distributed mass balance modelling on two neighbouring glaciers in ortles cevedale italy from 2004 to 2009

AbstractA 6 year application of an enhanced temperature-index mass-balance model to Careser and La Mare glaciers, Eastern Italian Alps, is presented. The two glaciers exhibit very different characteristics, and a comprehensive dataset of distributed mass-balance measurements was used to test the model performance. The model was run using meteorological data acquired outside the glaciers. The work was focused on two main aspects: (1) the development of a morphological redistribution procedure for snow, and (2) the comparison of three different melt algorithms proposed in the literature. The results show that the simple method proposed for snow redistribution can greatly improve simulation of winter balance, and further improvements would be achievable by collecting data on inaccessible and high-altitude areas. All three melt formulations displayed a good skill level and very similar results in modelling the mass-balance distribution over glacier areas, with slightly better results from a multiplicative algorithm in capturing the vertical balance gradient. The simulation errors are related to aspect and elevation, and tend to be spatially aggregated. Some assumptions concerning the spatial and temporal distribution of air temperature and incoming solar radiation, although reasonable and widely used in the literature, may be responsible for this aggregation. Hence, there is a need to further investigate the processes that regulate the distribution of melt energy, and that appear to control the current deglaciation phase in this area

Land use change in the Veneto floodplain and consequences on minor network drainage system

Anthropic pressure has been proven to be one of the most evident forces able to alter landscapes. Its impact on the surroundings can be easily detectable especially in a high-density populated country such as Italy. Among the most evident anthropic alterations, the most important are the urbanization processes but also changes in cultural techniques that have been occurring in rural areas. These modifications influence the hydrologic regimes in two ways: by modifying the direct runoff production and by having a strong impact on the drainage system itself. The main objectives of this work are to evaluate the impact of land cover changes in the Veneto region (north-east Italy) on the minor drainage network system, and to analyze changes in the direct runoff in the last 50 years. The study area is a typical agrarian landscape and it has been chosen considering its involvement in the major flood of 2010 and considering also the availability of data, including historical aerial photographs, historical information, and a high resolution LiDAR DTM. The results underline how land cover variations over the last 50 years have strongly increased the propension of the soil to produce direct runoff (increase of the Curve Number value) and they have also reduced the extent of the minor network system to the detriment of urbanized areas and changes of plots of land boundaries. As a consequence, the capacity of the minor network to attenuate and eventually laminate a flood event is decreased as well. These analysis can be considered useful tools for a suitable land use planning in flood prone areas

recognition of surface flow processes influenced by roads and trails in mountain areas using high resolution topography

AbstractRoad networks in mountainous forest landscapes have the potential to increase the susceptibility to erosion and shallow landsliding. The same issue is observed also for minor trail networks, with evidences of surface erosion due to surface flow redistribution. This could be a problem in regions such as the Italian Alps where forestry and tourist activities are a relevant part of the local economy. This is just one among the several effects of modern anthropogenic forcing: it is now well accepted by the scientific community that we are living in a new era where human activities may leave a significant signature on the Earth, by altering its morphology, and significantly affecting the related surface processes. In this work, we proposed a methodology for the automatic recognition of roads and trails induced flow direction changes. The algorithm is based on the calculation of the drainage area variation in the presence, or in the absence of anthropic features such as roads and trails on hillslopes. T..

Suitability of ground-based SfM-MVS for monitoring glacial and periglacial processes

Photo-based surface reconstruction is rapidly emerging as an alternative survey technique to lidar (light detection and ranging) in many fields of geoscience fostered by the recent development of computer vision algorithms such as structure from motion (SfM) and dense image matching such as multi-view stereo (MVS). The objectives of this work are to test the suitability of the ground-based SfM-MVS approach for calculating the geodetic mass balance of a 2.1km2 glacier and for detecting the surface displacement of a neighbouring active rock glacier located in the eastern Italian Alps. The photos were acquired in 2013 and 2014 using a digital consumer-grade camera during single-day field surveys. Airborne laser scanning (ALS, otherwise known as airborne lidar) data were used as benchmarks to estimate the accuracy of the photogrammetric digital elevation models (DEMs) and the reliability of the method. The SfM-MVS approach enabled the reconstruction of high-quality DEMs, which provided estimates of glacial and periglacial processes similar to those achievable using ALS. In stable bedrock areas outside the glacier, the mean and the standard deviation of the elevation difference between the SfM-MVS DEM and the ALS DEM was-0.42 \ub1 1.72 and 0.03 \ub1 0.74 m in 2013 and 2014, respectively. The overall pattern of elevation loss and gain on the glacier were similar with both methods, ranging between-5.53 and + 3.48 m. In the rock glacier area, the elevation difference between the SfM-MVS DEM and the ALS DEM was 0.02 \ub1 0.17 m. The SfM-MVS was able to reproduce the patterns and the magnitudes of displacement of the rock glacier observed by the ALS, ranging between 0.00 and 0.48 m per year. The use of natural targets as ground control points, the occurrence of shadowed and low-contrast areas, and in particular the suboptimal camera network geometry imposed by the morphology of the study area were the main factors affecting the accuracy of photogrammetric DEMs negatively. Technical improvements such as using an aerial platform and/or placing artificial targets could significantly improve the results but run the risk of being more demanding in terms of costs and logistics

Age of the Mt. Ortles ice cores, the Tyrolean Iceman and glaciation of the highest summit of South Tyrol since the Northern Hemisphere Climatic Optimum

In 2011 four ice cores were extracted from the summit of Alto dell'Ortles (3859 m), the highest glacier of South Tyrol in the Italian Alps. This drilling site is located only 37 km southwest from where the Tyrolean Iceman, similar to 5.3 kyrs old, was discovered emerging from the ablating ice field of Tisenjoch (3210 m, near the Italian-Austrian border) in 1991. The excellent preservation of this mummy suggested that the Tyrolean Iceman was continuously embedded in prehistoric ice and that additional ancient ice was likely preserved elsewhere in South Tyrol. Dating of the ice cores from Alto dell'Ortles based on Pb-210, tritium, beta activity and C-14 determinations, combined with an empirical model (COPRA), provides evidence for a chronologically ordered ice stratigraphy from the modern glacier surface down to the bottom ice layers with an age of similar to 7 kyrs, which confirms the hypothesis. Our results indicate that the drilling site has continuously been glaciated on frozen bedrock since similar to 7 kyrs BP. Absence of older ice on the highest glacier of South Tyrol is consistent with the removal of basal ice from bedrock during the Northern Hemisphere Climatic Optimum (6-9 kyrs BP), the warmest interval in the European Alps during the Holocene. Borehole inclinometric measurements of the current glacier flow combined with surface ground penetration radar (GPR) measurements indicate that, due to the sustained atmospheric warming since the 1980s, an acceleration of the glacier Alto dell'Ortles flow has just recently begun. Given the stratigraphic-chronological continuity of the Mt. Ortles cores over millennia, it can be argued that this behaviour has been unprecedented at this location since the Northern Hemisphere Climatic Optimum