Numerical modeling of deep-seated landslides interacting with man-made structures

This paper describes the interaction between deep-seated landslides and man-made structures such as dams, penstocks, viaducts, and tunnels. Selected case studies are reported first with the intent to gain insights into the complexities associated with the interaction of these structures with deep-seated landslides(generally referred to as deep-seated gravity slope deformations, DSGSDs). The main features, which characterize these landslides, are mentioned together with the interaction problems encountered in each case. Given the main objective of this paper, the numerical modeling methods adopted are outlined as means for increase in the understanding of the interaction problems being investigated. With the above in mind, the attention moves to an important and unique case history dealing with the interaction of a large-size twin-tunnel excavated with an earth pressure balance(EPB)tunnel boring machine(TBM) and a deep-seated landslide, which was reactivated due to the stress changes induced by tunnel excavation in landslide shear zone. The geological and geotechnical conditions are described together with the available monitoring data on the landslide movements, based on the advanced and conventional monitoring tools used. Numerical modeling is illustrated as an aid to back-analyze the monitored surface and subsurface deformations and to assist in finding the appropriate engineering solution for putting the tunnel into service and as a follow-up means for future understanding and control of the interaction problems. The simulation is based on a novel time-dependent model representing the landslide behavior.

Characteristics and Influencing Factors of Microplastics in Snow in the Inner Mongolia Plateau, China

Microplastics(MPs;<5 mm)have become one of the most prominent global environmental pollution problems.MPs can spread to high altitudes through atmospheric transport and can be deposited by rainfall or snowfall,potentially threatening the structure and function of natural ecosystems.MPs in terrestrial and aquatic ecosystems alter the growth and functional characteristics of organisms.However,little attention has been given to the possible harm associated with MPs deposited in snow,particularly in the context of global climate warming.MPs collected from surface snow in the Inner Mongolia Plateau,China,were used for quantitative analysis and identification.The results showed that MPs were easily detected,and the related concentration was approximately(68±10)–(199±22)MPsL1 in snow samples.Fibers were the most common morphology,the polymer composition was largely varied,and the abundance and composition of MPs were linked to human activity to a great extent.High-throughput sequencing results showed that the composition and abundance of microorganisms also differed in snow samples from areas with different MP pollution characteristics,indicating a considerable difference in microbial functional diversity.MPs may have an interference effect on the individual growth and functional expression of microorganisms in snow.In addition,the results showed that functional living areas(e.g.,landfills and suburban areas)in cities play an important role in the properties of MPs.For instance,the highest abundance of MPs was found in thermal power plants,whereas the abundance of polymers per sample was significantly lower in the suburban area.The MP contaminants hidden in snow can alter microbial structure and function and are therefore a potential threat to ecosystem health.

Considering and comparing regeneration in natural and man-made stands in northern Iran

In this study the regeneration diversity of Syahkal forests afforestated and natural stands in north of Iran was studied and compared from the point of view of evenness and diversity index. In order to accomplish this study two natural and man-made stands that almost are located in the same height above the sea level were chosen. The area of each stand was 30 ha and the inventory was done by the random-systematic method with a 5R land measurement （500 m2） selected. Also, in order to study the regeneration in the center of each sample piece 125 square meters micro plots were formed. The results show that regeneration diversity index in natural stands is more than that in man-made stands which in this case Mc-Arthur index with 2.41 has the most amount while Simpson index with 0.543 has the least amount. But the evenness indexes in man-made stands are more than that in natural stand which the main reason is the purity of the man-made stand.

