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This paper investigates the networked evolutionary model based on snow-drift game with the strategy of rewards and penalty. Firstly, by using the semi-tensor product of matrices approach, the mathematical model of the networked evolutionary game is built. Secondly, combined with the matrix expression of logic, the mathematical model is expressed as a dynamic logical system and next converted into its evolutionary dynamic algebraic form. Thirdly, the dynamic evolution process is analyzed and the final level of cooperation is discussed. Finally, the effects of the changes in the rewarding and penalty factors on the level of cooperation in the model are studied separately, and the conclusions are verified by examples.

Although most processes governing the surface mass balance on mountain glaciers are well understood, the causes and extent of spatial variability in accumulation remain poorly constrained. In the present study, the EBFM distributed mass balance model is newly coupled to terrain based modelling routines estimating mass redistribution by snowdrift, preferential deposition, and avalanching (ST-EBFM) in order to model winter balance on Storglaciären, Sweden. STEBFM improves the spatial accuracy of winter balance simulations and proves to be a versatile and computationally inexpensive model. Accumulation on Storglaciären is primarily driven by direct precipitation, which seems locally increased due to small scale orographic effects. Wind driven snow transport leads to significant deposition in the accumulation zone and slight erosion in the ablation zone. The pattern is generally consistent from year to year. Avalanching is the smallest contributor to winter balance, but cannot be neglected. The physical complexity of avalanches and high year to year variability render simulations of the process somewhat uncertain, but observations seem to confirm the large impact that the process can have on the glacier at very localised scales. The role of mass transporting processes in maintaining the current mass equilibrium on Storglaciären highlights the necessity to understand the links between climatic predictors and accumulation in order to accurately assess climate sensitivity.

The relationships in ASCE 7 for the determination of roof snow drift size are functions of the ground snow load and the upwind fetch of the snow source area. In a 2019 paper, O’Rourke and C...

Shallow Antarctic surface lakes belong to the most extreme aquatic environments on the Earth. In Vestfjella, proglacial surface lakes and ponds are characterized by a 2–5 month long period with liquid water and depths < 2 m. We give a detailed description of nine seasonal lakes and ponds situating at three nunataqs (Basen, Plogen and Fossilryggen) in western Dronning Maud Land. Their physical and geochemical properties are provided based on observations in four summers. Three main ‘lake categories‘ were found: 1) supraglacial lakes, 2) epiglacial ponds and 3) nunataq ponds. Category 3 lakes can be divided into two subgroups with regards to whether the meltwater source is glacial or just seasonal snow patches. Supraglacial lakes are ultra-oligotrophic (electrical conductivity < 10 μS cm−1, pH < 7), while in epiglacial ponds the concentrations of dissolved and suspended matter and trophic status vary over a wide range (electrical conductivity 20–110 μS cm−1, pH 6–9). In nunataq ponds, the maxima were an electrical conductivity of 1042 μS cm−1 and a pH of 10.1, and water temperature may have wide diurnal and day-to-day fluctuations (maximum 9.3°C) because snowfall, snow drift and sublimation influence the net solar irradiance.

A long-span sports centre generally comprises multiple stadiums and gymnasiums, for which mutual interference effects of wind-induced snow motion are not explicitly included in the specifications of various countries. This problem is addressed herein by performing wind tunnel tests and numerical simulations to investigate the snow distribution and mutual interference effect on the roofs of long-span stadiums and gymnasiums. The wind tunnel tests were used to analyse the influences of the opening direction (0°, 90°, 180°, and 270°) and spacing (0.3 L, 0.5 L, 1 L, 1.5 L, 2 L, and 2.5 L, where L is the gymnasium span) of the stadium and gymnasium. The wind tunnel tests and numerical simulations were used to analyse the influence of the wind direction angle (from 0° to 315°, there are a total of eight groups in 45° intervals). The following results were obtained. The stadium opening had a significant effect on the snow distribution on the surface of the two structures. An even snow distribution was obtained when the stadium opened directly facing the gymnasium, which corresponded to the safest condition for the structures’ surfaces. As the spacing between the buildings increased, the interference effect between the two structures was reduced. The interference was negligible for a spacing of 2 L. The stadium had the most significant amplification interference effect on the gymnasium for a wind direction angle of 45°, which was extremely unfavourable to the safety of the structure. The most favourable wind direction angle was 270°, where there were both amplification interference and blockage interference.

