On April 30,the 22nd China Xiza ng Mountai neering Conventi on in 2025 comme need.As its flagship eve nt,the Luodui Peak Mountaineering Expedition took place from May 2 to 3 in Yangbajain Town of Lhasa,attracting more...On April 30,the 22nd China Xiza ng Mountai neering Conventi on in 2025 comme need.As its flagship eve nt,the Luodui Peak Mountaineering Expedition took place from May 2 to 3 in Yangbajain Town of Lhasa,attracting more than 160 mountain climbing enthusiasts from all over the country.展开更多
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...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.展开更多
In Europe and especially in France,there is a growing enthusiasm for outdoor sports and recreation.In the meantime,the risk of both severe and frequent injuries associated with active pursuits is acknowledged,especial...In Europe and especially in France,there is a growing enthusiasm for outdoor sports and recreation.In the meantime,the risk of both severe and frequent injuries associated with active pursuits is acknowledged,especially in mountainous areas.The effectiveness of prevention must rely on detailed knowledge of typical circumstances and scenarios but thorough understanding of the mechanisms of accidentality remains limited by the fragmentation of sources and by mostly heterogeneous methodologies.This paper aims at giving insights on victims’profiles,season,location,and circumstances of mountaineering accidents in the French Alps,through the study of rescue interventions data from 2008 to 2018.Thanks to the analysis of the exhaustive database of search and rescue interventions from the French mountain national police force,and while questioning its limitations,we strive to answer two questions:what are the characteristics of the hazardous situations leading to a rescue intervention in mountaineering?Among these situations,what are the characteristics that tend to make them more harmful?展开更多
Editor's Notes: On May 8^(th),the Beijing Olympic torch relay team successfully reached the summit of Mt.Qomolangma. About 9:11a.m,at a spot 30 meters from the peak, Lozang Dradul ignited the first torch that had ...Editor's Notes: On May 8^(th),the Beijing Olympic torch relay team successfully reached the summit of Mt.Qomolangma. About 9:11a.m,at a spot 30 meters from the peak, Lozang Dradul ignited the first torch that had been named"Auspicious Clouds"and was held by the female Tibetan mountaineer Jiji.Then,the torch was relayed to Wang Yongfeng,Nyima Tsering,Huang Chungui。展开更多
For all the benefits of c ty life-diverse culture, food and people-it is a major source of stress. Crowds and noise can be oppressive,and commuting can kill you(it’s more taxing than What a fighter pilot experiences ...For all the benefits of c ty life-diverse culture, food and people-it is a major source of stress. Crowds and noise can be oppressive,and commuting can kill you(it’s more taxing than What a fighter pilot experiences in battle,according to American researchers).Is there any way to find relief? Two Beijingers think so:a research associate at the Chinese Academy of Social Sciences,and a South African working in PR and events management,reveal how they cope with urban pressures.展开更多
I have cherished the dream of climbing mountains from a very early age. But I had to suppress my urge for mountain-eering as there are not that many mountains in Egypt. Though Sinai has some moun-tains, I didn't f...I have cherished the dream of climbing mountains from a very early age. But I had to suppress my urge for mountain-eering as there are not that many mountains in Egypt. Though Sinai has some moun-tains, I didn't find them interesting as they have no greenery. So my dream never came true in Egypt.展开更多
The increased frequency and intensity of heavy rainfall events due to climate change could potentially influence the movement of nutrients from land-based regions into recipient rivers.However,little information is av...The increased frequency and intensity of heavy rainfall events due to climate change could potentially influence the movement of nutrients from land-based regions into recipient rivers.However,little information is available on how the rainfall affect nutrient dynamics in subtropicalmontane rivers with complex land use.This study conducted high-frequency monitoring to study the effects of rainfall on nutrients dynamics in an agricultural river draining to Lake Qiandaohu,a montane reservoir of southeast China.The results showed that riverine total nitrogen(TN)and total phosphorus(TP)concentrations increased continuously with increasing rainfall intensity,while TN:TP decreased.The heavy rainfall and rainstorm drove more than 30%of the annual N and P loading in only 5.20%of the total rainfall period,indicating that increased storm runoff is likely to exacerbate eutrophication in montane reservoirs.NO_(3)^(−)-N is the primary nitrogen form lost,while particulate phosphorus(PP)dominated phosphorus loss.Themain source of N is cropland,and themain source of P is residential area.Spatially,forestedwatersheds have better drainage quality,while it is still a potential source of nonpoint pollution during rainfall events.TN and TP concentrations were significantly higher at sites dominated by cropland and residential area,indicating their substantial contributions to deteriorating river water quality.Temporally,TN and TP concentrations reached high values in May-August when rainfall was most intense,while they were lower in autumn and winter than that in spring and summer under the same rainfall intensities.The results emphasize the influence of rainfall-runoff and land use on dynamics of riverine N and P loads,providing guidance for nutrient load reduction planning for Lake Qiandaohu.展开更多
