Alpine gullies system evolution : erosion drivers and control factors. Two examples from the western Italian Alps

Denudation processes affecting mountain slopes may vary according to different factors (e.g., lithology and structural setting of bedrock, climate, relief features), which may be very diverse at the local scale. Gully complex systems, characterised by morphological features similar to those developing in other climate contexts (i.e., pseudo-badlands) are also becoming common at higher altitudes and latitudes. The selected study cases of Gran Gorgia (Susa Valley) and Saint Nicolas (Aosta Valley), in the Western Italian Alps, are sites of geomorphological interest as they are specifically relevant for their scientific features. The aims of this work are (i) reconstructing the morphometric evolution of gully systems and vegetation colonisation time by means of multitemporal spatial analysis on surface morphological changes under water erosion; (ii) reconstructing in detail, through dendrogeomorphological analysis, the progressive spatial surface denudation and changes in erosion rates, by analysing trees and exposed roots and using different indicators (i.e., compression wood, traumatic resin ducts); (iii) obtaining data on successive aggradation/degradation episodes along slopes surrounding such hotspots through geopedological investigations; and (iv) identifying which control factors exert a predominant role on denudation patterns in such contexts. Multidisciplinary analyses regarding the study sites allowed for detailing of erosional history of the studied slopes detecting the prevailing drivers of their evolution. According to the results and considering the common climate and bedrock conditions, the structural background seems to have more influence on slope evolution at the Saint Nicolas site, while superficial geomorphic processes seem to be more relevant at the Gran Gorgia site. Because the sites have already been recognised as part of geoheritage by local authorities, the data obtained in the present research on their genesis, evolution, and local drivers affecting the rates of denudation (i.e., scientific relevance of the site) suggests that description of the sites for dissemination purposes should include links to the entire slope history

An Assessment of Coordinate Rotation Methods in Sonic Anemometer Measurements of Turbulent Fluxes over Complex Mountainous Terrain

The measurement of turbulent fluxes in the atmospheric boundary layer is usually performed using fast anemometers and the Eddy Covariance technique. This method has been applied here and investigated in a complex mountainous terrain. A field campaign has recently been conducted at Alpe Veglia (the Central-Western Italian Alps, 1746 m a.s.l.) where both standard and micrometeorological data were collected. The measured values obtained from an ultrasonic anemometer were analysed using a filtering procedure and three different coordinate rotation procedures: Double (DR), Triple Rotation (TR) and Planar Fit (PF) on moving temporal windows of 30 and 60 min. A quality assessment was performed on the sensible heat and momentum fluxes and the results show that the measured turbulent fluxes at Alpe Veglia were of a medium-high quality level and rarely passed the stationary flow test. A comparison of the three coordinate procedures, using quality assessment and sensible heat flux standard deviations, revealed that DR and TR were comparable, with significant differences, mainly under low-wind conditions. The PF method failed to satisfy the physical requirement for the multiple planarity of the flow, due to the complexity of the mountainous terrain

The enhancement of cultural landscapes in mountain environments : an artificial channel history (Torrent-Neuf, Canton Valais, Switzerland) and the role of trees as natural archives of water flow changes

Cultural landscapes represent one of the best examples of the interaction between human and natural environment and cultural trails are an effective way for their valorization. The Torrent-Neuf (Canton Valais, Switzerland) is a cultural trail realized in 2009 along one of the artificial channels used in the region since Medieval times to move water resources from tributary valleys to irrigated lands. Slope instability processes and high maintenance costs provoked the abandonment of the artificial channel in 1934. In 2005 water flow was restored in it. Dendrochronological analyses, carried out on trees growing along the artificial channel banks, allowed collecting information about natural and man-induced hydrological changes, contributing to increase the global value of the whole area

Fieldtrips and Virtual Tours as Geotourism Resources: Examples from the Sesia Val Grande UNESCO Global Geopark (NW Italy)