A new taller building adjacent to an existing building with a lower roof is a relatively common situation. The new building provides a snow source area, which results in snow drift atop the lower roof which likely was not anticipated in its original design. Since it is usually difficult to retrofit the existing roof structure, a solid wall can be considered to capture the expected snow transport on the upper roof. Using field measurement on snowdrift development around solid walls, ASCE 7 provisions and Drift Ratio parameter, two approaches based on average or conservative values are studied to determine the required height of the solid wall. The results indicate that conservative values provide arguably unrealistic values, while the average or combination of average and conservative values provides reasonable wall heights.

Thirty-six apple cultivars representing Malus × domestica Borkh. were evaluated for diversity in fruit quality. Colour traits ‘L’, ‘b’ and ‘Tint’ were positively correlated with TSS and fruit size. ‘a’ values showed negative correlation with TSS but was positively correlated with fruit firmness. ‘L’ values ranged from 32.66 (Well Spur) to 76.48 (Supermore Gold). Negative ‘a’ value was observed for Orange Val (−5.17), Snow Drift (−1.67) and Greensleeves (−7.70) indicating that these cultivars are green in colour at the time of harvesting. The ‘b’ values ranged from 6.86 (King Hacious) to 52.18 (Supermore Gold) indicating that these cultivars are yellow in colour and none blue. Positive ‘Tint’ value (2.36) was observed in Greensleeves cultivar and rest of the cultivars showed negative value. Fruit firmness ranged from 26.00 (Starkrimson Gold) to 90.85 RI (Top Red) and TSS from 11.80 °B (Razakwari) to 20.03 °B (Salvapobedetalian). Principal component analysis showed that first three components with Eigen values were able to explain more than 78% of total variation. PC1, PC2 and PC3 accounted for 37, 28 and 13% respectively, of the trait variability. Cluster analysis distinguished all the cultivars into five distinct groups/clusters and one cultivar Starkrimson Gold does not form the part of any cluster. Cluster analysis also revealed the importance of fruit weight and fruit firmness for grouping of apple cultivars while as TSS was found to have no significant role in grouping. The PCA and clustering analysis in this study indicated a high level of diversity in the apple cultivars. The present study is useful for identifying the apple cultivars with desirable fruit quality traits useful for commercialization and crop improvement through breeding.

We present climate data, direct surface mass balance (SMB) observations and model results for Mocho Glacier in the Chilean Lake District. Mean annual temperature on a nunatak of Mocho Glacier at an elevation of ~2000 m was +2.6°C in 2006–15 and mean annual precipitation in Puerto Fuy (13 km from the glacier, at an elevation of 600 m) was 4000 mm for the same period. High interannual variations in the SMB of Mocho Glacier were observed. A simple SMB model is able to reproduce the observed annual variations in SMB, but fails to predict the steep observed mass-balance gradient. The average of the measured annual glacier mass balances in the four hydrological years 2009/10–2012/13 was −0.90 m w.e. a−1and the average modelled annual glacier mass balance 2006/07–2014/15 was −1.05 m w.e. a−1. The observed distributed ablation shows a clear altitudinal dependency, while accumulation is determined by patterns of snow drift as well. These patterns are only poorly represented in the model and have to be included in order to be able to reproduce a realistic SMB map of the glacier.

A methodology for performing a snow drift transport analysis is provided that considers the demonstrated dependency of snow transport on approximately the fourth power of wind speed, giving...

Drift loads on roofs are arguably the most important snow load from a structural engineering perspective in the US, as they are the governing load for most cases of snow related structural ...

New ultra-long transnational railway megaprojects are currently being planned or under construction. Along their route, they increasingly cross arid and desert regions. In these regions, railways are vulnerable to windblown sand. Several failure cases recently occurred, e.g. along the Linhai-Ceke railway in China, or the Aus-Luderitz railway in Namibia. We consider windblown sand as an environmental key factor, analogously to wind or snow drift. We categorize its effects into Sand Ultimate Limit States and Sand Serviceability Limit States. In the design perspective, the quantitative prediction of the windblown sand sedimented along the railway is mandatory. We propose a probabilistic approach to sedimented windblown sand modelling because of the inborn variability of the phenomenon. The proposed method allows evaluating the design value of the accumulated windblown sand volume for a given site.

This chapter provides a fairly consistent picture of the unlimited range of actions and effects induced by the wind on the environment and territory. Accordingly, it describes the transition from ancient windmills to modern wind turbines. It deals with the role of the wind in the transport and diffusion of minute materials, highlighting three issues: the diffusion of pollutants introduced in the air during combustion processes, soil erosion, a phenomenon able of changing the geomorphological features of nature and of making soil dry up with devastating consequences, and the snow drift that causes severe problems for road and rail traffic as well as for built areas. The chapter also deals with natural and artificial barriers and their manifold uses, first of all, the protection of crops. Finally, it continues the description of the efforts mankind carried out since ancient times to build settlements and dwellings taking inspiration from bioclimatic principles; in this framework, city planning and architecture came into contact with environmental and climatic issues reassessed on scientific grounds.