The Qinba Mountains are climatically and ecologically recognized as the north-south transitional zone of China.Analysis of its phenology is critical for comprehending the response of vegetation to climatic change.We r...The Qinba Mountains are climatically and ecologically recognized as the north-south transitional zone of China.Analysis of its phenology is critical for comprehending the response of vegetation to climatic change.We retrieved the start of spring phenology(SOS)of eight forest communities from the MODIS products and adopted it as an indicator for spring phenology.Trend analysis,partial correlation analysis,and GeoDetector were employed to reveal the spatio-temporal patterns and climatic drivers of SOS.The results indicated that the SOS presented an advance trend from 2001 to 2020,with a mean rate of−0.473 d yr^(−1).The SOS of most forests correlated negatively with air temperature(TEMP)and positively with precipitation(PRE),suggesting that rising TEMP and increasing PRE in spring would forward and delay SOS,respectively.The dominant factors influencing the sensitivity of SOS to climatic variables were altitude,forest type,and latitude,while the effects of slope and aspect were relatively minor.The response of SOS to climatic factors varied significantly in space and among forest communities,partly due to the influence of altitude,slope,and aspect.展开更多
The mountainous rural regions of China are undergoing enormous changes in space and time.To a certain extent,this change has increased the difficulties in our understanding of rural development in mountainous areas an...The mountainous rural regions of China are undergoing enormous changes in space and time.To a certain extent,this change has increased the difficulties in our understanding of rural development in mountainous areas and brought challenges to development policies and revitalization strategies in mountainous rural regions,especially in karst mountainous areas.In light of the difficulty in and as the key to the development of China's mountainous rural areas,the scientific and systematic construction of indicators for evaluating the level of rural revitalization development and clarifying the level of rural revitalization development and influential factors in karst mountainous areas are of great significance to the implementation of the development of the strategy for the revitalization of the rural areas in karst mountainous areas in China.This study constructed an evaluation index system of the rural regional system and rural revitalization development(RTSRD)from the perspective of rural regional system theory,assessed the spatial differentiation patterns and influential factors of RTSRD,and refined a typical territorial model of rural revitalization development in karst mountainous areas by taking Guizhou Province,a typical karst mountainous region,as a case study area.The evaluation and spatial analyses show that the RTSRD indices of karst mountainous areas in the system perspective show a linear growth trend in all single dimensions,with industrial revitalization(IR)showing the most significant increase each year.In time,the RTSRD of karst mountainous regions has developed from low to high,with evident improvement;spatially,the RTSRD shows the characteristics of‘high in the middle and low in the surroundings,and low in the plateau and low in the depression,'with apparent spatial heterogeneity.In addition,this study found that the spatial and temporal differences in RTSRD result from a combination of endogenous push and exogenous pull in the rural system.In particular,this study has refined a typical regional model of rural revitalization development in karst mountainous regions,which provides theoretical support and case practice for rural development in other karst mountainous regions.At the same time,it provides a basis for decision-making for the county level government and rural development planning.展开更多
