A fast geo-hazard assessment for electro-energetic network systems using a simplified geo-hydrological model

Dams, powerlines, and power plants represent strategic energetic infrastructures and their future operativity maintenance is a challenge. Stakeholders are strongly interested in evaluating the potential risks that may affect their functionality, especially regarding natural hazards. In Italy, geo-hydrological hazards triggered by rainfall such as floods and landslides represent a serious threat to electrical infrastructure, since their magnitude is generally difficult to modelling and quantify properly.

Here, we present an application of the model proposed by Borga et. Al. for rainfall-induced shallow landslide hazard assessment. The model merges an infinite slope stability equation with a simplified hydrogeological model evaluating, for a defined rainfall duration, the critical rainfall ratio able to trigger the landslide failure. The model has been adapted to work automatically using Python scripts and has been extended proposing a new strategy for evaluating the Dynamic Contributing Area and for including soil moisture information. Rainfall return time was considered as a proxy of the magnitude of the geo-hydrological events, identifying the most hazardous area with respect to the position of powerlines for the case study basin of Trebbia River, Emilia, Italy. Model results were validated against the currently available local rainfall threshold curves, showing good skill in failure detection.

The instrument could be useful for planning purposes, addressing, and quantifying the location under which the critical infrastructure may encounter risk with respect to geo-hydrological threats, and giving useful insights about possible mitigation strategies to increase the overall electro-energetic system resilience.