Windward snow drifts are an important consideration for many roof geometrics, including roof steps, parapet walls, and various roof projections. Current code provisions for windward roof sn...

This contribution presents an automated terrestrial laser scanning (ATLS) setup, which was used during the winter 2016/17 to monitor the snow depth distribution on a NW-facing slope at a high-alpine study site. We collected data at high temporal [(sub-)daily] and spatial resolution (decimetre-range) over 0.8 km² with a Riegl LPM-321, set in a weather-proof glass fibre enclosure. Two potential ATLS-applications are investigated here: monitoring medium-sized snow avalanche events, and tracking snow depth change caused by snow drift. The results show the ATLS data’s high explanatory power and versatility for different snow research questions.

Cooperation is often considered as one of the key and unclear concepts, which differentiates multi-agent systems from other related fields such as distributed computing. One of the popular benchmarks for the verification of the effectiveness of various cooperation algorithms is multi-agent foraging task. Different approaches have been proposed among which Markov game based ones are widely used, though they could not select consistent equilibrium for the group. In this paper, an evolutionary game based method is proposed. In this method, the interactions among the agents are modeled by snow-drift game to evolve the evolutionary stable strategy (ESS) and bring the maximal reward for the group of agents. The simulation verified the efficiency of the proposed algorithm.

International audience; Wind and the associated snow drift are dominating factors determining the snow distribution and accumulation in alpine areas, resulting in a high spatial variability of snow depth that is difficult to evaluate and quantify. The terrain-based parameter Sx characterizes the degree of shelter or exposure of a grid point provided by the upwind terrain without the computational complexity of numerical wind field models. The parameter has shown to qualitatively predict snow redistribution with good reproduction of spatial patterns, but has failed to quantitatively describe the snow redistribution. By comparing the parameter with high-resolution snow surface data obtained through terrestrial laser scanning (TLS), we are able a) to identify areas of poor correlations between predicted and measured snow distribution and changes in snow depths, and b) to increase its ability to predict changes in snow depths by modifying the parameter, based on the TLS data and the terrain and wind conditions specific to our research site, the Col du Lac Blanc in the French Alps. We show how results improve if a snow surface model is used for calculating the parameter instead of a digital elevation model, and demonstrate the effects of changing the parameter's maximum search distance and of raster smoothing. Our analyses and results are important steps in the improvements of the parameter's ability to predict changes in snow depths.

As baseball gets more and more popular the interest of fans increases. Since baseball game in its nature is influenced very much by weather the necessity of a domed stadium has been raised. At this moment a membrane structured domed stadium is under construction. As can be understood from the roof collapse of Minnesota Metrom by a heavy snowfall in 2011, the snow load occupies a very important part in membrane structure. To calculate the snow load snowdrift prediction is necessary and snow is piled mainly at the side or roof of a building. Hence, in this study a snowdrift wind tunnel test of a domed stadium was made to simulate snowdrift; using it the maximum depth of fresh snowdrift is estimated to be in the range of 3.4cm-37cm on the roof of a domed stadium.

The blizzard phenomenon is the climate risk that has the greatest impact on the road-ways in the South-Eastern part of Romania. The E85 section between Urziceni and Buzau has a great vulnerability to blizzard. Its vulnerability was proved during the 26 of January – the 14 of February 2012, when the road-way was blocked for 10 days. In order to establish the vulnerability level for E85 road, the section between Urziceni and Buzau, the Roads Vulnerability to Blizzard Index (RVBI) has been calculated and spatially modelled by using the GIS techniques. This index integrates several factors, such as: road sections orientation, buildings density in the vicinity of the road, width of the villages that are crossed by E85, the snow drift potential, within built-up areaʼs orientation to E85, the negative relief forms along the road section. The calculation of the RVBI points out that 74% of total length of the road present high and very high vulnerability during blizzard phenomenon. The road sections with high and very high vulnerability need protective measures, such as: forest belts plantation, using bigger snow fences, increasing the snow fences density and achieving more equipment for snow moving off by the local authorities.