Based on comprehensive observations of 20 wire icing events during winter from 2019 to 2021,we investigated the characteristics of the icing properties,the atmospheric boundary layer structure,the raindrop size distri...Based on comprehensive observations of 20 wire icing events during winter from 2019 to 2021,we investigated the characteristics of the icing properties,the atmospheric boundary layer structure,the raindrop size distribution,and their associated effects on the ice accretion mechanism in the mountainous region of Southwest China.The maximum ice weight was positively correlated with the duration of ice accretion in the mountainous area.The duration of precipitation accounted for less than 20%of the icing period in the mountainous area,with solid-phase hydrometeors being predominant.Icing events,dominated by freezing rain(FR)and mixed rain–graupel(more than 70%),were characterized by glaze or highdensity mixed icing.The relationship between the melting energy and refreezing energy reflected the distribution characteristics of the proportion of FR under mixed-phase precipitation.The intensity of the warm layer and the dominant precipitation phase significantly affected the variations in the microphysical properties of FR.The melting of large dry snowflakes significantly contributed to FR in the mountainous areas,resulting in smaller generalized intercepts and larger mass-weighted mean diameters in the presence of a stronger warm layer.Under a weaker warm layer,the value of the massweighted mean diameter was significantly smaller because of the inability of large solid particles to melt.Finally,FR in the mountainous area dominated the ice weight during the rapid ice accumulation period.A numerical simulation of FR icing on wires effectively revealed the evolution of disaster-causing icing in mountainous areas.展开更多
Emission characteristics of biogenic volatile organic compounds(BVOCs)from dominant tree species in the subtropical pristine forests of China are extremely limited.Here we conducted in situ field measurements of BVOCs...Emission characteristics of biogenic volatile organic compounds(BVOCs)from dominant tree species in the subtropical pristine forests of China are extremely limited.Here we conducted in situ field measurements of BVOCs emissions from representative mature evergreen trees by using dynamic branch enclosures at four altitude gradients(600-1690ma.s.l.)in the Nanling Mountains of southern China.Composition characteristics as well as seasonal and altitudinal variations were analyzed.Standardized emission rates and canopyscale emission factors were then calculated.Results showed that BVOCs emission intensities in the wet season were generally higher than those in the dry season.Monoterpenes were the dominant BVOCs emitted from most broad-leaved trees,accounting for over 70%of the total.Schima superba,Yushania basihirsuta and Altingia chinensis had relatively high emission intensities and secondary pollutant formation potentials.The localized emission factors of isoprene were comparable to the defaults in the Model of Emissions of Gases and Aerosols fromNature(MEGAN),while emission factors of monoterpenes and sesquiterpenes were 2 to 58 times of those in the model.Our results can be used to update the current BVOCs emission inventory in MEGAN,thereby reducing the uncertainties of BVOCs emission estimations in forested regions of southern China.展开更多
The middle reaches of the Yellow River represent a critically ecologically sensitive and fragile area within the Yellow River Basin(YRB),holding significant scientific value for ecological security assessment and envi...The middle reaches of the Yellow River represent a critically ecologically sensitive and fragile area within the Yellow River Basin(YRB),holding significant scientific value for ecological security assessment and environmental management strategies.This study comprehensively evaluates the evolution of the eco-environment in the“Two Mountains,Seven Rivers,and One Basin”(TSO)area of Shanxi Province from 2000 to 2020 based on fraction vegetation cover(FVC)derived from the Normalized Difference Vegetation Index(NDVI),net primary productivity(NPP)calculated via the Carnegie–Ames–Stanford approach(CASA),and the remote sensing ecological index(RSEI).The results indicate a significant improvement in the TSO’s eco-environment from 2000 to 2020,with the RSEI values increased from 0.34 in 2000 to 0.41 in 2020(an increase of 17.76%).Both FVC and NPP demonstrated notable upward trends,with FVC increasing by 22.74%and NPP by 53.11%.Spatially,FVC rose by 21.84%,19.72%and 26.06%,respectively in the Two Mountains,Seven Rivers,and the YRB in Shanxi Province.Similarly,the NPPs increased by 51.60%,48.60%,and 61.65%in these regions over the past 21 years.Both FVC and NPP exhibited decreasing patterns from southeast to northwest,with significant eco-environmental improvements in the northern region and slower recovery in the southern region.Precipitation was the primary causes influencing vegetation recovery,showing positive trends in the central and northern TSO regions,while this trend reversed in the southern.The RSEI value indicate substantial eco-environment improvements in the central and northern areas(Sanggan,Daqing and Hutuo River Basins),whereas the southern regions(e.g.,Zhang,Qin,Fen and Sushui River Basins)remain in poor grade.Human activities,particularly land use/cover changes marked by increased forestation and urbanization alongside decreased cultivated land,significantly affected vegetation cover patterns.This study provides scientific references for formulating policies on ecological construction and high-quality development in the YRB.展开更多
