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    Energy globalization of China: Trade, investment, and embedded energy flows
    YANG Yu
    Journal of Geographical Sciences    2022, 32 (3): 377-400.   DOI: 10.1007/s11442-022-1952-2
    Abstract258)   HTML25)         

    China is in a critical period of transforming from the oil and gas era to the renewable energy era. To better understand the process of energy interaction between China and the rest of the world, this study aimed to investigate the basic theoretical cognition of global energy interaction and analyze the pattern and changes of energy interaction between China and the rest of the world with the method of complex networks, multi-region input-output analysis, and other technical methods. The main findings are as follows: (1) Chinas coal-based energy production structure and the huge demand for oil and gas indicate that ensuring overseas oil and gas supply is the most direct logic of energy interaction between China and the rest of the world, and the interaction scopes are mainly concentrated in oil- and gas-rich countries and regions. (2) With the development of renewable energy, the logic of energy interaction of China with the rest of the world has changed from countries and regions rich in oil and gas to countries with global renewable energy development and installation needs for its comparative advantages for manufacturing, which forms a renewable energy trade map that covers all major countries and regions in the world. (3) The overseas energy investment target of China has expanded from a limited number of host countries to Europe, Southeast Asia, and other countries and regions. The investment business is not only limited to the oil and gas field, but also expanded to solar energy, wind energy, hydro-power, and other renewable electricity generation projects. (4) As a global manufacturing and trading power, part of the energy consumed by China is embodied in the global production network and trade network for redistribution. The scope of energy interactions between China and the world will further expand to countries with general commodity trade relations with China, forming the global “energy hub” function. This study can provide a theoretical perspective and decision-making for a deeper understanding of the energy interactions between China and the world, maintaining national energy security, and participating in global energy economic governance.

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    Carbon neutrality and mitigating contribution of terrestrial carbon sink on anthropogenic climate warming in China, the United States, Russia and Canada
    CUI Yaoping, LI Nan, FU Yiming, CHEN Liangyu
    Journal of Geographical Sciences    2021, 31 (7): 925-937.   DOI: 10.1007/s11442-021-1878-0
    Abstract195)   HTML12)    PDF (3288KB)(22)      

    Carbon dioxide (CO2) is a major climate forcing factor, closely related to human activities. Quantifying the contribution of CO2 emissions to the global radiative forcing (RF) is therefore important to evaluate climate effects caused by anthropogenic and natural factors. China, the United States (USA), Russia and Canada are the largest countries by land area, at different levels of socio-economic development. In this study, we used data from the CarbonTracker CO2 assimilation model (CT2017 data set) to analyze anthropogenic CO2 emissions and terrestrial ecosystem carbon sinks from 2000 to 2016. We derived net RF contributions and showed that anthropogenic CO2 emissions had increased significantly from 2000 to 2016, at a rate of 0.125 PgC yr-1. Over the same period, carbon uptake by terrestrial ecosystems increased at a rate of 0.003 PgC yr-1. Anthropogenic CO2 emissions in China and USA accounted for 87.19% of the total, while Russian terrestrial ecosystems were the largest carbon sink and absorbed 14.69 PgC. The resulting cooling effect was -0.013 W m-2 in 2016, representing an offset of -45.06% on climate warming induced by anthropogenic CO2. This indicates that net climate warming would be significantly overestimated if terrestrial ecosystems were not included in RF budget analyses. In terms of cumulative effects, we analyzed RFs using reference atmospheres of 1750, at the start of the Industrial Revolution, and 2000, the initial year of this study. Anthropogenic CO2 emissions in the study area contributed by + 0.42 W m-2 and +0.32 W m-2 to the global RF, relative to CO2 levels of 1750 and 2000, respectively. We also evaluated correlations between global mean atmospheric temperature and net, anthropogenic and natural RFs. We found that the combined (net) RF caused by CO2 emissions accounted for 30.3% of global mean temperature variations in 2000-2016.

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    Visual method of analyzing COVID-19 case information using spatio-temporal objects with multi-granularity
    CHEN Yunhai, JIANG Nan, CAO Yibing, YANG Zhenkai, ZHAO Xinke
    Journal of Geographical Sciences    2021, 31 (7): 1059-1081.   DOI: 10.1007/s11442-021-1885-1
    Abstract140)   HTML6)    PDF (7476KB)(23)      

    Coronavirus disease 2019 (COVID-19) is continuing to spread globally and still poses a great threat to human health. Since its outbreak, it has had catastrophic effects on human society. A visual method of analyzing COVID-19 case information using spatio-temporal objects with multi-granularity is proposed based on the officially provided case information. This analysis reveals the spread of the epidemic, from the perspective of spatio-temporal objects, to provide references for related research and the formulation of epidemic prevention and control measures. The case information is abstracted, descripted, represented, and analyzed in the form of spatio-temporal objects through the construction of spatio-temporal case objects, multi-level visual expressions, and spatial correlation analysis. The rationality of the method is verified through visualization scenarios of case information statistics for China, Henan cases, and cases related to Shulan. The results show that the proposed method is helpful in the research and judgment of the development trend of the epidemic, the discovery of the transmission law, and the spatial traceability of the cases. It has a good portability and good expansion performance, so it can be used for the visual analysis of case information for other regions and can help users quickly discover the potential knowledge this information contains.

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    Evaluating changes in ecological land and effect of protecting important ecological spaces in China
    GAO Jixi, LIU Xiaoman, WANG Chao, WANG Yong, FU Zhuo, HOU Peng, LYU Na
    Journal of Geographical Sciences    2021, 31 (9): 1245-1260.   DOI: 10.1007/s11442-021-1896-y
    Abstract140)   HTML18)    PDF (1020KB)(127)      

    It is important to quantitatively analyze the effects of protection of important ecological spaces in China to ensure national ecological security. By considering changes in the ecological land, this study examines the effects of protecting three types of important natural ecological spaces in China from 1980 to 2018. Moreover, considering important ecological spaces and their surroundings yields differences in the effects of protection between internal and external spaces, where this can provide a scientific basis for the categorization and zoning of China’s land. The results show the following: (1) In 2018, the ratio of ecological land to important natural ecological spaces accounted for 92.64%. This land had a good ecological background that reflects the developmental orientation of important ecological spaces. (2) From 1980 to 2018, the area of ecological land in important ecological spaces shrank but the rate of reduction was lower than the national average, which shows the positive effect of regulating construction in natural ecological spaces. The restorative effects of ecological projects to convert farmland into forests and grasslands have been prominent. The expanded ecological land is mainly distributed in areas where such projects have been implemented, and the reduced area is concentrated in grain-producing areas of the Northeast China Plain and agricultural oases of Xinjiang. In the future, the government should focus on strengthening the management and control of these areas. (3) The area ratio of ecological land was the highest in national nature reserves. The rate of reduction in its area was the lowest and the trend of reduction was the smallest in national nature reserves, which reflects differences in the status of ecological protection among different spaces. (4) The ratio of ecological land to important ecological spaces was higher than that in the surrounding external space, and the rate of reduction in it was lower. Thus, the effects of internal and external protection had clear differences in terms of gradient.

