35 surface soil samples and 28 profile soil samples were collected in Longitudinal Range-Gorge Region, Southwest China. The distribution of pollen and spores and their relationship with the environment are analyzed. T...35 surface soil samples and 28 profile soil samples were collected in Longitudinal Range-Gorge Region, Southwest China. The distribution of pollen and spores and their relationship with the environment are analyzed. The results show that there are significant differences in pollen and spores taxa, amounts, dominant taxa and florae between the eastern and western flanks of the Ailao Mountain. There are more pollen and spores taxa, a greater amount and complexity on the western flank of the mountain than those on the eastern flank, while the dominant taxa are more centralized and prominent on the eastern flank of the Ailao Mountain. As for the plant florae distribution, there are significant differences in the number of taxa and composition between the eastern and the western flanks. The analysis of profile pollen and spores assemblage shows that its trends of variation are basically in accordance with the surface pollen and spores, which are also indicators of the environmental differences between the two flanks of the mountain. These significant spatial differences of pollen and spores are very close to the regional topography and climate difference. The mountain running perpendicular to the moisture-laden air flow serves as a barrier and the monsoon circulations the east and the west of the mountain result in different energy-moisture characteristics. We conclude that the main patterns of the pollen and spores can be attributed to the environmental differences.展开更多
The mountainous hydrological process usually shows high variation to climate change and human action. In the Longitudinal Range-Gorge Region（LRGR）, Southwestern China and Southeast Asian, the transboundary runoff va...The mountainous hydrological process usually shows high variation to climate change and human action. In the Longitudinal Range-Gorge Region（LRGR）, Southwestern China and Southeast Asian, the transboundary runoff variations are much more sensitive and complex under the interaction of climate change, ＂corridor-barrier＂ functions in LRGR,and dams building. In this paper, based on the long hydrological records（1956-2013） from three mainstream hydrological stations in Nu River,Lancang River, and Red River, the region runoff variations were analyzed. The results show out： i） the regional runoff changes were strongly influenced by the ＂Corridor-Barrier＂ functions in LRGR from west to east, the variability extent of annual runoff increased, but tended to decrease after 2009 and the reduced extents also increased; ii） the annual runoff change in the three rivers had high concentration degrees; iii） there were periodicities of 33 years of runoff change in Nu River and Lancang River, and 30 years in Red River, and the lower flow period would continue for 8-9 years in Nu River and Lancang River but only for 4 years in Red River; iv） since 2010, as the two mega dams of Xiaowan and Nuozhadu built in Lancang River mainstream, their variations of annual runoff were quite different. The research results could offer a scientific base for sustainable utilization,conservation, and management of the regional water resources展开更多
The major features of different road sections were identified.Methods quantitatively determining the ecological impact of highway construction were discussed,and a demonstration was presented.The Dabao highway(from Da...The major features of different road sections were identified.Methods quantitatively determining the ecological impact of highway construction were discussed,and a demonstration was presented.The Dabao highway(from Dali to Baoshan)and the Sixiao highway(from Simao to Xiaomengyang)passing through the Longitudinal Range-Gorge Region were used as examples in this paper.For the normal road sections having no important species to protect,a method of ecosystem health assessment was introduced to calculate the overall range of the ecological impact of highway construction.For the road sections having plants or soils of interest,indexes were selected and the range of impact was determined using mathematical methods such as regression analysis and variance analysis.The range of impact on animal populations was also discussed in terms of the minimum living areas required by animal populations and the fragmentation caused by highway construction.The results indicate that the zones impacted by highway construction were composed of both regular and anomalous figures,the range of impacts for different landforms of the two sample highways were substantially different;highway construction had dramatic effects on roadside ecosystem health;the impact on soil factors of farmland was greater than 200 m,and the distance may exceed 1000 m when important large animals were considered.展开更多
Taking two typical rivers in high mountains and steep gorge areas as example,this paper analyzes the spetiotemporal variability of the eco-hydrological characteristics and the driving forces leading to changes.Firstly...Taking two typical rivers in high mountains and steep gorge areas as example,this paper analyzes the spetiotemporal variability of the eco-hydrological characteristics and the driving forces leading to changes.Firstly,based on the species-environmental data processing,this paper adopts canonical correspondence analysis(CCA)method to identify the environmental factors influencing the distribu- tion of river bank vegetation.Secondly,this study uses the ecological diversity Index to represent the spatiotemporel variability of ecological characteristics.Thirdly,this paper uses the multiple correlation method to analyze the relationship between the hydrological factors and meteorological factors,and to identify the key factors leading to the hydrological regime changes.At last,based on the analysis of basin water quality data,this paper analyzes the regularity of spatiotemporal variability and its driving forces.By the systematic analysis on the outcome,we could get that the spatiotemporel distribution of eco-hydrological characteristics shows the regular changes from the upstream to downstream(from the north to the south),and the spatiotemporal variability of eco-hydrological characteristics is typical from the east to the west.Altitude,aspect and water distribution are the primary natural driving forces leading to the spatiotemporel variability of eco-hydrological characteristics;and exploitation and op- eration of hydroelectric power station,construction of road on the river bank,and basin land utilization are the main human driving forces.展开更多
