HYDRALP

The Baltschiederbach in the canton of Valais. During the October 2000 flood events, the village of Baltschieder was devastated by this torrent that deposited about 200'000 m3 of sediment  (Photo: A. Badoux, WSL)

Background

With the aim to intensify natural hazard research in the canton of Valais, the Board of the Swiss Federal Institutes of Technology (ETH Board) started the project HYDRALP early in the year 2002. Within this project the Swiss Federal Research Institute WSL, the Swiss Federal Institute of Technology Lausanne EPFL and the Office for Street and River Management of the canton of Valais work together as partners to advance understanding of sediment transport processes (debris flows and fluvial bedload transport) during flood events in torrents and mountain rivers. The formulation of the fundamental hazard assessment requirements within the canton and the compilation of necessary information is another aim of the project. 

Fluvial bedload transport

The quantification of bedload transport rates, of total transported sediment volumes, and of the temporal identification of the processes is a central challenge in bedload transport research.

Within the project HYDRALP a module was defined to investigate the installation of geophone sensors to quantify bedload transport in torrents in the Wallis. Such indirect means of measuring transport rates are highly useful, but unfortunately not used widely. The primary aim is to compile possible areas of applications for such sensors and to delineate criteria for successful positioning. In addition the WSL plans and maintains several geophone sensor arrays. (Research group „Torrents, Erosion and Landslides”)

Debris Flows

Debris flows are a substantial cause for hazard in the Alps and other mountainous regions worldwide. Debris flows often occur during or after extreme precipitation events and can cause major damage in the inhabited areas of fluvial fans. Furthermore, high transport rates often cause damage to protective structures.

The project HYDRALP mainly supports field studies and data collection of the WSL debris flow research. Amongst other things we investigate thresholds for debris flow activity considering a range of rainfall parameters for storm events occurred during the last few years. ("Debris flow" research group)

Collaborations

In the framework of the HYDRALP project we collaborate in several other projects carried out in the Canton of Valais:

• Climate change and hydropower in Valais
• CCES-APUNCH: Advanced Process UNderstanding and prediction of hydrological extremes and Complex Hazards
• Debris flow monitoring
• Alarm system Illgraben
• IFKIS-Hydro

Participants

• Mélanie Raymond Pralong
• François Dufour
• Alexandre Badoux

Contact

• Mélanie Raymond Pralong