As one of the methods of urban environmental assessment,sensitivity assessment of urban climatic environment can accurately reflect the problem areas of current urban climate and built environment through visual means...As one of the methods of urban environmental assessment,sensitivity assessment of urban climatic environment can accurately reflect the problem areas of current urban climate and built environment through visual means,and help cities to carry out sustainable transformation and renewal in the stock era to optimize the living environment.Taking the central urban area of Beijing as the research object,the sensitivity of climatic environment was evaluated by meteorological data and built environment element data.The results showed that the distribution of sensitive units showed a centrifugal radiation pattern of"high in the center and low in the periphery".Block units with high climate sensitivity were mostly concentrated in Xicheng District and Dongcheng District,accounting for 93%of the total number of units.Further research showed that complex built environment and lack of elements to regulate climatic environment were the main reasons for the poor local climatic environment in the region with high climate sensitivity.Finally,a comprehensive evaluation of the remolding capacity,renewal potential and future development intensity of different grades of climate sensitive units was given.The results will provide scientific reference for urban renewal and reconstruction under climatic and environmental changes,so as to promote urban sustainable development and improvement of living environment.展开更多
To have a clean, safe, and functional environment is not only essential for the purpose of preservation, but also imperative for safeguarding the most fundamental of human rights. Resolution 45/94 of the United Nation...To have a clean, safe, and functional environment is not only essential for the purpose of preservation, but also imperative for safeguarding the most fundamental of human rights. Resolution 45/94 of the United Nations (UN) General Assembly also stresses and acknowledges that: “all individuals are entitled to live in an environment adequate for their health and wellbeing” (United Nations Digital Library System, 1991). Environmental and climate justice, which: “emerged in the context of the local environmental struggles of directly oppressed groups”, is a global movement dedicated to ensuring equal protection of people’s human rights (i.e., water, health, life, etc.) in the face of the climate crisis. Moreover, health, environment and human rights are part of the 2030 agenda (in particular, SDG 1, SDG 5, SDG 6, SDG 7, SDG 13, SDG 16, SDG 17). Individually, both environmental and climate justice are rooted in an intersectional outlook, by which they highlight the common threads between communities and the people’s inclusion, irrespective of race, class, or gender, in the pursuit of justice. On the other hand, they recognise and acknowledge the role and consequences of climate change in economic, social, and political dimensions;thus, drawing emphasis on the rights of people under the emerging inequities. In the case of Palestine, the Palestinian community is increasingly becoming vulnerable to these effects and the resulting inequalities of climate change. This vulnerability stems from: 1) The right to life;clean WASH;equitable work opportunities;access to resources;and free movement;are all examples of human rights that the Israeli colonial regime infringes upon;2) Infrastructure is essential for climate adaptation: 61% of the West Bank is ultimately barred from building infrastructure (B’Tselem, 2019) and Gaza Strip has major gaps in infrastructure due to intentional destruction by Israel;3) Palestinian deprivation of the sovereign right to natural resources by Israel;4) Apartheid system in water accessibility: Israeli water usage per person is over three times higher than that of Palestinians (their usage is under the WHO recommended minimum per day) (B’Tselem, 2023);and 5) Violent settler attacks. In 2022 alone, the Applied Research Institute-Jerusalem (ARIJ) recorded 1527 settler attacks that targeted land, properties, livestock, agriculture and even Palestinian civilians. The ongoing neglect of these concerns and the persistent colonization of Palestine by Israel unequivocally and unwaveringly affect the human rights of Palestinians. The power dynamics at play especially hamper the Palestinian ability to exercise and fulfill their inalienable human rights and to tackle the obstacles to justice in their environment.展开更多
The new WIOD database allows for improved empirical analysis on a wide range of important environmental research questions.In this paper we demonstrate the scientific power of the WIOD database and analyze very urgent...The new WIOD database allows for improved empirical analysis on a wide range of important environmental research questions.In this paper we demonstrate the scientific power of the WIOD database and analyze very urgent policy questions on the impacts of international trade and structural change on the environment.We apply recent econometric approaches to show the impact of international trade on the environment via its different channels as for instance to increase welfare and potentially affect environmental regulation as well as countries'sector.This approach has become known as the econometric structural decomposition method.In addition to these guidelines by the literature,an econometric panel data approach is offered to shed some light on the impact of structural change and international trade on environmental pressure,where we especially address and solve several endogeneity issues that add further complexity to the analysis.展开更多
During the 2006/07 Antarctic summer,the species population,distribution and reproductive behavior of penguins in areas near the Great Wall Station were investigated.Five species of penguin were recorded:gentoo pengui...During the 2006/07 Antarctic summer,the species population,distribution and reproductive behavior of penguins in areas near the Great Wall Station were investigated.Five species of penguin were recorded:gentoo penguin(Pygoscelis papua),adelie penguin(P.adeliae),chinstrap penguin(P.antarctica), King penguin(Aptenodytes patagonicus) and Emperor penguin(A.forsteri). The first three species bred locally,while the other two species were observed occasionally.Ardley Island is one of the most important breeding areas for penguins.After the breeding season of 2006/07,there were a total of about 17 234 penguins and the breeding success rate was 0.40—1.41.Comparing with historical data,changes in penguin species populations and distribution were analyzed, and their relationships with the environment,climate change and human activity were investigated.展开更多
The development of modern cities has brought about tremendous changes in the climate environment.Faced with complex climate conditions,research on multi-scale climate change in cities is of great significance.The urba...The development of modern cities has brought about tremendous changes in the climate environment.Faced with complex climate conditions,research on multi-scale climate change in cities is of great significance.The urban environmental climate maps and the application of climate atlas tool in Stuttgart,Germany were studied,and the multi-scale application of urban environmental climate maps in Stuttgart,Germany was summarized through the analysis of the pre-planning,current construction situation,and landscape reconstruction of the German"Stuttgart 21"plan case.Besides,other important measures to cope with climate change in German were proposed,and finally multi-scale practical strategies to cope with urban climate and environment were summarized to provide ideas and methods for improving China’s future urban climate environment.展开更多
The use of Geographic Information System (GIS) has significantly helped managers provide optimal models of sustainable agricultural development, identify local features related to agricultural production and their pro...The use of Geographic Information System (GIS) has significantly helped managers provide optimal models of sustainable agricultural development, identify local features related to agricultural production and their proper zoning, identify agricultural needs and constraints and finally provide the appropriate structure of land use. The main purpose of this study was to determine areas capable of cultivating Pistachio according to the parameters affecting the Pistachio cultivation in Roshtkhar town. Statistics of meteorological stations of the town were taken from Meteorology Organization of Khorasan Razavi for the period of 1989-2010 in order to determine climatic parameters required to cultivate Pistachio. For mapping surface elevation, slope, aspect, and TIN of the geographic organization of armed forces with a scale of 1:250,000 topographic maps were used. For mapping vegetation and land use in the area under study, land capability map of the area on a scale of 1:250,000 from the institute of soil and water was used. Also information on cultivation and annual production of agricultural statistics, published by Agriculture was used. Finally, it was concluded that the northeast and southwest of Roshtkhar town are the most prone areas to cultivate Pistachio.展开更多
