Interactive Generation of Time-Evolving Snow-Covered Landscaped with Avalanches

We introduce a novel method for interactive generation of visually consistent, snow-covered landscapes and provide control of their dynamic evolution over time. Our main contribution is the real-time phenomenological simulation of avalanches and other user-guided events, such as tracks left by Nordic skiing, which can be applied to interactively sculpt the landscape. The terrain is modeled as a height field with additional layers for stable, compacted, unstable, and powdery snow, which behave in combination as a semi-viscous fluid. We incorporate the impact of several phenomena, including sunlight, temperature, prevailing wind direction, and skiing activities. The snow evolution includes snow-melt and snow-drift, which affect stability of the snow mass and the probability of avalanches. A user can shape landscapes and their evolution either with a variety of interactive brushes, or by prescribing events along a winter season time-line. Our optimized GPU-implementation allows interactive updates of snow type and depth across a large (10×10km) terrain, including real-time avalanches, making this suitable for visual assets in computer games. We evaluate our method through perceptual comparison against exiting methods and real snow-depth data

The importance of mountain geomorphosites for environmental education: examples from the Italian Dolomites and the Swiss Alps

Because of their specific physical characteristics (altitude, slope, orientation, climate), mountain environments have an important natural diversity. In particular, their geodiversity is generally much larger than in the lowlands, and because mountain geosites are often very aesthetic, mountain areas present a great potential for geoheritage, geoconservation and geotourism studies. This paper reviews six reasons why this potential is high and concludes that mountain areas are particularly interesting to develop educational programs on three current environmental issues: climate change; natural hazards; and human impacts on particularly sensitive geomorphological environments. Then, the paper reviews the principal research in the field of geoheritage currently carried out on these three topics and presents two case studies in the Italian Dolomites and the Swiss Alps

Mountains and climate change: From understanding to action

Mountains are among the regions most sensitive to climate change. Some of the most visible indicators of climate change come from mountain areas, such as the widespread retreat of glaciers that has been observed from polar to tropical regions in recent decades. The sensitive position of mountain areas has been clearly highlighted by the IPCC in its latest report in 2007. Mountains provide freshwater to half of the world’s population and are home to half of all global biodiversity hotspots. Mountains are also important areas for recreation in an increasingly urbanized world. This raises..

Riverscape Restoration: Tromsa River in Norway, after Dam Removal

Dams have been created in existing waterways to serve humans for centuries. For example, they have been used for different purposes, such as timber floating, grain mills, or electricity production. Today many of these dams remain unused and abandoned, disrupting ecosystems as they prevent the water from flowing naturally in the waterways. These human-made structures split habitats, fragment the landscape, and create hazards for migrating fish and other organisms living in the water. This global fragmentation raises concerns about habitat loss which may lead to species degradation and, in some cases, even distinction of certain species. As we know, nature is an interlinked web of ecological and geological processes where species are dependent and co-dependent on each other. When species disappear or populations dramatically decrease, it can cause chain reactions with an unknown outcome. An effort to help nature heal on sites at a local scale might also help at a broader scale as the number of restored sites increases. This thesis focuses on the case of the Tromsa river in Norway. At this site, a dam stopped being used for hydropower production in the 1060s and was partially removed in 2022. Such changes have considerable effects on the ecosystem in and around the river and affect any surrounding ecosystem. Through landscape analysis of the area, one solution was proposed, which evolved around recreating wetland areas similar to the site before and the remaining wetland areas. Any significant findings were generally that the place needs more harmony with the ecology and that important wetland areas have been transformed to serve anthropogenic interests. The proposal facilitates ecological connectivity and favors the migrating fish species, trout, and grayling, that have the Tromsa river as an essential part of their habitat. Parts of this thesis, such as analysis and discussion, are mainly represented graphically, supplemented with text where an explanation is needed

Realistic reconstruction and rendering of detailed 3D scenarios from multiple data sources

