Based on the data of gross domestic product(GDP),industrial added value and the proportion of industrial employees from 2000 to 2008,this paper studies the effect of industrial structure change on the regional economi...Based on the data of gross domestic product(GDP),industrial added value and the proportion of industrial employees from 2000 to 2008,this paper studies the effect of industrial structure change on the regional economic growth of Beijing-Tianjin-Hebei Metropolitan Region in China using the shift-share method.The results show that:1) In the 21st century,the industrial output of three industries,namely,primary,secondary,and tertiary,and the GDP grew rapidly in the study period.The tertiary industry grew the fastest;it had the largest contribution to the GDP and mean-while had become the most competitive industry in the metropolitan region.2) The development of cities within the region was not balanced.Firstly,compared with Tianjin,Beijing,as one of the two core cities,was more rational in the industrial structure.Secondly,the surrounding eight cities,which are Shijiazhuang,Qinhuangdao,Tangshan,Langfang,Baoding,Cangzhou,Zhangjiakou,and Chengde,were all uncompetitive than the two core cities.3) There was a great industrial gradient in the region(especially between the two core cities and the cities of Tangshan,Baoding,Zhangjia-kou,Chengde,Cangzhou,and Langfang).As a result,it is foreseeable that the industry transfer in the Bei-jing-Tianjin-Hebei Metropolitan Region will be one of the trends in regional development,and the industry transfer is inevitably to promote the regional integration.展开更多
In order to analyze the factors influencing carbon emissions in the region of Beijing-Tianjin-Hebei and to explore the pathways to developing a low-carbon economy,this paper begins with the terminal energy consumption...In order to analyze the factors influencing carbon emissions in the region of Beijing-Tianjin-Hebei and to explore the pathways to developing a low-carbon economy,this paper begins with the terminal energy consumption of three industries and residential consumption,and constructs an identical equation which is composed of population size,level of economic development,energy intensity,the proportion of energy consumption,energy structure,and the coefficient of carbon emissions.Based on the data of terminal energy consumption during 2000-2012,various factors are analyzed and their contribution is measured by Logarithmic Mean Divisia Index(LMDI).The results show that the levels of population and economy have a positive driving effect while energy intensity,energy structure,and carbon intensity have a negative driving effect;the proportion of energy consumption had a negative driving effect prior to 2006,then changed to positive.Among suggestions for a low-carbon economy are controlling population size,improving the quality of economic development,supporting research into new energy technology,accelerating regional integration and optimizing industrial structure,and enhancing environmental protection and spreading the concept of a low-carbon economy.展开更多
Since China broke the blockade and opened the country to the outside world, many township enterprises develop quickly. Together with the pollution caused by China’s coal-burning as the main source of national energy,...Since China broke the blockade and opened the country to the outside world, many township enterprises develop quickly. Together with the pollution caused by China’s coal-burning as the main source of national energy, the pollution caused by small and medium-sized enterprises in towns and villages due to their small investment, low technology level and weak environmental awareness, and the pollution caused by a sharp increase in motor vehicle emissions lead to the fact that fog-haze has been rampant in China’s cities and urban agglomerations for nearly two decades, especially in the Beijing-Tianjin-Hebei region. This paper sorted out the current situation of fog-haze and analyzed the causes of fog-haze from the two aspects of natural and man-made causes, discussed the harms of fog-haze to human body, environment and life, and put forward the concrete measures to solve the fog-haze problem.展开更多
As an effective environment governance tool,environment governance performance evaluation is an important content and method to promote the modernization of environment governance system and governance ability.The env...As an effective environment governance tool,environment governance performance evaluation is an important content and method to promote the modernization of environment governance system and governance ability.The environmental pollution of the Beijing-Tianjin-Hebei region has typical cross-administrative characteristics.Based on the analysis of the major environmental pollution problems in the Beijing-Tianjin-Hebei region,according to the international environment governance PSR model,a performance evaluation system that applies to the environment governance of Beijing-Tianjin-Hebei region is established.Meanwhile,the