Dissolved organic matter (DOM) is closely linked to human activities in drainage basins and plays a crucial role in maintaining ecosystem functioning and reflecting environmental quality. However, the impacts of clima...Dissolved organic matter (DOM) is closely linked to human activities in drainage basins and plays a crucial role in maintaining ecosystem functioning and reflecting environmental quality. However, the impacts of climate and anthropogenic-induced changes on DOM in riverine systems under increasingly warming conditions still need to be better understood, particularly at large regional scales. To address this knowledge gap, we analyzed a dataset containing 386 published measurements for nine major Chinese river systems, examining dissolved organic carbon (DOC) concentrations and optical properties of chromophoric DOM (CDOM) under diverse envi- ronmental conditions, including mean air temperature, precipitation, surface solar radiation, population density, and land use. Our findings indicate that riverine DOC concentrations are significantly higher in northern China (at ∼46.8%) than in the south. This disparity is primarily due to the high input of soil erosion-induced DOM from drying-affected lands (57.0%), farmland (49.1%), and forests in the north. The high temperate and strong hydrological conditions would lead to DOM degradation easily in the riverine system in the south of China. Our study highlights that various climatic and anthropogenic factors, such as agriculture, vegetation coverage, soil erosion, surface solar radiation, and precipitation, individually or in combination, can affect DOM dynamics in river systems. Therefore, considering alterations in DOM dynamics resulting from climate and environmental changes is crucial for carbon-neutral policies and sustainable river ecosystem assessments.展开更多
Two decades have passed since China and Japan jointly launched hydrological & climatological observations on the glaciers in Tanggula Pass, Tibetan Plateau. Although the research institutions involved have been eithe...Two decades have passed since China and Japan jointly launched hydrological & climatological observations on the glaciers in Tanggula Pass, Tibetan Plateau. Although the research institutions involved have been either restructured or renamed, their work, between 1989 and 1993, was ground-breaking and remains significant even to this day. Some observation sites established at that time are still utilized for large-scaled projects sponsored by GAME/Tibet, NSFC (Natural Science Foundation of China) and the Major State Basic Research Development Program of China (973 Program). Recently, a glacier monitoring system has been established on the cap of Dongkemadi Glacier, and is expected to make further contributions to research on the change of the cryospheric and climatic environment in the area.展开更多
To provide a genetic basis for japonica rice breeding, the genetic similarity and cluster of 139 accessions of improved japonica rice varieties from 12 provinces and cities of China were analyzed using 34 SSR markers....To provide a genetic basis for japonica rice breeding, the genetic similarity and cluster of 139 accessions of improved japonica rice varieties from 12 provinces and cities of China were analyzed using 34 SSR markers. Totally 198 alleles were detected among these improved japonica rice varieties with the average number of alleles per pair of primers was 5.3235. RM320, RM531, RM1, RM286, and RM336 showed more alleles, which were 15, 12, 11, 9, and 9, respectively. RM320, RM336, RM286 and RM531 showed higher genetic diversity indexes; which were 2.3324, 2.0292, 1.8996, and 1.7820, respectively. The range of genetic similar index among improved japonica rice varieties from different provinces was from 0.321 to 0.914, with the average of 0.686. There was a high genetic similarity among improved japonica rice varieties from Heilongjiang, Jilin, Liaoning, Ningxia, and Yunnan, which were located in similar latitude or similar ecological environment, while there was a low genetic similarity between improved japonica rice varieties from Guizhou and Jiangsu, and other provinces which were located in more different latitudes and ecological environments. The markers of RM320, RM531, RM1, RM286, and RM336 fit to be used in analysis of genetic diversity for improved japonica rice variety. The genetic similarity among improved japonica rice varieties from different provinces was closely associated with genetic basis of parents, and was also correlated with latitude and ecological environment where the varieties were bred.展开更多
Dome Argus (Dome A) in East Antarctica is a potentially likely site to meet one of the major objectives of the International Partnerships in Ice Core Sciences (IPICS) on the oldest ice core, and thus has aroused...Dome Argus (Dome A) in East Antarctica is a potentially likely site to meet one of the major objectives of the International Partnerships in Ice Core Sciences (IPICS) on the oldest ice core, and thus has aroused wide public and scientific interest. Since 2004/2005, many glaciological investigations have been conducted in this region. These have included GPS and ground-penetrating radar surveys, snow pit and ice core drilling, stake network measurements, and meteorological observations. In this article, the main results of these glaciological investigations in the Dome A region are summarized. We present details of the surface mass balance on different timescales and its spatial variability, geochemical characteristics of the surface snow, and paleo-environment reconstruction of ice cores. Finally, perspectives on the prospects for future studies are suggested.展开更多
Ultraviolet(UV) radiation has significant effects on ecosystems, environments, and human health, as well as atmospheric processes and climate change. Two ultraviolet radiation datasets are described in this paper. O...Ultraviolet(UV) radiation has significant effects on ecosystems, environments, and human health, as well as atmospheric processes and climate change. Two ultraviolet radiation datasets are described in this paper. One contains hourly observations of UV radiation measured at 40 Chinese Ecosystem Research Network stations from 2005 to 2015. CUV3 broadband radiometers were used to observe the UV radiation, with an accuracy of 5%, which meets the World Meteorology Organization's measurement standards. The extremum method was used to control the quality of the measured datasets. The other dataset contains daily cumulative UV radiation estimates that were calculated using an all-sky estimation model combined with a hybrid model. The reconstructed daily UV radiation data span from 1961 to 2014. The mean absolute bias error and root-mean-square error are smaller than 30% at most stations, and most of the mean bias error values are negative, which indicates underestimation of the UV radiation intensity. These datasets can improve our basic knowledge of the spatial and temporal variations in UV radiation. Additionally, these datasets can be used in studies of potential ozone formation and atmospheric oxidation, as well as simulations of ecological processes.展开更多
Computer simulation was used for predictive analysis of the effects of weather and soil type on crop yield in the U.S. crop insurance program. The Environmental Policy Integrated Climate (EPIC) model was modified to...Computer simulation was used for predictive analysis of the effects of weather and soil type on crop yield in the U.S. crop insurance program. The Environmental Policy Integrated Climate (EPIC) model was modified to include hail weather events, which completed the modifications necessary to simulate the four most frequent causes of crop yield loss (hail, excessive wet, excessive cold, and excessive dry) associated with soil type in Kansas, USA. At the region level, per hectare yields were simulated for corn, wheat, soybean, and sorghum. We concluded that it was possible to predict crop yields through computer simulation with greater than 93% accuracy. The hail damage model test indicated EPIC could predict hail-soil-induced yield losses reasonably well (R^2 〉 0.6). The investigation of soil type influence on dryland sorghum and wheat production indicated that Wymore silty clay loam soil and Kenorna silt loam produced the highest sorghum yields statistically; Kuma silt loam, Roxbury silt loam, Crete silty clay loam, and Woodson silt soils produced the second highest sorghum yields statistically; and Richfiled silt loam, Wells loam, and Canadian sandy loam produced the lowest sorghum yields. By contrast, wheat production showed less sensitivity to soil type variation. The less sensitive response of wheat yields to the soil type could be largely due to the unconsidered small-scale variability of soil features.展开更多