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    Dynamic features and driving mechanism of coal consumption for Guangdong province in China
    WANG Changjian, WANG Fei, ZHANG Xinlin, WANG Yang, SU Yongxian, YE Yuyao, WU Qitao, ZHANG Hong’ou
    Journal of Geographical Sciences    2022, 32 (3): 401-420.   DOI: 10.1007/s11442-022-1954-0
    Abstract135)   HTML12)         

    Guangdong Province, as one of China’s fast-developing regions, an important manufacturing base, and one of the national first round low-carbon pilots, still faces many challenges in controlling its total energy consumption. Coal dominates Guangdong’s energy consumption and remains the major source of CO2. Previous research on factors influencing energy consumption has lacked a systematic analysis both from supply side (factors related to scale, structure, and technologies) and demand side (investment, consumption, and trade). This paper develops the logarithmic mean Divisia index (LMDI) method that focuses on the supply side and the structural decomposition analysis (SDA) method that focuses on the demand side to systematically identify the key factors driving coal consumption in Guangdong. Results are as follows: (1) Supply side analysis indicates that economic growth has always been the most important factor driving coal consumption growth, while energy intensity is the most important constraining factor. Industrial structure and energy structure have different impacts on coal consumption control during different development phases. (2) Demand side analysis indicates that coal is consumed mainly for international exports, inter-provincial exports, fixed capital formation, and urban household. (3) Industries with the fastest coal consumption growth driven by final demand have experienced significant shifts. Increments in industrial sectors were mainly driven by inter-provincial exports and urban household consumption in recent years. (4) Research on energy consumption in subnational regions under China’s new development pattern of “dual circulation” should not only focus on exports in the context of economic globalization but also pay more attention to inter-provincial exports on the background of strengthened interregional connections.

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    Spatiotemporal patterns of the daily relative risk of COVID-19 in China
    CHENG Changxiu, JIANG Yifan, SONG Changqing, SHEN Shi, WU Yunfeng, ZHANG Tianyuan
    Journal of Geographical Sciences    2021, 31 (7): 1039-1058.   DOI: 10.1007/s11442-021-1884-2
    Abstract127)   HTML10)    PDF (1131KB)(26)      

    The coronavirus disease 2019 (COVID-19) pandemic continues to threaten lives and the economy around the world. Estimating the risk of COVID-19 can help in predicting spreading trends, identifying risk areas, and making public health decisions. In this study, we proposed a comparative risk assessment method to estimate comprehensive and dynamic COVID-19 risks by considering the pandemic severity and the healthcare system pressure and then employing the z-order curve and fractal theory. We took the COVID-19 cases from January 19-March 10, 2020 in China as our research object. The results and analysis revealed that (1) the proposed method demonstrated its feasibility to assess and illustrate pandemic risk; (2) the temporal patterns of the daily relative risk indices of 31 provinces were clustered into four groups (high-value, fluctuating-increase, inverted U-shaped, and low-stable); (3) the spatial distribution of the relative pandemic risk indicated a significant circular pattern centered on Hubei Province; and (4) healthcare system capacity is the key to reducing relative pandemic risk, and cases imported from abroad should be given more attention. The methods and results of this study will provide a methodological basis and practical guidance for regional pandemic risk assessment and public health decision-making.

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    Identification and alleviation pathways of multidimensional poverty and relative poverty in counties of China
    XU Lidan, DENG Xiangzheng, JIANG Qun’ou, MA Fengkui
    Journal of Geographical Sciences    2021, 31 (12): 1715-1736.   DOI: 10.1007/s11442-021-1919-8
    Abstract127)   HTML13)    PDF (9404KB)(68)      

    To realize efficient and sustainable poverty alleviation, this study firstly investigated the identification of multidimensional poverty and relative poverty, and then explored relevant poverty alleviation pathways. Poverty levels in 31 provinces including the autonomous regions and municipalities of China were identified at the county level using the average nighttime light index (ANLI), county multidimensional development index (CMDI), and a method combining multidimensional poverty index and relative poverty standards. Poverty alleviation pathways for poverty-stricken counties were explored from the aspects of industry, education, tourism and agriculture. The results revealed that nearly 60% of counties in China were primarily under relative poverty, most of which were corresponded to light relative poverty. In terms of ANLI and CMDI, 63% and 79% of the national poverty-stricken counties, as of 2018, could be identified, suggesting that CMDI had a higher performance for identifying poverty at the county level. In terms of poverty alleviation pathways, 414, 172, 442, and 298 poverty-stricken counties were receptive to industry poverty alleviation, education poverty alleviation, tourism poverty alleviation, and agriculture poverty alleviation, and 61% of counties had more poverty-causing factors, implying that multidimensional poverty alleviation is suitable in most of the counties.

