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  • 2020 Volume 40 Issue 8
    Published: 10 August 2020
      

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  • Liu Yansui
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    In the past 30 years, the theory of human-earth areal system has played an important support and guidance role in promoting the comprehensive research, disciplinary development and serving national strategic decision of geography. This study analyzes the scientific connotation and era value of human-earth areal system, explores the types and environment of modern human-earth system, and puts forward 'human-earth sphere' and the main contents and frontier fields of human-earth system science. The results show that: 1) The modern human-earth system is characterized by complexity, regionalism and dynamicity. The processes, pattern and comprehensive effect of human-earth interaction are undergoing profound changes, and the human-earth system on the surface of the earth has become the critical content and important theme of modern geosciences. 2) To scientifically understand and effectively coordinate the human-earth relationship, it is urgent to explore the coupling pattern and mechanism of human-earth relationship and to analyze the type, structure and dynamic mechanism of human-earth areal system. Based on the urban-rural relationship, the human-earth areal system can be divided into urban regional system, urban-rural integration system and rural regional system. Furthermore, the rural regional system is subdivided into agricultural system, village system, rural system and township system. 3) Modern human activities strongly affect the human-earth system on the surface of the earth, forming a new surface with the coupling and interaction between human and earth. In essence, it is a natural-economic-technological synthesis or human-earth coordination. They are also the main contents of deepening the researches on the coupling of human-earth system and supporting decision-making for coordinated development of human-earth system. 4) Human-earth system science or human-earth science is a new interdisciplinary subject which studies the coupling mechanism, evolution process and complex interaction effect of man earth system. It is the deep intersection and focus of modern geographic science and earth system science. Taking the modern human-earth sphere system as the research object, it is committed to exploring the state of human activities transforming and affecting the surface environment system, the interaction and coupling law of human-earth system, the formation mechanism and evolution process of human-earth coordination.Human-earth system coupling and sustainable development is the core of human-earth system science. Inheriting and innovating the theory of human-earth areal system and developing the human-earth system science will highlight the subjectivity of human on the earth surface, the process of human-earth coordination and the strategy of sustainable development, thus providing scientific guidance for the coordination of human-earth system and sustainable development decision-making.

  • Ye Qin, Zeng Gang
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    In the view of the theory of knowledge base, we take China's biomedical industry as an example of an analytical industry and China's environmental industry as an example of a synthetic industry. By establishing innovation networks based on the data of co-patents of the two industries, we compare the evolution, geography, and performance of the two types of networks in the 2004-2006 and 2011-2013. The results indicate: Firstly, there are distinct differences in the network structure: For the analytical industry, interregional cooperation is more important, and network structure shows a picture of sparse in general but strong connection in the part, what’s more, universities and research institutions occupy the central position in the network. For the synthetic industry, the network presents a core-peripherical structure in which some enterprises with strong connection occupy the core position and the development of the network is limited by geographical distance. Secondly, the two types of networks have different impact on innovation performance. Centrality has no significant impact on analytical industry innovation but a negative effect on synthetic industry innovation. With the evolution of networks, the positive impact of structural holes on analytical industry innovation has been enhancing, however changes happened in synthetic industry from positive to negative. The positive effect of cooperation depth on innovation performance is much higher in analytical industry than synthetic industry. While the cooperation breadth significantly promotes innovation in synthetic industry but not significant in analytical industry. Thirdly, from the perspective of evolution, the network closure's role in innovation performance changes from positive to negative in analytical industry but always negative in synthetic industry.