To improve seed yield of male sterile line,the relationship between outcrossing rate and climate factors was explored.Data of blooming period,outcrossing rate of male sterile line and climate during 2006–2016 growing...To improve seed yield of male sterile line,the relationship between outcrossing rate and climate factors was explored.Data of blooming period,outcrossing rate of male sterile line and climate during 2006–2016 growing seasons were investigated and analyzed.The shortest blooming period was 18.8 d with mean temperature of 24℃–25℃and 18.5 d with about 125 h natural illumination.More rainfall caused a longer blooming period,and a high outcrossing rate was found with about 100 mm rainfall and the mean temperature of 24℃–25℃.Increased natural illumination time by tapetum lucidum mulching improved outcrossing rate by 42.48%compared tocontrol.Overall,the selective combination of climate and environmental factors could be effective for increasing outcrossing rate and hybrid seed yield in the male sterile line of soybean.展开更多
Accumulated sand-belts refer to those formed along the oasis fringe,especially at the upwind location,due to the accumulation of sand blocked by farmland windbreak. In the 60 years since the foundation of new China,a ...Accumulated sand-belts refer to those formed along the oasis fringe,especially at the upwind location,due to the accumulation of sand blocked by farmland windbreak. In the 60 years since the foundation of new China,a lot of trees have been planted for desertification combating in northwest and north China,thus,accumulated sand-belts were formed at the upwind location. The formation and the ecological effects of the accumulated sand-belts along the oasis fringe is a new scientific concern. To study the formation causes of these belts in Hexi corridor,21 samples were selected,and the height / width of the belts,as well as the vegetation,soil,soil moisture and climatic factors were investigated. This paper analyzed the correlation between the height / width of the belts and the vegetation,soil,soil moisture and climatic factors using the methods of variance analysis,correlation analysis and canonical correlation analysis. The results indicate that: the accumulated sand-belts take a trend of being high and wide in the east whereas low and narrow in the west,and most of the parts tend to be stable; the species on the belts are dominated by Tamarix austromongolica,the vegetation cover and the pure vegetation cover of different dominant species on the leeward slope of the accumulated sand-belts vary significantly. The canonical correlation analysis shows that: the height and width of accumulated sand-belt is the interaction of precipitation,distance to the sand source,leeward vegetation cover and annual average wind speed. Moreover,the height of accumulated sand-belts are negatively correlated to the soil moisture at the depth of 30- 50 cm,air humidity and leeward vegetation cover,and the width of the belts is also negatively correlated with the distance to the sand source. The ecological effects of the accumulated sand-belts are both positive( stopping sands from moving into farmland,protective role as an obstacle)and negative( when the belts decay and activate one day,they will become the new sand sources). At present,there are no signs showing the negative effects of the belts. The ecological effects of the accumulated sand-belts are: firstly the protective role as an obstacle,and secondly to intercept and reduce the sands moving into farmlands.展开更多
Rangeland systems play an important role in ecological stabilization and the terrestrial carbon cycle in arid and semiarid regions. However, little is known about the vegetative carbon dynamics and climatic and topog-...Rangeland systems play an important role in ecological stabilization and the terrestrial carbon cycle in arid and semiarid regions. However, little is known about the vegetative carbon dynamics and climatic and topog- raphical factors that affect vegetative carbon stock in these rangelands. Our goal was to assess vegetative carbon stock by examining meteorological data in conjunction with NDVI (normalized difference vegetation index) time se- ries datasets from 2001-2012. An improved CASA (Carnegie Ames Stanford Approach) model was then applied to simulate the spatiotemporal dynamic variation of vegetative carbon stock, and analyze its response to climatic and topographical factors. We estimated the vegetative carbon stock of rangeland in Gansu province, China to be 4.4×10^14 gC, increasing linearly at an annual rate of 9.8×10^11 gC. The mean vegetative carbon density of the whole rangeland was 136.5 gC m-2. Vegetative carbon density and total carbon varied temporally and spatially and were highly associated with temperature, precipitation and solar radiation. Vegetative carbon density reached the maximal value on elevation at 2500-3500 m, a slope of 〉30°and easterly aspect. The effect of precipitation, tem- perature and solar radiation on the vegetative carbon density of five rangeland types (desert and salinized meadow, steppe, alpine meadow, shrub and tussock, and marginal grassland in the forest) depends on the acquired quantity of water and heat for rangeland plants at all spatial scales. The results of this study provide new evidence for ex- plaining spatiotemporal heterogeneity in vegetative carbon dynamics and responses to global change for rangeland vegetative carbon stock, and offer a theoretical and practical basis for grassland agriculture management in arid and semiarid regions.展开更多
Background:During the last 30 years,the development of geographical information systems and satellites for Earth observation has made important progress in the monitoring of the weather,climate,environmental and anthr...Background:During the last 30 years,the development of geographical information systems and satellites for Earth observation has made important progress in the monitoring of the weather,climate,environmental and anthropogenic factors that influence the reduction or the reemergence of vector-borne diseases.Analyses resulting from the combination of geographical information systems(GIS)and remote sensing have improved knowledge of climatic,environmental,and biodiversity factors influencing vector-borne diseases(VBDs)such as malaria,visceral leishmaniasis,dengue,Rift Valley fever,schistosomiasis,Chagas disease and leptospirosis.These knowledge and products developed using remotely sensed data helped and continue to help decision makers to better allocate limited resources in the fight against VBDs.Main body:Because VBDs are linked to climate and environment,we present here our experience during the last four years working with the projects under the,World Health Organization(WHO)/The Special Programme for Research and Training in Tropical Diseases(TDR)-International Development Research Centre(IDRC)Research Initiative on VBDs and Climate Change to integrate climate and environmental information into research and decision-making processes.The following sections present the methodology we have developed,which uses remote sensing to monitor climate variability,environmental conditions,and their impacts on the dynamics of infectious diseases.We then show how remotely sensed data can be accessed and evaluated and how they can be integrated into research and decision-making processes for mapping risks,and creating Early Warning Systems,using two examples from the WHO TDR projects based on schistosomiasis analysis in South Africa and Trypanosomiasis in Tanzania.Conclusions:The tools presented in this article have been successfully used by the projects under the WHO/TDRIDRC Research Initiative on VBDs and Climate Change.Combined with capacity building,they are an important piece of work which can significantly contribute to the goals of WHO Global Vector Control Response and to the Sustainable Development Goals especially those on health and climate action.展开更多
