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
Cropland abandonment has been a widespread phenomenon in mountainous areas due to the increasing number of natural disasters and the massive migration of rural labor in the process of rapid urbanization.Land transfer ...Cropland abandonment has been a widespread phenomenon in mountainous areas due to the increasing number of natural disasters and the massive migration of rural labor in the process of rapid urbanization.Land transfer is a crucial prerequisite for ensuring food security and fostering rural revitalization.How to promote land transfer in mountainous areas remains a challenging but important task.Nevertheless,there is a dearth of research examining land transfers among farm households that specifically address mountainous regions,and the influence of grassroots governance and geographic location has not been thoroughly elucidated within this particular context.Based on 895household samples collected in Dabie Mountainous Area in China,this study employs binary and ordinal logistic regression models to provide a more comprehensive analysis on land transfers among rural households and the determinants,including the decision to transfer land,the existence of land transfer rents,the channel of land transfer,the duration of the transfer,the pre-transfer cultivation situation,and the level of satisfaction with the land transfer rent.The findings reveal that grassroots governance,geographic location,livelihood capital,and demographic factors significantly influence land transfers among rural households.Specifically,villagers'public participation positively affects land transfer participation(β=0.235,p<0.05),while the operation of village rules and regulations negatively impacts it(β=-0.296,p<0.05).Village cadre satisfaction positively influences both land transfer rent(β=0.274,p<0.05)and rent satisfaction(β=0.303,p<0.05).Improved civil relations in the village correlate with lower land transfer rent(β=-0.511,p<0.05),while a better social atmosphere is associated with higher satisfaction with transfer rent(β=0.575,p<0.01).Households at higher elevations tend to prefer government-mediated land transfers with longer durations.The distances to the township and county centers have contrasting effects on land transfer rent,but their impacts on participation in land transfer,choice of transfer channel,and duration are consistent.The study also found that different types of livelihood capital,as well as the demographic characteristics of households,significantly affect various aspects of land transfer.These empirical findings can inform policymaking to promote more efficient land transfers in mountainous region.展开更多
This paper first analyzes the fundamental characteristics and the advantages and disadvantages in the development and utilization of land resources in China s mountainous areas. It then explores the five major strateg...This paper first analyzes the fundamental characteristics and the advantages and disadvantages in the development and utilization of land resources in China s mountainous areas. It then explores the five major strategic tasks facing the sustainable development and utilization of mountainous land resources in China. From the perspective of human-land coordination and sustainable development, the paper proposes countermeasures and recommendations for the sustainable development and utilization of land resources in China s mountainous areas.展开更多
Focusing on comprehensive land consolidation in mountainous areas, this paper explores the connotation of comprehensive land consolidation and its internal logic for promoting rural revitalization. Furthermore, it elu...Focusing on comprehensive land consolidation in mountainous areas, this paper explores the connotation of comprehensive land consolidation and its internal logic for promoting rural revitalization. Furthermore, it elucidates the effectiveness and experience of mountainous area comprehensive land consolidation in the rural revitalization process by using practical cases. The aim is to provide theoretical reference and practical guidance for leveraging the role of comprehensive land consolidation in mountainous areas for rural revitalization, thereby promoting the sustainable utilization of land resources and the coordinated development of the economy and society in mountainous regions.展开更多
According to the particularity of towns＇ construction in the southwestern mountainous areas of Yunnan Province, this study has built constructive land suit- ability evaluation index system which is different to flat ...According to the particularity of towns＇ construction in the southwestern mountainous areas of Yunnan Province, this study has built constructive land suit- ability evaluation index system which is different to flat area. Then this study deter- mined single evaluation factors index and comprehensive suitability index using ＂ex- treme conditions method＂ and ＂suitability index method＂, and analyzed and assessed the constructive land suitability on each evaluation unit polygons and its suitability level by using GIS software. Taking Lianghe County of Dehong Dai-Jingpo Au- tonomous Prefecture as an example to evaluate land suitability in Lianghe County＇s main towns around the gentle slope, the results show, in the evaluation area, the area of land suitable for construction and unsuitable for construction respectively ac- count 73.58% and 26.42%. And first-class, second and third-class of land suitable for construction should be composited at the ratio of about 11：49：40. The suitability evaluation index system and method developed in this paper is applicable for evalu- ating the construction land suitability in mountainous areas of southwest Yunnan Province, and will provide theoretical and technical support for land policy measures which strengthen the protection of farmland and promote the scientific development of urbanization in Yunnan Province and even similar mountainous areas of the whole China.展开更多
[Objective] The aim was to investigate ecological carrying capacity of Fangshan District in Beijing. [Method] Ecological footprint and carrying capacity of Fangshan District in 2007 and 2008 were analyzed with ecologi...[Objective] The aim was to investigate ecological carrying capacity of Fangshan District in Beijing. [Method] Ecological footprint and carrying capacity of Fangshan District in 2007 and 2008 were analyzed with ecological footprint model and the difference between ecological footprint and carrying capacity there was con- cluded. Furthermore, an assessment was made on relation between Fangshan de- velopment with local ecological carrying capacity to evaluate sustainable development of Fangshan District. [Result] Fangshan District is of lightly ecological deficit; ecologi- cal footprint per capita in 2007-2008 was deficit and tended to expand. Two meth- ods are available to reduce ecological ：deficit, including reduction of ecological foot- print and increase of carrying capacity. In general, supply and demand of carrying capacity in Fangshan are better, though with some problems. It is necessary to fur- ther develop related industries to final eliminate ecological deficit in order to achieve ecological conservation-orientation and sustainable development of Fangshan District. [Conclusion] The research provides theoretical references for overall evaluation on eco- logical carrying capacity of Fangshan District.展开更多
