2021 Vol. 31, No. 6
Display Method:
2021, 31(6): 951-965.
doi: 10.1007/s11769-021-1239-z
Abstract:
National urban planning, construction, and management levels have undergone qualitative changes in China since 2000. Nonetheless, problems caused by rapid urbanization are becoming increasingly prominent. The concept of the city health examination appears to tackle these problems and is being gradually implemented, starting from the implementation of a national strategy and leading to the concrete practice of high-quality urban development. This paper elaborates on the basic philosophy and theory of the city health examination, briefly explains indicator selection and aims, and comprehensively illustrates examination methods. It then describes the empirical research that operationalized the dataset collected from a satisfaction survey administered during the 2020 city health examination. It aims to provide a reference for the standardization, specialization, analysis, and application of the results of the city health examination in China; this may help promote a smooth elimination of ‘urban diseases’ and allow for the development of high-quality livable cities. This research shows that city residents are generally more satisfied with the landscape features, ecological livability, and security resilience; it also shows that residents are generally more dissatisfied with traffic issues. Residents with different characteristics showed different satisfaction levels toward different indicators. Residents were also shown to be more sensitive to innovation vitality, ecological livability, and health and comfort in considering whether to stay in their current city.
National urban planning, construction, and management levels have undergone qualitative changes in China since 2000. Nonetheless, problems caused by rapid urbanization are becoming increasingly prominent. The concept of the city health examination appears to tackle these problems and is being gradually implemented, starting from the implementation of a national strategy and leading to the concrete practice of high-quality urban development. This paper elaborates on the basic philosophy and theory of the city health examination, briefly explains indicator selection and aims, and comprehensively illustrates examination methods. It then describes the empirical research that operationalized the dataset collected from a satisfaction survey administered during the 2020 city health examination. It aims to provide a reference for the standardization, specialization, analysis, and application of the results of the city health examination in China; this may help promote a smooth elimination of ‘urban diseases’ and allow for the development of high-quality livable cities. This research shows that city residents are generally more satisfied with the landscape features, ecological livability, and security resilience; it also shows that residents are generally more dissatisfied with traffic issues. Residents with different characteristics showed different satisfaction levels toward different indicators. Residents were also shown to be more sensitive to innovation vitality, ecological livability, and health and comfort in considering whether to stay in their current city.
2021, 31(6): 966-978.
doi: 10.1007/s11769-021-1240-6
Abstract:
With the continuous development of urbanization in China, the country’s growing population brings great challenges to urban development. By mastering the refined population spatial distribution in administrative units, the quantity and agglomeration of population distribution can be estimated and visualized. It will provide a basis for a more rational urban planning. This paper takes Beijing as the research area and uses a new Luojia1-01 nighttime light image with high resolution, land use type data, Points of Interest (POI) data, and other data to construct the population spatial index system, establishing the index weight based on the principal component analysis. The comprehensive weight value of population distribution in the study area was then used to calculate the street population distribution of Beijing in 2018. Then the population spatial distribution was visualize using GIS technology. After accuracy assessments by comparing the result with the WorldPop data, the accuracy has reached 0.74. The proposed method was validated as a qualified method to generate population spatial maps. By contrast of local areas, Luojia 1-01 data is more suitable for population distribution estimation than the NPP/VIIRS (Net Primary Productivity/Visible infrared Imaging Radiometer) nighttime light data. More geospatial big data and mathematical models can be combined to create more accurate population maps in the future.
With the continuous development of urbanization in China, the country’s growing population brings great challenges to urban development. By mastering the refined population spatial distribution in administrative units, the quantity and agglomeration of population distribution can be estimated and visualized. It will provide a basis for a more rational urban planning. This paper takes Beijing as the research area and uses a new Luojia1-01 nighttime light image with high resolution, land use type data, Points of Interest (POI) data, and other data to construct the population spatial index system, establishing the index weight based on the principal component analysis. The comprehensive weight value of population distribution in the study area was then used to calculate the street population distribution of Beijing in 2018. Then the population spatial distribution was visualize using GIS technology. After accuracy assessments by comparing the result with the WorldPop data, the accuracy has reached 0.74. The proposed method was validated as a qualified method to generate population spatial maps. By contrast of local areas, Luojia 1-01 data is more suitable for population distribution estimation than the NPP/VIIRS (Net Primary Productivity/Visible infrared Imaging Radiometer) nighttime light data. More geospatial big data and mathematical models can be combined to create more accurate population maps in the future.