principal component analysis method is applied to conduct an empirical analysis of the environmental governance panel data for the 13 major cities in the Beijing-Tianjin-Hebei region from 2014 to 2016.The results show that most of the cities in the Beijing-Tianjin-Hebei region attach great importance to reduction of emission and pollutants,continuously alleviating the stress of environmental governance.However,the overall improvement of the environment governance performance in Beijing-Tianjin-Hebei region has presented a polarization imbalance.There is a clear tendency for subjective biases in the implementation of environment governance and a lack of comprehensive and systematic governance.According to the environment governance performance evaluation result of Beijing-Tianjin-Hebei region,the cross-administrative regional environment governance should improve the environment governance performance evaluation system as soon as possible,strengthen the consistency of the environment governance objectives,and implement comprehensive and systematic governance for the regional environment.展开更多
This paper adopts the perspective of urban economic linkage and the modified urban economic gravity model to conduct a comparative analysis of the economic gravity among cities in China’s three major urban agglomerat...This paper adopts the perspective of urban economic linkage and the modified urban economic gravity model to conduct a comparative analysis of the economic gravity among cities in China’s three major urban agglomerations,including the Beijing-Tianjin-Hebei region,the Yangtze River Delta,and the Pearl River Delta.The results show that,despite the ever-tightening economic linkages among cities in the urban agglomerations,the development of the Beijing-Tianjin-Hebei region falls behind that of the Yangtze River Delta and the Pearl River Delta in terms of coordination,closeness,and balance.The economic linkages among cities in the Beijing-Tianjin-Hebei region are not as cohesive as they could be and display a significant“siphon effect”through Beijing and Tianjin as well as a prominently unidirectional economic flow.This study suggests that efforts should be put into directing the orderly flow of resources from Beijing and Tianjin to cities in Hebei and promoting a balanced economic flow among cities,thus facilitating the coordination of regional development.展开更多
In this study, regional persistent haze events(RPHEs) in the Beijing–Tianjin–Hebei(BTH) region were identified based on the Objective Identification Technique for Regional Extreme Events for the period 1980–201...In this study, regional persistent haze events(RPHEs) in the Beijing–Tianjin–Hebei(BTH) region were identified based on the Objective Identification Technique for Regional Extreme Events for the period 1980–2013. The formation mechanisms of the severe RPHEs were investigated with focus on the atmospheric circulation and dynamic mechanisms. Results indicated that:(1) 49 RPHEs occurred during the past 34 years.(2) The severe RPHEs could be categorized into two types according to the large-scale circulation, i.e. the zonal westerly airflow(ZWA) type and the high-pressure ridge(HPR) type. When the ZWA-type RPHEs occurred, the BTH region was controlled by near zonal westerly airflow in the mid–upper troposphere.Southwesterly winds prevailed in the lower troposphere, and near-surface wind speeds were only 1–2 ms^-1. Warm and humid air originating from the northwestern Pacific was transported into the region, where the relative humidity was 70% to 80%, creating favorable moisture conditions. When the HPR-type RPHEs appeared, northwesterly airflow in the mid–upper troposphere controlled the region. Westerly winds prevailed in the lower troposphere and the moisture conditions were relatively weak.(3) Descending motion in the mid-lower troposphere caused by the above two circulation types provided a crucial dynamic mechanism for the formation of the two types of RPHEs. The descending motion contributed to a reduction in the height of the planetary boundary layer(PBL), which generated an inversion in the lower troposphere. This inversion trapped the abundant pollution and moisture in the lower PBL, leading to high concentrations of pollutants.展开更多
The existing models of population distribution often focus on the region with a single city or even multiple centers, and lack the detailed explorations of the common and special type of urbanization areas with two ce...The existing models of population distribution often focus on the region with a single city or even multiple centers, and lack the detailed explorations of the common and special type of urbanization areas with two centers. Taking Beijing-Tianjin region of China, which is a distinct dual-nuclei metropolitan area in the world, as an example and choosing Landsat-5 TM image in 2005, population, etc. as the data, this paper devotes to comprehending and illustrating a model of Cassini growth of population between the two metropolitan cities through the research of spatial