A new cranium and two mandibles of Ailuropoda melanoleuca from Xiangxi,Hunan Province are described here.The materials were discovered in a karst cave on the Bamian Mountain at an altitude of 1200 m,with AMC carbon-fo...A new cranium and two mandibles of Ailuropoda melanoleuca from Xiangxi,Hunan Province are described here.The materials were discovered in a karst cave on the Bamian Mountain at an altitude of 1200 m,with AMC carbon-fourteen isotope dating indicating an age of 2800±30 BP.Historically,the giant panda was widely distributed in southern China and parts of Southeast Asia during the Pleistocene epoch,but it is now confined and isolated to six mountain ranges in southwest China’s Sichuan,Shaanxi,and Gansu provinces.The subfossil materials reported here represent the first discovery of the living species of giant panda in Xiangxi,Hunan.This extends their geographical distribution in southern China during the Holocene epoch eastward to the eastern edge of the Yunnan-Guizhou Plateau and their recent altitude range down to 1200 m.展开更多
Prediction of water inflow into a tunnel is a crucial prerequisite for the waterproof and drainage design of mountain tunnels in water-rich areas.Based on the proposed Baiyun Mountain Tunnel project in Guangzhou,a num...Prediction of water inflow into a tunnel is a crucial prerequisite for the waterproof and drainage design of mountain tunnels in water-rich areas.Based on the proposed Baiyun Mountain Tunnel project in Guangzhou,a numerical percolation model of random fractured rock of a tunnel underpassing a water reservoir is established to study the seepage characteristics of surrounding rock,the law of water inflow,and the change of lining water pressure,considering the local artificial boundary conditions for seepage in large rock mass,.In addition,the influences of rock permeability,fracture aperture,grouting circle thickness,and penetration are analyzed.The results show that:(1)Only fractures with aperture wider than 0.1 mm can play a significant role in water conduction in rocks with the permeability lower than 10^(-11)m^(2);(2)The greater the permeability difference between the fractures and rocks,the more remarkable the effects of fractures on the surrounding rock seepage field and cavern water inflow;(3)The sensitivity of grouting waterproof function to grouting circle thickness,grouting ring penetration,and rock permeability is significantly higher than that of tunnel buried depth and fracture aperture;(4)The lining water head is much more sensitive to the grouting circle thickness and penetration than to the tunnel buried depth;(5)With the grouting range enlarging,the impact of grouting circle permeability on the precipitation pressure role of the grouting ring increases;(6)For the interesting tunnel designed to be built at the depth of 70 m,the grouting circle with the thickness of 0.5 m and permeability of 10-^(14)m^(2)is recommended.展开更多
Dear Xu Yan,How is everything going these days?I am writing to invite you to an outing I will organize on Sunday,May 10th.We will start at 6:30 in the morning at the school gate and then go to Yongfeng Mountain by bus...Dear Xu Yan,How is everything going these days?I am writing to invite you to an outing I will organize on Sunday,May 10th.We will start at 6:30 in the morning at the school gate and then go to Yongfeng Mountain by bus.We will climb the mountain there in the morning and then have a picnic at 12 o’clock at noon.If you can come,you don’t need to bring food but it’s best for you to wear sports shoes and suitable clothes.展开更多
Gongga Mountain National Nature Reserve Located in the Garze Tibetan Autonomous Prefecture of Sichuan Province,the Gongga Mountain National Nature Reserve is a landscape of breathtaking extremes and exceptional ecolog...Gongga Mountain National Nature Reserve Located in the Garze Tibetan Autonomous Prefecture of Sichuan Province,the Gongga Mountain National Nature Reserve is a landscape of breathtaking extremes and exceptional ecological value.Dominated by the towering Gongga Mountain-rising to 7,556 metres-it is the highest peak in both the Hengduan Mountains and Sichuan Province.展开更多
NEW DWELLERS OF MOUNTAINS Neweekly 15 September A growing number of people are turning towards the mountains,venturing into valleys and forests to explore a life as“new mountain dwellers”–a fresh way of mountain li...NEW DWELLERS OF MOUNTAINS Neweekly 15 September A growing number of people are turning towards the mountains,venturing into valleys and forests to explore a life as“new mountain dwellers”–a fresh way of mountain living.Immersed in the poetic scenery,they rest,hike,boat,read,attend valley concerts,or admire paintings in poetry halls.Everything blends with and respects nature.展开更多
文摘On April 30,the 22nd China Xiza ng Mountai neering Conventi on in 2025 comme need.As its flagship eve nt,the Luodui Peak Mountaineering Expedition took place from May 2 to 3 in Yangbajain Town of Lhasa,attracting more than 160 mountain climbing enthusiasts from all over the country.