2021, 31(6): 979-995.
doi: 10.1007/s11769-021-1237-1
Abstract:
The global value chains have become the core skeleton of the global economy. As a large-scale international cooperation initiative, the Belt and Road Initiative (BRI hereafter) may have a significant impact on the global economic landscape. In this context, the spatiotemporal pattern and evolution of the value chain connection of the Silk Road countries and whether the BRI will promote the value chain connections between China and these countries are important research questions for understanding the changing global economic landscape. This paper employs input-output analysis, network analysis and difference-in-differences based on Propensity Score Matching (PSM-DID) to conduct an in-depth quantitative study of these questions. The results show that, first, the overall value chain connection between China and the Silk Road countries has been rising since 2001. From the perspective of geographical distribution, Southeast Asia is the highest value chain connection region with China, and the growth in the central and eastern Europe is the most significant, whereas the central Asia is the lowest value connection region. From the perspective of complex network analysis, China’s position in the network of value flow among the Silk Road countries has been increasing continuously, and it has been in the lead position since 2008. Besides, the implementation of the BRI has had a significant positive influence on the overall value chain connection between China and the Silk Road countries, but this positive influence is limited to the central and eastern Europe region, whereas it is not significant in other regions. Finally, this paper suggests that to promote the development of value chain connection, the Silk Road countries need to develop more specific policies related to value chains. Policymakers need to be able to correctly identify the comparative advantages of the region and the types of value chains that are compatible with them and then find suitable partners and formulate targeted promotion policies.
The global value chains have become the core skeleton of the global economy. As a large-scale international cooperation initiative, the Belt and Road Initiative (BRI hereafter) may have a significant impact on the global economic landscape. In this context, the spatiotemporal pattern and evolution of the value chain connection of the Silk Road countries and whether the BRI will promote the value chain connections between China and these countries are important research questions for understanding the changing global economic landscape. This paper employs input-output analysis, network analysis and difference-in-differences based on Propensity Score Matching (PSM-DID) to conduct an in-depth quantitative study of these questions. The results show that, first, the overall value chain connection between China and the Silk Road countries has been rising since 2001. From the perspective of geographical distribution, Southeast Asia is the highest value chain connection region with China, and the growth in the central and eastern Europe is the most significant, whereas the central Asia is the lowest value connection region. From the perspective of complex network analysis, China’s position in the network of value flow among the Silk Road countries has been increasing continuously, and it has been in the lead position since 2008. Besides, the implementation of the BRI has had a significant positive influence on the overall value chain connection between China and the Silk Road countries, but this positive influence is limited to the central and eastern Europe region, whereas it is not significant in other regions. Finally, this paper suggests that to promote the development of value chain connection, the Silk Road countries need to develop more specific policies related to value chains. Policymakers need to be able to correctly identify the comparative advantages of the region and the types of value chains that are compatible with them and then find suitable partners and formulate targeted promotion policies.
2021, 31(6): 996-1010.
doi: 10.1007/s11769-021-1241-5
Abstract:
Climate is one important environmental variable that affects human life. As the regions along the Belt and Road (B & R) encompass vast territories and large populations, it is significant to assess climate suitability for human settlements, which will influence the migration of various surrounding countries. We selected seven regions including 65 countries along the B & R for the research area and adopted the temperature-humidity index (THI), to assess the climate suitability. We analyzed the spatial characteristics of THI and the correlation between population distribution and THI, the results of which enabled us to adjust the THI classification criteria. We finally assessed the climate suitability of each region. The results reveal that outside the Qinghai-Tibet Plateau, the THI values generally tend to decrease from west to east as longitude increases and downward with increasing latitude. The population distribution is significantly correlated with the THI. Regions with relative suitable climate, including high suitability areas (HASs), moderately suitable areas (MSAs) and low suitability areas (LSAs), account for 50.62% of the total area and encompass in excess of 90% of total population. These areas are widely distributed in the southern regions of 45°N latitude, again with the exception of the Qinghai-Tibet Plateau. Critical suitable area includes 19.48% of the entire area and 8.98% of total population. The non-suitable area accounts for less than 30% of total area, concentrated in the cold high-latitude and high-altitude areas.
