China is a mountainous country with a great diversity of landform and geomorphology.This diversity underlines the need for regionalization and classification.This study defines the mountain terrains and regions with t...China is a mountainous country with a great diversity of landform and geomorphology.This diversity underlines the need for regionalization and classification.This study defines the mountain terrains and regions with three criteria-elevation,relative height,and slope,and examines the extent of mountainous regions by using county as the basic administrative unit.According to the three parameters of economic base,resident income and development potential,we classified the economic development level in mountainous regions of China.The findings reveal that the extent of the mountainous region accounts for 74.9% of the China's Mainland's total area.The economic development of mountainous regions in China is classified into 4 main types and 23 subtypes.展开更多
Labor migration to urban centers is a common phenomenon in the Panxi region of the southwestern mountainous region of China, mainly owing to inadequate livelihood capital in rural areas. Numerous studies have been con...Labor migration to urban centers is a common phenomenon in the Panxi region of the southwestern mountainous region of China, mainly owing to inadequate livelihood capital in rural areas. Numerous studies have been conducted to explore the relationship between labor migration and its causes, such as individual and family characteristics, but few studies have focused on livelihood capital. This paper examines the impact factors on labor migration employment location selection and duration from a household livelihood capital perspective. A case study of 279 households from 10 villages in the area was carried out in February 2016. We used both qualitative and quantitative methods to analyze the data. On the basis of the 279 questionnaires, the proportion of households with non-labor migration is 48.4%, whereas households with labor migration within a local city and migration across regions account for 28.7% and 22.9%, respectively. Social, financial, and human capitals are the primary factors that influence migrants' employment location choice positively. Among them, social capital has a significant impact on both migration within a local city and across regions; each of the regression coefficients is 1.111 and 1.183. Social, human, and financial capitals also have a positive impact on the duration of labor migration, and similarly, social capital is the highest coefficient with 2.489. However, physical capital only partly impacts labor migration across regions, whereas the impact of labor migration within a local city, and the duration, are not significant. Furthermore, the impact of household natural capital on migration space and time are all negative relationships, especially for labor migration across the regions and duration, with coefficient scores of 4.836 and 3.450, respectively. That is to say, a laborer is inclined to migrate within a local city for a short term, or not migrate at all, if natural capital is abundant. Our analysis results show that household livelihood capital has a strong spatio-temporal impact on labor migration.展开更多
The gradation of cultivated land is to assess the suitability of cultivated land for agricultural production in terms of natural and economic properties of land. It can be used to evaluate sustainability of land use a...The gradation of cultivated land is to assess the suitability of cultivated land for agricultural production in terms of natural and economic properties of land. It can be used to evaluate sustainability of land use and soil management practices. Formal and informal surveys, Delphi and comprehensive index method are adopted to identify appropriate integrated indicators, and measure the gradation of cultivated land quality. The determination of integrated indicators presents three basic features of cultivated land quality: stable plant productivity, social acceptability and maintenance of environmental quality. Pronounced concentration-dissipation law of total function score value occurs in paddy field units, with three ranges, i.e., 79-68.5, 68.5-59 and 59-51. Total function score value in dryland units mainly ranges from 40 to 70, but slight concentration-dissipation law of each unit is still observed, with four ranges, i.e., 79-68, 68-51, 51-37 and 37-15. Paddy field quality is divided into three gradations, and the scales are 18 220.9 ha, 5410.6 ha and 2890.9 ha. Dryland quality is classified into four gradations, and the scales are 1548.6 ha, 8153.8 ha, 3316.3 ha and 685.2 ha. The total function score value of every gradation unit is conformed to the results of farmers' assessment. Research results meet with the needs of accurate degree of the gradation of cultivated land quality. Integrated indicators-based gradation of cultivated land assessment accords with the characteristics of land resources and human preference in the mountains of southwestern China. This study will be useful to promote the monitoring of cultivated land quality, and to supply fine ground and knowledge for establishing appropriate cultivated land management practices in Southwestern China.展开更多
Making rural settlements of Mountainous Regions in Western Sichuan as the study objects and using symbolic statistical methods, then combining the case study of Daofu County, the paper analyzes the negative impact of ...Making rural settlements of Mountainous Regions in Western Sichuan as the study objects and using symbolic statistical methods, then combining the case study of Daofu County, the paper analyzes the negative impact of the scattered rural settlements on infrastructure construction, farmers' income increase and mountain ecological reconstruction in mountainous regions of western Sichuan. The results indicate that economic density is positively related to both rural settlements density (R^2=0.73) and rural population density (R^2=0.77), and it is the same for relationship between towns density and rural settlements density (R^2=0.88) and between towns density and economic density (R^2=0.71), and the scattered distribution pattern of the rural settlements and shortage of economic centers is a major factor to the lagged socioeconomic development. On the eco-economic zoning to Daofu County, the paper indicates the spatial distribution model and the industrial development model of the rural settlements need to be changed, and rural population should be concentrated in larger rural settlements with development of off-farm industries while infrastructure construction is to reinforced.展开更多
Forest canopy height is one of the important forest parameters for accurately assessing forest biomass or carbon sequestration. ICESat-2 ATLAS provides the potential for retrieval of forest canopy height at global or ...Forest canopy height is one of the important forest parameters for accurately assessing forest biomass or carbon sequestration. ICESat-2 ATLAS provides the potential for retrieval of forest canopy height at global or regional scale, but the current canopy height product (ATL08) has coarse resolution and high uncertainty compared to airborne LiDAR-derived canopy height (hereafter ALCH) in mountainous regions, and is not ready for such applications as biomass modeling at finer scale. The objective of this research was to explore the approach to accurately retrieve canopy height from ATLAS data by incorporating an airborne-derived digital terrain model(DTM) and a data-filtering strategy. By linking ATLAS ATL03 with ATL08 products, the geospatial locations,types, and (absolute) heights of photons were obtained, and canopy heights at different lengths (from 20 to 200 m at 20-m intervals) of segments along a track were computed with the aid of airborne LiDAR DTM. Based on the relationship between the numbers of canopy photons within the segments and accuracy of ATLAS mean canopy height compared to ALCH, a filtering method for excluding a certain portion of unreliable segments was proposed.This method was further applied to different ATLAS ground tracks for retrieval of canopy heights and the results were evaluated using corresponding ALCH. The results show that the incorporation of high-precision DTM and ATLAS products can considerably improve the retrieval accuracy of forest canopy height in mountainous regions.Using the proposed filtering approach, the correlation coefficients (r) between ATLAS canopy height and corresponding ALCH were 0.61–0.91, 0.65–0.92, 0.68–0.94 for segment lengths of 20, 60, and 100 m, respectively;RMSE were 1.90–4.35, 1.55–3.63, and 1.34–3.23 m for the same segment lengths. The results indicate the necessity of using high-precision DTM and using the proposed filtering method to retrieve accurate canopy height from ICESat-2 ATLAS in mountainous regions with dense forest cover and complex terrain conditions.展开更多