  • Tang Jia, Zhen Feng, Wang Xia
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    Manuel Castells’ seminal book The Rise of the Network Society holistically explores the theory of network society, which has a great influence on human geography research. The influence of an academic publication often lies in its citation count. However, citation count cannot reflect the exact contribution of network society theory to the discipline of human geography, because citation count never takes knowledge of cited publications into account. Instead, citation content and context analysis can unveil the knowledge contribution of the network society theory to human geography. Through employing citation content and context analysis on 898 English journal articles and 363 Chinese journal articles which cited The Rise of the Network Society, this study investigates the knowledge contribution of the network society theory to human geography based on analysis and comparison of Chinese and English citations. We found that 1) knowledge on ‘space of flows’ is most frequently cited by both Chinese and English literature, with the cited ratio of ‘space of flows’ by Chinese literature is obviously higher than that by English literature; 2) Chinese and English literature shows different focuses on the theory of network society, with Chinese research pays more attention to the external space form of network society and its transformation while research in English pays more attention to the internal force for spatial transformation; 3) citations present nine citation functions and show 3 types of knowledge development contribution in human geography studies, which indicate different degree of influence on human geography. Among nine citation functions, critical citation is most important and worthy of in-depth analysis, which unveils scholars’ critical thinking towards the network society theory. Generally, citing authors argue that the spatial dualism of ‘of flows’ and ‘space of places’ is over abstract, the ‘space of flows’ is not superior to the ‘space of places’ in the network society, and the limitation of research data, methods and technological background restricts the improvement of empirical research on network. These critical citations will enlighten scholars to promote the application and innovation of network society theory in human geography.

  • Zhuang Delin, Wang Pengpeng, Xu Jilan, Zhang Di
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    Based on the data of China's cross-city venture capital investment in 2007 and 2017, the network linkages between 338 cities at prefectural level and above were constructed. The spatial structure evolution of the venture capital city networks of the four investment stages of seed, start-up, expansion and maturity and its influencing factors are investigated by using the social network analysis model. Major findings are as follows: Firstly, the venture capital city networks of the four investment stages have formed a network structure with three major urban agglomerations as the core connection areas. Secondly, the density and centralization trend of the venture capital city networks of the four investment stages are constantly increasing, and the tightness and synergistic development trend of the venture capital city networks of the expansion stage and the maturity stage are ahead of the seed and start-up stage. Thirdly, Beijing, Shanghai and Shenzhen have all evolved into the top three cities in terms of concentration and radiation in the venture capital city networks of the four investment stages. What's more, the agglomeration level of venture capital investment of the four investment stages shows a trend of further concentration to the core cities of the network; The radiation level of venture capital investment of the core cities in the city networks of the seed stage shows significant differentiation with the other three stages. Lastly, the venture capital city networks of the four investment stages indicate significant high administrative level urban orientation. The market size, development foundation of startups and government support all have a significant impact on the spatial structure evolution of the venture capital city networks of the four investment stages. The financial development level, development foundation of the venture capital industry and urban accessibility only affect the spatial structure evolution of some investment stages.

  • Li Bo, Tian Chuang, Jin Cui, Shi Zhaoyuan
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    Marine economy in China should with more quality and effectiveness, which is a new requirement for the development of marine economy under the new normal context background. Based on panel data of marine economic growth quality in the Bohai Rim region from 2000 to 2014, the spatial weighting matrix based on marine economy-space distance function is established to discuss spatial autocorrelation of marine economic growth quality for coastal cities in the Bohai Rim region from 2000 to 2014. By mean of the space Durbin model, this paper studies spatial spillover effects and influence mechanism of marine economic growth quality for coastal cities in the Bohai Rim region, which also make a deterministic of the subject’s spatial and spatial effects. The results show that, 1)The marine economic growth quality of coastal areas in the Bohai Rim region from 2000 to 2014 is spatially correlated but with significant heterogeneity, and the differences of marine economic development in coastal areas have become increasingly significant. 2)The spatial Durbin model shows that the spatial autoregressive coefficient is positive and significant. There is a positive feedback effect of the space spillover for marine economic growth quality. Among the influencing factors, contributions to local marine economic growth quality with direct effect are: Marine environment>Marine industry>Marine talent>Marine capital>Marine science and technology, other mechanisms have no significant effect on local marine economic growth quality. Contributions to neighborhood marine economic growth quality with spatial spillover effect are: Marine infrastructure construction > Marine talent>Marine capital. The research provides some reference for the formulation of targeted and differentiated marine policies in the Bohai Rim region.