During the last years, we have witnessed significant improvements in digital terrain modeling, mainly through photogrammetric techniques based on satellite and aerial photography, as well as laser scanning. These techniques allow the creation of Digital Elevation Models (DEM) and Digital Surface Models (DSM) that can be streamed over the network and explored through virtual globe applications like Google Earth or NASA WorldWind. The resolution of these 3D scenes has improved noticeably in the last years, reaching in some urban areas resolutions up to 1m or less for DEM and buildings, and less than 10 cm per pixel in the associated aerial imagery. However, in rural, forest or mountainous areas, the typical resolution for elevation datasets ranges between 5 and 30 meters, and typical resolution of corresponding aerial photographs ranges between 25 cm to 1 m. This current level of detail is only sufficient for aerial points of view, but as the viewpoint approaches the surface the terrain loses its realistic appearance. One approach to augment the detail on top of currently available datasets is adding synthetic details in a plausible manner, i.e. including elements that match the features perceived in the aerial view. By combining the real dataset with the instancing of models on the terrain and other procedural detail techniques, the effective resolution can potentially become arbitrary. There are several applications that do not need an exact reproduction of the real elements but would greatly benefit from plausibly enhanced terrain models: videogames and entertainment applications, visual impact assessment (e.g. how a new ski resort would look), virtual tourism, simulations, etc. In this thesis we propose new methods and tools to help the reconstruction and synthesis of high-resolution terrain scenes from currently available data sources, in order to achieve realistically looking ground-level views. In particular, we decided to focus on rural scenarios, mountains and forest areas. Our main goal is the combination of plausible synthetic elements and procedural detail with publicly available real data to create detailed 3D scenes from existing locations. Our research has focused on the following contributions: - An efficient pipeline for aerial imagery segmentation - Plausible terrain enhancement from high-resolution examples - Super-resolution of DEM by transferring details from the aerial photograph - Synthesis of arbitrary tree picture variations from a reduced set of photographs - Reconstruction of 3D tree models from a single image - A compact and efficient tree representation for real-time rendering of forest landscapesDurant els darrers anys, hem presenciat avenços significatius en el modelat digital de terrenys, principalment gràcies a tècniques fotogramètriques, basades en fotografia aèria o satèl·lit, i a escàners làser. Aquestes tècniques permeten crear Models Digitals d'Elevacions (DEM) i Models Digitals de Superfícies (DSM) que es poden retransmetre per la xarxa i ser explorats mitjançant aplicacions de globus virtuals com ara Google Earth o NASA WorldWind. La resolució d'aquestes escenes 3D ha millorat considerablement durant els darrers anys, arribant a algunes àrees urbanes a resolucions d'un metre o menys per al DEM i edificis, i fins a menys de 10 cm per píxel a les fotografies aèries associades. No obstant, en entorns rurals, boscos i zones muntanyoses, la resolució típica per a dades d'elevació es troba entre 5 i 30 metres, i per a les corresponents fotografies aèries varia entre 25 cm i 1m. Aquest nivell de detall només és suficient per a punts de vista aeris, però a mesura que ens apropem a la superfície el terreny perd tot el realisme. Una manera d'augmentar el detall dels conjunts de dades actuals és afegint a l'escena detalls sintètics de manera plausible, és a dir, incloure elements que encaixin amb les característiques que es perceben a la vista aèria. Així, combinant les dades reals amb instàncies de models sobre el terreny i altres tècniques de detall procedural, la resolució efectiva del model pot arribar a ser arbitrària. Hi ha diverses aplicacions per a les quals no cal una reproducció exacta dels elements reals, però que es beneficiarien de models de terreny augmentats de manera plausible: videojocs i aplicacions d'entreteniment, avaluació de l'impacte visual (per exemple, com es veuria una nova estació d'esquí), turisme virtual, simulacions, etc. En aquesta tesi, proposem nous mètodes i eines per ajudar a la reconstrucció i síntesi de terrenys en alta resolució partint de conjunts de dades disponibles públicament, per tal d'aconseguir vistes a nivell de terra realistes. En particular, hem decidit centrar-nos en escenes rurals, muntanyes i àrees boscoses. El nostre principal objectiu és la combinació d'elements sintètics plausibles i detall procedural amb dades reals disponibles públicament per tal de generar escenes 3D d'ubicacions existents. La nostra recerca s'ha centrat en les següents contribucions: - Un pipeline eficient per a segmentació d'imatges aèries - Millora plausible de models de terreny a partir d'exemples d’alta resolució - Super-resolució de models d'elevacions transferint-hi detalls de la fotografia aèria - Síntesis d'un nombre arbitrari de variacions d’imatges d’arbres a partir d'un conjunt reduït de fotografies - Reconstrucció de models 3D d'arbres a partir d'una única fotografia - Una representació compacta i eficient d'arbres per a navegació en temps real d'escenesPostprint (published version