Blowing snow is an important part of snow hydrologic processes in mountainous region, however the related researches were rare for the Qilian mountainous region where blowing snow is frequent. Using the observation da...Blowing snow is an important part of snow hydrologic processes in mountainous region, however the related researches were rare for the Qilian mountainous region where blowing snow is frequent. Using the observation dataset in 2008 snow season in Binggou wa- tershed in Qilian mountainous region, we systematically studied the energy and mass processes of blowing snow by field observation and model simulation. The results include the analysis of snow observation, the occurrence probability of blowing snow, blowing snow transport and blowing snow sublimation. It was found that blowing snow was obvious in high altitude region (4,146 m), the snow redislribution phenomena was remarkable. In Yakou station in the study region, blowing snow was easily occurred in midwinter and early spring when no snowmelt, the blowing snow transport was dominated in this period; when snowmelt beginning, the occur- rence probability of blowing snow decreased heavily because of the increasing air temperature, melt, and refrozen phenomena. The blowing snow sublimation accounted for 41.5% of total snow sublimation at Yakou station in 2008 snow season.展开更多
Investigating the interrelation between snow and vegetation is essential to explain the response of alpine ecosystems to climate change.Based on the MOD10 A1 daily cloud-free snow product and MOD13 A1 NDVI(normalized ...Investigating the interrelation between snow and vegetation is essential to explain the response of alpine ecosystems to climate change.Based on the MOD10 A1 daily cloud-free snow product and MOD13 A1 NDVI(normalized difference vegetation index)data,this study analysed the spatial and temporal patterns of snow phenology including snow onset date,snow end date,snow cover days,and vegetation phenology including the start of growing season,the end of growing season and the length of growing season in the Chinese Tianshan Mountainous Region(CTMR)from 2002 to 2018,and then investigated the snow phenological effects on the vegetation phenology among different ecogeographic zones and diverse vegetation types.The results indicated that snow onset date was earlier at higher elevations and later at lower elevations,while snow end date showed opposite spatial distribution characteristics.The end of growing season occurred later on the northwest slope of the CTMR and the Yili Valley.The earliest end of growing season was in the middle part of the CTMR.A long growing season was mainly distributed along the northern slope and the Yili Valley,while a short growing season was concentrated in the middle part of the CTMR.The response of vegetation phenology to changes in snow phenology varied among vegetation types and ecogeographic zones.The effect of snow phenology on vegetation phenology was more significant in IID5(Yili Valley)than in the other ecogeographic zones.A negative correlation was observed between the start of growing season and snow end date in nearly 54.78%of the study area,while a positive correlation was observed between the start of growing season and the snow end date in 66.85%of the study area.The sensitivity of vegetation phenology to changes in snow cover varied among different vegetation types.Snow onset date had the greatest effect on the start of growing season in the four vegetation cover types(alpine meadows,alpine steppes,shrubs,and alpine sparse vegetation),whereas the snow cover days had the least impact.Snow end date had the greatest impact on the end of growing season in the alpine steppes and shrub areas.The study results are helpful for understanding the vegetation dynamics under ongoing climate change,and can benefit vegetation management and pasture development in the CTMR.展开更多
Taking agricultural organization in China's southwestern mountainous regions as research object,on the basis of analysis of the status quo of agricultural organization development in China's southwestern mount...Taking agricultural organization in China's southwestern mountainous regions as research object,on the basis of analysis of the status quo of agricultural organization development in China's southwestern mountainous regions,we use related theoretical knowledge on economics and organization science,we probe into the process of innovation and mechanism of action concerning the structure of agricultural organization in China's southwestern mountainous regions over the past 30 years.Finally we draw several general conclusions regarding structure innovation of agricultural organization in China's southwestern mountainous regions as follows:first,the structure innovation of agricultural organization,a gradual process,proceeds ceaselessly along with ongoing progress and development of agriculture,and in this process,farmers always play a fundamental role;second,the structure innovation of agricultural organization is affected by many factors,and government institutional arrangement and change in market conditions is undoubtedly the most critical factor;third,the probable evolving direction of structure innovation of agricultural organization includes internal differentiation of the same form of agricultural organization,association of different forms of agricultural organization,and emergence of other forms of agricultural organization.展开更多
The analysis of hydrochemical characteristics and influencing factors of surface river on plateau is helpful to study water hydrological cycle and environmental evolution,which can scientifically guide rational develo...The analysis of hydrochemical characteristics and influencing factors of surface river on plateau is helpful to study water hydrological cycle and environmental evolution,which can scientifically guide rational development and utilization of water resources and planning of ecological environment protection.With the expansion and diversification of human activities,the quality of surface rivers will be more directly affected.Therefore,it is of great significance to pay attention to the hydrochemical characteristics of plateau surface rivers and the influence of human activities on their circulation and evolution.In this study,surface water in the Duoqu basin of Jinsha River located in Hengduan mountain region of Eastern Tibet was selected as the representative case.Twenty-three groups of surface water samples were collected to analyze the hydrochemical characteristics and ion sources based on correlation analysis,piper trigram,gibbs model,hydrogen and oxygen isotopic techniques.The results suggest the following:(1)The pH showed slight alkalinity with the value ranged from 7.25 to 8.62.Ca^(2+),Mg^(2+)and HCO_(3)^(–)were the main cations and anions.HCO_(3)^(-)Ca and HCO_(3)^(-)Ca·Mg were the primary hydrochemical types for the surface water of Duoqu River.The correlation analysis showed that TDS had the most significant correlation with Ca^(2+),Mg^(2+)and HCO_(3)^(–).Analysis on hydrogen and oxygen isotopes indicated that the surface rivers were mainly recharged by atmospheric precipitation and glacial melt water in this study area.