文摘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.
基金The Petzl foundation funded this research study。
文摘In Europe and especially in France,there is a growing enthusiasm for outdoor sports and recreation.In the meantime,the risk of both severe and frequent injuries associated with active pursuits is acknowledged,especially in mountainous areas.The effectiveness of prevention must rely on detailed knowledge of typical circumstances and scenarios but thorough understanding of the mechanisms of accidentality remains limited by the fragmentation of sources and by mostly heterogeneous methodologies.This paper aims at giving insights on victims’profiles,season,location,and circumstances of mountaineering accidents in the French Alps,through the study of rescue interventions data from 2008 to 2018.Thanks to the analysis of the exhaustive database of search and rescue interventions from the French mountain national police force,and while questioning its limitations,we strive to answer two questions:what are the characteristics of the hazardous situations leading to a rescue intervention in mountaineering?Among these situations,what are the characteristics that tend to make them more harmful?
文摘Editor's Notes: On May 8^(th),the Beijing Olympic torch relay team successfully reached the summit of Mt.Qomolangma. About 9:11a.m,at a spot 30 meters from the peak, Lozang Dradul ignited the first torch that had been named"Auspicious Clouds"and was held by the female Tibetan mountaineer Jiji.Then,the torch was relayed to Wang Yongfeng,Nyima Tsering,Huang Chungui。
文摘For all the benefits of c ty life-diverse culture, food and people-it is a major source of stress. Crowds and noise can be oppressive,and commuting can kill you(it’s more taxing than What a fighter pilot experiences in battle,according to American researchers).Is there any way to find relief? Two Beijingers think so:a research associate at the Chinese Academy of Social Sciences,and a South African working in PR and events management,reveal how they cope with urban pressures.
文摘I have cherished the dream of climbing mountains from a very early age. But I had to suppress my urge for mountain-eering as there are not that many mountains in Egypt. Though Sinai has some moun-tains, I didn't find them interesting as they have no greenery. So my dream never came true in Egypt.
基金supported by the National Natural Science Foundation of China(Nos.U2340209,and 42271126)the NIGLAS Foundation(No.NIGLAS2022GS03)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20220041)the US National Science Foundation Projects(Nos.1831096,1803697,and 2108917).
文摘The increased frequency and intensity of heavy rainfall events due to climate change could potentially influence the movement of nutrients from land-based regions into recipient rivers.However,little information is available on how the rainfall affect nutrient dynamics in subtropicalmontane rivers with complex land use.This study conducted high-frequency monitoring to study the effects of rainfall on nutrients dynamics in an agricultural river draining to Lake Qiandaohu,a montane reservoir of southeast China.The results showed that riverine total nitrogen(TN)and total phosphorus(TP)concentrations increased continuously with increasing rainfall intensity,while TN:TP decreased.The heavy rainfall and rainstorm drove more than 30%of the annual N and P loading in only 5.20%of the total rainfall period,indicating that increased storm runoff is likely to exacerbate eutrophication in montane reservoirs.NO_(3)^(−)-N is the primary nitrogen form lost,while particulate phosphorus(PP)dominated phosphorus loss.Themain source of N is cropland,and themain source of P is residential area.Spatially,forestedwatersheds have better drainage quality,while it is still a potential source of nonpoint pollution during rainfall events.TN and TP concentrations were significantly higher at sites dominated by cropland and residential area,indicating their substantial contributions to deteriorating river water quality.Temporally,TN and TP concentrations reached high values in May-August when rainfall was most intense,while they were lower in autumn and winter than that in spring and summer under the same rainfall intensities.The results emphasize the influence of rainfall-runoff and land use on dynamics of riverine N and P loads,providing guidance for nutrient load reduction planning for Lake Qiandaohu.
