Climate change is considered one of the primary threats to the sustainability of ski tourism around the world. Studies in several countries project the ski industry will be impacted by shorter ski seasons, greater snowmaking requirements, and a declining ski demand. Many supply-side studies suffer key limitations, such as the omission of snowmaking, leaving their conclusions highly questionable. This study utilizes the SkiSim 2 model to reassess the implications of projected climate change for two major ski tourism destinations in the Western USA (Vail, Colorado and Lake Tahoe, California) where previous studies projected major impacts when snowmaking was not considered. Historical climate data (1961-1990) and the stochastic weather generator LARS-WG are used to examine the impact of climate change scenarios for ski season length and snowmaking requirements by the 2050s. Comparisons with previous studies and implications for ski tourism development and planning will be discussed.

Climate change is considered one of the primary threats to the sustainability of ski tourism around the world. Studies in several countries project the ski industry will be impacted by shorter ski seasons, greater snowmaking requirements, and a declining ski demand. Many supply-side studies suffer key limitations, such as the omission of snowmaking, leaving their conclusions highly questionable. This study utilizes the SkiSim 2 model to reassess the implications of projected climate change for two major ski tourism destinations in the Western USA (Vail, Colorado and Lake Tahoe, California) where previous studies projected major impacts when snowmaking was not considered. Historical climate data (1961-1990) and the stochastic weather generator LARS-WG are used to examine the impact of climate change scenarios for ski season length and snowmaking requirements by the 2050s. Comparisons with previous studies and implications for ski tourism development and planning will be discussed.

A research on analysing the feasibility and the benefits obtained from the utilisation of the heat surplus from temperature independent snowmaking systems is proposed. The interest of this research relies on the fact that it is a way of making it viable both economically and environmentally, to use these systems, which are the solution for snow scarcity due to global warming.This will be done by studying the performance of three different alternatives for the installation of a TIS, considering it with and without heat recovery in order to show the importance of the latter. The study will be performed for the ski resort of Astún, in the Spanish Pyrenees, considering the desire to guarantee a ski slope of 3 km from November till end of April. The three cases studied are: • Case I: Temperature Independent Snowmaking system without heat recovery • Case II: Temperature Independent Snowmaking system with direct heat recovery • Case III: Temperature Independent Snowmaking system with direct heat recovery and snow storage The feasibility of each of the cases will be studied based on costs and energy savings and consumptions, while ecological impact, maintenance costs or the interest rates will not be included in order to simplify the results. The heat recovery will be performed thanks to a CO2 heat pump that will deliver over 6 GWh through water at 70 ºC to the residential and commercial buildings of the ski resort. The heat recovery has only been studied in detail for direct recovery, but the possibility of indirect heat recovery would be interesting in other situations, therefore, it has also been briefly described.As a way of introducing and justifying the project, a literature review has been performed, on the impact of climate change and the need for snowmaking, and also on the different snowmaking technologies and their limitations, leading finally to the need for temperature independent snowmaking. Moreover, calculations and simulations including heat transfer, fluid dynamics and theory of refrigeration technology are conducted. Finally, putting that together with estimated investment costs and prices gathered either from available public sources or personal communication with suppliers, the final comparison of the cases is performed.Based on the obtained results, the most suitable solution for the ski resort of Astún, considering the current heat demand of its buildings, is the case II, installation of a TIS with direct heat recovery. This case has a total investment cost of 1.957.464 €, and due to the savings generated from the reused heat, it comes with yearly savings of -249.872 €, which implies a payback time lower than 8 years, making it the most viable alternative.