(2)The surface water had a certain reverse cation alternating adsorption,and surface water ions were mainly derived from rock weathering,mainly controlled by weathering and dissolution of carbonates,and secondly by silicates and sodium rocks.(3)The influence of human activities was weak,while the development of cinnabar minerals had a certain impact on the hydrochemistry characteristics,which was the main factor for causing the increase of SO_(4)^(2–).The densely populated county towns and temples with frequent incense burning activities may cause some anomalies of surface water quality.At present,the Duoqu River watershed had gone through a certain influence of mineral exploitation,so the hydrological cycle and river eco-environment at watershed scale will still bound to be change.The results could provide basic support for better understanding water balance evolution as well as the ecological protection of Duoqu River watershed.展开更多
Land use changes in mountainous regions were greatly enhanced as the rapid development of economy due to the expanded population in developing countries. Acting geographically as the basic unit of mountainous regions,...Land use changes in mountainous regions were greatly enhanced as the rapid development of economy due to the expanded population in developing countries. Acting geographically as the basic unit of mountainous regions, valleys are the primary sites of economic activities. Therefore optimization of land use policy in valleys is of critical important to the sustainable development in mountainous regions. On the basis of land use data in 1995 and 2012, this study explored the changes of land use according to the assessment of varied topographic factors (i.e., altitude and slope) in typical valleys of the Beijing mountainous regions, China. Our results showed that the valley is an efficiently geographical unit to evaluate land use changes in mountainous regions. We also found that major land use changes in mountainous regions of Beijing from 1995 to 2012 were the dramatic losses of grassland to the cultivated and construction lands, while most of these changes took place at the altitude of 0-400m and the slope of 6-15~. Considering the ever increasing economic development in Beijing mountainous regions, the increases of the construction and cultivated lands are inevitable, however, the great changes at a steeper slope imply the need to tailor land use structure coming into line with topographic factors, and suggesting ecological barriers and water conservation must be exercised in the developments of these areas.展开更多
China has resolved its overall regional poverty in 2020 by attaining moderate societal prosperity.The country has entered a new development stage designed to achieve its second centenary goal.However,ecological fragil...China has resolved its overall regional poverty in 2020 by attaining moderate societal prosperity.The country has entered a new development stage designed to achieve its second centenary goal.However,ecological fragility and risk susceptibility have increased the risk of returning to ecological poverty.In this paper,the Liupan Mountain Region of China was used as a case study,and the counties were used as the scale to reveal the spatiotempora differentiation and influcing factors of the risk of returning to poverty in study area.The indicator data for returning to ecological poverty from 2011-2020 were collected and summarized in three dimensions:ecological,economic and social.The autoregressive integrated moving average model(ARIMA)time series and exponential smoothing method(ES)were used to predict the multidimensional indicators of returning to ecological poverty for 61 counties(districts)in the Liupan Mountain Region for 2021-2030.The back propagation neural network(BPNN)and geographic information system(GIS)were used to generate the spatial distribution and time variation for the index of the risk of returning to ecological poverty(RREP index).The results show that 1)ecological factors were the main factors in the risk of returning to ecological poverty in Liupan Mountain Region.2)The RREP index for the 61 counties(districts)exhibited a downward trend from 2021-2030.The RREP index declined more in medium-and high-risk areas than in low-risk areas.From 2021 to 2025,the RREP index exhibited a slight downward trend.From 2026 to2030,the RREP index was expected to decline faster,especially from 2029-2030.3)Based on the RREP index,it can be roughly divided into three types,namely,the high-risk areas,the medium-risk areas,and the low-risk areas.The natural resource conditions in lowrisk areas of returning to ecological poverty,were better than those in medium-and high-risk areas.展开更多
Land pressure and adaptation are the main factors determining environmental degradation in most of China's mountainous regions. Little attention so far has been paid to the adaptation strategies based on evaluation o...Land pressure and adaptation are the main factors determining environmental degradation in most of China's mountainous regions. Little attention so far has been paid to the adaptation strategies based on evaluation of land pressure in these regions. We evaluated the grain production pressure and economic development pressure for 21 small watersheds undergoing soil conservation measures in the northern mountainous region of China, compared the evaluation results with actual production for each of the watersheds, and analyzed the adaptation strategies. The results imply that land pressure was spatially heterogeneous among the sample watersheds, but there was a balancing trend between land pressure and productive capacity for each watershed. Under rising pressure, these watersheds developed a variety of adaptation strategies such as labor migration, increasing fruit and nut production, and expanding rural tourism if possible. These strategies result from evolution of the market economy in China, and persistent development of the national economy determines the variation of environment in these mountainous regions.展开更多
Rainfall erosivity is defined as the potential of rain to cause erosion.It has great potential for application in studies related to natural disasters,in addition to water erosion.The objectives of this study were:ⅰ)...Rainfall erosivity is defined as the potential of rain to cause erosion.It has great potential for application in studies related to natural disasters,in addition to water erosion.The objectives of this study were:ⅰ)to model the Rday using a seasonal model for the Mountainous Region of the State of Rio de Janeiro(MRRJ);ⅱ)to adjust thresholds of the Rday index based on catastrophic events which occurred in the last two decades;andⅲ)to map the maximum daily rainfall erosivity(Rmaxday)to assess the region's suscepti-bility to rainfall hazards according to the established Rday limits.The fitted Rday model presented a satisfactory result,thereby enabling its application as a Rday estimate in MRRJ.Events that resulted in Rday>1500 MJ ha-1.mm.h-1.day-1 were those with the highest number of fatalities.The spatial distribution of Rmaxday showed that the entire MRRJ has presented values that can cause major rainfall.The Rday index proved to be a promising indicator of rainfall disasters,which is more effective than those normally used that are only based on quantity(mm)and/or intensity(mm.h-1)of the rain.展开更多