Valley economy is a new mode in mountainous area development that is defined by various characters of valley development, and is a distinguishing economical geographic pattern for mountainous area development. The spe...Valley economy is a new mode in mountainous area development that is defined by various characters of valley development, and is a distinguishing economical geographic pattern for mountainous area development. The special spatial coupling relations in the distribution of different mountainous elements in valleys are new subjects for the mountain development studies, and such studies are meaningful both for researches and practices. Based on the long term researches on mountainous area development and following a brief exploration into the connotations and the spatial organizing process of valley economy, the authors analyzed the present situations of the development of valley economy in Beijing＇s mountainous areas, studied the characteristics and the impacts of the spatial structural changes of the valley economy in Beijing＇s mountainous areas, and finally proposed a rational arrangement of the spatial structure of the valley economy in Beijing＇s mountainous areas. It is considered in this study that valley economy plays an important role in the development and functional transformation in Beijing＇s mountainous areas in the new epoch. Firstly, valley economy is not outlined by the administrative boundaries, and it connects most of the villages in the mountainous areas roughly along the major transportation lines. Therefore, valley economy can exert positive influence on the development in the mountainous areas, at least in the aspects such as the rearrangement of industrial structure in the mountainous areas and the coordinated development of rural and urban areas. In addition, it is found that the valley economy in Beijing＇s mountainous areas is evolved in a spatial organizing stage of secondary concentration, which is characterized by resource-saving, ecological protection and industrial optimization. Therefore, the development of valley economy will be helpful to the coordination between ecological protection and economic development in the mountainous areas, and will promote the integrated development of the mountainous areas. The developing mode of the valley economy in Beijing＇s mountainous areas will provide the basis for the decision-making in the transformation of the functional roles of Beijing＇s mountainous areas, and on the other hand, will present experiences for the studies in the mountainous areas outside of Beijing.展开更多
Based on introducing wild plant resources of vertical greening in Qin-ba Mountainous area, the application of vertical greening plants of Qin-ba Mountainous area in garden greening were analyzed, the measures of utili...Based on introducing wild plant resources of vertical greening in Qin-ba Mountainous area, the application of vertical greening plants of Qin-ba Mountainous area in garden greening were analyzed, the measures of utilization and development were suggested.展开更多
Damp-heat karst mountainous areas are unique areas in terms of socialeconomic development, resource endowment and eco-environment in China, where natural resources are abundant,unique and diverse. However, fragile eco...Damp-heat karst mountainous areas are unique areas in terms of socialeconomic development, resource endowment and eco-environment in China, where natural resources are abundant,unique and diverse. However, fragile eco-environment, undeveloped economy and culture, and conflict of human and environment should not be ignored. In the research, a framework of integration of resource-development and environment-protection in damp-heat karst was designed on basis of resource and environment integration, which was applied to Daxin County in Guangxi Province. Furthermore, some integration models were proposed, including integration of development of characteristic agricultural resources and protection of eco-environment, integration of development of manganese ore resources and protection of eco-environment, integration of development of tourism resources and protection of ecoenvironment and integration of development of clean energy and protection of eco-environment.展开更多
Abstract Based on Second National Land Survey during 2007-2009 and land use type survey in ftatland areas, status quo of land use in mountainous areas in Yun- nan was measured, and analysis was made on land use in mou...Abstract Based on Second National Land Survey during 2007-2009 and land use type survey in ftatland areas, status quo of land use in mountainous areas in Yun- nan was measured, and analysis was made on land use in mountainous areas in terms of land use structure, degree and development potential, providing references for rational use of land in mountainous areas in Yunnan.展开更多
Accompanying the development of social economy,the land use model of mountainous area,typically eco-weak area,is changing gradually. Here the establishment of eco-friendly land use model in mountainous area,will pione...Accompanying the development of social economy,the land use model of mountainous area,typically eco-weak area,is changing gradually. Here the establishment of eco-friendly land use model in mountainous area,will pioneer the model of sustainable development in that area. Concerning Qianjiang District of Chongqing Municipality,huge change of land use model,mainly embodied in the unceasing increase of construction land and gradual decrease of agricultural use land,has taken place in recent years. To explore the eco-friendly land use model in mountainous area,Qianjiang District was chosen as the study object in the present study. Via analyzing the changes in land use model,we found that related eco-environment restrictive factors mainly regional climatic change,soil texture,hydrological environment as well as soil erosion and land degradation,etc. And based on these results,we further analyzed the effect of land use change on eco-environment and the factors restricting the maintenance of eco-environment and regional development,finally put forward the counter measures for balancing land use and co-environment in mountainous area. The results will be important for the development of social economy and eco-system construction in Qianjiang District.展开更多
Based on SPOT-5 images, 1：1 million topographic maps, the maps of the returning farmland to forest project and the Chongqing forest project, social and economic statistics, etc., this paper identifies the features an...Based on SPOT-5 images, 1：1 million topographic maps, the maps of the returning farmland to forest project and the Chongqing forest project, social and economic statistics, etc., this paper identifies the features and factors influencing farmland marginalization. The results showed： （1） During 2002-2012, the rate of farmland marginalization was 16.18%, which was mainly found in the high areas of northern Qiyao mountains and the medium-altitude areas of southern Qiyao mountains. And this farmland marginalization will increase, associated with non-agriculturalization of rural labourers and aging of the remaining labourers. （2） Elevation, distance radius from villages and road connections had a great in- fluence on farmland marginalization. Farmland marginalization rates showed an increasing trend with the increase of elevation, and 60.88% of the total farmland marginalization area is found at an altitude greater than 1000 m above sea level. The marginalization trend also increases with slope and distance from the distribution network. （3） Farmland area per labourer and the average age of farm labourers were major factors driving farmland marginalization. Farmland transfer and small agricultural machinery sets affect farmland marginalization with respect to management and productivity efficiency. （4） Farmland with ＂comparative-disadvantage-dominated marginalization＂ accounted for 55.32% of the total farmland marginalization area, followed by ＂location-dominated marginalization＂ （33.80%）. （5） According to the specifics of each real situation, different policies are suggested to mitigate the margin- alization. A ＂continuous marginalization＂ policy will encourage the return of farmland to forest in ＂terrain-dominated marginalization＂. An ＂anti-marginalization＂ policy is suggested to create new rural accommodation and improve the rural road system to counteract ＂terrain-dominated marginalization＂. And another ＂anti-marginalization＂ policy is planned to improve management and micro-mechanization for ＂comparative-disadvantage-dominated marginalization＂. A new idea was developed to integrate high resolution remote sensing and statistical data with survey information to identify land marginalization and its driving forces in mountainous areas.展开更多