Eco-environmental changes during interglacials with an astronomical background similar to that of the Holocene are potentially helpful for understanding the future climatic evolution.Marine oxygen isotope stage(MIS)19...Eco-environmental changes during interglacials with an astronomical background similar to that of the Holocene are potentially helpful for understanding the future climatic evolution.Marine oxygen isotope stage(MIS)19 is similar to the Holocene in astronomical background,both being characterized by a low eccentricity of the Earth’s orbit.However,MIS 19 has attracted research attention only recently and therefore less is known about eco-environmental changes during this interval,especially based on terrestrial records.In the Chinese Loess Plateau(CLP),the S7 paleosol can provide valuable terrestrial paleoclimatic and paleoenvironmental record for MIS 19.Here,high-resolution terrestrial snail records from the L8–L7 strata of the Huining,Xifeng and Luochuan sequences in the CLP were analyzed in order to characterize spatio-temporal changes in climate and eco-environment during MIS 20–18.The results show that in all three sections the late part of MIS 20 was dominated by abundant cold-aridiphilous mollusc species,indicating that cold and dry climatic conditions prevailed across the entire CLP,under the strong influence of the winter monsoon.The mollusc fauna of MIS 19 were dominated by warmth-loving and thermohumidiphilous species that enable the definition of two climatic stages.The early part of MIS 19(~790–778 ka)was marked by warm and humid conditions,as evidenced by high abundances of warmth-loving and thermo-humidiphilous species.This interval was slightly warmer than today and it lasted for^12 kyr.The climate of the later part of MIS 19(~778–761 ka)was more moderate,and increased proportions of cold-aridiphilous and warmth-loving species were recorded.The warmth of this period was similar to that of today,but the climatic fluctuations were stronger.During the early part of MIS 18(~761–745 ka),the Xifeng and Luochuan sections in the eastern CLP still maintained high abundances of warmth-loving and thermo-humidiphilous species,indicating that the moderate climatic conditions during late MIS 19 continued during early MIS 18,lasting for another^15 kyr,and that the influence of the summer monsoon remained strong in the eastern CLP during early MIS 18.However,in the western CLP,cold-aridiphilous species in the Huining section became dominant during early MIS 18,reflecting the prevalence of a cold and dry glacial climate,with the strong influence of the winter monsoon.These findings indicate that a steeper climatic gradient and a pronounced regional environmental difference existed between the eastern and western CLP during the early part of MIS 18.Comparison of our mollusc results with the variation of Earth orbital parameters suggested that climate changes in the CLP during MIS 20–18 were likely controlled mainly by insolation changes forced by the configuration of Earth orbital parameters.The unique orbital configuration during the low eccentricity interglacial-to-glacial transition could have strengthened the East Asian summer monsoon which favored the amelioration of the eco-environment in the CLP,especially in the eastern CLP where the summer monsoon exerted a strong influence.Thus we speculate that,under natural climatic conditions,the climate of the CLP may remain in a warm,humid state for another 30 kyr,although climatic instability and the seasonal differences between winter and summer could strengthen.展开更多
High-speed railway aerodynamics is the key basic science for solving the bottleneck problem of high-speed railway development.This paper systematically summarizes the aerodynamic research relating to China’s high-spe...High-speed railway aerodynamics is the key basic science for solving the bottleneck problem of high-speed railway development.This paper systematically summarizes the aerodynamic research relating to China’s high-speed railway network.Seven key research advances are comprehensively discussed,including train aerodynamic drag-reduction technology,train aerodynamic noise-reduction technology,train ventilation technology,train crossing aerodynamics,train/tunnel aerodynamics,train/climate environment aerodynamics,and train/human body aerodynamics.Seven types of railway aerodynamic test platform built by Central South University are introduced.Five major systems for a high-speed railway network—the aerodynamics theoretical system,the aerodynamic shape(train,tunnel,and so on)design system,the aerodynamics evaluation system,the 3D protection system for operational safety of the high-speed railway network,and the high-speed railway aerodynamic test/computation/analysis platform system—are also introduced.Finally,eight future development directions for the field of railway aerodynamics are proposed.For over 30 years,railway aerodynamics has been an important supporting element in the development of China’s high-speed railway network,which has also promoted the development of high-speed railway aerodynamics throughout the world.展开更多
The sedimentary sequence and landscape of the Hobq desert was observed through twelve profiles along five N-S sections extending through the entire desert.Aeolian sands were found to overlie the alluvial,diluvial,and ...The sedimentary sequence and landscape of the Hobq desert was observed through twelve profiles along five N-S sections extending through the entire desert.Aeolian sands were found to overlie the alluvial,diluvial,and lacustrine sediments in this desert.Optically stimulated luminescence(OSL)dating results were obtained from post-IR OSL signals of quartz fractions of sand samples at the bottom of sand dunes and hills by using the Double-SAR protocol.The OSL ages reveal that the latest sand accumulation began around 19 ka in the northwestern part and 9 ka in the eastern part of the Hobq Desert.Around 7 ka,the sand accumulation was strengthened and extended southward and northward 2 ka to develop the present desert landscape.Our study suggests that the aeolian sand accumulation around 19,9 and 7 ka resulted from the weakening of the Asian summer monsoon over this region.However,the rapid development of the present Hobq desert landscape since 2 ka was likely triggered by human activities in this desert.展开更多
Although sudden nocturnal warming events near the earth's surface in Australia and the United States have been examined in previous studies, similar events observed occasionally over the Loess Plateau of Northwest Ch...Although sudden nocturnal warming events near the earth's surface in Australia and the United States have been examined in previous studies, similar events observed occasionally over the Loess Plateau of Northwest China have not yet been investigated. The factors that lead to these warming events in such areas with their unique topography and climate remain not clear. To understand the formation mechanisms and associated thermal and dynamical features, a nocturnal warming event recorded in Gansu Province (northwest of the Loess Plateau) in June 2007 was investigated by using observations and model simulations with the Weather Research and Forecasting (WRF) model. Observations showed that this near-surface warming event lasted for 4 h and the temperature increased by 2.5℃. During this event, a decrease in humidity occurred simultaneously with the increase of temperature. The model simulation showed that the nocturnal warming was caused mainly by the transport of warmer and drier air aloft downward to the surface through enhanced vertical mixing. Wind shear played an important role in inducing the elevated vertical mixing, and it was enhanced by the continuous development of the atmospheric baroclinicity, which converted more potential energy to kinetic energy.展开更多
基金Sponsored by General Project of Natural Science Foundation of Beijing City(8202017)Youth Talent Support Program of 2018 Beijing Municipal University Academic Human Resources Development(PXM2018_014212_000043)。
文摘As one of the methods of urban environmental assessment,sensitivity assessment of urban climatic environment can accurately reflect the problem areas of current urban climate and built environment through visual means,and help cities to carry out sustainable transformation and renewal in the stock era to optimize the living environment.Taking the central urban area of Beijing as the research object,the sensitivity of climatic environment was evaluated by meteorological data and built environment element data.The results showed that the distribution of sensitive units showed a centrifugal radiation pattern of"high in the center and low in the periphery".Block units with high climate sensitivity were mostly concentrated in Xicheng District and Dongcheng District,accounting for 93%of the total number of units.Further research showed that complex built environment and lack of elements to regulate climatic environment were the main reasons for the poor local climatic environment in the region with high climate sensitivity.Finally,a comprehensive evaluation of the remolding capacity,renewal potential and future development intensity of different grades of climate sensitive units was given.The results will provide scientific reference for urban renewal and reconstruction under climatic and environmental changes,so as to promote urban sustainable development and improvement of living environment.