In this paper,an effective method of simulating the spatial distribution of climatic elements in mountainous areas by using the semi-empirical theory is presented.As an example,the spatial distributions of temperature...In this paper,an effective method of simulating the spatial distribution of climatic elements in mountainous areas by using the semi-empirical theory is presented.As an example,the spatial distributions of temperature, vapor pressure,relative humidity,wind speed and precipitation in the Jianyang region and the Shaxi basin of Fujian Province are computed with this method,and the simulated results are in good agreement with the observations.展开更多
Physical characteristics of soil structure and soil moisture of five kinds of artificia! forests were researched in Shengquan Temple Forestry Farm, in the southern mountainous area of Jinan City, in order to offer sci...Physical characteristics of soil structure and soil moisture of five kinds of artificia! forests were researched in Shengquan Temple Forestry Farm, in the southern mountainous area of Jinan City, in order to offer scientific management and nurture of forest vegetation in mountainous area of North China. Results indicated that: (1) In these artificial forests researched, some indexes expressing soil pedonydrological physical character, such as soil density, porosity, infiltration rate, were much better than those in bare land, and these indexes Showed this order: mixed forest 〉 pure forest, Kalopanax pictus 〉 Koelreuteria paniculata 〉 Pistacia chinensis. (2) In dry and rainy seasons, with the increasing of soil depth, soil water content decreased in most parts of forest, and their extent of change was less than those in bare land. (3) With the increasing of soil depth, soil saturated water content decreased in all kinds of forests. Water storing capacity of surface soil layer was the best in the mixed forest, while differences were little in other forest. Water storing and adjusting capacity was good in the mixed forest, while water offering capacity had little discrepancy in all forests. Conclusions show that judging from water conservation and water use efficiency, mixed forest is better than pure forest, and in pure forest K. pictus is better than K. paniculata. Therefore, it is proposed that in the future, mixed forest should be fostered and managed firstly, the species being made up of K. pictus and P. chinensis. In the pure forest, K. pictus is much better than others. Nowadays K. paniculata, and P, chinensis, especially their soil surface vegetation and litter, should be protected. As to poor forest, closing hill for afforestation should be adopted. Poor forest have better be reconstructed to be mixed forest in available conditions.展开更多
Transportation planning is a critical component for creating an orderly,intensive,and sustainable pattern of land development.By comprehensively considering the potential and suitability of transport construction,a co...Transportation planning is a critical component for creating an orderly,intensive,and sustainable pattern of land development.By comprehensively considering the potential and suitability of transport construction,a comprehensive method combining resources and environmental carrying capacity(RECC)and land development suitability(LDS)was developed by using techniques of GIS,analytic hierarchy process(AHP)and threedimensional magic cube.Taking Aba prefecture in Sichuan Province of Southwest China as a case study,LDS for transportation was analyzed from three aspects,including overall planning layout,different transport modes,and transportation projects.The results showed that the transport planning scales of most counties in Aba were suitable,and the order of LDS of different transport modes was railway>highway=superhighway>tourism track,which already included 42 new transportation projects.We found that two counties(Maoxian County and Jiuzhaigou County)should improve the ecological protection level of transportation,in which the railway network construction should be encouraged,and some transportation projects with low LDS should be postponed or constructed harmlessly.We suggest the combination of RECC and LDS for transportation could enhance the territorial space optimization and sustainable transport construction.展开更多
Tourism-led economic growth and tourism-driven urbanization have attracted increasing attention by provinces and regions in China with abundant tourism resources.Due to low data availability,the current tourism litera...Tourism-led economic growth and tourism-driven urbanization have attracted increasing attention by provinces and regions in China with abundant tourism resources.Due to low data availability,the current tourism literature lacks empirical evidence of the tourism network in lessdeveloped mountainous regions where the development of transport infrastructure is more variable.This paper aims to provide such evidence using Guangxi Zhuang Autonomous Region in China as a case study.Using User Generated Content(UGC)data,this study constructs a tourism network in Guangxi.By integrating social network analysis with spatial interaction modelling,we compared the impact of two different transport infrastructures,highway and high-speed railway,on tourist flows,particularly in less-developed mountainous regions.It was found that the product of node centrality and flow could best describe the significant pushing and pulling forces on the flow of tourists.The tourism by high-speed railway was sensitive to the position of trip destination on the whole tourism network but self-drive tourism was more sensitive to travelling time.The increase of high-speed railway density is crucial to promote local tourism-led economic development,however,large-scale karst landforms in the study area present a significant obstacle to the construction of high-speed railways.展开更多
The climatic environment,landscape environment and settlement environment of traditional mountainous human settlements in Mentougou of west Beijing are summarized.Based on the analysis from the perspective of water ad...The climatic environment,landscape environment and settlement environment of traditional mountainous human settlements in Mentougou of west Beijing are summarized.Based on the analysis from the perspective of water adaptability,the spatial database of water adaptability of traditional mountainous human settlements in Mentougou of west Beijing is constructed,and the experience of water adaptability construction of settlement location,irrigation and water conservancy,flood control and soil fixation in river beach and gully areas is summarized.The landscape system of water adaptability of traditional mountainous human settlements in Mentougou of west Beijing embodies the typical wisdom of water adaptability construction contained in traditional mountainous human settlements,and has high reference value in the related research of water adaptability.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.41571523)the Key Program of the Chinese Academy of Sciences(Grant No.KZZDEW-06-03)+1 种基金the National Basic Research Program of China(Grant No.2013CBA01808)the National Key Technology R&D Program of China(Grant No.2014BAC05B01)
文摘China is a mountainous country with a great diversity of landform and geomorphology.This diversity underlines the need for regionalization and classification.This study defines the mountain terrains and regions with three criteria-elevation,relative height,and slope,and examines the extent of mountainous regions by using county as the basic administrative unit.According to the three parameters of economic base,resident income and development potential,we classified the economic development level in mountainous regions of China.The findings reveal that the extent of the mountainous region accounts for 74.9% of the China's Mainland's total area.The economic development of mountainous regions in China is classified into 4 main types and 23 subtypes.