  • Wang Yantao, Zhang Yaya
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    This article measured the ecological efficiency of 30 provinces (Excluding Tibet, Hong Kong, Macao and Taiwan regions) in China based on the Super-SBM model considering the undesirable output, and analyzed the differences of different regional ecological efficiencies by using GINI, GE0 and GE1. On this basis, the Spatial Simultaneous Equation was introduced to explore the interaction effect and space spillover effect between industrial structure upgrading and ecological efficiency. The results showed that: 1) The overall level of ecological efficiency in China is relatively low and the development of it is unbalanced among regions. The ecological efficiency of the eastern region is higher than that of the central and the western regions, while the ecological efficiency of the western region is higher than that of the central region. 2) The three indicators of GINI, GE0 and GE1 show that there is a great differences in the inter-provincial ecological efficiency in the eastern region, and the degree of the difference has not been significantly improved, the difference of inter-provincial ecological efficiency in the central region is small, and the difference of inter-provincial ecological efficiency in the western region shows a trend of decreasing firstly, then increasing, and then decreasing. 3) There is a mutual promoting effect mechanism, a positive spillover effect and a positive interactive spatial spillover effect between industrial structure upgrading and ecological efficiency.

  • Yan Dongsheng, Sun Wei, Sun Xiaolu
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    The population distribution spatial-temporal pattern is an important indicator of the regional economic development pattern, as well as an important basis for relevant policy formulation. Under the background of the integration of the Yangtze River Delta into a national strategy, studying the regional population spatial-temporal pattern evolution and driving factors has important theoretical and practical value for better promoting regional high-quality development. With the methods of gravity analysis, population density and relative change rate of population density, we study the spatial-temporal pattern evolution of population distribution about the Yangtze River Delta from 2000 to 2018. Subsequently, based on the space panel regression method, natural and economic as well as social indicators are recognized to make quantitative analysis on the driving factors of spatial-temporal pattern evolution of population distribution in the Yangtze River Delta. The major conclusions can be drawn as follows: 1) Change in the direction of population gravity center from 2000 to 2018 reflects the change of population distribution pattern driven by regional development pattern, and the slowdown in migration speeds represents a shift in regional development to steady state. 2) On the basis of the relatively stable regional differences in the population density distribution of the Yangtze River Delta, the spatial-temporal evolution are a significant increase in Shanghai, South-Jiangsu and a decline in some cities in Mid-Jiangsu, North-Jiangsu as well as Anhui province from 2000 to 2012, but a significant change of the population density growth among some underdeveloped cities from 2012 to 2018. 3) The space panel regression of driving factors shows that under the ‘Matthew effect’ of population pattern evolution, the changes of driving factors are the enhancement of market power and the weakening of government influence, as well as the advancement of regional integration has also brought about the enhancement of spatial spillover effect.

  • Tong Lei, Zheng Ke, Su Fei, Tang Qing, Cao Yirong, Zheng Yanyan
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    Population health vulnerability has gradually become a new hotspot in the field of vulnerability research. Reducing the urban population health vulnerability and improving the population health resilience are not only important to the connotations of building healthy city, but also an important support to enhance the ability to respond to urban public health emergencies. This paper use authoritative data such as statistical yearbooks and government statistical bulletins to build a population health vulnerability assessment index system from the two dimensions of population health sensitivity and coping. Using the set pair analysis method to evaluate the health vulnerability of 11 cities in Zhejiang Province from three aspects: degree of identity, degree of difference and degree of opposition. The research shows that: 1) The ranking of the vulnerability index of each city maintains a high consistency with the sensitivity index, and shows heterogeneity and randomness with the coping index. 2) From the perspective of the overall trend, the impact of sensitivity on the vulnerability index is greater than coping index, indicating that attention should be paid to sensitivity indicators in constructing healthy cities, and reducing sensitivity is the key to reducing the urban population's health vulnerability index. 3) The main factors influencing the health vulnerability of the urban population tend to be the same, but the core leading factors are different. In the process of constructing a healthy city, the corresponding construction measures should be proposed on the basis of full evaluation and research. 4) Sensitivity and response capability to large public health emergencies should be taken into account in the assessment of urban population health vulnerability.