population distribution pattern, aided with RS and GIS techniques. Main technical processes include Kriging interpolation of the population data and character simulation of the Cassini ovals. According to the calculation of a/b, a key characteristic index of Cassini growth model, the spatial structures of population distribution were given. When a/b〈 1, it is a curve with two separated loops with a population density more than 3000 persons/km^2. When a/b=1, it is a lemniscate curve with a population density about 3000 persons/km^2. When 1〈a/b〈 √2, it is a dog-bone shaped concave curve with a population density between 500-3000 persons/km^2. When a/b= √2, it is an oblate curve with a population density about 500 persons/km^2. When a/b〉 √2, there is an oval-shaped convex curve with a population density less than 500 persons/km^2. The results show that owing to the combined action and influence of the regional dual-nuclei, the population distribution of Beijing-Tianjin region is in accord with Cassini model significantly. Therefore, there is Cassini growth of population between the two metropolitan cities in Beijing-Tianjin region. In addition, the process of Cassini growth has extraordinarily instructive significance for judging the development stages of the dual-nuclei metropolitan areas.展开更多
Hail is one of the important weather disasters that affects the Beijing-Tianjin(BT) region.To better understand and to improve the forecasting of hail events over the BT region,the precursor weather conditions for hai...Hail is one of the important weather disasters that affects the Beijing-Tianjin(BT) region.To better understand and to improve the forecasting of hail events over the BT region,the precursor weather conditions for hail based on 30 previous hail events were derived.It was found that the high-level trough and low-level cold front over the Mongolian region,the accumulated convective available potential energy,the decrease of the height of the 0℃-isotherm in the morning,and the persistence and intensification of these factors from morning to afternoon are valuable clues for forecasting the occurrence of hail events over the BT region.展开更多
Aiming for the restoration of degraded ecosystems, many ecological engineering projects have been implemented around the world. This study investigates the ecological engineering project effectiveness on vegetation re...Aiming for the restoration of degraded ecosystems, many ecological engineering projects have been implemented around the world. This study investigates the ecological engineering project effectiveness on vegetation restoration in the Beijing-Tianjin Sand Source Region(BTSSR) from 2000 to 2010 based on the rain use efficiency(RUE) trend in relation to the land cover. More than half of the BTSSR experienced a vegetation productivity increase from 2000 to 2010, with the increasing intensity being sensitive to the indicators chosen. A clear tendency towards smaller increasing areas was shown when using the net primary productivity(NPP, 51.30%) instead of the accumulated normalized difference vegetation index(59.30%). The short-term variation in the precipitation and intra-seasonal precipitation distribution had a great impact on the remote sensing-based vegetation productivity. However, the residual trends method(RESTREND) effectively eliminated this correlation, while incorporating the variance and skewness of the precipitation distribution increased the models′ ability to explain the vegetation productivity variation. The RUE combined with land cover dynamics was valid for the effectiveness assessment of the ecological engineering projects on vegetation restoration. Particularly, the result based on growing season accumulated normalized difference vegetation index(ΣNDVI) residuals was the most effective, showing that 47.39% of the BTSSR experienced vegetation restoration from 2000 to 2010. The effectiveness of the ecological engineering projects differed for each subarea and was proportional to the strength of ecological engineering. The water erosion region dominated by woodland showed the best restoration, followed by the wind-water erosion crisscross regions, while the wind erosion regions dominated by grassland showed the worst effect. Seriously degraded regions still cover more area in the BTSSR than restored regions. Therefore, more future effort should be put in restoring degraded land.展开更多