The asphalt pavement longitudinal crack is a common distress in cold regions,resulting from uneven deformation of the subgrade.Analysis of the correlation law between uneven deformation and crack distress is of positi...The asphalt pavement longitudinal crack is a common distress in cold regions,resulting from uneven deformation of the subgrade.Analysis of the correlation law between uneven deformation and crack distress is of positive significance for understanding the mechanism of crack initiation,and putting forward treatment measures.In view of the complexity of longitudinal crack inducement and road surface deformation,the grey relational method was used to analyze this relationship.Through long-term monitoring of the vertical deformation data of typical road sections,the vertical deformation law of the pavement surface and its deformation characteristics under the action of temperature field are analyzed.Parameters such as vertical relative deformation,vertical relative deformation rate and vertical differential deformation VDSr were constructed to describe vertical deformation characteristics.Typical distribution characteristics of longitudinal fractures and their length and distribution characteristics are also described.The grey correlation analysis theory was utilized to analyze the relationship between deformation characteristics of sections,cross sections and monitoring points and longitudinal crack characteristics(length and location).The analysis reveals a linear positive correlation or a high correlation between several indicators.This study can provide a deeper understanding of the occurrence and development mechanism of longitudinal cracks in asphalt pavement of cold areas,and give references for the research of road engineering structure,materials and distress prevention.展开更多
At present, embankment longitudinal cracks are a major problem in highways through permafrost regions, and seriously affect traffic safety and the normal operations of the highway. In the past, roadbed height in perma...At present, embankment longitudinal cracks are a major problem in highways through permafrost regions, and seriously affect traffic safety and the normal operations of the highway. In the past, roadbed height in permafrost regions was relatively low, and embankment cracks were rare and did not affect traffic safety. Thus, highway designers and researchers paid little attention to this problem, and they knew very little about distribution laws and mechanism of embankment longitudinal cracks. Due to this lack of knowledge, there is no uniform opinion on this problem, making it difficult to find measures that will mediate the impact of longi- tudinal crocks. Temperature is a major factor that affects and controls embankment stability in permafrost regions, especially in ice-rich and high-temperature regions, and solar radiation is the principal factor that determines surface temperatures. Under higher embankment, the difference of temperature will be larger between a sunny slope and a shady slope. Hence, the probability for longitudinal cracks generation is higher. In this paper, a survey and analysis of longitudinal cracks along the Qinghai-Tibet Highway were carried out. The longitudinal cracks are found to be related to the road strikes. Solar radiation is considered to play an important role in the generation of longitudinal cracks.展开更多
Taking Dabao （from Dali City to Baoshan City, Yunnan Province, China） and Sixiao （from Simao City to Xiaomengyang Town, Yunnan Province, China） highways in Longitudinal Range-Gorge Region as examples. Biomass, cov...Taking Dabao （from Dali City to Baoshan City, Yunnan Province, China） and Sixiao （from Simao City to Xiaomengyang Town, Yunnan Province, China） highways in Longitudinal Range-Gorge Region as examples. Biomass, coverage and photosynthesis rate of different plant types on sampling points （at the distances from road of 5, 20, 40, 80, 120 and 200 m） and their control points were estimated on ground. The relations among biomass, coverage, photosynthesis rate were analyzed with an aim to explore the mechanism of the effect caused by highway construction on plant biomass. The results show, i） the impacts of highway construction on plant biomass are both positive and negative. Arbor is mainly negatively impacted, while shrub and herbage are mainly positively impacted. The effect of highway construction decrease with the increase of distance from the road; ii） highway construction exert obvious influence on plant biomass through altering the physiologic processes （reflected by the plant number） and photosynthesis, iii） highway construc- tion will result in the decrease of arbor number, photosynthesis rate and biomass, and increase of plant number, photosynthesis rate and biomass of shrub and herbage.展开更多
基金National Basic Research Program of China, No.2003CB415101
文摘35 surface soil samples and 28 profile soil samples were collected in Longitudinal Range-Gorge Region, Southwest China. The distribution of pollen and spores and their relationship with the environment are analyzed. The results show that there are significant differences in pollen and spores taxa, amounts, dominant taxa and florae between the eastern and western flanks of the Ailao Mountain. There are more pollen and spores taxa, a greater amount and complexity on the western flank of the mountain than those on the eastern flank, while the dominant taxa are more centralized and prominent on the eastern flank of the Ailao Mountain. As for the plant florae distribution, there are significant differences in the number of taxa and composition between the eastern and the western flanks. The analysis of profile pollen and spores assemblage shows that its trends of variation are basically in accordance with the surface pollen and spores, which are also indicators of the environmental differences between the two flanks of the mountain. These significant spatial differences of pollen and spores are very close to the regional topography and climate difference. The mountain running perpendicular to the moisture-laden air flow serves as a barrier and the monsoon circulations the east and the west of the mountain result in different energy-moisture characteristics. We conclude that the main patterns of the pollen and spores can be attributed to the environmental differences.