  • Sun Wei, Wang Xiaonan, Sheng Kerong
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    Urban regeneration is an urban redevelopment process inevitable in urbanization, and it is gradually becoming a hot issue covering many disciplines such as economics, social management, public policy, and ecological environment. In this paper, we employed the bibliometric method and use the visualization tool, Citespace, to map knowledge domains of urban regeneration at home and abroad. Then, a quantitative comparative analysis on urban regeneration at home and abroad has been done in three aspects: evolutionary process, characteristics of published journals and research institutions, and research hotspots. Finally, the gaps and future research directions of urban regeneration research in China are put forward. The research indicates that: 1) The number of literatures published on urban regeneration at home and abroad shows a fluctuating upward trend, especially in the rapid development stage, when 117 articles and 238 articles were published each year. 2) Literatures mostly published in journals referring urban planning, regional research, urban design, and architecture. Compared with foreign journals, literature of urban regeneration in domestic is more concentrated. The top ten journals in China accounted for 46.65% of the total number of publications, while only 29.84% in foreign countries. 3) There is a preliminary cooperation network between research institutions both at home and abroad, but the degree of network connection and cooperation is still low. Compared with foreign institutions, links between domestic research institutions are relatively closer. 4) The foreign research hotspots mostly focus on partnership and participation, gentrification, sustainable development, urban transformation, and cultural creativity, while domestic research hotspots are reflected in urban renewal and estate development, protection and regeneration of historical blocks and industrial relics, exploration and practice of urban regeneration in Guangzhou-Shenzhen, and the preliminary discussion on participation, and so on.

  • Wang Zhaofeng, Liu Qingfang
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    Sports and leisure characteristic town is a spatial development platform of sports industry supported by sports industry and built with sports and leisure as the theme. GIS spatial analysis is used to explore the spatial differentiation characteristics of sports and leisure characteristic towns, and the dominant forming factors of spatial differentiation of sports and leisure characteristic towns are identified by means of Stepwise Regression Analysis. The results show that: 1) The Nearest Neighbor Index of sports and leisure characteristic towns is 0.77, which shows significant spatial agglomeration characteristics of sports and leisure characteristic towns. The towns are mainly distributed in Beijing City, Hebei Province and Hubei Province, with a spatial distribution pattern of “more in the south, less in the north, more in the east, and less in the west”. 2) The national Geographic Concentration Index is 20.07%, which is smaller than that in the eastern, the central and the western regions and shows obvious local concentration. The Imbalance Index is 0.17, and the number of sports and leisure characteristic towns in the eastern region, which is the most concentrated distribution, accounts for 47.92% of the country. 3) The sports and leisure characteristic towns in China are mainly distributed in the urban agglomerations in the Bohai Rim Region, the Pan Yangtze River Delta and the middle reaches of the Yangtze River. 4) Policy environment, tourism economy development level, sports industry demonstration units and sports industry demonstration projects become the leading factors influencing the spatial differentiation of sports and leisure characteristic towns in China.

  • Jiang Lili, Yuan Jiadong, Di Yushuang, Liu Yongqi
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    Combining economic flow with traffic flow, using social network analysis method and analyzing the characteristics of urban spatial connection network in Jilin Province, selecting local central cities in Jilin Province, and defining the hinterland of local central cities according to the degree of contact between cities (counties).The result are as follows: 1) The economic, road and railway links in Jilin Province are all low in density, and Changchun is at the core of each network. Degree of network contact varies greatly across the province; 2) From the perspective of the integrated network, the central region has closer links with other regions, and the links between the eastern and western regions are weak; The links between the two cohesive subgroups in the central region need to be strengthened. The integrated development of the central region of Jilin Province has a long way to go, and coordinated industrial development is the future development direction. The links within the southern region should be further enhanced to promote the development of the southern axis; 3) Combining the degree of centrality, point-in and point-out values and actual development needs of 47 cities (counties) in Jilin Province. Changchun, Jilin, Siping, Liaoyuan, Tonghua, Yanji and Baicheng were taken as local central cities in Jilin Province. Among them, Changchun has the largest radiation driving capacity and the lowest in Baicheng; Yanji and Dunhua should form a group in development and become the core of development in the eastern region, jointly driving the development of the eastern region; The Baicheng should strengthen its centrality and radiation-driven ability and take full effort to play the role of the western gateway city.