Coevolutionary games cast players that may change their strategies as well as their networks of interaction. In this paper a framework is introduced for describing coevolutionary game dynamics by landscape models. It is shown that coevolutionary games invoke dynamic landscapes. Numerical experiments are shown for a prisoner's dilemma (PD) and a snow drift (SD) game that both use either birth-death (BD) or death-birth (DB) strategy updating. The resulting landscapes are analyzed with respect to modality and ruggedness

Blowing and drifting snow continues to be a transportation and safety hazard with significant economic costs. Critical design criteria for the construction of a living (vegetated) snow fence are reviewed and presented using the most currently available design equations. Coupled with an analysis of climate and topographical data, the design criteria are applied to an area in Rocky Mountain National Park historically prone to snow drifting. The long-term average snow accumulation season (period beginning with the first blowing snow and ending with maximum drift density) was calculated from air temperature as between 4 November and 10 April, and these dates compared well with those based on nearby snow observations. Over the snow accumulation season, the potential for snow transport based on wind characteristics was 21.4 tonnes m−1 (all wind directions), of which 21.0 tonnes m−1 occurred along a mean drifting direction of 259° (nearly perpendicular to the road at the study site). The potential for s...

For about ten years, Meteo-France has developed and operated a real time operational suite aimed at snowpack simulation and avalanche risk forecasting: the numerical model chain Safran-Crocus-Mepra (SCM). It presently includes only a crude formulation of snowdrift effects at large spatial scales (massif). This paper presents the improvements to a snow drift module suited to the SCM chain. The new version, called SYTRON3 which aims at an improved simulation of snow drift effects at smaller spatial scales. It is coupled with the SCM environment, which provides hourly meteorological conditions and snow forcing. The main modifications concern the new parameterisation schemes, which are more realistic and more physically based. The increased number of vertical layers allows now to represent explicitly the three modes of movement during snow drift: creep, saltation and diffusion. The validation of this new version as well as comparisons with the previous version are performed at the Col du Lac Blanc test site (2700 m a.s.l., French Alps) by the use of digital photographs and field observations. D 2005 Elsevier B.V. All rights reserved.

An analytical procedure for simulating roof snow drift loads is presented. The procedure is based upon the physics of drift formation and consists of two elements. The first element is the transport rate which quantifies the snow flux from the snow source area. The second element is the trapping efficiency which quantifies the percentage of transported snow from the source area which is captured at the drift. Knowing wind speed and snowfall information for a given winter, the procedure can be used to simulate the annual maximum drift for a given snow source area. The method is applied to over 40 years of weather data at each of over 50 NWS first-order sites across the United States. The calculated annual maxima are fit with an extreme value distribution to determine 50-year drift loads for both roof step and gable roof geometries. It is shown that current leeward roof step drift provisions in ASCE 7-02 as well as gable roof drift provisions proposed for ASCE 7-05 yield loads with something close to a 50 year mean recurrence interval.

Formed metal deck roofs play an important role in steel building construction. There are many design variables in deck design to make it important for designers to put the right combination together to achieve a better design. In this paper, a procedure for the design of steel roofs subjected to non-uniform loads such as drifted snow is presented. The presented approach uses genetic algorithms to achieve optimal or near-optimal designs. The advantages of the model stem from two main points: (1) it searches for the optimum or near-optimum number of purlins for the roof; and (2) it determines the near-optimum spacing between purlins to minimize the structure weight. Details of model development are described and example applications are presented to demonstrate the model capabilities.

Three acoustic FlowCapt™ (IAV Engineering) drifting snow instruments were deployed during the 1999 and 2000 field season on Spitsbergen, Norway. Three different experiments were carried out to test the instruments for their use in snowdrift research. The data from the three instruments were compared during a study of drifting snow within an Arctic catchment and around a building. The principle of the instruments is based on the acoustic signal, generated by the mechanical impact of drifting snow particles on a vertical tube. Microphones inside the tube transmit the signal to a frequency analyser. By Fourier transformation, the signal can be divided into the high frequencies of the impacting snow particles and the low frequencies, resulting from the loosening wake eddies behind the tube. In this way, both snow drift flux and wind speed can be measured simultaneously. Results from the three experiments show that the instruments are useful tools to study drifting snow in remote areas. A reliable indication of the occurrence and strength of drifting snow events can be determined even if the absolute accuracy is difficult to quantify.

Snow drifting processes and wind speed profiles by a collector and a blower snow fences were investigated in a cold wind-tunnel. The purpose is to know the effect of wind direction on drift control by snow fences. Snowdrifts were compared among the following three cases about the both type fences. One is a case which the snow fence is perpendicular to the wind direction. The others are it has tilts by 30° and 45°. When the collector snow fence had tilts, amounts of snowdrift by the fence were much less than that in the case of perpendicular to the wind direction. This mainly caused by that the half width of the fence had no effect on decrease of wind speed. On the other hand, the effect of the blower snow fence did not decrease when it had tilts to the wind direction. It is necessary to be investigated where the blown snow deposit in the case that the blower snow fence has tilts.