基金Under the auspices of the National Natural Science Foundation of China(No.41471469,41601141)the National Key Basic Research Program of China(No.2015CB452706)+1 种基金the Humanities and Social Sciences Youth Project of Ministry of Education in China(No.14YJCZH130)Youth Talent Team Program of the Institute of Mountain Hazards and Environment,Chinese Academy of Sciences(No.SDSQB-2015-01)
文摘Labor migration to urban centers is a common phenomenon in the Panxi region of the southwestern mountainous region of China, mainly owing to inadequate livelihood capital in rural areas. Numerous studies have been conducted to explore the relationship between labor migration and its causes, such as individual and family characteristics, but few studies have focused on livelihood capital. This paper examines the impact factors on labor migration employment location selection and duration from a household livelihood capital perspective. A case study of 279 households from 10 villages in the area was carried out in February 2016. We used both qualitative and quantitative methods to analyze the data. On the basis of the 279 questionnaires, the proportion of households with non-labor migration is 48.4%, whereas households with labor migration within a local city and migration across regions account for 28.7% and 22.9%, respectively. Social, financial, and human capitals are the primary factors that influence migrants' employment location choice positively. Among them, social capital has a significant impact on both migration within a local city and across regions; each of the regression coefficients is 1.111 and 1.183. Social, human, and financial capitals also have a positive impact on the duration of labor migration, and similarly, social capital is the highest coefficient with 2.489. However, physical capital only partly impacts labor migration across regions, whereas the impact of labor migration within a local city, and the duration, are not significant. Furthermore, the impact of household natural capital on migration space and time are all negative relationships, especially for labor migration across the regions and duration, with coefficient scores of 4.836 and 3.450, respectively. That is to say, a laborer is inclined to migrate within a local city for a short term, or not migrate at all, if natural capital is abundant. Our analysis results show that household livelihood capital has a strong spatio-temporal impact on labor migration.
文摘The gradation of cultivated land is to assess the suitability of cultivated land for agricultural production in terms of natural and economic properties of land. It can be used to evaluate sustainability of land use and soil management practices. Formal and informal surveys, Delphi and comprehensive index method are adopted to identify appropriate integrated indicators, and measure the gradation of cultivated land quality. The determination of integrated indicators presents three basic features of cultivated land quality: stable plant productivity, social acceptability and maintenance of environmental quality. Pronounced concentration-dissipation law of total function score value occurs in paddy field units, with three ranges, i.e., 79-68.5, 68.5-59 and 59-51. Total function score value in dryland units mainly ranges from 40 to 70, but slight concentration-dissipation law of each unit is still observed, with four ranges, i.e., 79-68, 68-51, 51-37 and 37-15. Paddy field quality is divided into three gradations, and the scales are 18 220.9 ha, 5410.6 ha and 2890.9 ha. Dryland quality is classified into four gradations, and the scales are 1548.6 ha, 8153.8 ha, 3316.3 ha and 685.2 ha. The total function score value of every gradation unit is conformed to the results of farmers' assessment. Research results meet with the needs of accurate degree of the gradation of cultivated land quality. Integrated indicators-based gradation of cultivated land assessment accords with the characteristics of land resources and human preference in the mountains of southwestern China. This study will be useful to promote the monitoring of cultivated land quality, and to supply fine ground and knowledge for establishing appropriate cultivated land management practices in Southwestern China.
基金the Western China Program for Personnel Training of Chinese Academy of Sciences (L10416004)National Social Science Foundation of China (06BJY076)Knowledge Innovation Project Chinese Academy of Sciences
文摘Making rural settlements of Mountainous Regions in Western Sichuan as the study objects and using symbolic statistical methods, then combining the case study of Daofu County, the paper analyzes the negative impact of the scattered rural settlements on infrastructure construction, farmers' income increase and mountain ecological reconstruction in mountainous regions of western Sichuan. The results indicate that economic density is positively related to both rural settlements density (R^2=0.73) and rural population density (R^2=0.77), and it is the same for relationship between towns density and rural settlements density (R^2=0.88) and between towns density and economic density (R^2=0.71), and the scattered distribution pattern of the rural settlements and shortage of economic centers is a major factor to the lagged socioeconomic development. On the eco-economic zoning to Daofu County, the paper indicates the spatial distribution model and the industrial development model of the rural settlements need to be changed, and rural population should be concentrated in larger rural settlements with development of off-farm industries while infrastructure construction is to reinforced.
基金financially supported by the National Natural Science Foundation of China (No. 32171787)
文摘Forest canopy height is one of the important forest parameters for accurately assessing forest biomass or carbon sequestration. ICESat-2 ATLAS provides the potential for retrieval of forest canopy height at global or regional scale, but the current canopy height product (ATL08) has coarse resolution and high uncertainty compared to airborne LiDAR-derived canopy height (hereafter ALCH) in mountainous regions, and is not ready for such applications as biomass modeling at finer scale. The objective of this research was to explore the approach to accurately retrieve canopy height from ATLAS data by incorporating an airborne-derived digital terrain model(DTM) and a data-filtering strategy. By linking ATLAS ATL03 with ATL08 products, the geospatial locations,types, and (absolute) heights of photons were obtained, and canopy heights at different lengths (from 20 to 200 m at 20-m intervals) of segments along a track were computed with the aid of airborne LiDAR DTM. Based on the relationship between the numbers of canopy photons within the segments and accuracy of ATLAS mean canopy height compared to ALCH, a filtering method for excluding a certain portion of unreliable segments was proposed.This method was further applied to different ATLAS ground tracks for retrieval of canopy heights and the results were evaluated using corresponding ALCH. The results show that the incorporation of high-precision DTM and ATLAS products can considerably improve the retrieval accuracy of forest canopy height in mountainous regions.Using the proposed filtering approach, the correlation coefficients (r) between ATLAS canopy height and corresponding ALCH were 0.61–0.91, 0.65–0.92, 0.68–0.94 for segment lengths of 20, 60, and 100 m, respectively;RMSE were 1.90–4.35, 1.55–3.63, and 1.34–3.23 m for the same segment lengths. The results indicate the necessity of using high-precision DTM and using the proposed filtering method to retrieve accurate canopy height from ICESat-2 ATLAS in mountainous regions with dense forest cover and complex terrain conditions.