  • Zhu Linqi, Li Qiuyu, Liu Jisheng
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    This article establishes tourism system and regional development and improve people’s livelihood system, and applies the coupled coordination degree model to doing a quantitative evaluation about the relation of tourism with area development and improvement of people’s livelihood in Chinese 31 province in 2000-2013, and analyzes the evolution rules of coupling coordination degree from the view of space-time. The results show that: the comprehensive evaluation value of tourism and the value of regional development and improvement of people’s livelihood are both rising. The former grows slowly, and the latter grows relatively fast. The coupling coordination coefficient continues to increase, but the overall level of coupling coordination is not high, only 2 provinces achieving a high degree of coordination and having not yet appeared extremely coordinated area in 2013. The distribution of coupling degrees basically conforms to the rules that the eastern > the central > the west, the southeast > the northeast, and the southwest > the northwest. To further explore the coupling coordination role of indices of tourism system to the regional development and improvement of people’s livelihood, grey correlation degree analysis method is applied, concluding that the indexes of inbound tourism income, inbound tourists, and tourism college students number are the main factors influencing the regional development and the improvement of people’s livelihood and the teir coordinated development.

  • Wu Jilin, Liu Shuai, Liu Shuiliang, Xie Wenhai, Yao Chungui
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    Based on the connotation of rural tourism vulnerability, this paper constructs a vulnerability evaluation index system. Taking 334 rural households in 7 villages of Zhangjiajie as the research object, using the methods of participatory rural assessment (PRA), principal component analysis, cluster analysis and multiple linear regression, this paper analyzes the vulnerability index of different types of farmer and the influencing factors of vulnerability. The results show that: 1) Rural tourism vulnerability of farmers can be divided into five types: Consciousness vulnerability, social vulnerability, human vulnerability, development balance and total vulnerability; 2) In terms of the total vulnerability, the vulnerability of different types of farmers is fragile, their vulnerability indexes are different and non-tourism farmers are higher than tourism farmers; 3) In addition, the vulnerability index of folk culture factors of social vulnerable farmers is higher than that of cognitive factors, the vulnerability indexes of human quality, social network, livelihood capital and farmers' cognition of other types of farmers are higher than those of policy system, ecological environment and folk culture; 4) Human, cultural and ecological factors are the main factors that affect the vulnerability of rural tourism. Finally, some suggestions are put forward to reduce the vulnerability of rural tourism from the aspects of improving livelihood capital, inheriting folk culture and protecting ecological environment.

  • Wang Fuxi
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    It is an important guarantee to improve the urbanization quality and an inevitable choice to promote the steady and coordinated development between population urbanization and land urbanization. Taking Shandong Peninsula Urban Agglomeration as an example, based on the construction of population urbanization and land urbanization quality evaluation index system, this article measures the population and land urbanization quality and its spatiotemporal evolution characteristics of 8 cities in 2000 and 2018 by using the mean square error weight method. Using the elastic coefficient and coupling coordination degree model, this article discusses the coordination relationship between population urbanization and land urbanization. The results show that: 1) The quality of population urbanization and land urbanization is not high in Shandong Peninsula Urban Agglomeration in 2000, and the differences among subsystems are obvious. The quality of population urbanization is higher than that of land urbanization in 2018. 2) From 2000 to 2018, the elasticity coefficient of Jinan and Weifang is close to 1, which indicates that the population urbanization and land urbanization quality improvement speed of the two cities are equivalent, and the relationship between human and land is relatively harmonious. The elastic coefficient of Yantai and Zibo is less than 0.6, which indicates that the improvement speed of population urbanization quality lags behind land urbanization quality. The elasticity coefficient of human land quality of Dongying, Weihai, Qingdao and Rizhao is greater than 1, which reflects that the improvement speed of land urbanization quality in these cities has lagged behind that of population urbanization in 18 years. 3) Whether in 2000 or 2018, the coupling degree of population-land urbanization quality of Shandong Peninsula Urban Agglomeration is very high, but the coordination degree is low, and the space-time difference is very obvious. In 2000, the coupling coordination type of population-land urbanization quality in most cities belongs to maladjustment type. In 2018, all cities have developed into coordinated type.