基金funded by the National Key Research and Development Program of China(Grant No.2016YFA0601600)the Key Project of National Natural Science Foundation of China(Grant No.U1202232)
文摘The mountainous hydrological process usually shows high variation to climate change and human action. In the Longitudinal Range-Gorge Region（LRGR）, Southwestern China and Southeast Asian, the transboundary runoff variations are much more sensitive and complex under the interaction of climate change, ＂corridor-barrier＂ functions in LRGR,and dams building. In this paper, based on the long hydrological records（1956-2013） from three mainstream hydrological stations in Nu River,Lancang River, and Red River, the region runoff variations were analyzed. The results show out： i） the regional runoff changes were strongly influenced by the ＂Corridor-Barrier＂ functions in LRGR from west to east, the variability extent of annual runoff increased, but tended to decrease after 2009 and the reduced extents also increased; ii） the annual runoff change in the three rivers had high concentration degrees; iii） there were periodicities of 33 years of runoff change in Nu River and Lancang River, and 30 years in Red River, and the lower flow period would continue for 8-9 years in Nu River and Lancang River but only for 4 years in Red River; iv） since 2010, as the two mega dams of Xiaowan and Nuozhadu built in Lancang River mainstream, their variations of annual runoff were quite different. The research results could offer a scientific base for sustainable utilization,conservation, and management of the regional water resources
基金the National Natural Science Foundation of China(Grant No.40701173)the Public Benefit Project of Scientific Research on Environmental Protection(Grant No.200809072)。
文摘The major features of different road sections were identified.Methods quantitatively determining the ecological impact of highway construction were discussed,and a demonstration was presented.The Dabao highway(from Dali to Baoshan)and the Sixiao highway(from Simao to Xiaomengyang)passing through the Longitudinal Range-Gorge Region were used as examples in this paper.For the normal road sections having no important species to protect,a method of ecosystem health assessment was introduced to calculate the overall range of the ecological impact of highway construction.For the road sections having plants or soils of interest,indexes were selected and the range of impact was determined using mathematical methods such as regression analysis and variance analysis.The range of impact on animal populations was also discussed in terms of the minimum living areas required by animal populations and the fragmentation caused by highway construction.The results indicate that the zones impacted by highway construction were composed of both regular and anomalous figures,the range of impacts for different landforms of the two sample highways were substantially different;highway construction had dramatic effects on roadside ecosystem health;the impact on soil factors of farmland was greater than 200 m,and the distance may exceed 1000 m when important large animals were considered.
基金Supported by the National Basic Research Program of China(Grant No.2003CB415101)Key Project of Yunnan Natural Science Foundation of China(Grant No.2003C0002Z)
基金Supported by the National Basic Research Program of China(Grant No.2003CB415100)the Climate Change Program of China Meteorological Administration(Grant No.CCSF2007-23)High Performance Computer Center of Yunnan University
基金Supported by the National Basic Research Program of China(Grant No.2003CB415104)the National Natural Science Foundation of China(Grant Nos.40501067 and 40701173)
基金Supported by the National Basic Research Program of China(Grant No.2003CB415100)the Key Project of Natural Science Foundation of Yunnan Province(Grant No.2003C0002Z)
基金Many thanks are due to Dr. Liu Jiang and Prof. Cui Yuanlai for their great contribution to the English translation of the paper. This research was supported by funding from the National Key Project for Basic Research of P.R.China （Grand No. 2003CB415105）, National Key Project for Science and Technology Advance of P.R.China （Grand No. 2002BA901A22）, and the National Natural Science Foundation of China （Grand No. 40261001）.