基金National Key Research and Development Program of China,No.2023YFE0208100,No.2021YFC3000201Natural Science Foundation of Henan Province,No.232300420165。
文摘The Qinba Mountains are climatically and ecologically recognized as the north-south transitional zone of China.Analysis of its phenology is critical for comprehending the response of vegetation to climatic change.We retrieved the start of spring phenology(SOS)of eight forest communities from the MODIS products and adopted it as an indicator for spring phenology.Trend analysis,partial correlation analysis,and GeoDetector were employed to reveal the spatio-temporal patterns and climatic drivers of SOS.The results indicated that the SOS presented an advance trend from 2001 to 2020,with a mean rate of−0.473 d yr^(−1).The SOS of most forests correlated negatively with air temperature(TEMP)and positively with precipitation(PRE),suggesting that rising TEMP and increasing PRE in spring would forward and delay SOS,respectively.The dominant factors influencing the sensitivity of SOS to climatic variables were altitude,forest type,and latitude,while the effects of slope and aspect were relatively minor.The response of SOS to climatic factors varied significantly in space and among forest communities,partly due to the influence of altitude,slope,and aspect.
基金supported by the National Natural Science Foundation of China(Grant No.42061035)the Guizhou Provincial Program on Commercialization of Scientific and Technological Achievements([2022]010)。
文摘The mountainous rural regions of China are undergoing enormous changes in space and time.To a certain extent,this change has increased the difficulties in our understanding of rural development in mountainous areas and brought challenges to development policies and revitalization strategies in mountainous rural regions,especially in karst mountainous areas.In light of the difficulty in and as the key to the development of China's mountainous rural areas,the scientific and systematic construction of indicators for evaluating the level of rural revitalization development and clarifying the level of rural revitalization development and influential factors in karst mountainous areas are of great significance to the implementation of the development of the strategy for the revitalization of the rural areas in karst mountainous areas in China.This study constructed an evaluation index system of the rural regional system and rural revitalization development(RTSRD)from the perspective of rural regional system theory,assessed the spatial differentiation patterns and influential factors of RTSRD,and refined a typical territorial model of rural revitalization development in karst mountainous areas by taking Guizhou Province,a typical karst mountainous region,as a case study area.The evaluation and spatial analyses show that the RTSRD indices of karst mountainous areas in the system perspective show a linear growth trend in all single dimensions,with industrial revitalization(IR)showing the most significant increase each year.In time,the RTSRD of karst mountainous regions has developed from low to high,with evident improvement;spatially,the RTSRD shows the characteristics of‘high in the middle and low in the surroundings,and low in the plateau and low in the depression,'with apparent spatial heterogeneity.In addition,this study found that the spatial and temporal differences in RTSRD result from a combination of endogenous push and exogenous pull in the rural system.In particular,this study has refined a typical regional model of rural revitalization development in karst mountainous regions,which provides theoretical support and case practice for rural development in other karst mountainous regions.At the same time,it provides a basis for decision-making for the county level government and rural development planning.
