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    Exploring detailed urban-rural development under intersecting population growth and food production scenarios: Trajectories for China’s most populous agricultural province to 2030
    GAO Peichao, XIE Yiru, SONG Changqing, CHENG Changxiu, YE Sijing
    Journal of Geographical Sciences    2023, 33 (2): 222-244.   DOI: 10.1007/s11442-023-2080-3
    Abstract228)   HTML38)    PDF (31049KB)(214)      

    Henan, China, is likely the most populous agricultural province worldwide. It is China’s major grain-producing area, with a continuously increasing population (96 million), which is greater than 93% of countries worldwide. However, this province has been experiencing unprecedented urbanization recently due to national policies and measures, such as a plan to build the capital city of Henan into a national center, resulting in severe conflicts in land use that endanger food security regionally and globally. To facilitate decision-making on this problem, we explored the detailed urban-rural development of Henan by modeling these land-use conflicts. Conventional modeling of a region’s urban-rural development is to navigate trade-offs (a) solely between different land-use types (b) by assuming that each type provides a single service (e.g., croplands produce all the food), and (c) under a polynomial regression-based projection of population. In contrast, we considered both land-use type and intensity, resulting in a detailed land system for Henan. By introducing the concept of land system services (e.g., food production), we established a many-to-many relationship between land system classes and services. These allowed us to carry out the most comprehensive modeling of Henan’s urban-rural development under eighteen combined scenarios of population growth and land-use policies on food production. The modeling results of these scenarios provide a solid basis for making decisions regarding Henan’s urban-rural development. We also revealed the influence mechanism of population growth, land-use policies, and their combinations, highlighting the benefits of securing food production by agricultural intensification rather than merely expanding the area of cropland.

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    Spatio-temporal variation prediction on Cd content in the rice grains from Northern Zhejiang Plain during 2014-2019 based on high-precision soil geochemical data
    YIN Hanqin, LU Xinzhe, SUN Rui, HUANG Chunlei, KANG Zhanjun, XU Mingxing, WEI Yingchun, CAI ZiHua
    Journal of Geographical Sciences    2023, 33 (2): 413-426.   DOI: 10.1007/s11442-023-2089-7
    Abstract201)   HTML17)    PDF (6482KB)(60)      

    In recent years, Cadmium (Cd) pollution has been found in many soil geochemical surveys in Northern Zhejiang Plain, a crucial rice production area in East China, located in the lower Yangtze River. To more scientifically predict the effect of soil Cd on rice safety, data including 348 local rhizosphere soil-rice samples obtained in 2014 were used in this study. Meanwhile, we extracted 90% of random samples as variables based on soil Cd content (Cdsoil), soil organic matter (SOM), pH, and other indicators. In addition, a multivariate linear model for rice Cd content (Cdrice) prediction based on the indicators including the soil Cd content (Cdsoil), the soil organic matter (SOM), and the pH value. The remaining 10% of random samples were used for the significance test. Based on the 2014 soil Cd content (Cdsoil14) and the 2019 soil Cd content (Cdsoil19), this study predicted Cd content in 2019 rice grains (Cdp-rice19). The spatio-temporal variation of Cdrice was contrasted in the five years from 2014 to 2019, and the risk areas of rice safety production were analyzed using the Geographical Information System (GIS). The results indicated that compared with the actual Cd content in 2014 rice grains (Cdrice14), the proportion of Cdp-rice19, which exceeded the standard food level in China (GB2762-2017), increased dramatically. Moreover, the high-value areas of Cdrice distributed greatly coincidentally in these two years. By contrast, both Cdrice and Cdsoil show very different spatial scales. The dominant reason is the distribution of the local canal systems, indicating that economic activities and agricultural irrigation may aggravate the risk of soil Cd pollution, thus threatening safe rice production.