基金funded by the National Natural Science Foundation of China(Grant Nos.913252034100124041071227)
文摘Blowing snow is an important part of snow hydrologic processes in mountainous region, however the related researches were rare for the Qilian mountainous region where blowing snow is frequent. Using the observation dataset in 2008 snow season in Binggou wa- tershed in Qilian mountainous region, we systematically studied the energy and mass processes of blowing snow by field observation and model simulation. The results include the analysis of snow observation, the occurrence probability of blowing snow, blowing snow transport and blowing snow sublimation. It was found that blowing snow was obvious in high altitude region (4,146 m), the snow redislribution phenomena was remarkable. In Yakou station in the study region, blowing snow was easily occurred in midwinter and early spring when no snowmelt, the blowing snow transport was dominated in this period; when snowmelt beginning, the occur- rence probability of blowing snow decreased heavily because of the increasing air temperature, melt, and refrozen phenomena. The blowing snow sublimation accounted for 41.5% of total snow sublimation at Yakou station in 2008 snow season.
基金supported by the National Natural Science Foundation of China(41761014)the“One Hundred Outstanding Young Talents Training Program”of Lanzhou Jiaotong University,the National Natural Science Foundation of China(41971094)the Youth Innovation Promotion Association CAS(2019414)。
文摘Investigating the interrelation between snow and vegetation is essential to explain the response of alpine ecosystems to climate change.Based on the MOD10 A1 daily cloud-free snow product and MOD13 A1 NDVI(normalized difference vegetation index)data,this study analysed the spatial and temporal patterns of snow phenology including snow onset date,snow end date,snow cover days,and vegetation phenology including the start of growing season,the end of growing season and the length of growing season in the Chinese Tianshan Mountainous Region(CTMR)from 2002 to 2018,and then investigated the snow phenological effects on the vegetation phenology among different ecogeographic zones and diverse vegetation types.The results indicated that snow onset date was earlier at higher elevations and later at lower elevations,while snow end date showed opposite spatial distribution characteristics.The end of growing season occurred later on the northwest slope of the CTMR and the Yili Valley.The earliest end of growing season was in the middle part of the CTMR.A long growing season was mainly distributed along the northern slope and the Yili Valley,while a short growing season was concentrated in the middle part of the CTMR.The response of vegetation phenology to changes in snow phenology varied among vegetation types and ecogeographic zones.The effect of snow phenology on vegetation phenology was more significant in IID5(Yili Valley)than in the other ecogeographic zones.A negative correlation was observed between the start of growing season and snow end date in nearly 54.78%of the study area,while a positive correlation was observed between the start of growing season and the snow end date in 66.85%of the study area.The sensitivity of vegetation phenology to changes in snow cover varied among different vegetation types.Snow onset date had the greatest effect on the start of growing season in the four vegetation cover types(alpine meadows,alpine steppes,shrubs,and alpine sparse vegetation),whereas the snow cover days had the least impact.Snow end date had the greatest impact on the end of growing season in the alpine steppes and shrub areas.The study results are helpful for understanding the vegetation dynamics under ongoing climate change,and can benefit vegetation management and pasture development in the CTMR.
基金Supported by the 2010 Planning Project in Research Center of Development Ability of the West Regions in China (XNSDX01-003)Graduates Innovation Foundation in Guizhou University (2011045)The 2010 Research Project in Development Strategy Research Center in Karst Regions (KSTX01-002)
文摘Taking agricultural organization in China's southwestern mountainous regions as research object,on the basis of analysis of the status quo of agricultural organization development in China's southwestern mountainous regions,we use related theoretical knowledge on economics and organization science,we probe into the process of innovation and mechanism of action concerning the structure of agricultural organization in China's southwestern mountainous regions over the past 30 years.Finally we draw several general conclusions regarding structure innovation of agricultural organization in China's southwestern mountainous regions as follows:first,the structure innovation of agricultural organization,a gradual process,proceeds ceaselessly along with ongoing progress and development of agriculture,and in this process,farmers always play a fundamental role;second,the structure innovation of agricultural organization is affected by many factors,and government institutional arrangement and change in market conditions is undoubtedly the most critical factor;third,the probable evolving direction of structure innovation of agricultural organization includes internal differentiation of the same form of agricultural organization,association of different forms of agricultural organization,and emergence of other forms of agricultural organization.
基金financially supported by the Geological Survey Project of China Geological Survey(DD20230077,DD20230456,DD20230424)。
文摘The analysis of hydrochemical characteristics and influencing factors of surface river on plateau is helpful to study water hydrological cycle and environmental evolution,which can scientifically guide rational development and utilization of water resources and planning of ecological environment protection.With the expansion and diversification of human activities,the quality of surface rivers will be more directly affected.Therefore,it is of great significance to pay attention to the hydrochemical characteristics of plateau surface rivers and the influence of human activities on their circulation and evolution.In this study,surface water in the Duoqu basin of Jinsha River located in Hengduan mountain region of Eastern Tibet was selected as the representative case.Twenty-three groups of surface water samples were collected to analyze the hydrochemical characteristics and ion sources based on correlation analysis,piper trigram,gibbs model,hydrogen and oxygen isotopic techniques.The results suggest the following:(1)The pH showed slight alkalinity with the value ranged from 7.25 to 8.62.Ca^(2+),Mg^(2+)and HCO_(3)^(–)were the main cations and anions.HCO_(3)^(-)Ca and HCO_(3)^(-)Ca·Mg were the primary hydrochemical types for the surface water of Duoqu River.The correlation analysis showed that TDS had the most significant correlation with Ca^(2+),Mg^(2+)and HCO_(3)^(–).Analysis on hydrogen and oxygen isotopes indicated that the surface rivers were mainly recharged by atmospheric precipitation and glacial melt water in this study area.(2)The surface water had a certain reverse cation alternating adsorption,and surface water ions were mainly derived from rock weathering,mainly controlled by weathering and dissolution of carbonates,and secondly by silicates and sodium rocks.(3)The influence of human activities was weak,while the development of cinnabar minerals had a certain impact on the hydrochemistry characteristics,which was the main factor for causing the increase of SO_(4)^(2–).The densely populated county towns and temples with frequent incense burning activities may cause some anomalies of surface water quality.At present,the Duoqu River watershed had gone through a certain influence of mineral exploitation,so the hydrological cycle and river eco-environment at watershed scale will still bound to be change.The results could provide basic support for better understanding water balance evolution as well as the ecological protection of Duoqu River watershed.