  • Tan Xuelan, Wang Zhenkai, Jiang Lingxiao, An Yue, Lei Jihua, Ren Hui
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    The study on spatio-temporal evolution rules and influencing factors on agricultural functions is the scientific basis for guiding regional division of labor, highlighting regional value and promoting regional coordinated development. This paper built the evaluation index system respectively from the function of food production, employment and social security, ecological conservation and tourism and leisure, taking 24 cities districts or counties in Dongting Lake area as the study area, studied the dynamic changing process of agricultural functions, structure and stage characteristics and influence factors on it from 1997 to 2017 in Dongting Lake area by using the entropy weight method, spatiotemporal differential diagnosis model of agricultural functional changes, geo-detector and other method models. The study showed that: 1) the spatial and temporal changes of the agricultural function in Dongting Lake area from 1997 to 2017 were significant: The food production function in the whole Dongting Lake area was increasing, especially in the central area; the function of employment and social security was weakening, especially in municipal districts; the function of ecological conservation was changing greatly and to decline-shimen district, anhua district and other hilly areas decreased significantly while the plain area in the central Dongting Lake area increased; The tourism and leisure function showed a trend of enhancement: Especially in Shimen county, Taojiang county and other city areas. 2) The foundation of agricultural development was the decisive factor on the evolution of agricultural function; the level of regional development was the important factor on the evolution of agricultural function; the quality of production environment was the basic factor of the evolution on agricultural function in Dongting Lake area. The influence of the regional development level increased but of the quality of production environment decreased. There were interactions among influencing factors and the spatial and temporal evolution process and structure of agricultural function were affected by multiple factors, which indicated that the factors influencing the evolution of agricultural function in Dongting Lake area had significant complexity characteristics.

  • Xing Pei, Yang Ruozi, Du Wupeng, Dang Bing, Xuan Chunyi, Xiong Feilin
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    The spatiotemporal variation characteristics of high temperature days (HTDs) and heat wave (HW) events (frequency, duration, intensity) in North China were analyzed, using the daily maximum temperature data of 85 meteorological stations from 1961 to 2017. The results showed that the annual average HTDs had an increase trend, and increased significantly since the mid-1990s. The high temperature often appeared in the southern and western parts of North China, and HTDs of most stations were increasing. In terms of climate on average, there was slight advance trend in the first day of high temperature, and obvious delayed trend in the last day of high temperature; in space, the last day of high temperature for most stations was postponed, especially in the central and northern of Beijing-Tianjin-Hebei region. The accumulative frequency of total HW events, mild and moderate HW events was increasing overall, which obviously changed from less to more around 1990, while the increasing trend for severe HW events was more significant. Since 1987, the average effective accumulated high temperature obviously increased, indicating strengthened intensity of HW events. The spatial distribution of the total HW frequency for different grades was similar, and the high-frequency areas were concentrated in western Inner Mongolia, southwestern Shanxi, and southern Hebei. The trend of the cumulative HW frequency mainly increased in Inner Mongolia and Shanxi, and decreased in Beijing-Tianjin-Hebei region. The average duration and effective accumulated high temperature in most parts of North China showed increasing trend, except for individual stations in southwestern Shanxi and southern Hebei. Overall, since 1990s, the HTDs and HW events in North China were enhanced evidently , but also with obvious spatial differences. The results of this study contributed to further understanding of the regional characteristics of high temperature in North China.