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    Understanding the change of land space utilization efficiency with different functions and its coupling coordination: A case study of Urban Agglomeration in the Middle Reaches of the Yangtze River, China
    YANG Bin, YANG Jun, TAN Li, XIAO Jianying
    Journal of Geographical Sciences    2023, 33 (2): 289-310.   DOI: 10.1007/s11442-023-2083-0
    Abstract190)   HTML21)    PDF (2532KB)(89)      

    Land spaces function in capacities of urban development, agricultural production, and ecological conservation, among many others. Research of land space utilization efficiency (LSUE) and coupling coordination relationships among its subsystems are significant for sustainable land space development. In this study, taking the Urban Agglomeration in the Middle Reaches of the Yangtze River (UAMRYR) as the study area, we establish a measurement index system to evaluate the LSUE (2000-2018) and analyze its coupling coordination degree by utilizing an improved coupling coordination model. The main results include the following. (1) The average efficiency levels of urban space and agricultural space in the UAMRYR increased 2000-2018, while the average efficiency of ecological space declined. (2) The spatial pattern of the LSUE values varied greatly, with the distributions of high-efficiency and low-efficiency levels significantly different. (3) The coupling degree of LSUE includes three types, i.e., high-level coupling, break-in, and antagonism. Each coupling degree type was characterized by change over time. (4) The proportion of areas with high coupling coordination and moderate coupling coordination increased from 2000 to 2018, while the proportion of areas with basic coupling coordination, moderate imbalance, and serious imbalance declined during this period. Given that the spatial differentiation of the LSUE and its coupling coordination, it is necessary to implement a differential land space development strategy in the UAMRYR. This study is helpful to promote the efficient utilization and coordinated development of land space utilization systems.

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    Evaluation, simulation, and optimization of land use spatial patterns for high-quality de-velopment: A case study of Zhengzhou city, China
    ZHU Wenchao, JIANG Zhimeng, CEN Luyu, WU Hao
    Journal of Geographical Sciences    2023, 33 (2): 266-288.   DOI: 10.1007/s11442-023-2082-1
    Abstract186)   HTML18)    PDF (4966KB)(326)      

    High-intensity land use and resource overloaded-induced regional land use spatial pattern (LUSP) are essential and challenging for high-quality development. The empirical studies have shown that a scientific land uses spatial layout, and the supporting system should be based on a historical perspective and require better considering the double influence between the current characteristics and future dynamics. This study proposes a comprehensive framework that integrates the resource environment carrying capacity (RECC) and land use change (LUC) to investigate strategies for optimizing the spatial pattern of land use for high-quality development. China’s Zhengzhou city was the subject of a case study whose datasets include remote sensing, spatial monitoring, statistics, and open sources. Three significant results emerged from the analysis: (1) The RECC has significant spatial differentiation but does not follow a specific spatial law, and regions with relatively perfect ecosystems may not necessarily have better RECC. (2) From 2020 to 2030, the construction land and farmland will fluctuate wildly, with the former increasing by 346.21 km2 and the latter decreasing by 295.98 km2. (3) The study area is divided into five zones, including resource conservation, ecological carrying, living core, suitable construction, and grain supply zones, and each one has its LUSP optimization orientation. This uneven distribution of RECC reflects functional defects in the development and utilization of LUSP. In addition, the increase in construction land and the sharp decline of farmland pose potential threats to the sustainable development of the study area. Hence, these two elements cannot be ignored in the future high-quality development process. The findings indicate that the LUSP optimization based on dual dimensions of RECC and LUC is more realistic than a single-dimension solution, exhibiting the LUSP optimization’s effectiveness and applicability.

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    Latitudinal differentiation and patterns of temperate and subtropical plants in the Qinling-Daba Mountains
    LIU Junjie, ZHANG Baiping, YAO Yonghui, ZHANG Xinghang, WANG Jing, YU Fuqin, LI Jiayu
    Journal of Geographical Sciences    2023, 33 (5): 907-923.   DOI: 10.1007/s11442-023-2112-z
    Abstract180)   HTML49)    PDF (4446KB)(201)      

