Wildfires Effect on Debris Flow Occurrence in Italian Western Alps: Preliminary Considerations to Refine Debris Flow Early Warnings System Criteria

Rarely, a close correlation between wildfires and the occurrence of channelized debris flows has been observed in the Western Italian Alps. Only two cases in history have been reported, after brief and localized rainfall events of moderate intensity in Italy's Piemonte region (NW Italy) caused debris flows, on 18 July 2005, in Verbania province (Pallanzeno municipality), and on June 2018 in Turin province (Bussoleno municipality). These phenomena occurred after a large portion of the catchments were affected by wide wildfires in the preceding months. Debris flow deposits showed an unusually large number of fine-grained particles, forming dark-brown mud-rich deposits associated with burnt wood deposits. Rainfall analysis related to the period between the wildfires' occurrence and the debris flow events, using both raingauge and weather radar data, pointed out that the debris flows triggered in July 2005 and June 2018 were characterized by greater magnitude but associated with less precipitation intensity rates as compared with previous mud flows occurring just after wildfires. These behaviors can be explained by the presence of burned organic material and fine-grained sediment, generated from the soil's thermal reworking, which formed a thick layer, centimeters deep, covering a large percentage of catchments and slopes. Most of this layer, generated by wildfires' action were winnowed by rainfall events that had occurred in the months before the debris flow events, of significant magnitude, exhuming a discontinuous hydrophobic soil surface that changed the slopes' permeability characteristics. In such conditions, runoff increased, corrivation time shortened, and, consequently, discharge along the two catchments' channels-network increased as well. Consequently, the rainfall effects associated with rainfall events in July 2005 and June 2019 were more effective in mobilizing coarse sediments in channel beds than was typical for those catchments

Dinamiche epidemiologiche e governance sanitaria in Trentino-Alto Adige

[ITA] -- Nel quadro del progetto condiviso di realizzare un Atlante COVID-19 sulle geografie del contagio in Italia, il saggio si concentra sulle dinamiche epidemiologiche che hanno investito il territorio della Regione Trentino-Alto Adige durante la primavera del 2020. Attraverso la raccolta e l’analisi statistico-spaziale di dati open source pubblici, integrati in un sistema informativo territoriale in ambiente GIS, è stato possibile identificare alcuni dei focolai iniziali e le direttrici di diffusione del contagio ed elaborare cartografie tematiche. La lettura comparativa con dati demografici, sociali e ambientali ha permesso di identificare alcune relazioni che concorrono a tracciare un quadro epistemologico sui fattori che hanno influenzato la diffusione geografica dell’epidemia. In particolare, è stato possibile evidenziare la bassa preponderanza di fenomeni quali l’inquinamento dell’aria rispetto al ruolo decisamente più marcato di processi territoriali come gli spostamenti di prossimità e i flussi turistici. Il contesto regionale considerato, che rappresenta un unicum nel mosaico amministrativo italiano in quanto sottoposto alla governance sanitaria di due diverse Aziende Sanitarie afferenti rispettivamente alla Provincia Autonoma di Bolzano – Alto Adige e alla Provincia Autonoma di Trento, consente anche di riflettere sulle difficoltà insite nel raccogliere, comparare e analizzare dati prodotti da differenti Enti per ricostruire i trend di diffusione su territori sottoposti a misure autonome di monitoraggio e mitigazione. [ENG] -- Within the framework of the common project aimed at the production of a COVID-19 Atlas about the infection geographies in Italy, this essay focuses upon the epidemiological dynamics occurred across the territory of Trentino-Alto Adige Region during spring 2020. Through the collection and the spatial-statistical analysis of open source publicly available data, and their integration in a territorial informative infrastructure with GIS, we were able to detect some of the very first outbreaks and the main spreading directions of the pandemic, and we could produce thematic maps. The comparative analysis of demographic, social, economic, and environmental data allowed us to identify some relationships that contribute to outline an epistemological overview about the main factors that could have affected the geographical pattern of the pandemic. In particular, we could highlight the weak role of environmental factors like air pollution as opposed to the stronger effects of other territorial processes, like short-range displacements and touristic flows. The case studied hereby represents a unique entity within the Italian administrative system, as it undergoes two different Health Authorities, one controlled by the Autonomous Province of Trento, the other belonging to the Autonomous Province of Bolzano. It provides therefore the opportunity to deal with the intrinsic difficulties stemming from the collection, comparison and analysis of data produced by different entities while reconstructing the pandemic patterns within territories subjected to independent surveillance and mitigation measures. [DEU] -- Im Rahmen des gemeinsamen Projekts zur Erstellung eines COVID-19-Atlas über die Infektionsgeografien in Italien konzentriert sich dieser Aufsatz auf die epidemiologische Dynamik, die im Frühjahr 2020 auf dem Gebiet der Region Trentino-Südtirol aufgetreten ist. Die Erfassung und statistisch-räumliche Analyse öffentlicher Open-Source-Daten, die in ein territoriales Informationssystem mit GIS integriert waren, hat es ermöglicht, einige der ersten Ausbrüche und die Richtungen für die Ausbreitung der Infektion zu identifizieren sowie thematische Karten zu entwickeln. Die vergleichende Analyse demografischer, sozialer, wirtschaftlicher und ökologischer Daten ermöglichte es, einige Zusammenhänge zu identifizieren, die dazu beitragen, einen erkenntnistheoretischen Überblick über die Hauptfaktoren, die das geografische Pattern der Pandemie beeinflussten, zu zeichnen. Insbesondere konnte das geringe Überwiegen von Phänomenen wie Luftverschmutzung im Vergleich zu der ausgeprägteren Rolle territorialer Prozesse wie Kurzstreckenreisen und Touristenströme hervorgehoben werden. Der analysierte regionale Kontext stellt ein Unikat im italienischen Verwaltungssystem dar, da er der Gesundheitsverwaltung von zwei verschiedenen Gesundheitsbehörden unterliegt, die jeweils der Autonomen Provinz Bozen - Südtirol und der Autonomen Provinz Trient angehören. Dies ermöglicht es uns, über die Schwierigkeiten beim Sammeln, Vergleichen und Analysieren von Daten nachzudenken, die von verschiedenen Einrichtungen erstellt wurden, um die Verbreitungstrends in Gebieten, die autonomen Überwachungs- und Minderungsmaßnahmen unterzogen wurden, zu rekonstruieren