A progress review of black carbon deposition on Arctic snow and ice and its impact on climate change

The rapid warming of the Arctic,accompanied by glacier and sea ice melt,has significant consequences for the Earth’s climate,ecosystems,and economy.Black carbon(BC)deposition on snow and ice can trigger a significant reduction in snow albedo and accelerate melting of snow and ice in the Arctic.By reviewing the published literatures over the past decades,this work provides an overview of the progress in both the measurement and modeling of BC deposition and its impact on Arctic climate change.In summary,the maximum value of BC deposition appears in the western Russian Arctic(26 ng·g^(–1)),and the minimum value appears in Greenland(3 ng·g^(–1)).BC records in the Arctic ice core already peaked in 1920s and 1970s,and shows a regional difference between Greenland and Canadian Arctic.The different temporal variations of Arctic BC ice core records in different regions are closely related to the large variability of BC emissions and transportation processes across the Arctic region.Model simulations usually underestimate the concentration of BC in snow and ice by 2–3 times,and cannot accurately reflect the seasonal and regional changes in BC deposition.Wet deposition is the main removal mechanism of BC in the Arctic,and observations show different seasonal variations in BC wet deposition in Ny-Ålesund and Barrow.This discrepancy may result from varying contributions of anthropogenic and biomass burning(BB)emissions,given the strong influence by BC from BB emissions at Barrow.Arctic BC deposition significantly influences regional climate change in the Arctic,increasing fire activities in the Arctic have made BB source of Arctic BC more crucial.On average,BC in Arctic snow and ice causes an increase of+0.17 W·m^(–2)in radiative forcing and 8 Gt·a^(–1)in runoff in Greenland.As stressed in the latest Arctic Monitoring and Assessment Programme report,reliable source information and long-term and high-resolution observations on Arctic BC deposition will be crucial for a more comprehensive understanding and a better mitigation strategy of Arctic BC.In the future,it is necessary to collect more observations on BC deposition and the corresponding physical processes(e.g.,snow/ice melting,surface energy balance)in the Arctic to provide reliable data for understanding and clarifying the mechanism of the climatic impacts of BC deposition on Arctic snow and ice.

Inter-comparison of field snow measurements using different instruments in Türkiye

Snow is important in Türkiye especially in the mountainous eastern areas where it may stay on the ground for more than half of the year.This region plays a vital role in feeding the water resources of the trans-boundary Euphrates-Tigris Basin,supporting crucial dams for water supply,irrigation and energy production.Thus,easy,frequent,correct and economical ways of measuring the snowpack is crucial.The snow properties at specific locations in the mountainous eastern regions over the two snow seasons(2018 and 2019)were studied by using different instruments and techniques,snow pit(box/cylinder/wedge cutter types),snow tube(Federal Sampler)and SnoTel(Snowpack Analyzer).The results point out a 1.7%-7.1%variation between different cutter type snow density measurements within snow pit analysis and the long-term utilized snow tube observations show a closer relation to box/cylinder type cutters.As for the continuous SnoTel observations,a variation of 2.4%-9.8%with various cutter types and a 5.9%difference regarding the snow tube density results are detected.These findings indicate a close range among different instruments,but it is the best when all three systems complement each other to characterize the snowpack effectively in the complex terrain since each has its own advantages.

Ecology and Fish Biodiversity of Man-Made Lakes of Southern Benin (West Africa): Implications for Species Conservation and Fisheries Management