基金funded by the National Natural Science Foundation of China(Grant No.42325503)the Hubei Provincial Natural Science Foundation and the Meteorological Innovation and Development Project of China(Grant Nos.2023AFD096 and 2022CFD122)+1 种基金the Natural Science Foundation of Wuhan(Grant No.2024020901030454)the Beijige Foundation of NJIAS(Grant No.BJG202304)。
文摘Based on comprehensive observations of 20 wire icing events during winter from 2019 to 2021,we investigated the characteristics of the icing properties,the atmospheric boundary layer structure,the raindrop size distribution,and their associated effects on the ice accretion mechanism in the mountainous region of Southwest China.The maximum ice weight was positively correlated with the duration of ice accretion in the mountainous area.The duration of precipitation accounted for less than 20%of the icing period in the mountainous area,with solid-phase hydrometeors being predominant.Icing events,dominated by freezing rain(FR)and mixed rain–graupel(more than 70%),were characterized by glaze or highdensity mixed icing.The relationship between the melting energy and refreezing energy reflected the distribution characteristics of the proportion of FR under mixed-phase precipitation.The intensity of the warm layer and the dominant precipitation phase significantly affected the variations in the microphysical properties of FR.The melting of large dry snowflakes significantly contributed to FR in the mountainous areas,resulting in smaller generalized intercepts and larger mass-weighted mean diameters in the presence of a stronger warm layer.Under a weaker warm layer,the value of the massweighted mean diameter was significantly smaller because of the inability of large solid particles to melt.Finally,FR in the mountainous area dominated the ice weight during the rapid ice accumulation period.A numerical simulation of FR icing on wires effectively revealed the evolution of disaster-causing icing in mountainous areas.
基金supported by the National Natural Science Foundation of China (NSFC)Projects (Nos.42205105,42121004,and 42077190)the Science and Technology Project of Shaoguan (No.210811164532141)+3 种基金the National Key R&D Program of China (2022YFC3700604)the Science and Technology Program of Guangzhou City (No.202201010400)the Fundamental Research Funds for the Central Universities (No.21622319)the Research Center of Low Carbon Economy for Guangzhou Region (No.22JNZS50).
文摘Emission characteristics of biogenic volatile organic compounds(BVOCs)from dominant tree species in the subtropical pristine forests of China are extremely limited.Here we conducted in situ field measurements of BVOCs emissions from representative mature evergreen trees by using dynamic branch enclosures at four altitude gradients(600-1690ma.s.l.)in the Nanling Mountains of southern China.Composition characteristics as well as seasonal and altitudinal variations were analyzed.Standardized emission rates and canopyscale emission factors were then calculated.Results showed that BVOCs emission intensities in the wet season were generally higher than those in the dry season.Monoterpenes were the dominant BVOCs emitted from most broad-leaved trees,accounting for over 70%of the total.Schima superba,Yushania basihirsuta and Altingia chinensis had relatively high emission intensities and secondary pollutant formation potentials.The localized emission factors of isoprene were comparable to the defaults in the Model of Emissions of Gases and Aerosols fromNature(MEGAN),while emission factors of monoterpenes and sesquiterpenes were 2 to 58 times of those in the model.Our results can be used to update the current BVOCs emission inventory in MEGAN,thereby reducing the uncertainties of BVOCs emission estimations in forested regions of southern China.
基金This research was supported by the Fundamental Research Program of Shanxi Province(202203021212497,20210302123265)the Shanxi Normal University School Fund(Research Project on Major Issues of High-Quality Development in Shanxi Province,GZLFZ2327).
文摘The middle reaches of the Yellow River represent a critically ecologically sensitive and fragile area within the Yellow River Basin(YRB),holding significant scientific value for ecological security assessment and environmental management strategies.This study comprehensively evaluates the evolution of the eco-environment in the“Two Mountains,Seven Rivers,and One Basin”(TSO)area of Shanxi Province from 2000 to 2020 based on fraction vegetation cover(FVC)derived from the Normalized Difference Vegetation Index(NDVI),net primary productivity(NPP)calculated via the Carnegie–Ames–Stanford approach(CASA),and the remote sensing ecological index(RSEI).The results indicate a significant improvement in the TSO’s eco-environment from 2000 to 2020,with the RSEI values increased from 0.34 in 2000 to 0.41 in 2020(an increase of 17.76%).Both FVC and NPP demonstrated notable upward trends,with FVC increasing by 22.74%and NPP by 53.11%.Spatially,FVC rose by 21.84%,19.72%and 26.06%,respectively in the Two Mountains,Seven Rivers,and the YRB in Shanxi Province.Similarly,the NPPs increased by 51.60%,48.60%,and 61.65%in these regions over the past 21 years.Both FVC and NPP exhibited decreasing patterns from southeast to northwest,with significant eco-environmental improvements in the northern region and slower recovery in the southern region.Precipitation was the primary causes influencing vegetation recovery,showing positive trends in the central and northern TSO regions,while this trend reversed in the southern.The RSEI value indicate substantial eco-environment improvements in the central and northern areas(Sanggan,Daqing and Hutuo River Basins),whereas the southern regions(e.g.,Zhang,Qin,Fen and Sushui River Basins)remain in poor grade.Human activities,particularly land use/cover changes marked by increased forestation and urbanization alongside decreased cultivated land,significantly affected vegetation cover patterns.This study provides scientific references for formulating policies on ecological construction and high-quality development in the YRB.