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    Explicating the mechanisms of land cover change in the New Eurasian Continental Bridge Economic Corridor region in the 21st century
    FAN Zemeng, LI Saibo, FANG Haiyan
    Journal of Geographical Sciences    2021, 31 (10): 1403-1418.   DOI: 10.1007/s11442-021-1903-3
    Abstract121)   HTML5)    PDF (1806KB)(146)      

    Land cover change has presented clear spatial differences in the New Eurasian Continental Bridge Economic Corridor (NECBEC) region in the 21st century. A spatiotemporal dynamic probability model and a driving force analysis model of land cover change were developed to analyze explicitly the dynamics and driving forces of land cover change in the NECBEC region. The results show that the areas of grassland, cropland and built-up land increased by 114.57 million ha, 8.41 million ha and 3.96 million ha, and the areas of woodland, other land, and water bodies and wetlands decreased by 74.09 million ha, 6.26 million ha, and 46.59 million ha in the NECBEC region between 2001 and 2017, respectively. Woodland and other land were mainly transformed to grassland, and grassland was mainly transformed to woodland and cropland. Built-up land had the largest annual rate of increase and 50% of this originated from cropland. Moreover, since the Belt and Road Initiative (BRI) commenced in 2013, there has been a greater change in the dynamics of land cover change, and the gaps in the socio-economic development level have gradually decreased. The index of socio-economic development was the highest in western Europe, and the lowest in northern Central Asia. The impacts of socio-economic development on cropland and built-up land were greater than those for other land cover types. In general, in the context of rapid socio-economic development, the rate of land cover change in the NECBEC has clearly shown an accelerating trend since 2001, especially after the launch of the BRI in 2013.

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    Predicting and assessing changes in NPP based on multi-scenario land use and cover simulations on the Loess Plateau
    JIANG Xiaowei, BAI Jianjun
    Journal of Geographical Sciences    2021, 31 (7): 977-996.   DOI: 10.1007/s11442-021-1881-5
    Abstract115)   HTML5)    PDF (2766KB)(15)      

    Land use/cover change (LUCC) is a major factor affecting net primary production (NPP). According to the LUCC of the Loess Plateau from 2005 to 2015, the LUCC patterns in 2025 in three scenarios were predicted by using the Future Land Use Simulation (FLUS) model. Furthermore, taking the average NPP of various land use/cover types in 16 years as the reference scale, the changes in NPP in multi-scenario simulations are predicted and analyzed, and the impact of different land use/cover transfers on NPP is quantified. The results are as follows: (1) The land use/cover changes greatly in the baseline and fast development scenarios, and changes relatively little in the ecological protection scenarios. (2) The changes in NPP in different scenarios reflected the significant difference in the ecological protection effect. All the three scenarios promote an NPP increase, but the ecological protection scenario can promote NPP increases the most. (3) The changes in NPP caused by LUCC in the three scenarios reflected the significant difference in the various land use/cover types protection effect. Analyzing and predicting NPP changes in multi-scenario LUCC simulations in the future can provide a theoretical basis for decision makers to judge the future changes in ecological environments and ecological protection effects against different policy backgrounds.

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    The poverty evolution of typical countries along the Belt and Road and implications from China’s poverty reduction experiences
    SHI Linna, WANG Yongsheng, LIU Yansui, LI Yuheng
    Journal of Geographical Sciences    2022, 32 (3): 458-476.   DOI: 10.1007/s11442-022-1953-1
    Abstract110)   HTML2)         

    The world is facing a poverty crisis. Despite the great achievements that have been made in poverty alleviation over the past two decades, the extent of poverty in countries along the Belt and Road is still high. Successful poverty reduction in these countries is crucial to meeting the 2030 SDGs. Improving governance to eradicate poverty is a shortcoming that needs to be addressed urgently in poverty reduction pathways along the Belt and Road. In this study, the Standard Deviational Ellipse method was used to study the spatial trajectory of the poverty gravity center. Results showed that the poverty gravity center moved from east to west by 87.60 km annually, while the poverty population decreased by 1211.14 million along the Belt and Road from 2000 to 2020. In addition, the trajectory of the center has shifted due to the different effects of poverty reduction. Among the countries situated along the Belt and Road, China is the most significant contributor to poverty reduction. Accordingly, this study examined the implications of China’s successful poverty reduction strategies in order to understand how other countries can effectively respond to poverty. Ultimately, we propose that sustainable poverty alleviation development strategies should be established with the objectives of promoting social equity and improving the wellbeing of all people.

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    Evaluation of the carbon sequestration of Zhalong Wetland under climate change
    YU Chenglong, LIU Dan, ZHAO Huiying
    Journal of Geographical Sciences    2021, 31 (7): 938-964.   DOI: 10.1007/s11442-021-1879-z
    Abstract108)   HTML8)    PDF (1984KB)(35)      

    Wetland ecosystems are crucial to the global carbon cycle. In this study, the Zhalong Wetland was investigated. Based on remote sensing and meteorological observation data from 1975-2018 and the downscaled fifth phase of the coupled model intercomparison project (CMIP5) climate projection dataset from 1961-2100, the parameters of a net primary productivity (NPP) climatic potential productivity model were adjusted, and the simulation ability of the CMIP5 coupled models was evaluated. On this basis, we analysed the spatial and temporal variations of land cover types and landscape transformation processes in the Zhalong Nature Reserve over the past 44 years. We also evaluated the influence of climate change on the NPP of the vegetation, microbial heterotrophic respiration (Rh), and net ecosystem productivity (NEP) of the Zhalong Wetland and predicted the carbon sequestration potential of the Zhalong Wetland from 2019-2029 under the representative concentration pathways (RCP) 4.5 and RCP 8.5 scenarios. Our results indicate the following: (1) Herbaceous bog was the primary land cover type of the Zhalong Nature Reserve, occupying an average area of 1168.02 ± 224.05 km 2, equivalent to 51.84% of the total reserve area. (2) Since 1975, the Zhalong Nature Reserve has undergone a dry-wet-dry transformation process. Excluding several wet periods during the mid-1980s to early 1990s, the reserve has remained a dry habitat, with particularly severe conditions from 2000 onwards. (3) The 1975-2018 mean NPP, Rh, and NEP values of the Zhalong Wetland were 500.21±52.76, 337.59±10.80, and 162.62±45.56 gC·m-2·a-1, respectively, and an evaluation of the carbon balance indicated that the reserve served as a carbon sink. (4) From 1975-2018, NPP showed a significant linear increase, Rh showed a highly significant linear increase, while the increase in the carbon absorption rate was smaller than the increase in the carbon release rate. (5) Variations in NPP and NEP were precipitation-driven, with the correlations of NPP and NEP with annual precipitation and summer precipitation being highly significantly positive (P < 0.001); variations in Rh were temperature-driven, with the correlations of Rh with the average annual, summer, and autumn temperatures being highly significantly positive (P < 0.001). The interaction of precipitation and temperature enhances the impact on NPP, Rh and NEP. (6) Under the RCP 4.5 and RCP 8.5 scenarios, the predicted carbon sequestration by the Zhalong Wetland from 2019-2029 was 2.421 (± 0.225) × 1011 gC·a-1 and 2.407 (± 0.382) × 1011 gC·a-1, respectively, which were both lower than the mean carbon sequestration during the last 44 years (2.467 (± 0.950) × 1011 gC·a-1). Future climate change may negatively contribute to the carbon sequestration potential of the Zhalong Wetland. The results of the present study are significant for enhancing the abilities of integrated eco-meteorological monitoring, evaluation, and early warning systems for wetlands.