Geohazard recognition and inventory mapping are absolutely the keys to the establishment of reliable susceptibility and hazard maps. However, it has been challenging to implement geohazards recognition and inventory m...Geohazard recognition and inventory mapping are absolutely the keys to the establishment of reliable susceptibility and hazard maps. However, it has been challenging to implement geohazards recognition and inventory mapping in mountainous areas with complex topography and vegetation cover. Progress in the light detection and ranging(Li DAR) technology provides a new possibility for geohazard recognition in such areas. Specifically, this study aims to evaluate the performances of the Li DAR technology in recognizing geohazard in the mountainous areas of Southwest China through visually analyzing airborne Li DAR DEM derivatives. Quasi-3 D relief image maps are generated based on the sky-view factor(SVF), which makes it feasible to interpret precisely the features of geohazard. A total of 146 geohazards are remotely mapped in the entire 135 km^(2) study area in Danba County, Southwest China, and classified as landslide, rock fall, debris flow based on morphologic characteristics interpreted from SVF visualization maps. Field validation indicate the success rate of Li DAR-derived DEM in recognition and mapping geohazard with higher precision and accuracy. These mapped geohazards lie along both sides of the river, and their spatial distributions are related highly to human engineering activities, such as road excavation and slope cutting. The minimum geohazard that can be recognized in the 0.5 m resolution DEM is about 900 m^(2). Meanwhile, the SVF visualization method is demonstrated to be a great alternative to the classical hillshaded DEM method when it comes to the determination of geomorphological properties of geohazard. Results of this study highlight the importance of Li DAR data for creating complete and accurate geohazard inventories, which can then be used for the production of reliable susceptibility and hazard maps and thus contribute to a better understanding of the movement processes and reducing related losses.展开更多
Water resources in the arid land of Northwest China mainly derive from snow and glacier melt water in mountainous areas. So the study on onset, cessation, length, tempera- ture and precipitation of snowmelt period is ...Water resources in the arid land of Northwest China mainly derive from snow and glacier melt water in mountainous areas. So the study on onset, cessation, length, tempera- ture and precipitation of snowmelt period is of great significance for allocating limited water resources reasonably and taking scientific water resources management measures. Using daily mean temperature and precipitation from 8 mountainous weather stations over the pe- riod 1960-2010 in the arid land of Northwest China, this paper analyzes climate change of snowmelt period and its spatial variations and explores the sensitivity of runoff to length, temperature and precipitation of snowmelt period. The results show that mean onset of snowmelt period has shifted 15.33 days earlier while mean ending date has moved 9.19 days later. Onset of snowmelt period in southern Tianshan Mountains moved 20.01 days earlier while that in northern Qilian Mountains moved only 10.16 days earlier. Mean precipitation and air temperature increased by 47.3 mm and 0.857~C in the mountainous areas of Northwest China, respectively. The precipitation of snowmelt period increased the fastest, which is ob- served in southern Tianshan Mountains, up to 65 mm, and the precipitation and temperature in northern Kunlun Mountains increased the slowest, an increase of 25 mm and 0.617~C, respectively, while the temperature in northern Qilian Mountains increased the fastest, in- creasing by 1.05~C. The annual runoff is also sensitive to the variations of precipitation and temperature of snowmelt period, because variation of precipitation induces annual runoff change by 7.69% while change of snowmelt period temperature results in annual runoff change by 14.15%.展开更多
The karst mountainous area is an ecologically fragile region with prominent humanland contradictions.The resource-environment carrying capacity(RECC)of this region needs to be further clarified.The development of remo...The karst mountainous area is an ecologically fragile region with prominent humanland contradictions.The resource-environment carrying capacity(RECC)of this region needs to be further clarified.The development of remote sensing(RS)and geographic information system(GIS)provides data sources and processing platform for RECC monitoring.This study analyzed and established the evaluation index system of RECC by considering particularity in the karst mountainous area of Southwest China;processed multisource RS data(Sentinel-2,Aster-DEM and Landsat-8)to extract the spatial distributions of nine key indexes by GIS techniques(information classification,overlay analysis and raster calculation);proposed the methods of index integration and fuzzy comprehensive evaluation of the RECC by GIS;and took a typical area,Guangnan County in Yunnan Province of China,as an experimental area to explore the effectiveness of the indexes and methods.The results showed that:(1)The important indexes affecting the RECC of karst mountainous area are water resources,tourism resources,position resources,geographical environment and soil erosion environment.(2)Data on cultivated land,construction land,minerals,transportation,water conservancy,ecosystem services,topography,soil erosion and rocky desertification can be obtained from RS data.GIS techniques integrate the information into the RECC results.The data extraction and processing methods are feasible on evaluating RECC.(3)The RECC of Guangnan County was in the mid-carrying level in 2018.The midcarrying and low-carrying levels were the main types,accounting for more than 80.00%of the total study area.The areas with high carrying capacity were mainly distributed in the northern regions of the northwest-southeast line of the county,and other areas have a low carrying capacity comparatively.The coordination between regional resource-environment status and socioeconomic development is the key to improve RECC.This study explores the evaluation index system of RECC in karst mountainous area and the application of multisource RS data and GIS techniques in the comprehensive evaluation.The methods can be applied in related fields to provide suggestions for data/information extraction and integration,and sustainable development.展开更多