Climate is one important environmental variable that affects human life. As the regions along the Belt and Road (B & R) encompass vast territories and large populations, it is significant to assess climate suitability for human settlements, which will influence the migration of various surrounding countries. We selected seven regions including 65 countries along the B & R for the research area and adopted the temperature-humidity index (THI), to assess the climate suitability. We analyzed the spatial characteristics of THI and the correlation between population distribution and THI, the results of which enabled us to adjust the THI classification criteria. We finally assessed the climate suitability of each region. The results reveal that outside the Qinghai-Tibet Plateau, the THI values generally tend to decrease from west to east as longitude increases and downward with increasing latitude. The population distribution is significantly correlated with the THI. Regions with relative suitable climate, including high suitability areas (HASs), moderately suitable areas (MSAs) and low suitability areas (LSAs), account for 50.62% of the total area and encompass in excess of 90% of total population. These areas are widely distributed in the southern regions of 45°N latitude, again with the exception of the Qinghai-Tibet Plateau. Critical suitable area includes 19.48% of the entire area and 8.98% of total population. The non-suitable area accounts for less than 30% of total area, concentrated in the cold high-latitude and high-altitude areas.
2021, 31(6): 1011-1028.
doi: 10.1007/s11769-021-1236-2
Abstract:
Social interaction has become one of the key factors affecting the spatial reconstruction of rural settlements (SRRS). However, most studies ignored the multi-scale impact of social networks on the identification of restructuring types of rural settlements. This paper, taking Ezhou City of Hubei Province, China as the case study area, developed a potential inter-settlement network through considering settlements as nodes, and inter-settlement interactions induced by the spatial disparity of public facilities as edges, divided towns in Ezhou City into three zones based on community structure at the town level, and then identified four types of rural settlements in light of the characteristics of cluster patterns and centrality at the patch level. The results show that the inter-settlement network in Ezhou City presents apparent disparities in terms of community structure, cluster patterns and centrality. In community analysis, high inter-community and intra-community interactions are concentrated in well-developed areas in the north and east, while weak interactions between communities occur in the southern areas dominated by traditional agricultural production. Accordingly, three zones are divided such as the urban-leading zone, urban-rural integration zone and rural-leading zone. For the network centrality and cluster patterns, high-level rural settlements are mainly distributed in the urban-leading zone, followed by the urban-rural integration zone and the rural-leading zone. Moreover, the lump cluster pattern is observed in each zone, but the chain pattern and dispersed pattern largely occur in the rural-leading zone. At same time, four types of rural settlements are identified, namely urbanized settlements, central settlements, grassroots settlements and relocated settlements. The corresponding plans are discussed in different zones regarding urbanization, integration and characteristics to provide meaningful insights for policymakers to guide SRRS. This study would contribute to our understanding of the impact of social network involved in daily life on rural settlement reconstruction, and expect to provide theoretical and methodological support for rural sustainable development in practice.