文摘To have a clean, safe, and functional environment is not only essential for the purpose of preservation, but also imperative for safeguarding the most fundamental of human rights. Resolution 45/94 of the United Nations (UN) General Assembly also stresses and acknowledges that: “all individuals are entitled to live in an environment adequate for their health and wellbeing” (United Nations Digital Library System, 1991). Environmental and climate justice, which: “emerged in the context of the local environmental struggles of directly oppressed groups”, is a global movement dedicated to ensuring equal protection of people’s human rights (i.e., water, health, life, etc.) in the face of the climate crisis. Moreover, health, environment and human rights are part of the 2030 agenda (in particular, SDG 1, SDG 5, SDG 6, SDG 7, SDG 13, SDG 16, SDG 17). Individually, both environmental and climate justice are rooted in an intersectional outlook, by which they highlight the common threads between communities and the people’s inclusion, irrespective of race, class, or gender, in the pursuit of justice. On the other hand, they recognise and acknowledge the role and consequences of climate change in economic, social, and political dimensions;thus, drawing emphasis on the rights of people under the emerging inequities. In the case of Palestine, the Palestinian community is increasingly becoming vulnerable to these effects and the resulting inequalities of climate change. This vulnerability stems from: 1) The right to life;clean WASH;equitable work opportunities;access to resources;and free movement;are all examples of human rights that the Israeli colonial regime infringes upon;2) Infrastructure is essential for climate adaptation: 61% of the West Bank is ultimately barred from building infrastructure (B’Tselem, 2019) and Gaza Strip has major gaps in infrastructure due to intentional destruction by Israel;3) Palestinian deprivation of the sovereign right to natural resources by Israel;4) Apartheid system in water accessibility: Israeli water usage per person is over three times higher than that of Palestinians (their usage is under the WHO recommended minimum per day) (B’Tselem, 2023);and 5) Violent settler attacks. In 2022 alone, the Applied Research Institute-Jerusalem (ARIJ) recorded 1527 settler attacks that targeted land, properties, livestock, agriculture and even Palestinian civilians. The ongoing neglect of these concerns and the persistent colonization of Palestine by Israel unequivocally and unwaveringly affect the human rights of Palestinians. The power dynamics at play especially hamper the Palestinian ability to exercise and fulfill their inalienable human rights and to tackle the obstacles to justice in their environment.
文摘The new WIOD database allows for improved empirical analysis on a wide range of important environmental research questions.In this paper we demonstrate the scientific power of the WIOD database and analyze very urgent policy questions on the impacts of international trade and structural change on the environment.We apply recent econometric approaches to show the impact of international trade on the environment via its different channels as for instance to increase welfare and potentially affect environmental regulation as well as countries'sector.This approach has become known as the econometric structural decomposition method.In addition to these guidelines by the literature,an econometric panel data approach is offered to shed some light on the impact of structural change and international trade on environmental pressure,where we especially address and solve several endogeneity issues that add further complexity to the analysis.
基金supported by the National Natural Science Foundation of China(Grants No.40876104D0611)
文摘During the 2006/07 Antarctic summer,the species population,distribution and reproductive behavior of penguins in areas near the Great Wall Station were investigated.Five species of penguin were recorded:gentoo penguin(Pygoscelis papua),adelie penguin(P.adeliae),chinstrap penguin(P.antarctica), King penguin(Aptenodytes patagonicus) and Emperor penguin(A.forsteri). The first three species bred locally,while the other two species were observed occasionally.Ardley Island is one of the most important breeding areas for penguins.After the breeding season of 2006/07,there were a total of about 17 234 penguins and the breeding success rate was 0.40—1.41.Comparing with historical data,changes in penguin species populations and distribution were analyzed, and their relationships with the environment,climate change and human activity were investigated.
基金Sponsored by General Project of Natural Science Foundation of Beijing City(8202017)。
文摘The development of modern cities has brought about tremendous changes in the climate environment.Faced with complex climate conditions,research on multi-scale climate change in cities is of great significance.The urban environmental climate maps and the application of climate atlas tool in Stuttgart,Germany were studied,and the multi-scale application of urban environmental climate maps in Stuttgart,Germany was summarized through the analysis of the pre-planning,current construction situation,and landscape reconstruction of the German"Stuttgart 21"plan case.Besides,other important measures to cope with climate change in German were proposed,and finally multi-scale practical strategies to cope with urban climate and environment were summarized to provide ideas and methods for improving China’s future urban climate environment.
文摘The use of Geographic Information System (GIS) has significantly helped managers provide optimal models of sustainable agricultural development, identify local features related to agricultural production and their proper zoning, identify agricultural needs and constraints and finally provide the appropriate structure of land use. The main purpose of this study was to determine areas capable of cultivating Pistachio according to the parameters affecting the Pistachio cultivation in Roshtkhar town. Statistics of meteorological stations of the town were taken from Meteorology Organization of Khorasan Razavi for the period of 1989-2010 in order to determine climatic parameters required to cultivate Pistachio. For mapping surface elevation, slope, aspect, and TIN of the geographic organization of armed forces with a scale of 1:250,000 topographic maps were used. For mapping vegetation and land use in the area under study, land capability map of the area on a scale of 1:250,000 from the institute of soil and water was used. Also information on cultivation and annual production of agricultural statistics, published by Agriculture was used. Finally, it was concluded that the northeast and southwest of Roshtkhar town are the most prone areas to cultivate Pistachio.