Man-made lakes are alternative and potential habitats for biodiversity conservation, fisheries and extensive aquaculture. We investigated the ecology and the fish community structure of two (2) sand-dragged man-made lakes, Lake Ahozon and Lake Bewacodji of Southern Benin, with implications for species conservation, fisheries management and aquaculture valorization. From August 2014 to July 2015, habitats conditions were evaluated and fishes were sampled monthly with seine, cast net, experimental gill net and hooks in the open water and aquatic vegetation habitats of both lakes. Overall, the water quality of Lake Ahozon was globally favorable for the growth and the survival of the fish resources whereas Lake Bewacodji exhibited a poor water quality indicated mainly by an acid pH (mean: 6.32 ± 0.58) and low dissolved oxygen concentrations (mean: 3.52 ± 1.25 mg/l) caused by dense floating plants, Nymphea sp mainly and huge daily dumping of domestic wastes. The study revealed low species richness, d = 5.89 and d = 3.87, and low species diversity, H’ = 0.76 and H’ = 0.48 for Lakes Ahozon and Bewacodji, respectively, with Lake Ahozon more diverse than Lake Bewacodji. The fish community of Lake Ahozon comprised six (6) species, 3 cichlids Sarotherodon galilaeus, Oreochromis niloticus and Tilapia guineensis, the silver catfish, Chrysichthys nigrodigitatus (Claroteidae), the African bonytongue, Heterotis niloticus (Osteoglossidae), and the African catfish, Clarias gariepinus (Clariidae). Numerically, S. galilaeus dominated Lake Ahozon and made 85.21% of the sample. In Lake Bewacodji, the fish composition comprised four (4) species, Sarotherodon galilaeus multifasciatus, the dominant species making numerically 91.58% of the total sample, T. guineensis, C. gariepinus and C. nigrodigitatus. With regard to trophic structure, the fish assemblages of both lakes were numerically dominated by planktinovores/ detritivores, mainly S. galilaeus, O. niloticus, T. guineensis and C. nigrodigitatus making together 99.46% of Lake Ahozon fish community, and S. galilaeus multifasciatus, T. guineensis and C. nigrodigitatus accounting together for about 98.59% of Lake Bewacodji. In Lake Ahozon, standard length (SL) frequencies histograms showed an unimodal size distribution for H. niloticus, the nile tilapia O. niloticus and C. gariepinus whereas the two cichlids, S. galilaeus and T. guineensis exhibited a bimodal size distribution. In Lake Bewacodji, S. galilaeus multifasciatus, C. nigrodigitatus and C. gariepinus exhibited an unimodal size distribution. A sustainable exploitation of both man-made lakes requires the implementation of an integrated management scheme which should include habitat restoration and protection plan, fisheries/aquacultural valorization, ecological sound agriculture/ecotourism and environmental monitoring.

The 25th CIMFC(Bengbu 2019):Exploring the future of the man-made fibers

The 25th China International Man-made Fiber Conference (Bengbu 2019)(hereinafter referred to as CIMFC 2019), themed on “Opening and Integaration for Interactive Development — Coordinated Progress of Global Man-Made Fiber Industry”, was convened in Bengbu City, Anhui Province. CIMFC 2019 was sponcored by China National Textile and Apparel Council (CNTAC), organized by China Chemical Fibers Association, Chi-na Textile International Exchange Center, and China BBCA Group Corp., supported by Bengbu Municipal People’s Goverment, and co-organized by Bengbu Investment Promotion and Foreign cooperation Center, Bengbu Municipal Bureau of Commerce and Foreign Affairs, and Oerlikon Man-made Fiber.

Numerical Simulations of Snow Accumulation in the Bogie Region of a Train Considering Snow Particle Rotation

To investigate the influence of snow particle rotational motion on the accumulation of snow in the bogie region of high-speed trains,an Euler‒Lagrange numerical approach is adopted.The study examines the effects of snow particle diameter and train speed on the ensuing dynamics.It is shown that considering snow particle rotational motion causes significant deviation in the particle trajectories with respect to non-rotating particles.Such a deviation increases with larger snow particle diameters and higher train speeds.The snow accumulation on the overall surface of the bogie increases,and the amount of snow on the vibration reduction device varies greatly.In certain conditions,the amount of accumulated snow can increase by several orders of magnitudes.

Spatiotemporal Changes of Snow Depth in Western Jilin,China from 1987 to 2018

Seasonal snow cover is a key global climate and hydrological system component drawing considerable attention due to glob-al warming conditions.However,the spatiotemporal snow cover patterns are challenging in western Jilin,China due to natural condi-tions and sparse observation.Hence,this study investigated the spatiotemporal patterns of snow cover using fine-resolution passive mi-crowave(PMW)snow depth(SD)data from 1987 to 2018,and revealed the potential influence of climate factors on SD variations.The results indicated that the interannual range of SD was between 2.90 cm and 9.60 cm during the snowy winter seasons and the annual mean SD showed a slightly increasing trend(P>0.05)at a rate of 0.009 cm/yr.In snowmelt periods,the snow cover contributed to an increase in volumetric soil water,and the change in SD was significantly affected by air temperature.The correlation between SD and air temperature was negative,while the correlation between SD and precipitation was positive during December and March.In March,the correlation coefficient exceeded 0.5 in Zhenlai,Da’an,Qianan,and Qianguo counties.However,the SD and precipitation were neg-atively correlated over western Jilin in October,and several subregions presented a negative correlation between SD and precipitation in November and April.