Les interactions dynamiques des conditions d'enneigement avec l'activité touristique des stations de sport d'hiver reposent sur de multiples enjeux sociaux, économiques, environnementaux et climatiques intégrés par les élus chargés du développement des territoires de montagne et industriels responsables de l'exploitation des domaines skiables. Depuis l'expérience vécue de la vulnérabilité des domaines skiables au déficit d'enneigement au début des années 1990 et plus encore depuis l'introduction des problématiques du changement climatique dans le débat public au début des années 2000, l'attente de la part des décideurs politiques et des professionnels de la neige pour des éléments fiables et pertinents sur l'impact du climat sur l'activité des sports d'hiver - dans laquelle s'intègre ce travail - n'a cessé de croître.Ce travail s'est attaché à la compréhension du rôle intégrateur de l'opérateur de domaine skiable dans son approche socio-économique d'une part et nivo-climatologique d'autre part de la gestion de la neige dans sa station dans le but de développer une chaîne de modélisation de la dynamique des interactions entre les conditions d'enneigement (variabilité, imprévisibilité) et les activités humaines (objectifs, moyens).Un état des lieux a été établi sur les priorités poursuivies, les moyens mis en œuvre (damage, neige de culture) et les contraintes subies (météorologiques, organisationnelles, structurelles) par les gestionnaires de domaines skiables dans leurs opérations quotidiennes de gestion de la neige grâce à une enquête auprès de 55 stations françaises et aux échanges réguliers avec quatre stations partenaires de ce travail (Autrans, Tignes, Chamrousse et Les Deux Alpes).Une modélisation physique des impacts de la gestion de la neige a été développée sur la base d'un modèle de neige et confrontée à des observations réalisées au cours de deux saisons hivernales consécutives dans ces quatre stations partenaires.Ces éléments ont été intégrés dans une chaîne de modélisation couplée permettant des études spatialisées des conditions d'enneigement et in fine la détermination d'indicateurs de la viabilité de l'enneigement à l'échelle de la station, dans l'ensemble des Alpes françaises. Cette méthode extrapolable à l'ensemble des massifs français a été appliquée dans les Alpes françaises sur la période passée 1958 – 2014 et a révélé la corrélation des indicateurs d'enneigement avec les données économiques des stations de sport d'hiver. Notre approche a ainsi montré sa pertinence pour des études prospectives de l'impact du changement climatique et/ou des infrastructures des domaines skiables sur la viabilité de l'enneigement et ses conséquences pour l'activité économique des stations de sport d'hiver. / The industrial activity of ski resorts is based upon multiple concerns including social, economic, environmental and climatic issues which ski resorts stakeholders have to cope with.In the early 1990's ski resorts experienced several consecutive seasons with poor snow conditions in the European Alps when climate and environmental questions were discussed as a global concern after the United Nations held their first international conferences on climate change. This raised the interest of ski resorts stakeholders and representatives of host communities for reliable and relevant indicators of climate induced impacts on snow conditions and on the related economic activity of ski resorts.This research focused on the role played by ski resorts operators in crossing socio-economic concerns with meteorological and snow concerns, to provide a modelling approach of dynamics and interactions between snow conditions (variability, low predictability) and human activities (defined by purposes and means). The objectives pursued by operators, the means they employ (grooming, snowmaking) and constraints they face (meteorological, structural or organization issues) have been investigated through a survey of 55 French ski resorts and frequent discussions with four partner ski resorts (Tignes, Autrans, Les Deux Alpes, Chamrousse). A physically based modelling approach of the impact of grooming and snowmaking on snow properties was integrated in a snowpack model and evaluated with respect to field observations in the four partner ski resorts over two consecutive winter seasons. This was crossed with a socio economic database of ski resorts to provide an explicit spatial modelling of managed snow conditions on ski slopes for the entire French Alps ski resorts. This method was applied for the 1958 - 2014 period and snow indicators were defined and computed, revealing a significant correlation of snow reliability indicators with economic data on ski resorts. This approach therefore proved its ability to provide relevant indicators of snow conditions in ski resorts with respect to economic implications and may be used for further prospective investigations of evolutions of facilities and/or climate change impacts on snow conditions and the related economy of the ski industry.

Virginia's Smart Road, to be completed by early 2000, is a test bed for numerous research activities including snow and ice control, remote sensor testing, snow removal management, safety and human factors, and vehicle dynamics. An all-weather testing system will feature 75 automated snowmaking towers. In order to provide timely and repeatable weather scenarios, equipment operators will need to understand fully the limitations and capabilities of the snowmaking system. The research presented herein addresses the hydraulic and hydrologic variables and design methodology to implement efficient snowmaking at a transportation research facility. Design variables include nozzle configuration, water pressure and flowrate, compressed air pressure and flowrate, tower orientation, snow inducer concentration, water and compressed air temperature, and ambient weather conditions. Testing and data collection was performed at the Snow Economics, Inc. research and development site at Seven Springs Mountain Resort in Champion, PA. The results of this work will be used to guide the operators of the Smart Road on the most efficient use of the snowmaking equipment. / Master of Science