基金supported by the Beijing Philosophy and Social Science Planning Project(Grant No.15JGC193)Beijing Postdoctoral Research Foundation(Grant No.2015ZZ-128)Beijing academy of social sciences youth project
文摘Land use changes in mountainous regions were greatly enhanced as the rapid development of economy due to the expanded population in developing countries. Acting geographically as the basic unit of mountainous regions, valleys are the primary sites of economic activities. Therefore optimization of land use policy in valleys is of critical important to the sustainable development in mountainous regions. On the basis of land use data in 1995 and 2012, this study explored the changes of land use according to the assessment of varied topographic factors (i.e., altitude and slope) in typical valleys of the Beijing mountainous regions, China. Our results showed that the valley is an efficiently geographical unit to evaluate land use changes in mountainous regions. We also found that major land use changes in mountainous regions of Beijing from 1995 to 2012 were the dramatic losses of grassland to the cultivated and construction lands, while most of these changes took place at the altitude of 0-400m and the slope of 6-15~. Considering the ever increasing economic development in Beijing mountainous regions, the increases of the construction and cultivated lands are inevitable, however, the great changes at a steeper slope imply the need to tailor land use structure coming into line with topographic factors, and suggesting ecological barriers and water conservation must be exercised in the developments of these areas.
基金Under the auspices of National Natural Science Foundation of China(No.42071230)。
文摘China has resolved its overall regional poverty in 2020 by attaining moderate societal prosperity.The country has entered a new development stage designed to achieve its second centenary goal.However,ecological fragility and risk susceptibility have increased the risk of returning to ecological poverty.In this paper,the Liupan Mountain Region of China was used as a case study,and the counties were used as the scale to reveal the spatiotempora differentiation and influcing factors of the risk of returning to poverty in study area.The indicator data for returning to ecological poverty from 2011-2020 were collected and summarized in three dimensions:ecological,economic and social.The autoregressive integrated moving average model(ARIMA)time series and exponential smoothing method(ES)were used to predict the multidimensional indicators of returning to ecological poverty for 61 counties(districts)in the Liupan Mountain Region for 2021-2030.The back propagation neural network(BPNN)and geographic information system(GIS)were used to generate the spatial distribution and time variation for the index of the risk of returning to ecological poverty(RREP index).The results show that 1)ecological factors were the main factors in the risk of returning to ecological poverty in Liupan Mountain Region.2)The RREP index for the 61 counties(districts)exhibited a downward trend from 2021-2030.The RREP index declined more in medium-and high-risk areas than in low-risk areas.From 2021 to 2025,the RREP index exhibited a slight downward trend.From 2026 to2030,the RREP index was expected to decline faster,especially from 2029-2030.3)Based on the RREP index,it can be roughly divided into three types,namely,the high-risk areas,the medium-risk areas,and the low-risk areas.The natural resource conditions in lowrisk areas of returning to ecological poverty,were better than those in medium-and high-risk areas.
基金National Natural Science Foundation of China, No.40671009
文摘Land pressure and adaptation are the main factors determining environmental degradation in most of China's mountainous regions. Little attention so far has been paid to the adaptation strategies based on evaluation of land pressure in these regions. We evaluated the grain production pressure and economic development pressure for 21 small watersheds undergoing soil conservation measures in the northern mountainous region of China, compared the evaluation results with actual production for each of the watersheds, and analyzed the adaptation strategies. The results imply that land pressure was spatially heterogeneous among the sample watersheds, but there was a balancing trend between land pressure and productive capacity for each watershed. Under rising pressure, these watersheds developed a variety of adaptation strategies such as labor migration, increasing fruit and nut production, and expanding rural tourism if possible. These strategies result from evolution of the market economy in China, and persistent development of the national economy determines the variation of environment in these mountainous regions.
基金We acknowledge the Coordination of Superior Level Staff Improvement-CAPES[grant number 88882.306661/2018-01]the National Council for Scientific and Technological Development-CNPQ[grant number 301556/2017-2]for supporting and funding this work.
文摘Rainfall erosivity is defined as the potential of rain to cause erosion.It has great potential for application in studies related to natural disasters,in addition to water erosion.The objectives of this study were:ⅰ)to model the Rday using a seasonal model for the Mountainous Region of the State of Rio de Janeiro(MRRJ);ⅱ)to adjust thresholds of the Rday index based on catastrophic events which occurred in the last two decades;andⅲ)to map the maximum daily rainfall erosivity(Rmaxday)to assess the region's suscepti-bility to rainfall hazards according to the established Rday limits.The fitted Rday model presented a satisfactory result,thereby enabling its application as a Rday estimate in MRRJ.Events that resulted in Rday>1500 MJ ha-1.mm.h-1.day-1 were those with the highest number of fatalities.The spatial distribution of Rmaxday showed that the entire MRRJ has presented values that can cause major rainfall.The Rday index proved to be a promising indicator of rainfall disasters,which is more effective than those normally used that are only based on quantity(mm)and/or intensity(mm.h-1)of the rain.
基金Projects are supported by the Science Fund of the Institution of Higher Learning.
