LandAware

NEWS received from
Davide Tiranti, Regional Agency for Environmental Protection of Piedmont region, Italy

New article “Wildfires Effect on Debris Flow Occurrence in Italian Western Alps: Preliminary Considerations to Refine Debris Flow Early Warnings System Criteria” published in the special issue of Geosciences journal on “Local and Territorial Landslide Early Warning Systems“

In this paper, two case studies in the Italian western Alps on the relationship between wildfires and debris flows occurrence have been analyzed to understand how to integrate this factor in the regional debris flow early warning system (DFEWS). To define these correlations, the authors conducted analyses to characterize changes in the conditions and behavior of catchments after wildfires. The Curve Number (CN) method was adopted to estimate hydrological variations before and after wildfires and identify the differences in catchments response to rainfall events, due to its simple applicability over a large number of catchments. Rainfall analyses, using both data from raingauges and weather radars to identify the actual distribution of precipitation intensity fields, were addressed. The case studies described have led to some interesting results, both regarding the understanding of the wildfires effects on debris flows triggering in small Alpine catchments and on the necessary technical and operational adjustments to improve the DFEWS performance in case of wildfire occurrence.

Reference: Tiranti D., Cremonini R., Sanmartino D. (2021) Wildfires Effect on Debris Flow Occurrence in Italian Western Alps: Preliminary Considerations to Refine Debris Flow Early Warnings System Criteria. Geosciences 11, 422. https://doi.org/10.3390/geosciences11100422

NEWS received from
Paulo Hader – São Paulo State University (UNESP)

New article: Risk cross-referencing for landslide risk assessment at a municipal scale, by Paulo Hader and co-authors from São Paulo State University, Brazil

This recently published paper proposes a model for landslide risk assessment at the municipal scale, useful for early waninrg purposes.
Three products, being rainfall thresholds, landslide susceptibility map and social vulnerability map were produced statistically. To couple them, the authors used a two-matrix approach, where in the first matrix the susceptibility map and the vulnerability map were crossed, constituting the socio-natural criterion; and in the second matrix, the rainfall thresholds were coupled to the socionatural criterion, allowing a real-time assessment.
The authors found that the model offers easy adaptation and calibration once new data emerges, as well as being able to be integrated into a landslide early warning system to make explicit the areas of highest degree of loss, where interventions can be made in advance to reduce the risk in specific areas.

Reference: Hader, P.R.P., Reis, F.A.G.V. & Peixoto, A.S.P. (2021) Landslide risk assessment considering socionatural factors: methodology and application to Cubatão municipality, São Paulo, Brazil. Natural Hazards. 
https://doi.org/10.1007/s11069-021-04991-4