The Three Gorges Reservoir Area(TGRA)is typical of an ecologically vulnerable area,comprised of rural and mountainous areas,and with high immigration.Because of its economic and ecologic importance,studying the tradit...The Three Gorges Reservoir Area(TGRA)is typical of an ecologically vulnerable area,comprised of rural and mountainous areas,and with high immigration.Because of its economic and ecologic importance,studying the traditional agroecosystem changes in the TGRA is key to rural development and revitalization.In this study,we apply a framework of theoretical analysis,empirical study,and trend prediction to the Caotangxi River watershed within the TGRA.Using QuickBird high-resolution remote sensing images from 2012 to 2017 to evaluate natural resources and farmers’behavior,we analyze the transition and trends in the traditional agroecosystem in mountainous areas of the TGRA at spatial scale of the man-land relationship.We find that the agroecosystem in the TGRA can be divided into four modes using 100 m interval buffer rings:high-low-low,high-low-high,low-high-low and low-low-high mode where the different modes represent the agricultural development stages in the TGRA.Furthermore,the traditional agroecosystem in TGRA,represented by system elements such as farmers and sloping farmland,is transforming to accommodate the diversification of farmer livelihoods.For example,sloping farmland,which was dominated by a production function,now has equal emphasis on ecological and economic functions.Spatially,the range of the agroecosystem transition has migrated beyond high mountain areas to flat valley areas.Generally,this study provides an overview of land use in rural areas,controls on soil and water loss in mountainous areas,and better rural living environments in the TGRA.展开更多
The rocky desert in a karst area directly causes the lack of soil, water and forest, hence leading to the poverty there. In 1990, the villagers from the Muzhe Village in Benggu Township, Xichou County, Yunnan declared...The rocky desert in a karst area directly causes the lack of soil, water and forest, hence leading to the poverty there. In 1990, the villagers from the Muzhe Village in Benggu Township, Xichou County, Yunnan declared a war against rocky desert in an attempt to ask the fields for more yields. They invented a distinctive land rehabilitation and sustainable use pattern called “transforming heavenand earth” that had been practiced in Southwest China’s karst areas. The key mechanism of the pattern was to develop terraced fields with well conserved soil, water and fertility by exploding rocks in the fields, building stone walls, gathering more soil, and improving soil quality and productivity for the fields in combination with building of irrigation facilities and roads, as well as with forestation and agriculture structure adjustment. The purpose of the pattern was to alleviate poverty in the karst areas by improving soil productivity and promoting agriculturaldevelopment. A typical area was studied with the help of Participatory Rural Appraisal (PRA) and the pattern was carried out there for fifteen years, have produced excellent ecological benefits and good economic benefits. Its application in the area approved that it was a sustainable land use pattern for rocky desert areas.展开更多
Analyzing the agricultural landscape patterns in mountainous areas is critical to clarify the dynamic changes and development direction of agricultural landscapes.This also plays a significant role in the rational pla...Analyzing the agricultural landscape patterns in mountainous areas is critical to clarify the dynamic changes and development direction of agricultural landscapes.This also plays a significant role in the rational planning and management of agricultural land.A theoretical framework for agricultural landscape pattern transitions in mountainous areas is proposed to fill the gap of current research with an empirical study in the Caotangxi Watershed,Three Gorges Reservoir Area(TGRA),China.The transition characteristics of agricultural landscape patterns from 2000 to 2018 as represented by sloping farmland,abandoned land,and orchards are analyzed from a holistic-local perspective.The results indicate that the orchards expanded along river valleys,and abandoned land expanded at high elevations,which led to reduced sloping farmland.This phenomenon gives regional landscape differences at the holistic and local levels.Namely,it enhances the region’s holistic landscape diversity but causes fragmentation and aggregation of landscape patches in local areas.The agricultural landscape pattern transitions within the farming range in the study area are manifested primarily in four modes:sloping farmland-orchard conversion type(FOCT),comprehensive conversion type(CCT),partially abandoned type(PAT),and wholly abandoned type(WAT).Each transition mode reveals different development stages of the mountainous agricultural landscape patterns.In general,the agricultural landscape pattern transition is driven by socioeconomic factors in mountainous areas of the TGRA and is bidirectional.This attribute is expressed as the transition from the traditional grain-planting landscape with an even distribution to the eco-economic win-win orchard in valleys and transitions from sloping farmland to abandoned land in high-elevation areas.Overall,the results of this study reveal the uniqueness of agricultural landscape pattern evolutions in China’s mountainous areas in recent decades,which has enlightened the in-depth understandings of rural land use and agricultural ecosystems in mountainous areas of the TGRA,as well as improvements in rural developments and ecological environments.展开更多
Leveraging the commercial CFD software FLUENT,the fine-scale three-dimensional wind structure over the Paiya Mountains on the Dapeng Peninsula near Shenzhen,a city on the seashore of South China Sea,during the landfal...Leveraging the commercial CFD software FLUENT,the fine-scale three-dimensional wind structure over the Paiya Mountains on the Dapeng Peninsula near Shenzhen,a city on the seashore of South China Sea,during the landfall of Typhoon Molave has been simulated and analyzed.Through the study,a conceptual wind structure model for mountainous areas under strong wind condition is established and the following conclusions are obtained as follows:(1)FLUENT can reasonably simulate a three-dimensional wind structure over mountainous areas under strong wind conditions;(2)the kinetic effect of a mountain can intensify wind speed in the windward side of the mountain and the area over the mountain peak;and(3)in the leeward side of the mountain,wind speed is relatively lower with relatively stronger wind shear and turbulence.展开更多
