Workpackage number: 2

Start date or starting event: Project start date

Lead contractor number: 2 - University of Milan-Bicocca

Person-months per partner: 1-2; 2-30; 3-3; 4-3; 5-2; 6-0

Objectives and input to workpackage

1. Data collection on rockfalls and debris flows at basin scales up to 3000 km² in focus areas.

2. Development of GIS models for debris flow/rockfall hazard and risk assessment applicable at local to regional scale.

3. Testing and adoption of different numerical techniques for rockfall and granular flow modelling.

Description of work

1. Data collection (field survey, high resolution topographical surveys with ALTM, and aerial photography), including historical event and physical property data, and creation of a database for GIS and numerical modelling. Generation of accurate Digital Terrain Models (DTM) for fans susceptible to debris flow reactivation, using 1:2000 and 1:5000 scale maps.

2. Using the database and fan DTMs, develop GIS hazard and risk models considering source area for rapid slope failure, debris flow tracks and alluvial fans. Approach will be statistically as well as physically based, the latter including development of a rockfall model from DTMs and maps. Approach will also use hydrological models (eg. SHETRAN from WP4) to describe soil saturation as a debris flow trigger and will incorporate debris flow impact modelling (track and fan) (e.g. from WP3). Demonstration application in focus area B.

3. Compare available rockfall and granular flow models. Compared with classical approaches, the more sophisticated rockfall codes can simulate the failure of falling blocks. Particulate flow codes model the initiation and spreading of granular flows and enable the effectiveness of passive countermeasures to be tested.

Deliverables

D3) Databases, thematic maps and DTMs, as input to WP5.

D4) GIS statistically and physically based technology for hazard and risk assessment, including code for simulation of rockfalls from GIS data. Input to WP5.

D5) Review of rockfall and granular flow models. Input to WP3.

Milestones and expected result

Month 18: Recommendations on granular flow model, for WP3.

Month 24: Preliminary hazard and risk assessment technology for WP5; databases for WP5.

Month 30: Final assessment technology, for WP5.

Result: Quantitative hazard and risk modelling technology for rockfalls and debris flows.