In the 20th anniversary year of the European Geopark Network, and 5 years on from the receipt of the UNESCO label for the geoparks, this research focuses on geotourism contents and solutions within one of the most recently designated geoparks, admitted for membership in 2013: the Sesia Val Grande UNESCO Global Geopark (Western Italian Alps). The main aim of this paper is to corroborate the use of fieldtrips and virtual tours as resources for geotourism. The analysis is developed according to: i) geodiversity and geoheritage of the geopark territory; ii) different approaches for planning fieldtrip and virtual tours. The lists of 18 geotrails, 68 geosites and 13 off-site geoheritage elements (e.g., museums, geolabs) are provided. Then, seven trails were selected as a mirror of the geodiversity and as container of on-site and off-site geoheritage within the geopark. They were described to highlight the different approaches that were implemented for their valorization. Most of the geotrails are equipped with panels, and supported by the presence of thematic laboratories or sections in museums. A multidisciplinary approach (e.g., history, ecology) is applied to some geotrails, and a few of them are translated into virtual tours. The variety of geosciences contents of the geopark territory is hence viewed as richness, in term of high geodiversity, but also in term of diversification for its valorization

ACTIVE GEOMORPHOSITES IN DIFFERENT MORPHOCLIMATIC ENVIRONMENTS: PROCESSES, EVOLUTION, EROSION RATES AND STRATEGIES FOR EDUCATIONAL DISSEMINATION

Geomorphosites are a recent research topic in geomorphology and they represent one of the most important vehicle for dissemination of Earth sciences. More in particular active geomorphosites are the most suitable at this scope for the evidence of processes and deriving landforms. These sites have been chosen in order to structure a research project that focus on monitoring, evaluating and disseminating of data regarding modeling processes interesting meaningful geomorphosites, always in relation with the geological component of the landscape. The importance of monitoring active geomorphosites and reconstructing the main geomorphological past events affecting them is twofold. On one side, the investigation of processes modalities may be useful for predicting the velocity of evolution of these sites that can be considered natural assets, often threatened by the same geomorphic processes ongoing. On the other side it has to be considered the educational importance of active geomorphosites in particular because of their high representativeness in term of geomorphic processes and their evolution characterized by times that are comparable to human timescale, and for this reason more comprehensible by the educational targets. So their importance as educational tools requires a rigorous characterization of geomorphic processes from a scientific point of view, also because they may represent source of hazards that can be translated in risk scenarios, especially in touristic contexts. The aims of the research project have been the structuring and testing of a general procedure to be proposed to work on geomorphosites. At this scope the research project has been articulated in three main sections: quantification of evolution rates of selected geomorphosites, structuring of a database for evaluation and selection of active geomorphosites for different scopes, and elaboration of educational applications starting from the scientific data that derive from the monitoring of sites and basing on the results obtained from evaluation of sites through the database. More in detail for the first section, the integration of different investigation techniques has been applied. In the different morphoclimatic and morphogenetic contexts (Monte Oliveto Maggiore, Trebbia River, Pyramid\ue9s d\u2019Euseigne) the dendrogeomorphological techniques have been compared to quantitative geomorphology, topographic survey and ortophoto analysis in order to obtain different sets of data, to be calibrated each others. Dendrogeomorphology allows also a more detailed analysis of the ecological support role of geomorphosites, that is an important feature characterizing the scientific value of sites. The structuring of the database allows to take into consideration the importance of sites not only from a geomorphological point of view but also for the interactions with geological and vegetation elements of the landscape as well as with the human components inserted in it. The results of evaluation through the database, that are presented here, derived from two testing areas (Trebbia River and Miage Glacier). For what concerns educational applications, they have been thought in order to consider all the aspects herein described and three main proposals are presented. An educational project has been developed with a secondary school along the Trebbia River, in order to focus on the time concept in evolution of a complex geomorphosites like the fluvial landscape, taking into consideration geomorphology, geology, vegetation and human components of the landscape. Then the geological and vegetation aspect have been deepened through the investigations respectively of climbing walls (Montestrutto and Arnad), in order to make people more confident to lithological aspect using recreational activities, and of a coniferous stand along an artificial channel (Torrent Neuf) in order to understand the interaction of vegetation with human components of the landscape. The monitoring of sites, integrating different techniques basing on both biological and a-biological components of the landscape, allows the acquisition of scientific data on the evolution of active geomorphosites in different morphoclimatic and morphogenetic contexts (i.e. fluvial, glacial and calanchi landscapes). The results of dendrogeomorphological investigations well integrate and refine the data obtained with other geomorphological applications, for important active geomorphosites, for both erosion rates (e.g. at Monte Oliveto Maggiore through quantitative geomorphology, 1,5 cm a-1, and through roots exposure, 1,86 cm a-1) and evolution rates (e.g. anticipation of the age of bankfull maximum shrinkage to 1985-1987 through dendrochronological dating of stable surfaces, instead of 1990, obtained through ortophoto analysis). The elaboration of an evaluation and selection methodology for both single sites and complex itineraries may be considered a useful tools for researchers and operators in the framework of touristic sector. On the base of historical and new acquired data, the structuring of the database allows to select sites for educational purposes basing on ad-hoc criteria for geomorphosites selection suitable to varied scopes. The results from the deriving different educational applications allow, in the case of the project with the secondary school, to confirm the importance of both classroom lessons and fieldwork in raising the awareness of time role and interactions among the different physical components in the evolution of physical landscape (e.g. the influence of geological substrate on fluvial landforms). Then, the preliminary results of using climbing sport as vehicle for Earth sciences dissemination confirm the possibility of linking the geological and geomorphological features of climbing walls with the modalities of climbing progression. Finally the results deriving from the study on vegetation-artificial channel interaction illustrate both the role of climate and water availability deriving by human infrastructure on vegetation and they may be proposed as additional elements in already started touristic itineraries. Generally, the importance of dissemination of Earth sciences, and in the specific case of processes that model Earth surface affecting geomorphosites, lays in the possibility of using these situations for raising awareness in tourists, and people in general, of the dynamicity of the environment in order to consciously travel inside the natural environments. In addition the evolution rate of geomorphosites should be taken into consideration for touristic planning activities and revision of geomorphosites evaluations. All these results highlight that the proposed methodology may be considered a good practice for valorizing these natural assets. The further perspective may be the extension of this investigation methodology to more numerous study cases in order to find out more differentiated educational strategies basing on the different natural and human features that characterize each morphoclimatic and morphogenetic environment