Impact of Climate Change on Mountaineering Activities in Haba Snow Mountain Reserve and the Development of Surrounding Communities

In the context of global climate change, this study reviews and discusses the three aspects of ecology, economic development of surrounding communities, ecological balance and snow mountain activities in the Haba Snow Mountain Reserve through literature collation and research. 1) The Hengduan Mountain Plate of Haba Snow Mountain is affected by the high altitude temperate monsoon and is sensitive to climate change. There has been continuous glacier melting and snow line fluctuations. Although there is no forest line movement, the vegetation at the junction of the forest line has increased. 2) Human activities in the Haba Snow Mountain Reserve have shown an active trend, and the Biomass in various ecosystems in the region is inversely correlated. 3) Climate change will have a negative impact on landscape attraction and tourism safety in snowy mountain areas. 4) Haba Snow Mountain Reserve needs more perfect biological species statistical research and dynamic vegetation research to support the establishment of a perfect ecological protection strategy and ecological early warning in the region. 5) As the frequency of tourist activities in the Haba Protected Area increases, corresponding environmental protection signage, garbage cleaning methods, and tourist education have not been synchronizedly improved.

Changes in Spring Snow Cover over the Eastern and Western Tibetan Plateau and Their Associated Mechanism

The spring snow cover(SC)over the western Tibetan Plateau(TP)(TPSC)(W_TPSC)and eastern TPSC(E_TPSC)have displayed remarkable decreasing and increasing trends,respectively,during 1985–2020.The current work investigates the possible mechanisms accounting for these distinct TPSC changes.Our results indicate that the decrease in W_TPSC is primarily attributed to rising temperatures,while the increase in E_TPSC is closely linked to enhanced precipitation.Local circulation analysis shows that the essential system responsible for the TPSC changes is a significant anticyclonic system centered over the northwestern TP.The anomalous descending motion and adiabatic heating linked to this anticyclone leads to warmer temperatures and consequent snowmelt over the western TP.Conversely,anomalous easterly winds along the southern flank of this anticyclone serve to transport additional moisture from the North Pacific,leading to an increase in snowfall over the eastern TP.Further analysis reveals that the anomalous anticyclone is associated with an atmospheric wave pattern that originates from upstream regions.Springtime warming of the subtropical North Atlantic(NA)sea surface temperature(SST)induces an atmospheric pattern resembling a wave train that travels eastward across the Eurasian continent before reaching the TP.Furthermore,the decline in winter sea ice(SIC)over the Barents Sea exerts a persistent warming influence on the atmosphere,inducing an anomalous atmospheric circulation that propagates southeastward and strengthens the northwest TP anticyclone in spring.Additionally,an enhancement of subtropical stationary waves has resulted in significant increases in easterly moisture fluxes over the coastal areas of East Asia,which further promotes more snowfall over eastern TP.

MAN-MADE

前情提要 似水与流年根据博士日记上面的提示一路找到太阳遗迹，终于见到了博士，博士向两人说明了一切，原来，流年竟是人造人……

MAN-MADE

名月背叛了虎帝大人，他要所有的新型M-M战士听命于他。于是，被博士利用变身药丸救出的流年他们决定要阻止名月。

Study on Image Recognition Algorithm for Residual Snow and Ice on Photovoltaic Modules