Social interaction has become one of the key factors affecting the spatial reconstruction of rural settlements (SRRS). However, most studies ignored the multi-scale impact of social networks on the identification of restructuring types of rural settlements. This paper, taking Ezhou City of Hubei Province, China as the case study area, developed a potential inter-settlement network through considering settlements as nodes, and inter-settlement interactions induced by the spatial disparity of public facilities as edges, divided towns in Ezhou City into three zones based on community structure at the town level, and then identified four types of rural settlements in light of the characteristics of cluster patterns and centrality at the patch level. The results show that the inter-settlement network in Ezhou City presents apparent disparities in terms of community structure, cluster patterns and centrality. In community analysis, high inter-community and intra-community interactions are concentrated in well-developed areas in the north and east, while weak interactions between communities occur in the southern areas dominated by traditional agricultural production. Accordingly, three zones are divided such as the urban-leading zone, urban-rural integration zone and rural-leading zone. For the network centrality and cluster patterns, high-level rural settlements are mainly distributed in the urban-leading zone, followed by the urban-rural integration zone and the rural-leading zone. Moreover, the lump cluster pattern is observed in each zone, but the chain pattern and dispersed pattern largely occur in the rural-leading zone. At same time, four types of rural settlements are identified, namely urbanized settlements, central settlements, grassroots settlements and relocated settlements. The corresponding plans are discussed in different zones regarding urbanization, integration and characteristics to provide meaningful insights for policymakers to guide SRRS. This study would contribute to our understanding of the impact of social network involved in daily life on rural settlement reconstruction, and expect to provide theoretical and methodological support for rural sustainable development in practice.
2021, 31(6): 1045-1056.
doi: 10.1007/s11769-021-1238-0
Abstract:
The service capacity of urban public open spaces is an important indicator of the justness and soundness of the allocation of public space resources, such as parks and green spaces, in the process of urban development. Improving the service capacity of urban public open spaces is conductive to healthy, sustainable urban development. In this study, taking Shengyang City, China as a case study, a Gaussian-based two-step floating catchment area method (2SFCA) is used to calculate an accessibility index and identify residential areas with a poor accessibility to urban public open spaces. Then, a particle swarm algorithm (PSA) is used to optimize the locations of new open space developments. Finally, the optimization results are verified using the analytic network process (ANP). The results show that the service capacity of public open spaces in the center of Shenyang City (covering six districts) is relatively low and exhibits an uneven spatial distribution. In the service scope of the existing urban public open spaces, the accessibility for 48.6% of the residential estates is moderately poor or poor. The layout is optimized when the number of optimization points is set to 8. These points are mainly located in old town areas such as the Tiexi, Huanggu, and Dadong districts. The optimization increases the green space area accessible by motor vehicles (60 min), bicycles (60 min), and walking (30 min) by 4.67%, 5.38%, and 8.03% of the study area, respectively. Finally, green space planning recommendations are offered from two perspectives: spatial layout and transport system optimization.
The service capacity of urban public open spaces is an important indicator of the justness and soundness of the allocation of public space resources, such as parks and green spaces, in the process of urban development. Improving the service capacity of urban public open spaces is conductive to healthy, sustainable urban development. In this study, taking Shengyang City, China as a case study, a Gaussian-based two-step floating catchment area method (2SFCA) is used to calculate an accessibility index and identify residential areas with a poor accessibility to urban public open spaces. Then, a particle swarm algorithm (PSA) is used to optimize the locations of new open space developments. Finally, the optimization results are verified using the analytic network process (ANP). The results show that the service capacity of public open spaces in the center of Shenyang City (covering six districts) is relatively low and exhibits an uneven spatial distribution. In the service scope of the existing urban public open spaces, the accessibility for 48.6% of the residential estates is moderately poor or poor. The layout is optimized when the number of optimization points is set to 8. These points are mainly located in old town areas such as the Tiexi, Huanggu, and Dadong districts. The optimization increases the green space area accessible by motor vehicles (60 min), bicycles (60 min), and walking (30 min) by 4.67%, 5.38%, and 8.03% of the study area, respectively. Finally, green space planning recommendations are offered from two perspectives: spatial layout and transport system optimization.
2021, 31(6): 1057-1069.
doi: 10.1007/s11769-021-1235-3
Abstract:
Recognizing land use changes (LUC) and evaluating their relationship with producing dust sources are considered effective to manage the environment. Taking Kermanshah Province, Iran as study area, dusty days from 2008 to 2015 were selected and dust sources were identified applying thermal-infrared dust index (TDI), hybrid single-particle lagrangian integrated trajectory (HYSPLIT), false color composite (FCC) and true color composite (TCC) of MODerate resolution Imaging Spectroradiometer (MODIS) images. Afterwards, the land use change map was produced using Landsat images in 2000 and 2015. Then, the distribution and frequency of the sources in each land-use change class and important dust production areas were specified. Eventually, two non-parametric tests including Chi-square and Kruskal-Wallis were applied to examine the relationship between LUC and dust sources. Results indicated that the distribution of dust sources was not identical in the study area, and the sources were mainly generated in the areas where land-use change had occurred. In fact, different classes of LUC have different contributions to dust production, and the highest contribution refers to the deflation in gentle slope areas and lowlands where the rangeland has been converted into agriculture land. The findings from this study are useful to manage and control dust in the identified sources.