Dominated by an arid and semiarid continental climate,the Beijing-Tianjin Sandstorm Source Region(BTSSR)is a typical ecologically fragile region with frequently occurring droughts.To provide information for regional v...Dominated by an arid and semiarid continental climate,the Beijing-Tianjin Sandstorm Source Region(BTSSR)is a typical ecologically fragile region with frequently occurring droughts.To provide information for regional vegetation protection and drought prevention,we assessed the relations between vegetation cover change(measured by the Normalized Difference Vegetation Index,NDVI)and the Standardized Precipitation Evapotranspiration Index(SPEI)at different time-scales,in different growth stages,in different subregions and for different vegetation types based on the Pearson's correlation coefficient in the BTSSR from 2000 to 2017.Results showed that 88.19%of the vegetated areas experienced increased NDVI in the growing season;48.3%of the vegetated areas experi-enced significantly increased NDVI(P<0.05)and were mainly in the south of the BTSSR.During the growing season,a wetter climate contributed to the increased vegetation cover from 2000 to 2017,and NDVI anomalies were closely related to SPEI.The maximum correlation coefficient in the growing season(Rmax)was significantly positive(P<0.05)in 97.84%of the total vegetated areas.In the vegetated areas with significantly positive Rmax,pixels with short time-scales(1-3 mon)accounted for the largest proportion(33.9%).The sensitivity of vegetation to the impact of drought rose first and then decreased in the growing season,with a peak in July.Compared with two subregions in the south,subregions in the north of the BTSSR were more sensitive to the impacts of drought variations,especially in the Xilingol Plateau and Wuzhumuqin Basin.All four major vegetation types were sensitive to the effects of drought variations,especially grasslands.The time-scales of the most impacting droughts varied with growth stages,regions,and vegetation types.These results can help us understand the relations between vegetation and droughts,which are important for ecological restoration and drought prevention.展开更多
Regional economic integration is the main trend in the world,the region participate inthe international competition as a whole.China has formed Yangtze River Delta and Pearl River Delta region which have showed strong...Regional economic integration is the main trend in the world,the region participate inthe international competition as a whole.China has formed Yangtze River Delta and Pearl River Delta region which have showed strong competitive and plays an important role in enhancing theoverall competitiveness of a country.As the third largest area,Beijing-Tianjin-Hebei'slocation is very important,Beijing,Tianjin and regional development has also attracted great attention of national leaders,China will enhance the economic development of Beijing,Tianjin region to the national strategic level,However,the process of economic integration in Beijing,Tianjin and regional development has been relatively slow,Hebei Province in Beijing and the day Tianjin two big cities have been developing weak,Beijing City,but also faced with the problem of excessive development,This paper points out the problems faced by the integration of Beijing,Tianjin,and puts forward some countermeasures,hoping to discuss how to promote the integration process.展开更多
This article taking national current affairs decisions as entry points, the theory related to regional economy as basis, analyzes the development relation between regional economy and local universities, thus puts for...This article taking national current affairs decisions as entry points, the theory related to regional economy as basis, analyzes the development relation between regional economy and local universities, thus puts forward countermeasures to achieve the interactive and coordinating development of Hebei coastal regional economy and local universities.展开更多
基金Under the auspices of Major Program of National Social Science Foundation of China (No. 10ZD&022)Youth Research Project of Ministry of Education (Humanities and Social Sciences) (No. 10YJC790020)Central University of Finance and Economics'121 Talent Project' Fundation for Youth Doctor Development (No. QBJGL201004)
文摘Based on the data of gross domestic product(GDP),industrial added value and the proportion of industrial employees from 2000 to 2008,this paper studies the effect of industrial structure change on the regional economic growth of Beijing-Tianjin-Hebei Metropolitan Region in China using the shift-share method.The results show that:1) In the 21st century,the industrial output of three industries,namely,primary,secondary,and tertiary,and the GDP grew rapidly in the study period.The tertiary industry grew the fastest;it had the largest contribution to the GDP and mean-while had become the most competitive industry in the metropolitan region.2) The development of cities within the region was not balanced.Firstly,compared with Tianjin,Beijing,as one of the two core cities,was more rational in the industrial structure.Secondly,the surrounding eight cities,which are Shijiazhuang,Qinhuangdao,Tangshan,Langfang,Baoding,Cangzhou,Zhangjiakou,and Chengde,were all uncompetitive than the two core cities.3) There was a great industrial gradient in the region(especially between the two core cities and the cities of Tangshan,Baoding,Zhangjia-kou,Chengde,Cangzhou,and Langfang).As a result,it is foreseeable that the industry transfer in the Bei-jing-Tianjin-Hebei Metropolitan Region will be one of the trends in regional development,and the industry transfer is inevitably to promote the regional integration.