The accumulation of snow and ice on PV modules can have a detrimental impact on power generation,leading to reduced efficiency for prolonged periods.Thus,it becomes imperative to develop an intelligent system capable of accurately assessing the extent of snow and ice coverage on PV modules.To address this issue,the article proposes an innovative ice and snow recognition algorithm that effectively segments the ice and snow areas within the collected images.Furthermore,the algorithm incorporates an analysis of the morphological characteristics of ice and snow coverage on PV modules,allowing for the establishment of a residual ice and snow recognition process.This process utilizes both the external ellipse method and the pixel statistical method to refine the identification process.The effectiveness of the proposed algorithm is validated through extensive testing with isolated and continuous snow area pictures.The results demonstrate the algorithm’s accuracy and reliability in identifying and quantifying residual snow and ice on PV modules.In conclusion,this research presents a valuable method for accurately detecting and quantifying snow and ice coverage on PV modules.This breakthrough is of utmost significance for PV power plants,as it enables predictions of power generation efficiency and facilitates efficient PV maintenance during the challenging winter conditions characterized by snow and ice.By proactively managing snow and ice coverage,PV power plants can optimize energy production and minimize downtime,ensuring a sustainable and reliable renewable energy supply.

Classifying moisture sources associated with snowfall in the mountains of Lesotho

An average of eight snowfall events occur each year in the eastern Lesotho Highlands.These snowfall events are typically associated with cut-off low(CoLs)systems and mid-latitude cyclones.However,the moisture sources of the snowfall are unclassified and unclear.The Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)model,an air mass back trajectory model,has been used to evaluate moisture source waters locally in southern Africa and internationally in China and Europe.This study uses HYSPLIT to determine the source moisture of snow in Lesotho.A list of all 82 snowfall events in Lesotho spanning 2017 to 2022 was compiled using the Snow Report SA Instagram page,including the date and location of snowfall.A 72-hour back trajectory for each snowfall event was initiated for both Afriski and the whole of Lesotho.This amounts to models of moisture source trajectories for 28 and 82 snowfall days,respectively.These air mass pathways are classified according to their frequency per snowfall event,per month in the snow season,per year and for the full period.From this,associated moisture source regions and dominant air mass trajectories were identified.This study reports that the air mass trajectories associated with Afriski and Lesotho as a whole are very similar.The most common pathway of air mass trajectories transporting snow-bearing moisture to Lesotho was an inland trajectory from the northern regions of southern Africa.This pathway makes up 16.6%of all trajectories reported and is associated with the Angola Low,the Congo Air Boundary and the St.Helena High Pressure.

Numerical Investigation of Snow Prevention in the Bogie Region of High-Speed Trains with Active Blowing under Crosswind Conditions

In this study,the unsteady Reynolds-averaged Navier–Stokes algorithm coupled with the Discrete Phase Model(DPM)was used to study the accumulation of snow in the bogie region of a high-speed train under crosswind conditions.Moreover,the impact of active blowing schemes on the airflow around the bogie and the dynamics and deposition of snow particles were also assessed.According to the results:in the crosswind environment,active blowing changes the flow field in the bogie area,reducing the flow of air coming from the windward side and bottom of the bogie.The trajectory of snow particles carried by crosswinds is modified due to the reduced airflow into the bogie region.With no active blowing,snow accumulation is mainly concentrated in the bogie cavity,frame,and primary suspension;while it is reduced by nearly an order of magnitude as soon as blowing is enabled.Blowing speeds need to be distributed appropriately in order to achieve the best possible snow protection.Continuously increasing the blowing speed on one side does not improve the amount of snow in the bogie region.The optimal condition for snow prevention of the entire train is achieved with a windward side blowing speed of 4 m/s and a leeward side blowing speed of 6 m/s,resulting in a snow reduction rate of 95.6%.Moreover,higher blowing speeds on the leeward side are beneficial for mitigating snow accumulation in the bogie region.