文摘A new cranium and two mandibles of Ailuropoda melanoleuca from Xiangxi,Hunan Province are described here.The materials were discovered in a karst cave on the Bamian Mountain at an altitude of 1200 m,with AMC carbon-fourteen isotope dating indicating an age of 2800±30 BP.Historically,the giant panda was widely distributed in southern China and parts of Southeast Asia during the Pleistocene epoch,but it is now confined and isolated to six mountain ranges in southwest China’s Sichuan,Shaanxi,and Gansu provinces.The subfossil materials reported here represent the first discovery of the living species of giant panda in Xiangxi,Hunan.This extends their geographical distribution in southern China during the Holocene epoch eastward to the eastern edge of the Yunnan-Guizhou Plateau and their recent altitude range down to 1200 m.
文摘Prediction of water inflow into a tunnel is a crucial prerequisite for the waterproof and drainage design of mountain tunnels in water-rich areas.Based on the proposed Baiyun Mountain Tunnel project in Guangzhou,a numerical percolation model of random fractured rock of a tunnel underpassing a water reservoir is established to study the seepage characteristics of surrounding rock,the law of water inflow,and the change of lining water pressure,considering the local artificial boundary conditions for seepage in large rock mass,.In addition,the influences of rock permeability,fracture aperture,grouting circle thickness,and penetration are analyzed.The results show that:(1)Only fractures with aperture wider than 0.1 mm can play a significant role in water conduction in rocks with the permeability lower than 10^(-11)m^(2);(2)The greater the permeability difference between the fractures and rocks,the more remarkable the effects of fractures on the surrounding rock seepage field and cavern water inflow;(3)The sensitivity of grouting waterproof function to grouting circle thickness,grouting ring penetration,and rock permeability is significantly higher than that of tunnel buried depth and fracture aperture;(4)The lining water head is much more sensitive to the grouting circle thickness and penetration than to the tunnel buried depth;(5)With the grouting range enlarging,the impact of grouting circle permeability on the precipitation pressure role of the grouting ring increases;(6)For the interesting tunnel designed to be built at the depth of 70 m,the grouting circle with the thickness of 0.5 m and permeability of 10-^(14)m^(2)is recommended.
文摘Dear Xu Yan,How is everything going these days?I am writing to invite you to an outing I will organize on Sunday,May 10th.We will start at 6:30 in the morning at the school gate and then go to Yongfeng Mountain by bus.We will climb the mountain there in the morning and then have a picnic at 12 o’clock at noon.If you can come,you don’t need to bring food but it’s best for you to wear sports shoes and suitable clothes.
文摘Gongga Mountain National Nature Reserve Located in the Garze Tibetan Autonomous Prefecture of Sichuan Province,the Gongga Mountain National Nature Reserve is a landscape of breathtaking extremes and exceptional ecological value.Dominated by the towering Gongga Mountain-rising to 7,556 metres-it is the highest peak in both the Hengduan Mountains and Sichuan Province.
文摘NEW DWELLERS OF MOUNTAINS Neweekly 15 September A growing number of people are turning towards the mountains,venturing into valleys and forests to explore a life as“new mountain dwellers”–a fresh way of mountain living.Immersed in the poetic scenery,they rest,hike,boat,read,attend valley concerts,or admire paintings in poetry halls.Everything blends with and respects nature.