基金supported by Research on humanistic and social science from the Department of Education[grant number 13YJAZH122]
文摘In order to analyze the factors influencing carbon emissions in the region of Beijing-Tianjin-Hebei and to explore the pathways to developing a low-carbon economy,this paper begins with the terminal energy consumption of three industries and residential consumption,and constructs an identical equation which is composed of population size,level of economic development,energy intensity,the proportion of energy consumption,energy structure,and the coefficient of carbon emissions.Based on the data of terminal energy consumption during 2000-2012,various factors are analyzed and their contribution is measured by Logarithmic Mean Divisia Index(LMDI).The results show that the levels of population and economy have a positive driving effect while energy intensity,energy structure,and carbon intensity have a negative driving effect;the proportion of energy consumption had a negative driving effect prior to 2006,then changed to positive.Among suggestions for a low-carbon economy are controlling population size,improving the quality of economic development,supporting research into new energy technology,accelerating regional integration and optimizing industrial structure,and enhancing environmental protection and spreading the concept of a low-carbon economy.
文摘Since China broke the blockade and opened the country to the outside world, many township enterprises develop quickly. Together with the pollution caused by China’s coal-burning as the main source of national energy, the pollution caused by small and medium-sized enterprises in towns and villages due to their small investment, low technology level and weak environmental awareness, and the pollution caused by a sharp increase in motor vehicle emissions lead to the fact that fog-haze has been rampant in China’s cities and urban agglomerations for nearly two decades, especially in the Beijing-Tianjin-Hebei region. This paper sorted out the current situation of fog-haze and analyzed the causes of fog-haze from the two aspects of natural and man-made causes, discussed the harms of fog-haze to human body, environment and life, and put forward the concrete measures to solve the fog-haze problem.
基金financially supported by Youth Project of National Social Science Fund of China(Grant No.17CZZ021).
文摘As an effective environment governance tool,environment governance performance evaluation is an important content and method to promote the modernization of environment governance system and governance ability.The environmental pollution of the Beijing-Tianjin-Hebei region has typical cross-administrative characteristics.Based on the analysis of the major environmental pollution problems in the Beijing-Tianjin-Hebei region,according to the international environment governance PSR model,a performance evaluation system that applies to the environment governance of Beijing-Tianjin-Hebei region is established.Meanwhile,the principal component analysis method is applied to conduct an empirical analysis of the environmental governance panel data for the 13 major cities in the Beijing-Tianjin-Hebei region from 2014 to 2016.The results show that most of the cities in the Beijing-Tianjin-Hebei region attach great importance to reduction of emission and pollutants,continuously alleviating the stress of environmental governance.However,the overall improvement of the environment governance performance in Beijing-Tianjin-Hebei region has presented a polarization imbalance.There is a clear tendency for subjective biases in the implementation of environment governance and a lack of comprehensive and systematic governance.According to the environment governance performance evaluation result of Beijing-Tianjin-Hebei region,the cross-administrative regional environment governance should improve the environment governance performance evaluation system as soon as possible,strengthen the consistency of the environment governance objectives,and implement comprehensive and systematic governance for the regional environment.
文摘This paper adopts the perspective of urban economic linkage and the modified urban economic gravity model to conduct a comparative analysis of the economic gravity among cities in China’s three major urban agglomerations,including the Beijing-Tianjin-Hebei region,the Yangtze River Delta,and the Pearl River Delta.The results show that,despite the ever-tightening economic linkages among cities in the urban agglomerations,the development of the Beijing-Tianjin-Hebei region falls behind that of the Yangtze River Delta and the Pearl River Delta in terms of coordination,closeness,and balance.The economic linkages among cities in the Beijing-Tianjin-Hebei region are not as cohesive as they could be and display a significant“siphon effect”through Beijing and Tianjin as well as a prominently unidirectional economic flow.This study suggests that efforts should be put into directing the orderly flow of resources from Beijing and Tianjin to cities in Hebei and promoting a balanced economic flow among cities,thus facilitating the coordination of regional development.