基金the National Natural Science Foun-dation of China(Grants No.41925002,42221001,42230509)received financial support from the Haihe Laboratory of Sustainable Chemical Transformations.
文摘Dissolved organic matter (DOM) is closely linked to human activities in drainage basins and plays a crucial role in maintaining ecosystem functioning and reflecting environmental quality. However, the impacts of climate and anthropogenic-induced changes on DOM in riverine systems under increasingly warming conditions still need to be better understood, particularly at large regional scales. To address this knowledge gap, we analyzed a dataset containing 386 published measurements for nine major Chinese river systems, examining dissolved organic carbon (DOC) concentrations and optical properties of chromophoric DOM (CDOM) under diverse envi- ronmental conditions, including mean air temperature, precipitation, surface solar radiation, population density, and land use. Our findings indicate that riverine DOC concentrations are significantly higher in northern China (at ∼46.8%) than in the south. This disparity is primarily due to the high input of soil erosion-induced DOM from drying-affected lands (57.0%), farmland (49.1%), and forests in the north. The high temperate and strong hydrological conditions would lead to DOM degradation easily in the riverine system in the south of China. Our study highlights that various climatic and anthropogenic factors, such as agriculture, vegetation coverage, soil erosion, surface solar radiation, and precipitation, individually or in combination, can affect DOM dynamics in river systems. Therefore, considering alterations in DOM dynamics resulting from climate and environmental changes is crucial for carbon-neutral policies and sustainable river ecosystem assessments.
基金funded by the Major State Basic Research Development Program of China (973 Program) under Grant No.2010CB951701the Natural ScienceFoundation of China (No.41071042)supported by the Innovation Project of Chinese Academy of Sciences(KZCX2-YW-BR-22)
文摘Two decades have passed since China and Japan jointly launched hydrological & climatological observations on the glaciers in Tanggula Pass, Tibetan Plateau. Although the research institutions involved have been either restructured or renamed, their work, between 1989 and 1993, was ground-breaking and remains significant even to this day. Some observation sites established at that time are still utilized for large-scaled projects sponsored by GAME/Tibet, NSFC (Natural Science Foundation of China) and the Major State Basic Research Development Program of China (973 Program). Recently, a glacier monitoring system has been established on the cap of Dongkemadi Glacier, and is expected to make further contributions to research on the change of the cryospheric and climatic environment in the area.
基金supported by the National Key Technology R&D Program of China(2006BAD13B01)the Protective Program of Crop Germpalsm of China[NB07-2130135(25-30-01)]
文摘To provide a genetic basis for japonica rice breeding, the genetic similarity and cluster of 139 accessions of improved japonica rice varieties from 12 provinces and cities of China were analyzed using 34 SSR markers. Totally 198 alleles were detected among these improved japonica rice varieties with the average number of alleles per pair of primers was 5.3235. RM320, RM531, RM1, RM286, and RM336 showed more alleles, which were 15, 12, 11, 9, and 9, respectively. RM320, RM336, RM286 and RM531 showed higher genetic diversity indexes; which were 2.3324, 2.0292, 1.8996, and 1.7820, respectively. The range of genetic similar index among improved japonica rice varieties from different provinces was from 0.321 to 0.914, with the average of 0.686. There was a high genetic similarity among improved japonica rice varieties from Heilongjiang, Jilin, Liaoning, Ningxia, and Yunnan, which were located in similar latitude or similar ecological environment, while there was a low genetic similarity between improved japonica rice varieties from Guizhou and Jiangsu, and other provinces which were located in more different latitudes and ecological environments. The markers of RM320, RM531, RM1, RM286, and RM336 fit to be used in analysis of genetic diversity for improved japonica rice variety. The genetic similarity among improved japonica rice varieties from different provinces was closely associated with genetic basis of parents, and was also correlated with latitude and ecological environment where the varieties were bred.
基金supported by the Natural Science Foundation of China (Grant no. 41330526)Natural Science Foundation of Shanghai (Grant no. 17ZR1433200)National Key R & D Program of China (Grant no. 2016YFC1400302)
文摘Dome Argus (Dome A) in East Antarctica is a potentially likely site to meet one of the major objectives of the International Partnerships in Ice Core Sciences (IPICS) on the oldest ice core, and thus has aroused wide public and scientific interest. Since 2004/2005, many glaciological investigations have been conducted in this region. These have included GPS and ground-penetrating radar surveys, snow pit and ice core drilling, stake network measurements, and meteorological observations. In this article, the main results of these glaciological investigations in the Dome A region are summarized. We present details of the surface mass balance on different timescales and its spatial variability, geochemical characteristics of the surface snow, and paleo-environment reconstruction of ice cores. Finally, perspectives on the prospects for future studies are suggested.
文摘Ultraviolet(UV) radiation has significant effects on ecosystems, environments, and human health, as well as atmospheric processes and climate change. Two ultraviolet radiation datasets are described in this paper. One contains hourly observations of UV radiation measured at 40 Chinese Ecosystem Research Network stations from 2005 to 2015. CUV3 broadband radiometers were used to observe the UV radiation, with an accuracy of 5%, which meets the World Meteorology Organization's measurement standards. The extremum method was used to control the quality of the measured datasets. The other dataset contains daily cumulative UV radiation estimates that were calculated using an all-sky estimation model combined with a hybrid model. The reconstructed daily UV radiation data span from 1961 to 2014. The mean absolute bias error and root-mean-square error are smaller than 30% at most stations, and most of the mean bias error values are negative, which indicates underestimation of the UV radiation intensity. These datasets can improve our basic knowledge of the spatial and temporal variations in UV radiation. Additionally, these datasets can be used in studies of potential ozone formation and atmospheric oxidation, as well as simulations of ecological processes.
基金supported by the Risk Management Agency Strategic Data Acquisition and Analysis Division Research Fund of United States Department of Agriculture (No.53-3151-2-00017)
文摘Computer simulation was used for predictive analysis of the effects of weather and soil type on crop yield in the U.S. crop insurance program. The Environmental Policy Integrated Climate (EPIC) model was modified to include hail weather events, which completed the modifications necessary to simulate the four most frequent causes of crop yield loss (hail, excessive wet, excessive cold, and excessive dry) associated with soil type in Kansas, USA. At the region level, per hectare yields were simulated for corn, wheat, soybean, and sorghum. We concluded that it was possible to predict crop yields through computer simulation with greater than 93% accuracy. The hail damage model test indicated EPIC could predict hail-soil-induced yield losses reasonably well (R^2 〉 0.6). The investigation of soil type influence on dryland sorghum and wheat production indicated that Wymore silty clay loam soil and Kenorna silt loam produced the highest sorghum yields statistically; Kuma silt loam, Roxbury silt loam, Crete silty clay loam, and Woodson silt soils produced the second highest sorghum yields statistically; and Richfiled silt loam, Wells loam, and Canadian sandy loam produced the lowest sorghum yields. By contrast, wheat production showed less sensitivity to soil type variation. The less sensitive response of wheat yields to the soil type could be largely due to the unconsidered small-scale variability of soil features.