Vertical response of snow albedo to seasonal climate change in the Tibetan Plateau

The snow cover in the Tibetan Plateau(TP)responds keenly to global climate and hydrological shifts,with snow albedo variation serving as a pivotal indicator of these changes.In this study,we explored snow albedo changes over the period(2001-2022)in the TP combined with the high-resolution near-surface meteorological forcing datasets(2001-2022).The study utilized Ding’s method to separate precipitation patterns,and then employed path analysis to evaluate the vertical response of snow albedo to air temperature,rainfall,and snowfall across four periods.The findings are as follows:(1)Snow albedo in area above 4000 m ranged from 0.4 to 0.7,while below 4000 m,snow albedo was primarily below 0.4.Snow albedo was generally higher in the northern TP.(2)During the snow accumulation period(October to December),snow albedo showed a decreasing trend in most areas of the TP.Conversely,snow albedo exhibited overall increasing trends during the snow stable period(January to February),snowmelt period(March to May),and snowless period(June to September).Especially in the central TP,snow albedo showed significant decrease during the snow accumulation period,and it increased significantly in the other periods.(3)Air temperature,rainfall,and snowfall influenced directly and predominantly snow albedo changes in the TP.Especially,air temperature and snowfall were the primary driving factors in most areas.(4)During different periods,air temperature was the main factor driving changes in snow albedo below 5000 m,but snowfall had a stronger influence above 5000 m.Except during the snow accumulation period,the impact of rainfall on snow albedo decreased with increasing altitude.During the snowless period,rainfall affected snow albedo obviously,but snowfall remained the dominant factor in areas above 6500 m.These results provide new insights on climate-driven changes in the snow albedo over the TP.

Man-made fiber industry enjoys optimistic transformation and upgrading

As an important fundamental industry of the national economy,the man-made fiber industrial chain is integrated into the era development and it assumes the responsibility of advancing.Each link of the industrial chain is connected with each other.After the development and accumulation of several decades,the new produced polyester,PTA and other plants keep

A World of Ice and Snow Being also Invaluable Asset:A Case Study of the"Snow Village"

Based on field visit and interview,the current situation of snow village in China is summarized from four aspects:core scenic spots in snow village,skiing industry in snow village,film and television industry in snow village,and ice and snow agritainment.The investigation found that there are still significant problems in homogenization,scenic area infrastructure,and government regulation in snow village.Targeted solutions are proposed from four aspects:tapping internal advantages,strengthening top-level design and infrastructure construction,promoting tourism industry upgrading,and collaborating to innovate the ice and snow tourism supply chain,in order to further promote the economic development of snow village.

Cross-calibration between MWRI and AMSR2 to improve consistency of snow depth products

The Microwave Radiation Imager(MWRI),boarded on the FY-3 series satellites:FY-3B,FY-3C,and FY-3D,is the first satellite-based microwave radiometer in China,commencing passive microwave brightness temperature data acquisition since 2010.The Advanced Microwave Scanning Radiometer 2(AMSR2) boarded on the Global Change Observation Mission 1st-Water(GCOM-W1),has been operational since 2012.Despite the FY-3 series satellites are equipped with the same MWRI and all MWRIs sharing comparable parameters and configurations as AMSR2,disparities in observation times and satellite platforms result in inconsistencies in the data obtained by different satellites,which further impacting the consistency of retrieved geophysical parameters.To improve the consistency of brightness temperatures from FY-3B,FY-3C,FY-3D/MWRI,and GCOM-W1/AMSR2,cross-calibrations were conducted among brightness temperatures at ten-channel from above four platforms.The consistency of derived snow depth from MWRIs and AMSR2 in China before and after the calibration were also analyzed.The results show that the correlation coefficients of brightness temperatures at all channels between sensors exceed0.98.After cross-calibration,the RMSEs and biases of brightness temperatures at all frequencies and snow depth in China derived from them reduce to varying degrees.The consistencies in both brightness temperatures and snow depth of FY-3B/MWRI,FY-3D/MWRI,and AMSR2 are higher than those of FY-3C and others.These findings advocate for the utilization of cross-calibrated brightness temperatures from FY-3B/MWRI,FY-3D/MWRI,and AMSR2,which share similar satellite overpass time,to derived a long-term snow depth dataset.