基金jointly sponsored by the National Basic Research Program of China(973 Program)(Grant No.2013CB430202)the National Natural Science Foundation of China(Grant No.41401056)+1 种基金the China Meteorological Administration Special Public Welfare Research Fund(Grant No.GYHY201406001)the Research Innovation Program for College Graduates of Jiangsu Province(Grant No.KYLX15 0858)
文摘In this study, regional persistent haze events(RPHEs) in the Beijing–Tianjin–Hebei(BTH) region were identified based on the Objective Identification Technique for Regional Extreme Events for the period 1980–2013. The formation mechanisms of the severe RPHEs were investigated with focus on the atmospheric circulation and dynamic mechanisms. Results indicated that:(1) 49 RPHEs occurred during the past 34 years.(2) The severe RPHEs could be categorized into two types according to the large-scale circulation, i.e. the zonal westerly airflow(ZWA) type and the high-pressure ridge(HPR) type. When the ZWA-type RPHEs occurred, the BTH region was controlled by near zonal westerly airflow in the mid–upper troposphere.Southwesterly winds prevailed in the lower troposphere, and near-surface wind speeds were only 1–2 ms^-1. Warm and humid air originating from the northwestern Pacific was transported into the region, where the relative humidity was 70% to 80%, creating favorable moisture conditions. When the HPR-type RPHEs appeared, northwesterly airflow in the mid–upper troposphere controlled the region. Westerly winds prevailed in the lower troposphere and the moisture conditions were relatively weak.(3) Descending motion in the mid-lower troposphere caused by the above two circulation types provided a crucial dynamic mechanism for the formation of the two types of RPHEs. The descending motion contributed to a reduction in the height of the planetary boundary layer(PBL), which generated an inversion in the lower troposphere. This inversion trapped the abundant pollution and moisture in the lower PBL, leading to high concentrations of pollutants.
基金Under the auspices of National High-Tech Research and Development Program of China(863 Program)(No. 2007AAl22235)National Natural Science Foundation ofChina(No.40471058)
文摘The existing models of population distribution often focus on the region with a single city or even multiple centers, and lack the detailed explorations of the common and special type of urbanization areas with two centers. Taking Beijing-Tianjin region of China, which is a distinct dual-nuclei metropolitan area in the world, as an example and choosing Landsat-5 TM image in 2005, population, etc. as the data, this paper devotes to comprehending and illustrating a model of Cassini growth of population between the two metropolitan cities through the research of spatial population distribution pattern, aided with RS and GIS techniques. Main technical processes include Kriging interpolation of the population data and character simulation of the Cassini ovals. According to the calculation of a/b, a key characteristic index of Cassini growth model, the spatial structures of population distribution were given. When a/b〈 1, it is a curve with two separated loops with a population density more than 3000 persons/km^2. When a/b=1, it is a lemniscate curve with a population density about 3000 persons/km^2. When 1〈a/b〈 √2, it is a dog-bone shaped concave curve with a population density between 500-3000 persons/km^2. When a/b= √2, it is an oblate curve with a population density about 500 persons/km^2. When a/b〉 √2, there is an oval-shaped convex curve with a population density less than 500 persons/km^2. The results show that owing to the combined action and influence of the regional dual-nuclei, the population distribution of Beijing-Tianjin region is in accord with Cassini model significantly. Therefore, there is Cassini growth of population between the two metropolitan cities in Beijing-Tianjin region. In addition, the process of Cassini growth has extraordinarily instructive significance for judging the development stages of the dual-nuclei metropolitan areas.
基金supported by the Scientific Research Foundation for Returned Scholars of the State Personnel Ministry of China,the Research Foundation of Institute of Urban Meteorology, CMA (Grant No. UMRF 200809)the R&D Special Fund for Public Welfare Industry (Meteorology) (Grant No. GYHY200906003)the National Basic Research Program of China (Grant No. 2009CB421406)
文摘Hail is one of the important weather disasters that affects the Beijing-Tianjin(BT) region.To better understand and to improve the forecasting of hail events over the BT region,the precursor weather conditions for hail based on 30 previous hail events were derived.It was found that the high-level trough and low-level cold front over the Mongolian region,the accumulated convective available potential energy,the decrease of the height of the 0℃-isotherm in the morning,and the persistence and intensification of these factors from morning to afternoon are valuable clues for forecasting the occurrence of hail events over the BT region.