Recognizing land use changes (LUC) and evaluating their relationship with producing dust sources are considered effective to manage the environment. Taking Kermanshah Province, Iran as study area, dusty days from 2008 to 2015 were selected and dust sources were identified applying thermal-infrared dust index (TDI), hybrid single-particle lagrangian integrated trajectory (HYSPLIT), false color composite (FCC) and true color composite (TCC) of MODerate resolution Imaging Spectroradiometer (MODIS) images. Afterwards, the land use change map was produced using Landsat images in 2000 and 2015. Then, the distribution and frequency of the sources in each land-use change class and important dust production areas were specified. Eventually, two non-parametric tests including Chi-square and Kruskal-Wallis were applied to examine the relationship between LUC and dust sources. Results indicated that the distribution of dust sources was not identical in the study area, and the sources were mainly generated in the areas where land-use change had occurred. In fact, different classes of LUC have different contributions to dust production, and the highest contribution refers to the deflation in gentle slope areas and lowlands where the rangeland has been converted into agriculture land. The findings from this study are useful to manage and control dust in the identified sources.
2021, 31(6): 1070-1081.
doi: 10.1007/s11769-021-1211-y
Abstract:
Due to the complex dynamic of aeolian and fluvial interacted processes behind the landform development, most of previous works started from classifying the types of landscape characterized by various aeolian and fluvial features. Such classifications are usually generalized based on large geomorphic data set abstracted from satellite images without field verification and dynamic field data. In this study, we identified river banks in deserts as a unique geographical unit dominated by aeolian-fluvial processes. Three distinct locations have been identified as representative study cases, which are in the Keriya River Basin in the west, the Mu Bulag River Basin in the middle and the Xar Moron River Basin in the east of the northern China. The aeolian-fluvial interaction types were quantified based on site observation and measurement, topographic mapping and remote-sensing image analysis. Dimensional morphological relationship between river channel and adjacent sand dunes areas were explored. We concluded that different channels are often associated with different distributions of riparian dunes. The quantitative data enabled us to distinguish statistically four different types of landscape in aeolian-fluvial dominant environment, namely riverside dunes-straight channel, symmetrical interleaving dunes-meandering channel, river-island dunes- braiding channel, and grid-like dunes-anastomosing channel, aiming to provide compensational information to current aeolian-fluvial interaction studies. The angle of interaction between aeolian and fluvial systems, the windward and leeward sites of the bank, vegetation coverage and underlying landform determines the distribution, morphology, scale and direction of extension of the riparian dunes. The results of the work study can provide a reference for study of aeolian-fluvial interactions at different spatial scales in arid region.
Due to the complex dynamic of aeolian and fluvial interacted processes behind the landform development, most of previous works started from classifying the types of landscape characterized by various aeolian and fluvial features. Such classifications are usually generalized based on large geomorphic data set abstracted from satellite images without field verification and dynamic field data. In this study, we identified river banks in deserts as a unique geographical unit dominated by aeolian-fluvial processes. Three distinct locations have been identified as representative study cases, which are in the Keriya River Basin in the west, the Mu Bulag River Basin in the middle and the Xar Moron River Basin in the east of the northern China. The aeolian-fluvial interaction types were quantified based on site observation and measurement, topographic mapping and remote-sensing image analysis. Dimensional morphological relationship between river channel and adjacent sand dunes areas were explored. We concluded that different channels are often associated with different distributions of riparian dunes. The quantitative data enabled us to distinguish statistically four different types of landscape in aeolian-fluvial dominant environment, namely riverside dunes-straight channel, symmetrical interleaving dunes-meandering channel, river-island dunes- braiding channel, and grid-like dunes-anastomosing channel, aiming to provide compensational information to current aeolian-fluvial interaction studies. The angle of interaction between aeolian and fluvial systems, the windward and leeward sites of the bank, vegetation coverage and underlying landform determines the distribution, morphology, scale and direction of extension of the riparian dunes. The results of the work study can provide a reference for study of aeolian-fluvial interactions at different spatial scales in arid region.