Geomorphic systems, sediment connectivity and geomorphodiversity: relations within a small mountain catchment in the Lepontine Alps

Mountain regions are characterized by a spatial geomorphic heterogeneity that confers to the environment a significant geomorphodiversity, functioning as a substrate for biodiversity. It is hence important to understand the geomorphic dynamics and its evolution in space and time. A different spatial scale approach was developed to evaluate the relationship existing among geomorphological processes, sediment connectivity and geomorphodiversity. The study areas are the Veglia-Devero Natural Park (Lepontine Alps) and a small mountain catchment (Buscagna catchment) where the analysis was carried out at a highest detail. At the natural park scale, a preliminary geomorphological map was realized and then the index of Geomorphodiversity was computed highlighting the differentiation between the two sides of the Buscagna glacial valley. In the Buscagna catchment where also the index of Connectivity was calculated, the integrated analysis of the two indices allowed to identifying different geomorpho-connectivity sectors, testifying the role of geomorphic processes in regulating sediment fluxes and, consequently, controlling landscape units

The influence of climate change on glacier geomorphosites : the case of two Italian glaciers (Miage Glacier, Forni Glacier) investigated through dendrochronology = L\u2019influence du changement climatique sur les g\ue9omorphosites glaciaires : le cas de deux glaciers italiens (Glacier du Miage, Glacier des Forni) analys\ue9s par dendrochronologie

