been set up considering this human influences and the high natural heterogeneity in topography and land cover, including glaciers. Overall, the hydrological model performs mostly well for the catchment with highest NSE values of 0.78 for the calibration and 0.79 for the validation period, also considering the use of homogeneous parameter fields and the uncertainty of the derived local discharge values. The derived runoff data proved to be useful information for the model calibration. Further analysis, examining the water balance and its components as well as snow cover, showed satisfactory simulation results. In conclusion, a unique runoff dataset for a small scale high-alpine catchment has been created to establish a hydrological flow prediction model which in a further step can be used for improved and sustainable hydropower management.

Highlights

The European Alps are the water towers of large parts of Europe (Viviroli et al 2007)
In order to provide this data, we present a method to derive the local runoff for small catchments within a high-alpine hydropower scheme on the basis of secondary information
A hydropower scheme is situated in the catchment and is managed by the ÖBB Infrastructure for electricity production in order to satisfy its energy demand. It consists of seven reservoirs and four main hydropower stations

Summary

Introduction

The European Alps are the water towers of large parts of Europe (Viviroli et al 2007). The uplift and subsequent cooling of air due to the high elevations and the general east-west orientation of the Alpine Arch lead to high precipitation sums. This is caused by moist weather systems originating from the Mediterranean in the south and from the Atlantic in the north-west. The low temperature due to the high elevation causes storage of precipitation as snow over the winter season. The melting of the snowpack in spring and summer leads to a distinguished runoff seasonality in months in which water demand tends to be high (Čenčur Curk et al 2014). The contribution to runoff can rise to 80%, as is the case with the Po River (Alpine Convention 2009)

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