文摘In this paper,an effective method of simulating the spatial distribution of climatic elements in mountainous areas by using the semi-empirical theory is presented.As an example,the spatial distributions of temperature, vapor pressure,relative humidity,wind speed and precipitation in the Jianyang region and the Shaxi basin of Fujian Province are computed with this method,and the simulated results are in good agreement with the observations.
基金The project was supported by national key science and technology item in "10th five-year" granted by the National Natural Science Foundation of China(2001BA510B0404).
文摘Physical characteristics of soil structure and soil moisture of five kinds of artificia! forests were researched in Shengquan Temple Forestry Farm, in the southern mountainous area of Jinan City, in order to offer scientific management and nurture of forest vegetation in mountainous area of North China. Results indicated that: (1) In these artificial forests researched, some indexes expressing soil pedonydrological physical character, such as soil density, porosity, infiltration rate, were much better than those in bare land, and these indexes Showed this order: mixed forest 〉 pure forest, Kalopanax pictus 〉 Koelreuteria paniculata 〉 Pistacia chinensis. (2) In dry and rainy seasons, with the increasing of soil depth, soil water content decreased in most parts of forest, and their extent of change was less than those in bare land. (3) With the increasing of soil depth, soil saturated water content decreased in all kinds of forests. Water storing capacity of surface soil layer was the best in the mixed forest, while differences were little in other forest. Water storing and adjusting capacity was good in the mixed forest, while water offering capacity had little discrepancy in all forests. Conclusions show that judging from water conservation and water use efficiency, mixed forest is better than pure forest, and in pure forest K. pictus is better than K. paniculata. Therefore, it is proposed that in the future, mixed forest should be fostered and managed firstly, the species being made up of K. pictus and P. chinensis. In the pure forest, K. pictus is much better than others. Nowadays K. paniculata, and P, chinensis, especially their soil surface vegetation and litter, should be protected. As to poor forest, closing hill for afforestation should be adopted. Poor forest have better be reconstructed to be mixed forest in available conditions.
基金funded by Key Scientific Research Project of the Ministry of Transport(No.2020-MS4113)Scientific and Technological Development Project,Transport Planning and Research Institute of the Ministry of Transport(No.092117-434)Science and Technology Project of Henan Provincial Department of Transport(No.2020G-2-15)。
文摘Transportation planning is a critical component for creating an orderly,intensive,and sustainable pattern of land development.By comprehensively considering the potential and suitability of transport construction,a comprehensive method combining resources and environmental carrying capacity(RECC)and land development suitability(LDS)was developed by using techniques of GIS,analytic hierarchy process(AHP)and threedimensional magic cube.Taking Aba prefecture in Sichuan Province of Southwest China as a case study,LDS for transportation was analyzed from three aspects,including overall planning layout,different transport modes,and transportation projects.The results showed that the transport planning scales of most counties in Aba were suitable,and the order of LDS of different transport modes was railway>highway=superhighway>tourism track,which already included 42 new transportation projects.We found that two counties(Maoxian County and Jiuzhaigou County)should improve the ecological protection level of transportation,in which the railway network construction should be encouraged,and some transportation projects with low LDS should be postponed or constructed harmlessly.We suggest the combination of RECC and LDS for transportation could enhance the territorial space optimization and sustainable transport construction.
基金funded by the Guangxi Natural Science Foundation(Grant No.2020GXNSFAA159065)the Opening Fund of Key Laboratory of Environment Change and Resources Use in Beibu Gulf under Ministry of Education(Nanning Normal University)+1 种基金Guangxi Key Laboratory of Earth Surface Processes and Intelligent Simulation(Nanning Normal University)(Grant No.GTEU-KLOP-K1701)the seventh batch of distinguished experts in Guangxi and National Natural Science Foundation of China(Grant No.41867071)。
文摘Tourism-led economic growth and tourism-driven urbanization have attracted increasing attention by provinces and regions in China with abundant tourism resources.Due to low data availability,the current tourism literature lacks empirical evidence of the tourism network in lessdeveloped mountainous regions where the development of transport infrastructure is more variable.This paper aims to provide such evidence using Guangxi Zhuang Autonomous Region in China as a case study.Using User Generated Content(UGC)data,this study constructs a tourism network in Guangxi.By integrating social network analysis with spatial interaction modelling,we compared the impact of two different transport infrastructures,highway and high-speed railway,on tourist flows,particularly in less-developed mountainous regions.It was found that the product of node centrality and flow could best describe the significant pushing and pulling forces on the flow of tourists.The tourism by high-speed railway was sensitive to the position of trip destination on the whole tourism network but self-drive tourism was more sensitive to travelling time.The increase of high-speed railway density is crucial to promote local tourism-led economic development,however,large-scale karst landforms in the study area present a significant obstacle to the construction of high-speed railways.
基金Sponsored by Youth Science Fund Project of National Natural Science Foundation of China“Building of Water Adaptive Landscape Security Pattern Model for Mountainous Rural Environment with the Case Study on Mentougou District in Beijing”(51808005)General Social Science Project of Beijing Municipal Education Commission“Investigation and Database Establishment of Water Adaptive Landscapes in the Mountainous Rural Area in Western Beijing”(SM201910009008)+1 种基金Youth Yuyou Talent Training Plan of North China University of Technology“Engineering Frontier Oriented Research on Climate-Adaptive Planning and Construction Technology with the Case Study of Beijing”(NCUT2020)Innovation and Entrepreneurship Training Program for Beijing Municipal College Students“Construction of Spatial Database of Mountainous Ancient Villages in Mentougou of West Beijing”(NCUT2021)。
文摘The climatic environment,landscape environment and settlement environment of traditional mountainous human settlements in Mentougou of west Beijing are summarized.Based on the analysis from the perspective of water adaptability,the spatial database of water adaptability of traditional mountainous human settlements in Mentougou of west Beijing is constructed,and the experience of water adaptability construction of settlement location,irrigation and water conservancy,flood control and soil fixation in river beach and gully areas is summarized.The landscape system of water adaptability of traditional mountainous human settlements in Mentougou of west Beijing embodies the typical wisdom of water adaptability construction contained in traditional mountainous human settlements,and has high reference value in the related research of water adaptability.