Located in the western hinterland,Southwest China is a typical mountainous area covered by plateaus,mountains and hills.Its ruggedness hinders regional internal and external connections,and its poor transportation inf...Located in the western hinterland,Southwest China is a typical mountainous area covered by plateaus,mountains and hills.Its ruggedness hinders regional internal and external connections,and its poor transportation infrastructure has long constrained the socioeconomic development of Southwest China.Based on the GIS transportation database,this paper explored the spatiotemporal evolution and characteristics of the land transportation networks and the accessibility of Southwest China from 1917 to 2017.Regional accessibility in Southwest China has significantly improved,and transportation infrastructure has gradually integrated the transportation circles of the52 central cities.The transportation network has followed an evolutionary process from a"hub-spoke pattern"to a"network pattern",while the construction of a high-speed railway(HSR)has brought about significant spatial polarization.We argue that innovation in transportation technology is one of the most effective factors for promoting a significant change in regional accessibility.In addition,the spatial distribution and evolution of accessibility in Southwest China presents a verticalcharacteristic that distinguishes it from the plains,as the spillover effects of new transportation infrastructure on accessibility improvement are partly offset by the mountainous terrain.Additionally,in Southwest China,there is significant"path dependence"in the evolution of the transportation network,since a large portion of the population is concentrated along transportation corridors in mountainous areas.展开更多
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(Grant Nos.42371315,41901213)the Humanities and Social Sciences General Research Program of the Ministry of Education(Grant No.23YJC790141)。
文摘Cropland abandonment has been a widespread phenomenon in mountainous areas due to the increasing number of natural disasters and the massive migration of rural labor in the process of rapid urbanization.Land transfer is a crucial prerequisite for ensuring food security and fostering rural revitalization.How to promote land transfer in mountainous areas remains a challenging but important task.Nevertheless,there is a dearth of research examining land transfers among farm households that specifically address mountainous regions,and the influence of grassroots governance and geographic location has not been thoroughly elucidated within this particular context.Based on 895household samples collected in Dabie Mountainous Area in China,this study employs binary and ordinal logistic regression models to provide a more comprehensive analysis on land transfers among rural households and the determinants,including the decision to transfer land,the existence of land transfer rents,the channel of land transfer,the duration of the transfer,the pre-transfer cultivation situation,and the level of satisfaction with the land transfer rent.The findings reveal that grassroots governance,geographic location,livelihood capital,and demographic factors significantly influence land transfers among rural households.Specifically,villagers'public participation positively affects land transfer participation(β=0.235,p<0.05),while the operation of village rules and regulations negatively impacts it(β=-0.296,p<0.05).Village cadre satisfaction positively influences both land transfer rent(β=0.274,p<0.05)and rent satisfaction(β=0.303,p<0.05).Improved civil relations in the village correlate with lower land transfer rent(β=-0.511,p<0.05),while a better social atmosphere is associated with higher satisfaction with transfer rent(β=0.575,p<0.01).Households at higher elevations tend to prefer government-mediated land transfers with longer durations.The distances to the township and county centers have contrasting effects on land transfer rent,but their impacts on participation in land transfer,choice of transfer channel,and duration are consistent.The study also found that different types of livelihood capital,as well as the demographic characteristics of households,significantly affect various aspects of land transfer.These empirical findings can inform policymaking to promote more efficient land transfers in mountainous region.
文摘This paper first analyzes the fundamental characteristics and the advantages and disadvantages in the development and utilization of land resources in China s mountainous areas. It then explores the five major strategic tasks facing the sustainable development and utilization of mountainous land resources in China. From the perspective of human-land coordination and sustainable development, the paper proposes countermeasures and recommendations for the sustainable development and utilization of land resources in China s mountainous areas.
文摘Focusing on comprehensive land consolidation in mountainous areas, this paper explores the connotation of comprehensive land consolidation and its internal logic for promoting rural revitalization. Furthermore, it elucidates the effectiveness and experience of mountainous area comprehensive land consolidation in the rural revitalization process by using practical cases. The aim is to provide theoretical reference and practical guidance for leveraging the role of comprehensive land consolidation in mountainous areas for rural revitalization, thereby promoting the sustainable utilization of land resources and the coordinated development of the economy and society in mountainous regions.
基金Supported by National Natural Science Foundation of China(41261018)Lianghe Government Authorized Project~~
文摘According to the particularity of towns＇ construction in the southwestern mountainous areas of Yunnan Province, this study has built constructive land suit- ability evaluation index system which is different to flat area. Then this study deter- mined single evaluation factors index and comprehensive suitability index using ＂ex- treme conditions method＂ and ＂suitability index method＂, and analyzed and assessed the constructive land suitability on each evaluation unit polygons and its suitability level by using GIS software. Taking Lianghe County of Dehong Dai-Jingpo Au- tonomous Prefecture as an example to evaluate land suitability in Lianghe County＇s main towns around the gentle slope, the results show, in the evaluation area, the area of land suitable for construction and unsuitable for construction respectively ac- count 73.58% and 26.42%. And first-class, second and third-class of land suitable for construction should be composited at the ratio of about 11：49：40. The suitability evaluation index system and method developed in this paper is applicable for evalu- ating the construction land suitability in mountainous areas of southwest Yunnan Province, and will provide theoretical and technical support for land policy measures which strengthen the protection of farmland and promote the scientific development of urbanization in Yunnan Province and even similar mountainous areas of the whole China.
文摘[Objective] The aim was to investigate ecological carrying capacity of Fangshan District in Beijing. [Method] Ecological footprint and carrying capacity of Fangshan District in 2007 and 2008 were analyzed with ecological footprint model and the difference between ecological footprint and carrying capacity there was con- cluded. Furthermore, an assessment was made on relation between Fangshan de- velopment with local ecological carrying capacity to evaluate sustainable development of Fangshan District. [Result] Fangshan District is of lightly ecological deficit; ecologi- cal footprint per capita in 2007-2008 was deficit and tended to expand. Two meth- ods are available to reduce ecological ：deficit, including reduction of ecological foot- print and increase of carrying capacity. In general, supply and demand of carrying capacity in Fangshan are better, though with some problems. It is necessary to fur- ther develop related industries to final eliminate ecological deficit in order to achieve ecological conservation-orientation and sustainable development of Fangshan District. [Conclusion] The research provides theoretical references for overall evaluation on eco- logical carrying capacity of Fangshan District.