基金Supported by the National Basic Research Program of China(Grant No.2003CB415104)
文摘Taking two typical rivers in high mountains and steep gorge areas as example,this paper analyzes the spetiotemporal variability of the eco-hydrological characteristics and the driving forces leading to changes.Firstly,based on the species-environmental data processing,this paper adopts canonical correspondence analysis(CCA)method to identify the environmental factors influencing the distribu- tion of river bank vegetation.Secondly,this study uses the ecological diversity Index to represent the spatiotemporel variability of ecological characteristics.Thirdly,this paper uses the multiple correlation method to analyze the relationship between the hydrological factors and meteorological factors,and to identify the key factors leading to the hydrological regime changes.At last,based on the analysis of basin water quality data,this paper analyzes the regularity of spatiotemporal variability and its driving forces.By the systematic analysis on the outcome,we could get that the spatiotemporel distribution of eco-hydrological characteristics shows the regular changes from the upstream to downstream(from the north to the south),and the spatiotemporal variability of eco-hydrological characteristics is typical from the east to the west.Altitude,aspect and water distribution are the primary natural driving forces leading to the spatiotemporel variability of eco-hydrological characteristics;and exploitation and op- eration of hydroelectric power station,construction of road on the river bank,and basin land utilization are the main human driving forces.
基金funded by Key Scientific Research Project of Heilongjiang Provincial Department of Transportation(Grant number MH20200828)National Natural Science Foundation of China joint fund for regional innovation and development(Grant number U20A20315)。
文摘The asphalt pavement longitudinal crack is a common distress in cold regions,resulting from uneven deformation of the subgrade.Analysis of the correlation law between uneven deformation and crack distress is of positive significance for understanding the mechanism of crack initiation,and putting forward treatment measures.In view of the complexity of longitudinal crack inducement and road surface deformation,the grey relational method was used to analyze this relationship.Through long-term monitoring of the vertical deformation data of typical road sections,the vertical deformation law of the pavement surface and its deformation characteristics under the action of temperature field are analyzed.Parameters such as vertical relative deformation,vertical relative deformation rate and vertical differential deformation VDSr were constructed to describe vertical deformation characteristics.Typical distribution characteristics of longitudinal fractures and their length and distribution characteristics are also described.The grey correlation analysis theory was utilized to analyze the relationship between deformation characteristics of sections,cross sections and monitoring points and longitudinal crack characteristics(length and location).The analysis reveals a linear positive correlation or a high correlation between several indicators.This study can provide a deeper understanding of the occurrence and development mechanism of longitudinal cracks in asphalt pavement of cold areas,and give references for the research of road engineering structure,materials and distress prevention.
基金funded by the Transportation Construction Projects from the Ministry of Transport of the People's Republic of China (Contract No.:2002 318 795 02)
文摘At present, embankment longitudinal cracks are a major problem in highways through permafrost regions, and seriously affect traffic safety and the normal operations of the highway. In the past, roadbed height in permafrost regions was relatively low, and embankment cracks were rare and did not affect traffic safety. Thus, highway designers and researchers paid little attention to this problem, and they knew very little about distribution laws and mechanism of embankment longitudinal cracks. Due to this lack of knowledge, there is no uniform opinion on this problem, making it difficult to find measures that will mediate the impact of longi- tudinal crocks. Temperature is a major factor that affects and controls embankment stability in permafrost regions, especially in ice-rich and high-temperature regions, and solar radiation is the principal factor that determines surface temperatures. Under higher embankment, the difference of temperature will be larger between a sunny slope and a shady slope. Hence, the probability for longitudinal cracks generation is higher. In this paper, a survey and analysis of longitudinal cracks along the Qinghai-Tibet Highway were carried out. The longitudinal cracks are found to be related to the road strikes. Solar radiation is considered to play an important role in the generation of longitudinal cracks.
文摘Taking Dabao （from Dali City to Baoshan City, Yunnan Province, China） and Sixiao （from Simao City to Xiaomengyang Town, Yunnan Province, China） highways in Longitudinal Range-Gorge Region as examples. Biomass, coverage and photosynthesis rate of different plant types on sampling points （at the distances from road of 5, 20, 40, 80, 120 and 200 m） and their control points were estimated on ground. The relations among biomass, coverage, photosynthesis rate were analyzed with an aim to explore the mechanism of the effect caused by highway construction on plant biomass. The results show, i） the impacts of highway construction on plant biomass are both positive and negative. Arbor is mainly negatively impacted, while shrub and herbage are mainly positively impacted. The effect of highway construction decrease with the increase of distance from the road; ii） highway construction exert obvious influence on plant biomass through altering the physiologic processes （reflected by the plant number） and photosynthesis, iii） highway construc- tion will result in the decrease of arbor number, photosynthesis rate and biomass, and increase of plant number, photosynthesis rate and biomass of shrub and herbage.