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    2020 Top 10 Research Achievements of Chinese Geography Unveiled
    Journal of Geographical Sciences    2021, 31 (7): 1082-1083.  
    Abstract94)   HTML2)    PDF (1627KB)(11)      
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    Climate change and multi-dimensional sustainable urbanization
    CHEN Mingxing, XIAN Yue, WANG Pengling, DING Zijin
    Journal of Geographical Sciences    2021, 31 (9): 1328-1348.   DOI: 10.1007/s11442-021-1895-z
    Abstract92)   HTML7)    PDF (1783KB)(154)      

    Global large-scale urbanization and climate change have become indisputable scientific facts yet are unresolved issues, and are a common concern for mankind. The relationship between these two topics is unclear and it is not known how to deal appropriately at the scientific level with climate change in the process of urbanization. Further exploration of the science, management and practice, are needed to achieve global and regional sustainable development. This paper first considers the basic facts concerning mass urbanization and climate change and summarizes the interactions and possible mechanisms of urbanization and climate change. Urbanization leads to the heat island effect, an uneven distribution of precipitation and extreme weather, together with a local-regional-global multi-scale superposition effect, which aggravates the consequences of global climate change. The impact of climate change on urbanization is mainly manifested in aspects such as changes of energy consumption, mortality, and the spread of infectious diseases, sea level rise, extreme weather damage to infrastructure, and water shortages. This paper also briefly reviews relevant international research programs and action coalitions and puts forward an analysis framework of multi-dimensional sustainable urbanization which can adapt to and mitigate climate change, from the perspective of the four key dimensions—population, land use, economy, and society. It is imperative that we strengthen the interdisciplinary activities involving the natural and social sciences, take urbanization and other human activities into consideration of the land - atmosphere system, and explore the human-land-atmosphere coupling process. The adaptation and mitigation from the perspective of human activities, as represented by urbanization, might be the most critical and realistic way to deal with climate change.

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    Vertical distribution changes in land cover between 1990 and 2015 within the Koshi River Basin, Central Himalayas
    WU Xue, PAUDEL Basanta, ZHANG Yili, LIU Linshan, WANG Zhaofeng, XIE Fangdi, GAO Jungang, SUN Xiaomin
    Journal of Geographical Sciences    2021, 31 (10): 1419-1436.   DOI: 10.1007/s11442-021-1904-2
    Abstract89)   HTML1)    PDF (1716KB)(78)      

    The study of mountain vertical natural belts is an important component in the study of regional differentiation. These areas are especially sensitive to climate change and have indicative function, which is the core of three-dimensional zonality research. Thus, based on high precision land cover and digital elevation model (DEM) data, and supported by MATLAB and ArcGIS analyses, this paper aimed to study the present situation and changes of the land cover vertical belts between 1990 and 2015 on the northern and southern slopes of the Koshi River Basin (KRB). Results showed that the vertical belts on both slopes were markedly different from one another. The vertical belts on the southern slope were mainly dominated by cropland, forest, bare land, and glacier and snow cover. In contrast, grassland, bare land, sparse vegetation, glacier and snow cover dominated the northern slope. Study found that the main vertical belts across the KRB within this region have not changed substantially over the past 25 years. In contrast, on the southern slope, the upper limits of cropland and bare land have moved to higher elevation, while the lower limits of forest and glacier and snow cover have moved to higher elevation. The upper limit of alpine grassland on the northern slope retreated and moved to higher elevation, while the lower limits of glacier and snow cover and vegetation moved northward to higher elevations. Changes in the vertical belt were influenced by climate change and human activities over time. Cropland was mainly controlled by human activities and climate warming, and the reduced precipitation also led to the abandonment of cropland, at least to a certain extent. Changes in grassland and forest ecosystems were predominantly influenced by both human activities and climate change. At the same time, glacier and snow cover far away from human activities was also mainly influenced by climate warming.

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    Characteristics and progress of land use/cover change research during 1990-2018
    HE Chunyang, ZHANG Jinxi, LIU Zhifeng, HUANG Qingxu
    Journal of Geographical Sciences    2022, 32 (3): 537-559.   DOI: 10.1007/s11442-022-1960-2
    Abstract89)   HTML1)         

    Land use/cover change (LUCC) is the foundation and frontier for integrating multiple land surface processes. This paper aims to systematically review LUCC research from 1990 to 2018. Based on qualitative and quantitative analyses, we delineated the history of LUCC research and summarized their characteristics and major progress at different stages. We also identified the main challenges and proposed future directions for LUCC research. We found that the number of publications on LUCC research and their total citations grew exponentially. The research foci shifted from the process of LUCC during 1990-2004 to the impact of LUCC during 2005-2013 and then to the sustainability of LUCC from 2014 onwards. Currently, LUCC research is facing theoretical, methodological and practical challenges ranging from integrating the framework of sustainability science, adopting emerging technologies to supporting territorial spatial planning. To move forward, LUCC research should be closely integrated with landscape sustainability science and geodesign and take the leading role in territorial spatial planning to achieve the related Sustainable Development Goals.