2021, 31(6): 1082-1096.
doi: 10.1007/s11769-021-1243-3
Abstract:
The karst landform is a typical ecologically vulnerable region, and the problem of karst rocky desertification in southtern and western China has led to impoverishment and a degraded local ecological environment, which severely limits local socioeconomic development. An effective and appropriate control of karst rocky desertification in southtern and western China requires knowledge about its characteristics of variation and driving mechanisms. In this study, we chose eight regions in the southtern and western China as research areas and analysed the characteristics of the changes in karst ecosystem patterns and rocky desertification from 2000 to 2015. Based on these characteristics, we present the mechanisms that drive karst rocky desertification in the southtern and western China by utilizing the redundancy analysis (RDA) ordination method. The results show that the total area of rocky desertification in southtern and western China had been continuously decreasing from 2000 to 2015, revealing a positive development trend in rocky desertification. Rocky desertification variations were mainly affected by human activities. The reduction in farmland area improved farmland management and increased regional gross industrial product, which together with continuously rising gross domestic product of the tertiary industry caused a positive rocky desertification development. However, the local karst tourism has a certain effect on inducing slight rocky desertification.
The karst landform is a typical ecologically vulnerable region, and the problem of karst rocky desertification in southtern and western China has led to impoverishment and a degraded local ecological environment, which severely limits local socioeconomic development. An effective and appropriate control of karst rocky desertification in southtern and western China requires knowledge about its characteristics of variation and driving mechanisms. In this study, we chose eight regions in the southtern and western China as research areas and analysed the characteristics of the changes in karst ecosystem patterns and rocky desertification from 2000 to 2015. Based on these characteristics, we present the mechanisms that drive karst rocky desertification in the southtern and western China by utilizing the redundancy analysis (RDA) ordination method. The results show that the total area of rocky desertification in southtern and western China had been continuously decreasing from 2000 to 2015, revealing a positive development trend in rocky desertification. Rocky desertification variations were mainly affected by human activities. The reduction in farmland area improved farmland management and increased regional gross industrial product, which together with continuously rising gross domestic product of the tertiary industry caused a positive rocky desertification development. However, the local karst tourism has a certain effect on inducing slight rocky desertification.
2021, 31(6): 1097-1107.
doi: 10.1007/s11769-021-1244-2
Abstract:
The research on ecosystem service values (ESVs) estimation in arid region is weak. We took the Alxa League of China’s Inner Mongolia Autonomous Region, an extreme arid region, as an example and constructed an equivalent coefficient method to assess its ESVs from 1975 to 2015, by determining the standard unit of ESVs and the basic equivalent of the value of different ecosystem services per unit area based on the regional characteristics, literature research, expert knowledge and land use data. The results show that the ESVs first decreased from 83 170.4 million yuan (RMB) in 1975 to 82 337.8 million yuan (RMB) in 2000 and then increased to 84 033.6 million yuan (RMB) in 2015, and the ESV of sparse grassland and desert account for about 33% and 29% of the total ESVs, respectively. Among the four service types, the regulating services, support services, supply services and cultural services account for 66.5%, 22.8%, 6.0% and 4.7%, respectively. The changes of ESVs in Alxa League are determined by the socio-economic development and ecological changes. This study provides a new method to estimate the ESVs in arid region by integrating existing methods and regional characteristics, such as the cost of water for arid ecosystems.