Global warming is inducing huge changes in Alpine environment: glaciers defined as glacial geomorphosites are affected by severe shrinkage and new territories are progressively becoming suitable for study and evaluation. Landforms related to glacial erosion and deposition are visible at different scales and the consequences of climate change on vegetation (e.g., faster colonisation of new areas) are also evident. Research on the evolution of glacier geomorphosites is significant in order to define their scientific attribute and characteristics as \u201cmodel of evolution\u201d. This paper presents a proposal to investigate the \u201cnatural\u201d evolution of glacier geomorphosites using tree vegetation. The basic concept is that information can be gathered about past and present dynamics by analysing tree-growth on debris-covered glaciers and on their proglacial areas. Moreover, by investigating trees which colonise the glacial forefield of debris-free glaciers, the effects of climate change on tree colonisation can be analysed. New territories deriving from glacial shrinkage are revealed and may be integrated to the glacial geomorphosite defined. The use of dendrochronology for evaluating the evolution of glacial geomorphosites is proposed and discussed on the basis of past studies and of new data collected at two sample sites: the Miage Glacier (western Italian Alps) and the Forni Glacier (central Italian Alps).Le changement climatique induit actuellement de nombreuses modifications \ue0 l\u2019environnement alpin : les glaciers class\ue9s comme g\ue9omorphosites sont affect\ue9s par un important retrait et de nouvelles aires sont progressivement disponibles pour \ueatre \ue9tudi\ue9es et valoris\ue9es. Un examen des formes de relief li\ue9es \ue0 l\u2019\ue9rosion et aux d\ue9p\uf4ts glaciaires a \ue9t\ue9 effectu\ue9 pour documenter les cons\ue9quences du r\ue9chauffement climatique sur la v\ue9g\ue9tation ; la colonisation des surfaces r\ue9cemment d\ue9glac\ue9es est d\ue9sormais plus rapide. Les recherches sur l\u2019\ue9volution des g\ue9omorphosites glaciaires sont importantes pour la connaissance scientifique et pour l\u2019\ue9laboration de \uab mod\ue8les d\u2019\ue9volution \ubb. Utilisant les arbres qui poussent sur la surface des glaciers recouverts de d\ue9bris rocheux, des investigations men\ue9es sur l\u2019\ue9volution \uab naturelle \ubb des g\ue9omorphosites glaciaires sont pr\ue9sent\ue9es, permettant d\u2019analyser les dynamiques pass\ue9e et pr\ue9sente des zones proglaciaires. En outre, en \ue9tudiant les arbres qui poussent dans les zones proglaciaires des glaciers \uab blancs \ubb, il est possible d\u2019appr\ue9hender les effets du changement climatiques sur la croissance des arbres qui colonisent ces aires. Ainsi, les nouveaux espaces qui apparaissent suite au retrait glaciaire peuvent \ueatre ins\ue9r\ue9s dans les g\ue9omorphosites glaciaires, et utilis\ue9s pour affiner leur \ue9valuation. Cet article montre, au final, l\u2019int\ue9r\ueat de la dendrochronologie pour appr\ue9hender l\u2019\ue9volution des g\ue9omorphosites glaciaires face aux changements climatiques. Cette th\ue9matique est discut\ue9e sur la base des r\ue9sultats obtenus \ue0 partir de deux sites d\u2019\ue9tude : le glacier du Miage (Alpes occidentales) et le glacier des Forni (Alpes centrales)

A multidisciplinary approach for physical landscape analysis: scientific value and risk of degradation of outstanding landforms in the glacial plateau of the Loana Valley (Central-Western Italian Alps)

Landforms characterized by high scientific value (i.e. geomorphosites) might undergo modifications due to intrinsic and extrinsic factors (natural and human-induced processes). In the framework of geoheritage analyses, the assessment of the value (scientific or additional) of geomorphosites should be performed side by side with the analysis on the risk of degradation (fragility and vulnerability). A multidisciplinary method is proposed for the analysis of landforms that are potentially fragile but outstanding for their scientific value related to geological, geomorphological and ecological values. A geomorphological map was produced for the glacial plateaux of the Loana Valley (Central-Western Italian Alps), where an outstanding geomorphosite was detected: the Cortenuovo Calcareous Ridge. The site is herein analysed in terms of the representativeness of geological and (paleo)geomorphological features as well as for its support role to the ecosystem. For dissemination purposes, a simplified version of the geomorphological map (i.e., geomorphological box) was prepared for the site. Specific morphometric and dendrogeomorphological analyses were then performed to investigate more in detail the risk of degradation of the site. It resulted to be a spatially restricted hotspot of geodiversity, characterized by an average surface lowering rate (0.44 cm/y on average) comparable to that achieved in similar geomorphologic contexts in the Alpine environment. The obtained results testify to a potential vulnerability to natural processes of this highly scientific valued site, which will surely benefit from a legal recognition as a component of geoheritage, with a specific regulation for its protection, that could prove to be strategic