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    Model construction of urban agglomeration expansion simulation considering urban flow and hierarchical characteristics
    WANG Haijun, WU Yue, DENG Yu, XU Shan
    Journal of Geographical Sciences    2022, 32 (3): 499-516.   DOI: 10.1007/s11442-022-1958-9
    Abstract88)   HTML4)         

    Since the launch of China’s reform and opening up policy, the process of urbanization in China has accelerated significantly. With the development of cities, inter-city interactions have become increasingly close, forming urban agglomerations that tend to be integrated. Urban agglomerations are regional spaces with network relationships and hierarchies, and have always been the main units for China to promote urbanization and regional coordinated development. In this paper, we comprehensively consider the network and hierarchical characteristics of an urban agglomeration, while using urban flow to describe the interactions of the inter-city networks and the hierarchical generalized linear model (HGLM) to reveal the hierarchical driving mechanism of the urban agglomeration. By coupling the HGLM with a cellular automata (CA) model, we introduced the HGLM-CA model for the simulation of the spatial expansion of an urban agglomeration, and compared the simulation results with those of the logistic-CA model and the biogeography-based optimization CA (BBO-CA) model. According to the results, we further analyzed the advantages and disadvantages of the proposed HGLM-CA model. We selected the middle reaches of the Yangtze River in China as the research area to conduct this empirical research, and simulated the spatial expansion of the urban agglomeration in 2017 on the basis of urban land-use data from 2007 and 2012. The results indicate that the spatial expansion of the urban agglomeration can be attributed to various driving factors. As a driving factor at the urban level, urban flow promotes the evolution of land use in the urban agglomeration, and also plays an important role in regulating cell-level factors, making the cell-level factors of different cities show different driving effects. The HGLM-CA model is able to obtain a higher simulation accuracy than the logistic-CA model, which indicates that the simulation results for urban agglomeration expansion considering urban flow and hierarchical characteristics are more accurate. When compared with the intelligent algorithm model, i.e., BBO-CA, the HGLM-CA model obtains a lower simulation accuracy, but it can analyze the interaction of the various driving factors from a hierarchical perspective. It also has a strong explanatory effect for the spatial expansion mechanism of urban agglomerations.

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    Biogeographical patterns of arbuscular mycorrhizal fungi diversity in China’s grasslands
    TENG Jialing, TIAN Jing, YU Guirui
    Journal of Geographical Sciences    2021, 31 (7): 965-976.   DOI: 10.1007/s11442-021-1880-6
    Abstract88)   HTML7)    PDF (1492KB)(74)      

    Arbuscular mycorrhizal fungi (AMF) are universally mutualistic symbionts that colonize the fine roots of most vascular plants. However, the biogeographical patterns and driving factors of AMF diversity of plant roots in grasslands are not well investigated. In this study, we used high-throughput sequencing techniques and bioinformatics to evaluate the AMF richness of 333 individual plant roots in 21 natural grassland ecosystems in northern China, including the Loess Plateau (LP), the Mongolian Plateau (MP), and the Tibetan Plateau (TP). The AMF richness showed a significant parabolic trend with increasing longitude. In regional situations, the AMF richness in the grasslands of the MP (60.4 ± 1.47) was significantly higher than those of the LP (46.4 ± 1.43) and TP (44.3 ± 1.64). Plant traits (including plant families, genera, and functional groups) explained the most variation in the AMF richness across China’s grasslands, followed by energy and water; soil properties had the least effects. The results showed the biogeographical patterns of the AMF richness and the underlying dominant factors, providing synthetic data compilation and analyses in the AMF diversity in China’s grasslands.

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    Three modes of climate change since the Last Glacial Maximum in arid and semi-arid regions of the Asian continent
    ZHANG Yuxin, LI Yu
    Journal of Geographical Sciences    2022, 32 (2): 195-213.   DOI: 10.1007/s11442-022-1942-4
    Abstract86)   HTML8)    PDF (1316KB)(80)      

    The westerly winds and East Asian summer monsoon play a leading role in climate change of southwestern North America and eastern Asia since the Last Glacial Maximum (LGM), respectively. Their convergence in arid and semi-arid regions of the Asian continent (AAC) makes the regional climate change more complicated on the millennial-scale. There are still limitations in applying paleoclimate records and climate simulations of characteristic periods to investigate climate change patterns since the LGM in this region. In this study, we adopt two indexes indicating effective moisture and rely on a continuous simulation, a time slice simulation, and numerous paleoclimate records to comprehensively investigate the climate change modes and their driving mechanisms since the LGM in AAC. Results demonstrate a millennial-scale climate differentiation phenomenon and three climate change modes possibly occurring in AAC since the LGM. The western AAC largely controlled by the westerly winds is featured as wet climates during the LGM but relatively dry climates during the mid-Holocene (MH), coinciding with the climate change mode in southwestern North America. Conversely, dry conditions during the LGM and relatively wet conditions during the MH are reflected in eastern AAC governed by the East Asian summer monsoon, which leans to the climate change mode in eastern Asia. If climate change in central AAC is forced by the interaction of two circulations, it expresses wet conditions in both the LGM and MH, tending to a combination of the southwestern North American and eastern Asian modes. Precipitation and evaporation exert different intensities in influencing three climate modes of different periods. Furthermore, we identify the significant driving effects of greenhouse gases and ice sheets on westerly-dominated zones of AAC, while orbit-driven insolation on monsoon-dominated zones of AAC.

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    Simulation of land-cover change in Jing-Jin-Ji region under different scenarios of SSP-RCP
    FAN Zemeng
    Journal of Geographical Sciences    2022, 32 (3): 421-440.   DOI: 10.1007/s11442-022-1955-z
    Abstract86)   HTML11)         

    How to simulate land-cover change, driven by climate change and human activity, is not only a hot issue in the field of land-cover research but also in the field of sustainable urbanization. A surface-modeling method of land cover scenario (SSMLC) driven by the coupling of natural and human factors was developed to overcome limitations in existing land-cover models. Based on the climatic scenario data of CMIP6 SSP1-2.6, SSP2-4.5, and SSP5-8.5 released by IPCC in 2020, which combines shared socioeconomic paths (SSPs) with typical concentration paths (RCPs), observation climatic data concerning meteorological stations, the population, GDP, transportation data, land-cover data from 2020, and related policy refences, are used to simulate scenarios of land-cover change in the Jing-Jin-Ji region using SSP1-2.6, SSP2-4.5, and SSP5-8.5 for the years 2040, 2070 and 2100, respectively. The simulation results show that the total accuracy of SSMLC in the Jing-Jin-Ji region attains 93.52%. The change intensity of land cover in the Jing-Jin-Ji region is the highest (plus 3.12% per decade) between 2020 and 2040, gradually decreasing after 2040. Built-up land has the fastest increasing rate (plus 5.07% per decade), and wetland has the fastest decreasing rate (minus 3.10% per decade) between 2020 and 2100. The change intensity of land cover under scenario SSP5-8.5 is the highest among the abovementioned three scenarios in the Jing-Jin-Ji region between 2020 and 2100. The impacts of GDP, population, transportation, and policies on land-cover change are generally greater than those on other land-cover types. The results indicate that the SSMLC method can be used to project the change trend and intensity of land cover under the different scenarios. This will help to optimize the spatial allocation and planning of land cover, and could be used to obtain key data for carrying out eco-environmental conservation measures in the Jing-Jin-Ji region in the future.