基金National Natural Science Foundation of China, No.40635029
文摘Valley economy is a new mode in mountainous area development that is defined by various characters of valley development, and is a distinguishing economical geographic pattern for mountainous area development. The special spatial coupling relations in the distribution of different mountainous elements in valleys are new subjects for the mountain development studies, and such studies are meaningful both for researches and practices. Based on the long term researches on mountainous area development and following a brief exploration into the connotations and the spatial organizing process of valley economy, the authors analyzed the present situations of the development of valley economy in Beijing＇s mountainous areas, studied the characteristics and the impacts of the spatial structural changes of the valley economy in Beijing＇s mountainous areas, and finally proposed a rational arrangement of the spatial structure of the valley economy in Beijing＇s mountainous areas. It is considered in this study that valley economy plays an important role in the development and functional transformation in Beijing＇s mountainous areas in the new epoch. Firstly, valley economy is not outlined by the administrative boundaries, and it connects most of the villages in the mountainous areas roughly along the major transportation lines. Therefore, valley economy can exert positive influence on the development in the mountainous areas, at least in the aspects such as the rearrangement of industrial structure in the mountainous areas and the coordinated development of rural and urban areas. In addition, it is found that the valley economy in Beijing＇s mountainous areas is evolved in a spatial organizing stage of secondary concentration, which is characterized by resource-saving, ecological protection and industrial optimization. Therefore, the development of valley economy will be helpful to the coordination between ecological protection and economic development in the mountainous areas, and will promote the integrated development of the mountainous areas. The developing mode of the valley economy in Beijing＇s mountainous areas will provide the basis for the decision-making in the transformation of the functional roles of Beijing＇s mountainous areas, and on the other hand, will present experiences for the studies in the mountainous areas outside of Beijing.
基金Supported by Technology Item of Ankang City(09AK06-02)~~
文摘Based on introducing wild plant resources of vertical greening in Qin-ba Mountainous area, the application of vertical greening plants of Qin-ba Mountainous area in garden greening were analyzed, the measures of utilization and development were suggested.
基金Supported by National Natural Science Foundation of China(40961004,40761027)Guangxi Natural Science Foundation(2011jjA50016)+1 种基金Guangxi Philosophy and Social Science Research Project of 11th Five-Year Plan(06FJY023)Key Laboratory Funds of Ministry of Education(B3G1110)~~
文摘Damp-heat karst mountainous areas are unique areas in terms of socialeconomic development, resource endowment and eco-environment in China, where natural resources are abundant,unique and diverse. However, fragile eco-environment, undeveloped economy and culture, and conflict of human and environment should not be ignored. In the research, a framework of integration of resource-development and environment-protection in damp-heat karst was designed on basis of resource and environment integration, which was applied to Daxin County in Guangxi Province. Furthermore, some integration models were proposed, including integration of development of characteristic agricultural resources and protection of eco-environment, integration of development of manganese ore resources and protection of eco-environment, integration of development of tourism resources and protection of ecoenvironment and integration of development of clean energy and protection of eco-environment.
基金Supported by National Natural Science Foundation of China(41261018)~~
文摘Abstract Based on Second National Land Survey during 2007-2009 and land use type survey in ftatland areas, status quo of land use in mountainous areas in Yun- nan was measured, and analysis was made on land use in mountainous areas in terms of land use structure, degree and development potential, providing references for rational use of land in mountainous areas in Yunnan.
文摘Accompanying the development of social economy,the land use model of mountainous area,typically eco-weak area,is changing gradually. Here the establishment of eco-friendly land use model in mountainous area,will pioneer the model of sustainable development in that area. Concerning Qianjiang District of Chongqing Municipality,huge change of land use model,mainly embodied in the unceasing increase of construction land and gradual decrease of agricultural use land,has taken place in recent years. To explore the eco-friendly land use model in mountainous area,Qianjiang District was chosen as the study object in the present study. Via analyzing the changes in land use model,we found that related eco-environment restrictive factors mainly regional climatic change,soil texture,hydrological environment as well as soil erosion and land degradation,etc. And based on these results,we further analyzed the effect of land use change on eco-environment and the factors restricting the maintenance of eco-environment and regional development,finally put forward the counter measures for balancing land use and co-environment in mountainous area. The results will be important for the development of social economy and eco-system construction in Qianjiang District.
基金The NSFC-IIASA Major International Joint Research Project, No.41161140352 Natural Science Foundation of Chongqing, No.2010JJ0069 Science and Technology Great Special Project on Controlling and Fathering Water Pollution during the National 12th Five-year Plan, No.2012ZX07104-003
文摘Based on SPOT-5 images, 1：1 million topographic maps, the maps of the returning farmland to forest project and the Chongqing forest project, social and economic statistics, etc., this paper identifies the features and factors influencing farmland marginalization. The results showed： （1） During 2002-2012, the rate of farmland marginalization was 16.18%, which was mainly found in the high areas of northern Qiyao mountains and the medium-altitude areas of southern Qiyao mountains. And this farmland marginalization will increase, associated with non-agriculturalization of rural labourers and aging of the remaining labourers. （2） Elevation, distance radius from villages and road connections had a great in- fluence on farmland marginalization. Farmland marginalization rates showed an increasing trend with the increase of elevation, and 60.88% of the total farmland marginalization area is found at an altitude greater than 1000 m above sea level. The marginalization trend also increases with slope and distance from the distribution network. （3） Farmland area per labourer and the average age of farm labourers were major factors driving farmland marginalization. Farmland transfer and small agricultural machinery sets affect farmland marginalization with respect to management and productivity efficiency. （4） Farmland with ＂comparative-disadvantage-dominated marginalization＂ accounted for 55.32% of the total farmland marginalization area, followed by ＂location-dominated marginalization＂ （33.80%）. （5） According to the specifics of each real situation, different policies are suggested to mitigate the margin- alization. A ＂continuous marginalization＂ policy will encourage the return of farmland to forest in ＂terrain-dominated marginalization＂. An ＂anti-marginalization＂ policy is suggested to create new rural accommodation and improve the rural road system to counteract ＂terrain-dominated marginalization＂. And another ＂anti-marginalization＂ policy is planned to improve management and micro-mechanization for ＂comparative-disadvantage-dominated marginalization＂. A new idea was developed to integrate high resolution remote sensing and statistical data with survey information to identify land marginalization and its driving forces in mountainous areas.