  • Su Xiaoxia, Mao Xufeng, Wei Xiaoyan, Ling Jiankang, Zhang Yanchun, Bao Xianxia
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    To improve the restoration efficiency of alpine wetlands, accurate and comprehensive restoration effect assessment work is particularly important. In the past, the assessment research on alpine wetlands focused on biological factors, and the assessment of wetland environment and function restoration was not sufficient. Assessment results are difficult to directly guide restoration practice. In this study, a degraded meadow wetland in the Three Rivers Source Region of Qinghai Province was selected as the research sites to examine different restoration measures. A BES model based on Biology-Environment-Service function (involving 3 biological indicators, 4 environmental indicators, 8 ecosystem service function indicators) was developed to evaluate the effects of three wetland restoration techniques including restoration measure I-supplement grass seed + growth period enclosure, II-fence enclosure and III-rat-proof plot. Based on the monitoring data of 2017 and 2018, the Comprehensive Wetland Health Index (CHI) and Net Variation Index (NVI) were calculated, and the restoration processes and degrees of wetland health under different restoration measures were analyzed. Results show that: 1) Three restoration techniques have achieved good restoration performance in meadow wetlands. The comprehensive health index of meadow wetland was increased from 0.499 with no restoration measures in 2016 to 0.712, 0.716, and 0.650, respectively, and the health level of wetlands recovered from Alert to Good; 2) Restoration techniques I and II presented much better performance on wetland restoration during the evaluation period than that of restoration measures III, however, no significant difference between restoration techniques I and II was detected; 3) The biological indicators and supply indicators of alpine wetlands recover faster and better, while some indicators such as soil support recovered more slowly. Sowing grass seeds can help restore wetland vegetation in an efficient manner with a short term, while the restoration of soil environmental and wetland function requires more measures such as enclosure and other measures in a long term. The results of this case study may provide a reference for the future implementation of meadow wetland restoration and protection projects in the Qinghai-Tibet Plateau.

  • Zhou Aihong, Ning Zhijie
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    In recent years, a variety of debris flow risk assessment models have been put forward. But due to the effect of various factors on the occurrence mechanism of debris flow, those evaluation models inevitably have problems in the prediction process. In order to improve the accuracy of single gully debris flow risk assessment and promote the application of various evaluation models in the field of debris flow risk assessment, based on the debris flow data of Yunnan area, Jishixia Reservoir area in the Yellow River, Beichuan County and Longchi area of Dujiangyan in Sichuan Province, this paper takes the two representative debris flow evaluation model, Grey Relation Analysis (GRA) model and Support Vector Machine (SVM) model, as an example. And then this paper discusses the problems in the selection of parameters, the imbalance of sample data, the generalization ability and the spatial variability of debris flow system in the single gully debris flow risk assessment models. The results show that: the optimization algorithm can improve the efficiency of model parameter selection and prediction accuracy; the generalization ability is an inherent property of the model, which is difficult to be improved through sample expansion; spatial variability affects the accuracy of the assessment model by controlling the importance of the evaluation index. The research process of this paper provides a new way to deal with the related problems of single gully debris flow risk assessment model, and the conclusion will provide guidance for the application of various debris flow risk assessment models in the future.

  • Zhang Wei, Tang Qianyu, Liu Liang, Shen Junjie, Li Yapeng, Cheng Ran
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    The area elevation analysis of the basin is usually used to reveal the stage of geomorphological development, which is of great scientific significance for exploring the evolution of the basin environment. In this paper, the Yuqu River Basin of middle Tenasserim Chain is used as the research area. Using the hydrological analysis tools in Arcgis, the Yuqu River Basin is divided into 1 030 sub-basin basins. The area-elevation integral value (HI) of sub-basin basin is calculated using the elevation fluctuation ratio method. Combined with the tectonic movement, lithology, topographic relief and glacial action in the study area, the distribution characteristics and main influencing factors of HI values are discussed, and the geomorphological evolution stage of the study area is determined. The results display that: 1) The HI value of all sub-basin basins in the Yuqu River Basin is between 0.18 and 0.70, and the average HI is 0.44. The whole is in the strong and old stage of the erosion cycle. 2) The two major faults of the Changmaoling large fault and the Wahe large fault pass through the Yuqu basin, and the average HI values of the two faults are 0.47 and 0.42, respectively. The activity of the Changmaoling fault is higher than that of the Wahe fault, indicating that the construction factor has a certain influence on the HI value. 3) Due to the different lithologic erosion resistance in different sub-basin basins, the HI values are quite different. Intrusive rocks such as granite and diorite (average 0.55)> Conglomerate, limestone and other sedimentary rocks (average 0.49)> Marine carbonate rocks (average 0.47)> Mixed with siltstone, shale, Feldspar quartz sandstone of mudstone (average 0.42)> Quaternary alluvial and glacial till (average 0.35). 4) For the Yuqu River brainage, precipitation has little influence on HI value.