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    Dynamic evolution trend of comprehensive transportation green efficiency in China: From a spatio-temporal interaction perspective
    MA Qifei, JIA Peng, SUN Caizhi, KUANG Haibo
    Journal of Geographical Sciences    2022, 32 (3): 477-498.   DOI: 10.1007/s11442-022-1957-x
    Abstract85)   HTML8)         

    It is urgent and important to explore the dynamic evolution in comprehensive transportation green efficiency (CTGE) in the context of green development. We constructed a social development index that reflects the social benefits of transportation services, and incorporated it into the comprehensive transportation efficiency evaluation framework as an expected output. Based on the panel data of 30 regions in China from 2003-2018, the CTGE in China was measured using the slacks-based measure-data envelopment analysis (SBM-DEA) model. Further, the dynamic evolution trends of CTGE were determined using the spatial Markov model and exploratory spatio-temporal data analysis (ESTDA) technique from a spatio-temporal perspective. The results showed that the CTGE shows a U-shaped change trend but with an overall low level and significant regional differences. The state transition of CTGE has a strong spatial dependence, and there exists the phenomenon of “club convergence”. Neighbourhood background has a significant impact on the CTGE transition types, and the spatial spillover effect is pronounced. The CTGE has an obvious positive correlation and spatial agglomeration characteristics. The geometric characteristics of the LISA time path show that the evolution process of local spatial structure and local spatial dependence of China’s CTGE is stable, but the integration of spatial evolution is weak. The spatio-temporal transition results of LISA indicate that the CTGE has obvious transfer inertness and has certain path-dependence and spatial locking characteristics, which will become the major difficulty in improving the CTGE.

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    Spatially explicit changes of forestland in Taiwan Province from 1910 to 2010
    YANG Xuhong, JIN Xiaobin, YANG Yongke, SONG Jiani, ZHANG Tong, ZHOU Yinkang
    Journal of Geographical Sciences    2022, 32 (3): 441-457.   DOI: 10.1007/s11442-022-1956-y
    Abstract84)   HTML6)         

    Reconstructing long-term changes of forest cover (FC) can provide reliable underlying data for carbon source/sink accounting and simulation of the effects of land use on the climate and environment. Historical maps contain a wealth of forest related information and can provide first-hand data for studying the changes in FC over a long time period. Taking the reconstruction of FC in Taiwan Province from 1910-2010 as the research object, we used map extraction and mining methods to extract forest distribution information from historical forest thematic survey maps, topographic and land cover maps, and reconstructed the spatiotemporal patterns of FC in Taiwan from 1910-2010. The results show that: first, the relative bias of the FC area extracted from the historical maps of Taiwan was below 8%, meaning the FC information contained in maps is highly accurate. Second, the FC of Taiwan has generally declined in the past 100 years. From 1910-2010, the forest area declined from 2.62×106 ha to 2.47×106 ha, with relatively obvious forest reduction having occurred. In stages, the forest area of Taiwan decreased by 26.39×104 ha from 1910 to 1950; and increased by 10.53×104 ha during the period 1950-2010. Forest reduction was obvious during the Japanese occupation period, while forest increase was remarkable during the Kuomintang period. Third, during the study period, the total area of patches maintained as forests was 2.17×106 ha with little change in the overall pattern, and forests were mainly distributed in the mountain regions. The loss of forest mainly occurred in the plains, with expanding forest areas mainly in the mountain regions at high elevations and on steep slopes. Fourth, land clearing for agriculture during the Japanese occupation period has been the important driver of forest reduction in Taiwan over the past century. After retreated to Taiwan, the Kuomintang government introduced effective and remarkable reforms that led to effective restoration of forest vegetation in many areas where forests had previously disappeared.

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    Spatial evolution and growth mechanism of urban networks in western China: A multi-scale perspective
    YANG Liangjie, WANG Jing, YANG Yongchun
    Journal of Geographical Sciences    2022, 32 (3): 517-536.   DOI: 10.1007/s11442-022-1959-8
    Abstract84)   HTML4)         

    Globalization and informatization promote the evolution of urban spatial organization from a hierarchical structure mode to a network structure mode, forming a complex network system. This study considers the coupling of “space of flows” and “spaces of places” as the core and “embeddedness” as the link and a relevant theoretical basis; then we construct a conceptual model of urban networks and explore the internal logic of enterprise networks and city networks. Using the interlocking-affiliate network model and data from China’s top 500 listed companies, this study constructs a directed multi-valued relational matrix between cities in western China from 2005 to 2015. Using social network analysis and the multiple regression of quadratic assignment program model (MRQAP), this study adopts a “top-down” research perspective to analyze the spatio-temporal evolution and growth mechanism of the city network in western China from three nested spatial scales: large regions, intercity agglomerations, and intracity agglomerations. The results show the following: (1) Under the large regional scale, the city network has good symmetry, obvious characteristics of hierarchical diffusion, neighborhood diffusion, and cross-administrative regional connection, presenting the “core-periphery” structural pattern. (2) The network of intercity agglomerations has the characteristics of centralization, stratification, and geographical proximity. (3) The internal network of each urban agglomeration presents a variety of network structure modes, such as dual-core, single-core, and multicore modes. (4) Administrative subordination and economic system proximity have a significant positive impact on the city network in western China. The differences in internet convenience, investment in science and technology, average time distance, and economic development have negative effects on the growth and development of city networks. (5) The preferential attachment is the internal driving force of the city network development.