基金The research was supported by the National Innovation Research Group Science Fund(No.41521002)the National Key Research and Development Program of China(No.2018YFC1505202)。
文摘Geohazard recognition and inventory mapping are absolutely the keys to the establishment of reliable susceptibility and hazard maps. However, it has been challenging to implement geohazards recognition and inventory mapping in mountainous areas with complex topography and vegetation cover. Progress in the light detection and ranging(Li DAR) technology provides a new possibility for geohazard recognition in such areas. Specifically, this study aims to evaluate the performances of the Li DAR technology in recognizing geohazard in the mountainous areas of Southwest China through visually analyzing airborne Li DAR DEM derivatives. Quasi-3 D relief image maps are generated based on the sky-view factor(SVF), which makes it feasible to interpret precisely the features of geohazard. A total of 146 geohazards are remotely mapped in the entire 135 km^(2) study area in Danba County, Southwest China, and classified as landslide, rock fall, debris flow based on morphologic characteristics interpreted from SVF visualization maps. Field validation indicate the success rate of Li DAR-derived DEM in recognition and mapping geohazard with higher precision and accuracy. These mapped geohazards lie along both sides of the river, and their spatial distributions are related highly to human engineering activities, such as road excavation and slope cutting. The minimum geohazard that can be recognized in the 0.5 m resolution DEM is about 900 m^(2). Meanwhile, the SVF visualization method is demonstrated to be a great alternative to the classical hillshaded DEM method when it comes to the determination of geomorphological properties of geohazard. Results of this study highlight the importance of Li DAR data for creating complete and accurate geohazard inventories, which can then be used for the production of reliable susceptibility and hazard maps and thus contribute to a better understanding of the movement processes and reducing related losses.
基金National Basic Research Program of China (973 Program), No.2010CB951003National Natural Science Foundation of China, No.40901105Knowledge Innovation Program of the CAS, No.KZCX2-YW-Q10-3-4
文摘Water resources in the arid land of Northwest China mainly derive from snow and glacier melt water in mountainous areas. So the study on onset, cessation, length, tempera- ture and precipitation of snowmelt period is of great significance for allocating limited water resources reasonably and taking scientific water resources management measures. Using daily mean temperature and precipitation from 8 mountainous weather stations over the pe- riod 1960-2010 in the arid land of Northwest China, this paper analyzes climate change of snowmelt period and its spatial variations and explores the sensitivity of runoff to length, temperature and precipitation of snowmelt period. The results show that mean onset of snowmelt period has shifted 15.33 days earlier while mean ending date has moved 9.19 days later. Onset of snowmelt period in southern Tianshan Mountains moved 20.01 days earlier while that in northern Qilian Mountains moved only 10.16 days earlier. Mean precipitation and air temperature increased by 47.3 mm and 0.857~C in the mountainous areas of Northwest China, respectively. The precipitation of snowmelt period increased the fastest, which is ob- served in southern Tianshan Mountains, up to 65 mm, and the precipitation and temperature in northern Kunlun Mountains increased the slowest, an increase of 25 mm and 0.617~C, respectively, while the temperature in northern Qilian Mountains increased the fastest, in- creasing by 1.05~C. The annual runoff is also sensitive to the variations of precipitation and temperature of snowmelt period, because variation of precipitation induces annual runoff change by 7.69% while change of snowmelt period temperature results in annual runoff change by 14.15%.
基金the support given by the government and official in Guangnan Countyfunded by[National Natural Science Foundation of China]grant number[41361020,40961031]+3 种基金[Joint Fund of Yunnan Provincial Science and Technology Department and Yunnan University]grant number[2018FY001(-017)][Project of Innovative Talents Cultivation for Graduate Students of Yunnan University]grant number[C176230200][Project of Internationalization and Cultural Inheritance and Innovation of Yunnan University]grant number[C176250202][Science Research Fund of Yunnan Provincial Education Department in 2020:Postgraduate]grant number[2020Y0030]。
文摘The karst mountainous area is an ecologically fragile region with prominent humanland contradictions.The resource-environment carrying capacity(RECC)of this region needs to be further clarified.The development of remote sensing(RS)and geographic information system(GIS)provides data sources and processing platform for RECC monitoring.This study analyzed and established the evaluation index system of RECC by considering particularity in the karst mountainous area of Southwest China;processed multisource RS data(Sentinel-2,Aster-DEM and Landsat-8)to extract the spatial distributions of nine key indexes by GIS techniques(information classification,overlay analysis and raster calculation);proposed the methods of index integration and fuzzy comprehensive evaluation of the RECC by GIS;and took a typical area,Guangnan County in Yunnan Province of China,as an experimental area to explore the effectiveness of the indexes and methods.The results showed that:(1)The important indexes affecting the RECC of karst mountainous area are water resources,tourism resources,position resources,geographical environment and soil erosion environment.(2)Data on cultivated land,construction land,minerals,transportation,water conservancy,ecosystem services,topography,soil erosion and rocky desertification can be obtained from RS data.GIS techniques integrate the information into the RECC results.The data extraction and processing methods are feasible on evaluating RECC.(3)The RECC of Guangnan County was in the mid-carrying level in 2018.The midcarrying and low-carrying levels were the main types,accounting for more than 80.00%of the total study area.The areas with high carrying capacity were mainly distributed in the northern regions of the northwest-southeast line of the county,and other areas have a low carrying capacity comparatively.The coordination between regional resource-environment status and socioeconomic development is the key to improve RECC.This study explores the evaluation index system of RECC in karst mountainous area and the application of multisource RS data and GIS techniques in the comprehensive evaluation.The methods can be applied in related fields to provide suggestions for data/information extraction and integration,and sustainable development.
基金Key Basic Science and Cutting Edge Technology Research Plan of Chongqing,No.cstc2015jcyjB0439Chongqing University Innovation Team for 2016,No.CXTDX201601017+1 种基金National Natural Science Foundation of China,No.41661020Chongqing Research Program of Basic Research and Frontier Technology,No.cstc2018jcyjAX0539。
文摘The Three Gorges Reservoir Area(TGRA)is typical of an ecologically vulnerable area,comprised of rural and mountainous areas,and with high immigration.Because of its economic and ecologic importance,studying the traditional agroecosystem changes in the TGRA is key to rural development and revitalization.In this study,we apply a framework of theoretical analysis,empirical study,and trend prediction to the Caotangxi River watershed within the TGRA.Using QuickBird high-resolution remote sensing images from 2012 to 2017 to evaluate natural resources and farmers’behavior,we analyze the transition and trends in the traditional agroecosystem in mountainous areas of the TGRA at spatial scale of the man-land relationship.We find that the agroecosystem in the TGRA can be divided into four modes using 100 m interval buffer rings:high-low-low,high-low-high,low-high-low and low-low-high mode where the different modes represent the agricultural development stages in the TGRA.Furthermore,the traditional agroecosystem in TGRA,represented by system elements such as farmers and sloping farmland,is transforming to accommodate the diversification of farmer livelihoods.For example,sloping farmland,which was dominated by a production function,now has equal emphasis on ecological and economic functions.Spatially,the range of the agroecosystem transition has migrated beyond high mountain areas to flat valley areas.Generally,this study provides an overview of land use in rural areas,controls on soil and water loss in mountainous areas,and better rural living environments in the TGRA.