基金Under the auspices of National Natural Science Foundation of China(No.41571421)National Science and Technology Major Project of China(No.21-Y30B05-9001-13/15)
文摘Aiming for the restoration of degraded ecosystems, many ecological engineering projects have been implemented around the world. This study investigates the ecological engineering project effectiveness on vegetation restoration in the Beijing-Tianjin Sand Source Region(BTSSR) from 2000 to 2010 based on the rain use efficiency(RUE) trend in relation to the land cover. More than half of the BTSSR experienced a vegetation productivity increase from 2000 to 2010, with the increasing intensity being sensitive to the indicators chosen. A clear tendency towards smaller increasing areas was shown when using the net primary productivity(NPP, 51.30%) instead of the accumulated normalized difference vegetation index(59.30%). The short-term variation in the precipitation and intra-seasonal precipitation distribution had a great impact on the remote sensing-based vegetation productivity. However, the residual trends method(RESTREND) effectively eliminated this correlation, while incorporating the variance and skewness of the precipitation distribution increased the models′ ability to explain the vegetation productivity variation. The RUE combined with land cover dynamics was valid for the effectiveness assessment of the ecological engineering projects on vegetation restoration. Particularly, the result based on growing season accumulated normalized difference vegetation index(ΣNDVI) residuals was the most effective, showing that 47.39% of the BTSSR experienced vegetation restoration from 2000 to 2010. The effectiveness of the ecological engineering projects differed for each subarea and was proportional to the strength of ecological engineering. The water erosion region dominated by woodland showed the best restoration, followed by the wind-water erosion crisscross regions, while the wind erosion regions dominated by grassland showed the worst effect. Seriously degraded regions still cover more area in the BTSSR than restored regions. Therefore, more future effort should be put in restoring degraded land.
基金Under the auspices of National Natural Science Foundation of China(No.41807177,41701017)the Pioneer‘Hundred Talents Program’of Chinese Academy of Sciences。
文摘Dominated by an arid and semiarid continental climate,the Beijing-Tianjin Sandstorm Source Region(BTSSR)is a typical ecologically fragile region with frequently occurring droughts.To provide information for regional vegetation protection and drought prevention,we assessed the relations between vegetation cover change(measured by the Normalized Difference Vegetation Index,NDVI)and the Standardized Precipitation Evapotranspiration Index(SPEI)at different time-scales,in different growth stages,in different subregions and for different vegetation types based on the Pearson's correlation coefficient in the BTSSR from 2000 to 2017.Results showed that 88.19%of the vegetated areas experienced increased NDVI in the growing season;48.3%of the vegetated areas experi-enced significantly increased NDVI(P<0.05)and were mainly in the south of the BTSSR.During the growing season,a wetter climate contributed to the increased vegetation cover from 2000 to 2017,and NDVI anomalies were closely related to SPEI.The maximum correlation coefficient in the growing season(Rmax)was significantly positive(P<0.05)in 97.84%of the total vegetated areas.In the vegetated areas with significantly positive Rmax,pixels with short time-scales(1-3 mon)accounted for the largest proportion(33.9%).The sensitivity of vegetation to the impact of drought rose first and then decreased in the growing season,with a peak in July.Compared with two subregions in the south,subregions in the north of the BTSSR were more sensitive to the impacts of drought variations,especially in the Xilingol Plateau and Wuzhumuqin Basin.All four major vegetation types were sensitive to the effects of drought variations,especially grasslands.The time-scales of the most impacting droughts varied with growth stages,regions,and vegetation types.These results can help us understand the relations between vegetation and droughts,which are important for ecological restoration and drought prevention.
文摘Regional economic integration is the main trend in the world,the region participate inthe international competition as a whole.China has formed Yangtze River Delta and Pearl River Delta region which have showed strong competitive and plays an important role in enhancing theoverall competitiveness of a country.As the third largest area,Beijing-Tianjin-Hebei'slocation is very important,Beijing,Tianjin and regional development has also attracted great attention of national leaders,China will enhance the economic development of Beijing,Tianjin region to the national strategic level,However,the process of economic integration in Beijing,Tianjin and regional development has been relatively slow,Hebei Province in Beijing and the day Tianjin two big cities have been developing weak,Beijing City,but also faced with the problem of excessive development,This paper points out the problems faced by the integration of Beijing,Tianjin,and puts forward some countermeasures,hoping to discuss how to promote the integration process.
文摘This article taking national current affairs decisions as entry points, the theory related to regional economy as basis, analyzes the development relation between regional economy and local universities, thus puts forward countermeasures to achieve the interactive and coordinating development of Hebei coastal regional economy and local universities.