Perceptions of land abandonment in the Swiss Alps and the role of Regional Natural Parks in revitalizing them

Agricultural and natural ecosystems are major shapers and products of a landscape; over time, the perception of interactions between the two has evolved significantly. In recent years, there has been a growing recognition of agriculture's dual role in sustaining both human livelihoods and natural habitats, signaling its potential significance in nature conservation efforts. Moreover, the phenomenon of land abandonment has emerged as a pivotal trend influencing landscapes, particularly in mountainous regions. By exploring local actors’ perceptions of land abandonment within the Trient Valley, a mountainous area in the Swiss Alps currently in the process of becoming a Swiss Regional Natural Park, this study establishes a groundwork for understanding the role that Regional Natural Parks can assume in supporting the agricultural sector to reverse or prevent land abandonment (LA). A reflexive photography approach, combining a photo taking activity, interviews and group discussions, in two distinct segments of study was applied. One part focused on understanding local farmers’ perception of LA through their activities and how Regional Natural Parks can support them. The other part focused on how the potential Regional Natural Parks in the Trient valley can engage non-farmers in the mitigation of LA, by studying their perception of this phenomenon, of its possible mitigation and of their potential role in the latter. It underscored the necessity for collaborative efforts among stakeholders, drawing on local engagement, ecological considerations, and cultural preservation as guiding principles. This study found that Regional Nature Parks can counter land abandonment by fostering understanding, supporting various revitalization strategies and revitalizing the importance of agriculture and cultural heritage among locals and visitors, thus aligning themselves with their overarching objectives of conservation, biodiversity enhancement and sustainable development

High Mountain Areas

The cryosphere (including, snow, glaciers, permafrost, lake and river ice) is an integral element of high-mountain regions, which are home to roughly 10% of the global population. Widespread cryosphere changes affect physical, biological and human systems in the mountains and surrounding lowlands, with impacts evident even in the ocean. Building on the IPCC’s Fifth Assessment Report (AR5), this chapter assesses new evidence on observed recent and projected changes in the mountain cryosphere as well as associated impacts, risks and adaptation measures related to natural and human systems. Impacts in response to climate changes independently of changes in the cryosphere are not assessed in this chapter. Polar mountains are included in Chapter 3, except those in Alaska and adjacent Yukon, Iceland, and Scandinavia, which are included in this chapter

Europe's ecological backbone: recognising the true value of our mountains

Europe's mountain areas have social, economic and environmental capital of significance for the entire continent. This importance has been recognised since the late 19th century through national legislation; since the 1970s through regional structures for cooperation; and since the 1990s through regional legal instruments for the Alps and Carpathians. The European Union (EU) first recognised the specific characteristics of mountain areas in 1975 through the designation of Less Favoured Areas (LFAs). During the last decade, EU cohesion policy and the Treaty of Lisbon have both focused specifically on mountain