基金supported by the Earmarked Fund for China Agricultural Research System(CARS-04)。
文摘To improve seed yield of male sterile line,the relationship between outcrossing rate and climate factors was explored.Data of blooming period,outcrossing rate of male sterile line and climate during 2006–2016 growing seasons were investigated and analyzed.The shortest blooming period was 18.8 d with mean temperature of 24℃–25℃and 18.5 d with about 125 h natural illumination.More rainfall caused a longer blooming period,and a high outcrossing rate was found with about 100 mm rainfall and the mean temperature of 24℃–25℃.Increased natural illumination time by tapetum lucidum mulching improved outcrossing rate by 42.48%compared tocontrol.Overall,the selective combination of climate and environmental factors could be effective for increasing outcrossing rate and hybrid seed yield in the male sterile line of soybean.
基金Supported by the Pre-phase Project of the 973 Program(2014CB460611)
文摘Accumulated sand-belts refer to those formed along the oasis fringe,especially at the upwind location,due to the accumulation of sand blocked by farmland windbreak. In the 60 years since the foundation of new China,a lot of trees have been planted for desertification combating in northwest and north China,thus,accumulated sand-belts were formed at the upwind location. The formation and the ecological effects of the accumulated sand-belts along the oasis fringe is a new scientific concern. To study the formation causes of these belts in Hexi corridor,21 samples were selected,and the height / width of the belts,as well as the vegetation,soil,soil moisture and climatic factors were investigated. This paper analyzed the correlation between the height / width of the belts and the vegetation,soil,soil moisture and climatic factors using the methods of variance analysis,correlation analysis and canonical correlation analysis. The results indicate that: the accumulated sand-belts take a trend of being high and wide in the east whereas low and narrow in the west,and most of the parts tend to be stable; the species on the belts are dominated by Tamarix austromongolica,the vegetation cover and the pure vegetation cover of different dominant species on the leeward slope of the accumulated sand-belts vary significantly. The canonical correlation analysis shows that: the height and width of accumulated sand-belt is the interaction of precipitation,distance to the sand source,leeward vegetation cover and annual average wind speed. Moreover,the height of accumulated sand-belts are negatively correlated to the soil moisture at the depth of 30- 50 cm,air humidity and leeward vegetation cover,and the width of the belts is also negatively correlated with the distance to the sand source. The ecological effects of the accumulated sand-belts are both positive( stopping sands from moving into farmland,protective role as an obstacle)and negative( when the belts decay and activate one day,they will become the new sand sources). At present,there are no signs showing the negative effects of the belts. The ecological effects of the accumulated sand-belts are: firstly the protective role as an obstacle,and secondly to intercept and reduce the sands moving into farmlands.
基金National Natural Science Foundation of China(30960264 and 31160475)Science and technology program of Gansu province(1107RJYA058)+1 种基金open project of Key Laboratory of Grassland Ecosystem(Gansu Agricultural University),Ministry of Education(CYZS–2011014)Fund of technology innovation commemorated Sheng Tongsheng in Gansu Agricultural University(GSAU-STS-1304 and GSAU-STS-1505)
文摘Rangeland systems play an important role in ecological stabilization and the terrestrial carbon cycle in arid and semiarid regions. However, little is known about the vegetative carbon dynamics and climatic and topog- raphical factors that affect vegetative carbon stock in these rangelands. Our goal was to assess vegetative carbon stock by examining meteorological data in conjunction with NDVI (normalized difference vegetation index) time se- ries datasets from 2001-2012. An improved CASA (Carnegie Ames Stanford Approach) model was then applied to simulate the spatiotemporal dynamic variation of vegetative carbon stock, and analyze its response to climatic and topographical factors. We estimated the vegetative carbon stock of rangeland in Gansu province, China to be 4.4×10^14 gC, increasing linearly at an annual rate of 9.8×10^11 gC. The mean vegetative carbon density of the whole rangeland was 136.5 gC m-2. Vegetative carbon density and total carbon varied temporally and spatially and were highly associated with temperature, precipitation and solar radiation. Vegetative carbon density reached the maximal value on elevation at 2500-3500 m, a slope of 〉30°and easterly aspect. The effect of precipitation, tem- perature and solar radiation on the vegetative carbon density of five rangeland types (desert and salinized meadow, steppe, alpine meadow, shrub and tussock, and marginal grassland in the forest) depends on the acquired quantity of water and heat for rangeland plants at all spatial scales. The results of this study provide new evidence for ex- plaining spatiotemporal heterogeneity in vegetative carbon dynamics and responses to global change for rangeland vegetative carbon stock, and offer a theoretical and practical basis for grassland agriculture management in arid and semiarid regions.
基金UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases(TDR),Geneva,Switzerland and the International Development Research Center,CanadaNASA ROSES grant:“NASA SERVIR PROJECT NNX12AQ70G Development and Implementation of Flood Risk Mapping,Water Bodies Monitoring and Climate Information for Disaster Management and Human Health。
文摘Background:During the last 30 years,the development of geographical information systems and satellites for Earth observation has made important progress in the monitoring of the weather,climate,environmental and anthropogenic factors that influence the reduction or the reemergence of vector-borne diseases.Analyses resulting from the combination of geographical information systems(GIS)and remote sensing have improved knowledge of climatic,environmental,and biodiversity factors influencing vector-borne diseases(VBDs)such as malaria,visceral leishmaniasis,dengue,Rift Valley fever,schistosomiasis,Chagas disease and leptospirosis.These knowledge and products developed using remotely sensed data helped and continue to help decision makers to better allocate limited resources in the fight against VBDs.Main body:Because VBDs are linked to climate and environment,we present here our experience during the last four years working with the projects under the,World Health Organization(WHO)/The Special Programme for Research and Training in Tropical Diseases(TDR)-International Development Research Centre(IDRC)Research Initiative on VBDs and Climate Change to integrate climate and environmental information into research and decision-making processes.The following sections present the methodology we have developed,which uses remote sensing to monitor climate variability,environmental conditions,and their impacts on the dynamics of infectious diseases.We then show how remotely sensed data can be accessed and evaluated and how they can be integrated into research and decision-making processes for mapping risks,and creating Early Warning Systems,using two examples from the WHO TDR projects based on schistosomiasis analysis in South Africa and Trypanosomiasis in Tanzania.Conclusions:The tools presented in this article have been successfully used by the projects under the WHO/TDRIDRC Research Initiative on VBDs and Climate Change.Combined with capacity building,they are an important piece of work which can significantly contribute to the goals of WHO Global Vector Control Response and to the Sustainable Development Goals especially those on health and climate action.
