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

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

Soils as a useful tool for reconstructing geomorphic dynamics in high mountain environments: The case of the Buscagna stream hydrographic basin (Lepontine Alps)

The soil formation, its development, and its preservation in high mountain environments are largely determined by topography and geomorphological dynamic. Therefore, soil development in alpine areas is often non-linear over time, and characterized by phases of progressive and regressive evolution. The interaction among soil-forming factors is preserved in soils as physical/chemical properties and pedological features. In particular, the action of surface geomorphological processes can be observed as stone lines or sequences of buried surfaces. In this light, exhaustive investigation of soils and paleosols could provide enough information to reconstruct past environmental conditions and spatio-temporal changes in denudation/deposition processes. The main aim of this study is to assess the role of soil as a useful archive for retracing the geomorphological processes that are responsible for the landscape evolution during the Late Holocene in a typical alpine catchment such as the Buscagna stream hydrographic basin (Veglia-Devero Natural Park, Lepontine Alps). The asymmetry in valley slopes, due to lithology and structural control, generates a great variety of geomorphic processes and landforms. Therefore, seven soil profiles were selected along the two slopes, in different morphological contexts, to reveal the influence of the different active geomorphic processes in soil development. Soils were investigated by means of field and laboratory analyses, and geomorphological maps of the area surrounding the profiles were made. On the southeastern slope, characterized by calcschist substratum, the soil profiles are composed of two superimposed pedological units, separated by an instability hiatus. On the northwestern slope, characterized by gneiss and ultramafic rocks, and on the valley bottom, the soils record instability phases in different ways, fitting well with the geomorphological context. In this mountain environment, the close relationship between soil development and geomorphic processes allows us to confirm the role of soil as a useful archive to potentially reconstruct the past geomorphological conditions

Reach-scale morphological adjustments and stages of channel evolution : the case of the Trebbia River (northern Italy)

A multitemporal series of aerial photos and cross-section topographic surveys have been used to analyze reach-scale channel evolution along a segment (length of about 22. km) of the lower Trebbia River (Northern Italy) with the aims to investigate the relations between channel width vs. bed-level adjustments and to identify spatio-temporal patterns of stages of channel evolution. Dendrochronology was used to determine the age of tree establishment of riparian and island forests during channel evolution. We identified a first phase of major adjustments (1954-1992) following a series of disturbances, dominated by channel narrowing and bed incision. During the final stage of narrowing, woody vegetation establishment contributed to stabilize new floodplain or island surfaces. A period of partial morphological recovery occurred from 1992 to 2010, dominated by an inversion of trend of channel width. During the phase of partial recovery, a stage of widening combined with a continuation of bed incision was identified, and a last stage characterized by widening and initial aggradation was observed on the central portion of the study reaches. Suitability and differences of existing channel evolution models (CEMs) derived in other geographical contexts were discussed, and a specific conceptual model comprising four stages of channel evolution was developed for the lower Trebbia River