The research on ecosystem service values (ESVs) estimation in arid region is weak. We took the Alxa League of China’s Inner Mongolia Autonomous Region, an extreme arid region, as an example and constructed an equivalent coefficient method to assess its ESVs from 1975 to 2015, by determining the standard unit of ESVs and the basic equivalent of the value of different ecosystem services per unit area based on the regional characteristics, literature research, expert knowledge and land use data. The results show that the ESVs first decreased from 83 170.4 million yuan (RMB) in 1975 to 82 337.8 million yuan (RMB) in 2000 and then increased to 84 033.6 million yuan (RMB) in 2015, and the ESV of sparse grassland and desert account for about 33% and 29% of the total ESVs, respectively. Among the four service types, the regulating services, support services, supply services and cultural services account for 66.5%, 22.8%, 6.0% and 4.7%, respectively. The changes of ESVs in Alxa League are determined by the socio-economic development and ecological changes. This study provides a new method to estimate the ESVs in arid region by integrating existing methods and regional characteristics, such as the cost of water for arid ecosystems.
2021, 31(6): 1108-1122.
doi: 10.1007/s11769-021-1245-1
Abstract:
As the source of the Yellow River, Yangtze River, and Lancang River, the Three-River Source Region (TRSR) in China is very important to China’s ecological security. In recent decades, TRSR’s ecosystem has degraded because of climate change and human disturbances. Therefore, a range of ecological projects were initiated by Chinese government around 2000 to curb further degradation. Current research shows that the vegetation of the TRSR has been initially restored over the past two decades, but the respective contribution of ecological projects and climate change in vegetation restoration has not been clarified. Here, we used the Moderate Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) to assess the spatial-temporal variations in vegetation and explore the impact of climate and human actions on vegetation in TRSR during 2001–2018. The results showed that about 26.02% of the TRSR had a significant increase in EVI over the 18 yr, with an increasing rate of 0.010/10 yr (P < 0.05), and EVI significantly decreased in only 3.23% of the TRSR. Residual trend analysis indicated vegetation restoration was jointly promoted by climate and human actions, and the promotion of human actions was greater compared with that of climate, with relative contributions of 59.07% and 40.93%, respectively. However, the degradation of vegetation was mainly caused by human actions, with a relative contribution of 71.19%. Partial correlation analysis showed that vegetation was greatly affected by temperature (r = 0.62, P < 0.05) due to the relatively sufficient moisture but lower temperature in TRSR. Furthermore, the establishment of nature reserves and the implementation of the Ecological Protection and Restoration Program (EPRP) improved vegetation, and the first stage EPRP had a better effect on vegetation restoration than the second stage. Our findings identify the driving factors of vegetation change and lay the foundation for subsequent effective management.
As the source of the Yellow River, Yangtze River, and Lancang River, the Three-River Source Region (TRSR) in China is very important to China’s ecological security. In recent decades, TRSR’s ecosystem has degraded because of climate change and human disturbances. Therefore, a range of ecological projects were initiated by Chinese government around 2000 to curb further degradation. Current research shows that the vegetation of the TRSR has been initially restored over the past two decades, but the respective contribution of ecological projects and climate change in vegetation restoration has not been clarified. Here, we used the Moderate Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) to assess the spatial-temporal variations in vegetation and explore the impact of climate and human actions on vegetation in TRSR during 2001–2018. The results showed that about 26.02% of the TRSR had a significant increase in EVI over the 18 yr, with an increasing rate of 0.010/10 yr (P < 0.05), and EVI significantly decreased in only 3.23% of the TRSR. Residual trend analysis indicated vegetation restoration was jointly promoted by climate and human actions, and the promotion of human actions was greater compared with that of climate, with relative contributions of 59.07% and 40.93%, respectively. However, the degradation of vegetation was mainly caused by human actions, with a relative contribution of 71.19%. Partial correlation analysis showed that vegetation was greatly affected by temperature (r = 0.62, P < 0.05) due to the relatively sufficient moisture but lower temperature in TRSR. Furthermore, the establishment of nature reserves and the implementation of the Ecological Protection and Restoration Program (EPRP) improved vegetation, and the first stage EPRP had a better effect on vegetation restoration than the second stage. Our findings identify the driving factors of vegetation change and lay the foundation for subsequent effective management.
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