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    A review of the ecohydrology discipline: Progress, challenges, and future directions in China
    XIA Jun, ZHANG Yongyong, MU Xingmin, ZUO Qiting, ZHOU Yujian, ZHAO Guangju
    Journal of Geographical Sciences    2021, 31 (8): 1085-1101.   DOI: 10.1007/s11442-021-1886-0
    Abstract81)   HTML15)    PDF (2960KB)(64)      

    In recent decades, the ecohydrology discipline was developed to provide theoretical and technical foundations for the protection and restoration of complex ecological systems (e.g., mountains, rivers, forests, farmlands, and lakes), and to further ecological civilization construction and green development in China. In this study, the progress and challenges of the ecohydrology discipline are elaborated, and the future development directions are proposed according to international scientific frontiers and national ecological civilization construction demands. Overall, the main discipline directions are to develop new ecohydrological monitoring methods, to comprehensively understand ecohydrological mechanisms and their basic theories, to promote integration of multi-scale and multi-variable models by considering both terrestrial and aquatic ecosystems, and to encourage multidisciplinary integration, particularly with the social sciences. Furthermore, the future research interests in China include: combining multi-source information, constructing comprehensive monitoring systems, studying spatiotemporal patterns of key ecohydrological variables and their variation characteristics, developing integrated models of ecological, hydrological, and economic processes, estimating their uncertainty; and conducting interdisciplinary studies that include the natural and social sciences. The application prospects in China are further explored for a variety of ecosystems, including forests, grasslands, rivers, lakes, wetlands, farmlands, and cities. This study will provide a reference to support the development of the ecohydrology discipline in China, and will provide a solid theoretical and technical foundation for the implementation of national ecological civilization construction.

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    Clustering stream profiles to understand the geomorphological features and evolution of the Yangtze River by using DEMs
    ZHAO Fei, XIONG Liyang, WANG Chun, WEI Hong, MA Junfei, TANG Guoan
    Journal of Geographical Sciences    2021, 31 (11): 1555-1574.   DOI: 10.1007/s11442-021-1911-3
    Abstract80)   HTML16)    PDF (12133KB)(107)      

    Stream morphology is an important indicator for revealing the geomorphological features and evolution of the Yangtze River. Existing studies on the morphology of the Yangtze River focus on planar features. However, the vertical features are also important. Vertical features mainly control the flow ability and erosion intensity. Furthermore, traditional studies often focus on a few stream profiles in the Yangtze River. However, stream profiles are linked together by runoff nodes, thus affecting the geomorphological evolution of the Yangtze River naturally. In this study, a clustering method of stream profiles in the Yangtze River is proposed by plotting all profiles together. Then, a stream evolution index is used to investigate the geomorphological features of the stream profile clusters to reveal the evolution of the Yangtze River. Based on the stream profile clusters, the erosion base of the Yangtze River generally changes from steep to gentle from the upper reaches to the lower reaches, and the evolution degree of the stream changes from low to high. The asymmetric distribution of knickpoints in the Hanshui River Basin supports the view that the boundary of the eastward growth of the Tibetan Plateau has reached the vicinity of the Daba Mountains.

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    Sustainable poverty alleviation and green development in China’s underdeveloped areas
    GUO Yuanzhi, LIU Yansui
    Journal of Geographical Sciences    2022, 32 (1): 23-43.   DOI: 10.1007/s11442-021-1932-y
    Abstract79)   HTML8)    PDF (663KB)(83)      

    In 2020, the decisive victory of building a moderately well-off society in all aspects means that absolute poverty in rural China has been completely eliminated. Consolidating and expanding the achievements of poverty alleviation and establishing a long-term mechanism to solve relative poverty have become key issues in high-quality development of underdeveloped areas. In this study, human-earth system is employed to analyze the element composition, structural organization and functional state of underdeveloped areas. The results show that poverty in underdeveloped areas stems from the lack of the coupling and coordinating mechanism among human, economic, resource and environmental elements, which is not conducive to transforming the ecological advantages into the advantages of regional development. In the antipoverty stage, underdeveloped areas innovate the human-earth coupling and coordinating mechanism through a series of targeted measures, promote the organic combination of poverty alleviation, ecological conservation and sustainable development, and boost the transformation of regional development and the increase of farmers’ incomes. Focusing on the 14th Five-year Plan (2021-2025) and the long-term goal of 2035, governments in underdeveloped areas should make full use of the policy support to explore scientific methods of modern governance and sustainable development. In particular, it is necessary to practice the concept that “clear waters and lush mountains are invaluable assets” and take the road of the ecologicalization of industry and the industrialization of ecology by establishing a policy system of “green land”, “green people”, “green industry” and “green right”, thus building an endogenous growth mechanism of sustainable poverty alleviation and green development in China’s underdeveloped areas.

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    Evaluation of ontological value of regional tourism resources: A case study of Hainan Island, China
    ZHANG Tongyan, WANG Yingjie, ZHANG Shengrui, WANG Yingying, YU Hu
    Journal of Geographical Sciences    2021, 31 (7): 1015-1038.   DOI: 10.1007/s11442-021-1883-3
    Abstract77)   HTML4)    PDF (5853KB)(10)      

    Evaluation of tourism resources is necessary for tourism regionalization and planning and for the development of tourism destinations. Furthermore, the scientific evaluation of the status of existing tourism resources is important for optimally combining and rationally developing regional tourism resources. In this study, a conceptual model for estimating the ontological value of tourism resources was developed and an evaluation indicator system was designed for the ontological value. On the basis of the quantitative and spatial characteristics of regional tourism resources, six indicators were constructed: quantitative density, richness, dominance, combination, aggregation, and accessibility. Furthermore, spatial differentiation characteristics of the ontological value indicators of county-level tourism resources on Hainan Island were analyzed, and the ontological value of the tourism resources was comprehensively evaluated and ranked by using a fuzzy clustering evaluation method. Finally, the evaluation results were verified on the basis of the quantity, quality, and accessibility of regional tourism resources by using an expert scoring method. The results showed that the test results were consistent with the inferences drawn from the ontological value, indicating that the evaluation indicator system is scientific and reliable and that it is an effective alternative to existing evaluation indexes of regional tourism resources, which are inconsistent. The fuzzy clustering evaluation method overcomes the subjectivity in the evaluation process and is practical for the quantitative evaluation of regional tourism resources. The evaluation indicator system for regional tourism resources designed in this study can provide a reference for the evaluation of the tourism resource development value on a regional scale, and the evaluation results can facilitate informed policymaking for the rational development of regional tourism resources.