基金supported by the National Natural Science Foundation of China(Grant No.41430103)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB26000000)the China Postdoctoral Science Foundation(Grant No.2017M620895)。
文摘Eco-environmental changes during interglacials with an astronomical background similar to that of the Holocene are potentially helpful for understanding the future climatic evolution.Marine oxygen isotope stage(MIS)19 is similar to the Holocene in astronomical background,both being characterized by a low eccentricity of the Earth’s orbit.However,MIS 19 has attracted research attention only recently and therefore less is known about eco-environmental changes during this interval,especially based on terrestrial records.In the Chinese Loess Plateau(CLP),the S7 paleosol can provide valuable terrestrial paleoclimatic and paleoenvironmental record for MIS 19.Here,high-resolution terrestrial snail records from the L8–L7 strata of the Huining,Xifeng and Luochuan sequences in the CLP were analyzed in order to characterize spatio-temporal changes in climate and eco-environment during MIS 20–18.The results show that in all three sections the late part of MIS 20 was dominated by abundant cold-aridiphilous mollusc species,indicating that cold and dry climatic conditions prevailed across the entire CLP,under the strong influence of the winter monsoon.The mollusc fauna of MIS 19 were dominated by warmth-loving and thermohumidiphilous species that enable the definition of two climatic stages.The early part of MIS 19(~790–778 ka)was marked by warm and humid conditions,as evidenced by high abundances of warmth-loving and thermo-humidiphilous species.This interval was slightly warmer than today and it lasted for^12 kyr.The climate of the later part of MIS 19(~778–761 ka)was more moderate,and increased proportions of cold-aridiphilous and warmth-loving species were recorded.The warmth of this period was similar to that of today,but the climatic fluctuations were stronger.During the early part of MIS 18(~761–745 ka),the Xifeng and Luochuan sections in the eastern CLP still maintained high abundances of warmth-loving and thermo-humidiphilous species,indicating that the moderate climatic conditions during late MIS 19 continued during early MIS 18,lasting for another^15 kyr,and that the influence of the summer monsoon remained strong in the eastern CLP during early MIS 18.However,in the western CLP,cold-aridiphilous species in the Huining section became dominant during early MIS 18,reflecting the prevalence of a cold and dry glacial climate,with the strong influence of the winter monsoon.These findings indicate that a steeper climatic gradient and a pronounced regional environmental difference existed between the eastern and western CLP during the early part of MIS 18.Comparison of our mollusc results with the variation of Earth orbital parameters suggested that climate changes in the CLP during MIS 20–18 were likely controlled mainly by insolation changes forced by the configuration of Earth orbital parameters.The unique orbital configuration during the low eccentricity interglacial-to-glacial transition could have strengthened the East Asian summer monsoon which favored the amelioration of the eco-environment in the CLP,especially in the eastern CLP where the summer monsoon exerted a strong influence.Thus we speculate that,under natural climatic conditions,the climate of the CLP may remain in a warm,humid state for another 30 kyr,although climatic instability and the seasonal differences between winter and summer could strengthen.
文摘High-speed railway aerodynamics is the key basic science for solving the bottleneck problem of high-speed railway development.This paper systematically summarizes the aerodynamic research relating to China’s high-speed railway network.Seven key research advances are comprehensively discussed,including train aerodynamic drag-reduction technology,train aerodynamic noise-reduction technology,train ventilation technology,train crossing aerodynamics,train/tunnel aerodynamics,train/climate environment aerodynamics,and train/human body aerodynamics.Seven types of railway aerodynamic test platform built by Central South University are introduced.Five major systems for a high-speed railway network—the aerodynamics theoretical system,the aerodynamic shape(train,tunnel,and so on)design system,the aerodynamics evaluation system,the 3D protection system for operational safety of the high-speed railway network,and the high-speed railway aerodynamic test/computation/analysis platform system—are also introduced.Finally,eight future development directions for the field of railway aerodynamics are proposed.For over 30 years,railway aerodynamics has been an important supporting element in the development of China’s high-speed railway network,which has also promoted the development of high-speed railway aerodynamics throughout the world.
基金supported by the National Natural Science Foundation of China(Grant Nos.41172163,40972116)the Chinese National Programs for Fundamental Research and Development(Grant No.2010CB950202)+1 种基金the program for New Century Excellent Talents in University(Grant No.NCET-12-0251)the Fundamental Research Funds for the Central Universities(Grant No.LZUJBKY-2013-K17)
文摘The sedimentary sequence and landscape of the Hobq desert was observed through twelve profiles along five N-S sections extending through the entire desert.Aeolian sands were found to overlie the alluvial,diluvial,and lacustrine sediments in this desert.Optically stimulated luminescence(OSL)dating results were obtained from post-IR OSL signals of quartz fractions of sand samples at the bottom of sand dunes and hills by using the Double-SAR protocol.The OSL ages reveal that the latest sand accumulation began around 19 ka in the northwestern part and 9 ka in the eastern part of the Hobq Desert.Around 7 ka,the sand accumulation was strengthened and extended southward and northward 2 ka to develop the present desert landscape.Our study suggests that the aeolian sand accumulation around 19,9 and 7 ka resulted from the weakening of the Asian summer monsoon over this region.However,the rapid development of the present Hobq desert landscape since 2 ka was likely triggered by human activities in this desert.
基金Supported by the National Natural Science Foundation of China(41375109)National(Key)Basic Research and Development(973)Program of China(2014CB441406)Key Laboratory of Meteorological Disaster of Ministry of Education,Nanjing University of Information Science&Technology(KLME1412)
文摘Although sudden nocturnal warming events near the earth's surface in Australia and the United States have been examined in previous studies, similar events observed occasionally over the Loess Plateau of Northwest China have not yet been investigated. The factors that lead to these warming events in such areas with their unique topography and climate remain not clear. To understand the formation mechanisms and associated thermal and dynamical features, a nocturnal warming event recorded in Gansu Province (northwest of the Loess Plateau) in June 2007 was investigated by using observations and model simulations with the Weather Research and Forecasting (WRF) model. Observations showed that this near-surface warming event lasted for 4 h and the temperature increased by 2.5℃. During this event, a decrease in humidity occurred simultaneously with the increase of temperature. The model simulation showed that the nocturnal warming was caused mainly by the transport of warmer and drier air aloft downward to the surface through enhanced vertical mixing. Wind shear played an important role in inducing the elevated vertical mixing, and it was enhanced by the continuous development of the atmospheric baroclinicity, which converted more potential energy to kinetic energy.