文摘The rocky desert in a karst area directly causes the lack of soil, water and forest, hence leading to the poverty there. In 1990, the villagers from the Muzhe Village in Benggu Township, Xichou County, Yunnan declared a war against rocky desert in an attempt to ask the fields for more yields. They invented a distinctive land rehabilitation and sustainable use pattern called “transforming heavenand earth” that had been practiced in Southwest China’s karst areas. The key mechanism of the pattern was to develop terraced fields with well conserved soil, water and fertility by exploding rocks in the fields, building stone walls, gathering more soil, and improving soil quality and productivity for the fields in combination with building of irrigation facilities and roads, as well as with forestation and agriculture structure adjustment. The purpose of the pattern was to alleviate poverty in the karst areas by improving soil productivity and promoting agriculturaldevelopment. A typical area was studied with the help of Participatory Rural Appraisal (PRA) and the pattern was carried out there for fifteen years, have produced excellent ecological benefits and good economic benefits. Its application in the area approved that it was a sustainable land use pattern for rocky desert areas.
基金National Natural Science Foundation of China,No.41661020Chongqing Basic and Frontier Research Innovation Project,No.cstc2018jcyjAX0539,No.cstc2017jcyjB0317+1 种基金Chongqing Normal University Graduate Student Research Innovation Project,No.YKC20049,No.YKC20030Academician Expert Workstation Academician Guided Science and Technology Innovation Special Project,No.CXTDX201601017。
文摘Analyzing the agricultural landscape patterns in mountainous areas is critical to clarify the dynamic changes and development direction of agricultural landscapes.This also plays a significant role in the rational planning and management of agricultural land.A theoretical framework for agricultural landscape pattern transitions in mountainous areas is proposed to fill the gap of current research with an empirical study in the Caotangxi Watershed,Three Gorges Reservoir Area(TGRA),China.The transition characteristics of agricultural landscape patterns from 2000 to 2018 as represented by sloping farmland,abandoned land,and orchards are analyzed from a holistic-local perspective.The results indicate that the orchards expanded along river valleys,and abandoned land expanded at high elevations,which led to reduced sloping farmland.This phenomenon gives regional landscape differences at the holistic and local levels.Namely,it enhances the region’s holistic landscape diversity but causes fragmentation and aggregation of landscape patches in local areas.The agricultural landscape pattern transitions within the farming range in the study area are manifested primarily in four modes:sloping farmland-orchard conversion type(FOCT),comprehensive conversion type(CCT),partially abandoned type(PAT),and wholly abandoned type(WAT).Each transition mode reveals different development stages of the mountainous agricultural landscape patterns.In general,the agricultural landscape pattern transition is driven by socioeconomic factors in mountainous areas of the TGRA and is bidirectional.This attribute is expressed as the transition from the traditional grain-planting landscape with an even distribution to the eco-economic win-win orchard in valleys and transitions from sloping farmland to abandoned land in high-elevation areas.Overall,the results of this study reveal the uniqueness of agricultural landscape pattern evolutions in China’s mountainous areas in recent decades,which has enlightened the in-depth understandings of rural land use and agricultural ecosystems in mountainous areas of the TGRA,as well as improvements in rural developments and ecological environments.
基金National Natural Science Foundation of China(91215302,51278308)Open Project for State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry,Institute of Atmospheric Physics(LAPC)
文摘Leveraging the commercial CFD software FLUENT,the fine-scale three-dimensional wind structure over the Paiya Mountains on the Dapeng Peninsula near Shenzhen,a city on the seashore of South China Sea,during the landfall of Typhoon Molave has been simulated and analyzed.Through the study,a conceptual wind structure model for mountainous areas under strong wind condition is established and the following conclusions are obtained as follows:(1)FLUENT can reasonably simulate a three-dimensional wind structure over mountainous areas under strong wind conditions;(2)the kinetic effect of a mountain can intensify wind speed in the windward side of the mountain and the area over the mountain peak;and(3)in the leeward side of the mountain,wind speed is relatively lower with relatively stronger wind shear and turbulence.
基金supported by the National Natural Science Foundation of China(Grants No.41671159)Fundamental Research Funds for the Central Universities for funding(Grants No.XDJK2018B011)Major Projects on Philosophy and Social Sciences of Chongqing Education Commission(Grants No.19SKZDZX08)。
文摘Located in the western hinterland,Southwest China is a typical mountainous area covered by plateaus,mountains and hills.Its ruggedness hinders regional internal and external connections,and its poor transportation infrastructure has long constrained the socioeconomic development of Southwest China.Based on the GIS transportation database,this paper explored the spatiotemporal evolution and characteristics of the land transportation networks and the accessibility of Southwest China from 1917 to 2017.Regional accessibility in Southwest China has significantly improved,and transportation infrastructure has gradually integrated the transportation circles of the52 central cities.The transportation network has followed an evolutionary process from a"hub-spoke pattern"to a"network pattern",while the construction of a high-speed railway(HSR)has brought about significant spatial polarization.We argue that innovation in transportation technology is one of the most effective factors for promoting a significant change in regional accessibility.In addition,the spatial distribution and evolution of accessibility in Southwest China presents a verticalcharacteristic that distinguishes it from the plains,as the spillover effects of new transportation infrastructure on accessibility improvement are partly offset by the mountainous terrain.Additionally,in Southwest China,there is significant"path dependence"in the evolution of the transportation network,since a large portion of the population is concentrated along transportation corridors in mountainous areas.