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    A strategy of the rural governance for territorial spatial planning in China
    GE Dazhuan, LU Yuqi
    Journal of Geographical Sciences    2021, 31 (9): 1349-1364.   DOI: 10.1007/s11442-021-1900-6
    Abstract76)   HTML7)    PDF (834KB)(119)      

    Rural spatial governance has become an important part of the spatial governance system under the unified management of urban and rural spaces. In-depth theoretical and practical research on rural spatial governance in terms of promoting national spatial planning can help improve the planning and regulation system of rural space. Beginning with a description of rural spatial governance, this paper constructs a theoretical analysis framework of rural spatial governance based on the comprehensive perspective of spatial governance. The study also discusses the internal processes and feasible paths of rural spatial governance in territorial spatial planning and outlines the theoretical and practical research for enhancing rural spatial governance. The conclusions are as follows: (1) Rural spatial governance starts with the coordination theory of human-land relationships in the rural regional system. Through planning and negotiation, governance has effective regulation of rural space and allocates spatial rights in an orderly manner. Rural spatial governance highlights the comprehensive governance processes that combine “top-down” and “bottom-up” participation by multiple subjects. (2) Through the “action-efficiency-target” system, the comprehensive governance analysis framework of “matter-organization-ownership” in rural space provides an effective scheme for constructing rural spatial governance. Rural spatial governance is characterized by both rigidity and flexibility, the interaction between physical space and spatial relationships, and the superposition of spatial ownership and spatial organization. (3) The rural spatial governance features of interconnecting various scales (regional-village-plot) are conducive to improving the rural spatial governance system. (4) The governance means, participation modes, and value-sharing mechanisms of rural spatial governance help enrich the territorial spatial planning system, promote the integration of multiple regulations, refine the regulation of land use, and ensure good rural governance and ecological governance.

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    Spatio-temporal analysis of cropland change in the Guanzhong area, China, from 1650 to 2016
    WEI Xueqiong, LI Yuanfang, GUO Yu, CHEN Tiexi, LI Beibei
    Journal of Geographical Sciences    2021, 31 (9): 1381-1400.   DOI: 10.1007/s11442-021-1902-4
    Abstract76)   HTML5)    PDF (7274KB)(136)      

    As one of the most critical impact factors of global change, historical land-use change is an indispensable input in climate and environment simulations. To better understand the cropland change in the Guanzhong area, gazetteers, statistics, and survey data were collected as data sources. Methods of registered tax-paying cropland data collection, selection of time points, and data interpolation and calibration were used to reconstruct changes in the cropland area. The cropland area data at the county level were allocated to 1 km×1 km grid cells. The total cropland area in the Guanzhong area was influenced by changes in population, wars, natural disasters, and land-use types, and it fluctuated from 1650 to 2016. From 1780 to 1830, the cropland expanded in the northern and western parts of Guanzhong area, and the cropland in the north of Qinling Mountains increased slightly. The spatial pattern of cropland reached its maximum range in 1980, and the cropland area declined in the whole study area, especially in the cities of Xi’an and Xianyang in 2016. The comparison between HYDE 3.2 and the data obtained in this study showed that the grid cells of HYDE 3.2 exhibit lower values of cropland area fractions in the Guanzhong Basin and higher values in high-altitude areas around the Guanzhong Basin as compared to those in this study.

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    Intensified risk to ecosystem productivity under climate change in the arid/humid transition zone in northern China
    YIN Yunhe, DENG Haoyu, MA Danyang, WU Shaohong
    Journal of Geographical Sciences    2021, 31 (9): 1261-1282.   DOI: 10.1007/s11442-021-1897-x
    Abstract76)   HTML2)    PDF (14163KB)(114)      

    Assessing the climate change risk faced by the ecosystems in the arid/humid transition zone (AHTZ) in northern China holds scientific significance to climate change adaptation. We simulated the net primary productivity (NPP) for four representative concentration pathways (RCPs) using an improved Lund-Potsdam-Jena model. Then a method was established based on the NPP to identify the climate change risk level. From the midterm period (2041-2070) to the long-term period (2071-2099), the risks indicated by the negative anomaly and the downward trend of the NPP gradually extended and increased. The higher the scenario emissions, the more serious the risk. In particular, under the RCP8.5 scenario, during 2071-2099, the total risk area would be 81.85%, that of the high-risk area would reach 54.71%. In this high-risk area, the NPP anomaly would reach -96.00±46.95 gC·m-2·a-1, and the rate of change of the NPP would reach -3.56±3.40 gC·m-2·a-1. The eastern plain of the AHTZ and the eastern grasslands of Inner Mongolia are expected to become the main risk concentration areas. Our results indicated that the management of future climate change risks requires the consideration of the synergistic effects of warming and intensified drying on the ecosystem.

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    Method for UAV-based 3D topography reconstruction of tidal creeks
    ZHANG Xuhui, LI Huan, GONG Zheng, ZHOU Zeng, DAI Weiqi, WANG Lizhu, Samuel DARAMOLA
    Journal of Geographical Sciences    2021, 31 (12): 1852-1872.   DOI: 10.1007/s11442-021-1926-9
    Abstract68)   HTML1)    PDF (17156KB)(72)      

    It is common to obtain the topography of tidal flats by the Unmanned Aerial Vehicle (UAV) photogrammetry, but this method is not applicable in tidal creeks. The residual water will lead to inaccurate depth inversion results, and the topography of tidal creeks mainly depends on manual survey. The present study took the tidal creek of Chuandong port in Jiangsu Province, China, as the research area and used UAV oblique photogrammetry to reconstruct the topography of the exposed part above the water after the ebb tide. It also proposed a Trend Prediction Fitting (TPF) method for the topography of the unexposed part below the water to obtain a complete 3D topography. The topography above the water measured by UAV has the vertical precision of 12 cm. When the TPF method is used, the cross-section should be perpendicular the central axis of the tidal creek. A polynomial function can be adapted to most shape of sections, while a Fourier function obtains better results in asymmetrical sections. Compared with the two-order function, the three-order function lends itself to more complex sections. Generally, the TPF method is more suitable for small, straight tidal creeks with clear texture and no vegetation cover.

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