    Geographically, the Qinling-Daba Mountains serve as the main body of the north-south transitional zone of China. However, the transitional patterns of their plant species still need to be clarified. This study analyzed latitudinal variations of plant species richness, relative importance values (RIV), and plant species abundance based on plant community field survey data for 163 sample sites along three north-south transect lines in the eastern, middle, and western parts of the study areas. The difference in RIV between subtropical and temperate species (SND-RIV) was selected to reveal the latitudinal interlacing pattern of northern and southern plant species. Along the eastern (Sanmenxia-Yichang), middle (Xi’an-Dazhou), and western (Tianshui-Guangyuan) transects, the richness and RIV of subtropical plant species increased while those of temperate plant species decreased from north to south. In the eastern transect, temperate plant species richness and RIV were the highest at Shennongjia and Funiu Mountain, respectively, because of their high elevations. In the middle transect, subtropical plant species richness and RIV were the highest in the Daba Mountains. In the western transect, richness and RIV were higher for subtropical than temperate plant species from the south of Longnan. The crisscrossing areas of northern and southern plant species were ~180 km, ~100 km, and ~60 km wide for the eastern, middle, and western transects, respectively, showing a narrowing trend from east to west. For the eastern and western transects, decreases in subtropical plant species distribution from south to north could be attributed to a decrease in mean annual precipitation in the same direction. However, for the middle transect, mean annual temperature had a slightly greater influence on plant species’ latitudinal distribution than the moisture index. This study provides a more solid scientific basis for future investigations of this key geographical boundary in China.

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    Understanding land for high-quality development
    JIN Gui, PENG Jian, ZHANG Lixiao, ZHANG Zhengyu
    Journal of Geographical Sciences    2023, 33 (2): 217-221.   DOI: 10.1007/s11442-023-2079-9
    Abstract176)   HTML40)    PDF (150KB)(152)      
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    Identification of regional pattern of climate change risk in China under different global warming targets
    WU Shaohong, CHAO Qingchen, GAO Jiangbo, LIU Lulu, FENG Aiqing, DENG Haoyu, ZUO Liyuan, LIU Wanlu
    Journal of Geographical Sciences    2023, 33 (3): 429-448.   DOI: 10.1007/s11442-023-2090-1
    Abstract175)   HTML67)    PDF (9189KB)(245)      

    Climate change will bring huge risks to human society and the economy. Regional climate change risk assessment is an important basic analysis for addressing climate change, which can be expressed as a regional system of comprehensive climate change risk. This study establishes regional systems of climate change risks under the proposed global warming targets. Results of this work are spatial patterns of climate change risks in China, indicated by the degree of climate change and the status of the risk receptors. Therefore, the risks show significant spatial differences. The high-risk regions are mainly distributed in East, South, and central China, while the medium-high risk regions are found in North and southwestern China. Under the 2°C warming target, more than 1/4 of China’s area would be at high and medium-high risk, which is more severe than under the 1.5°C warming target, and would extend to the western and northern regions. This work provides regional risk characteristics of climate change under different global warming targets as a foundation for dealing with climate change.

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    Drivers of water pollutant discharge in urban agglomerations and their scale effects: Empirical analysis of 305 counties in the Yangtze River Delta
    ZHOU Kan, YIN Yue, CHEN Yufan
    Journal of Geographical Sciences    2023, 33 (1): 195-214.   DOI: 10.1007/s11442-022-2066-6
    Abstract174)   HTML15)    PDF (3770KB)(76)      

    Revealing the drivers and scale effects of water pollutant discharges is an important issue in the study of the environmental consequences during urban agglomeration evolution. It is also a prerequisite for realizing collaborative water pollutant reduction and environmental governance in urban agglomerations. This paper takes 305 counties in the Yangtze River Delta (YRD) as an example and selects chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) as two distinctive pollutant indicators, using the Spatial Lag Model (SLM) and Spatial Error Model (SEM) to estimate the drivers of water pollutant discharges in 2011 and 2016. Then the Multiscale Geographically Weighted Regression (MGWR) model is constructed to diagnose the scale effect and spatial heterogeneity of the drivers. The findings show that the size of population, the level of urbanization, and the economic development level show global-level increase impacts on water pollutant discharges, while the level of industrialization, social fixed assets investment, foreign direct investment, and local fiscal decentralization are local-level impacts. The spatial heterogeneity of local drivers presents the following characteristics: Social fixed assets investment has a strong promoting effect on both COD and NH3-N discharges in the Hangzhou-Jiaxing-Huzhou region and the coastal area of the YRD; industrialization has a promoting effect on COD discharges in the Taihu Lake basin and Zhejiang province; foreign direct investment has a local inhibitory effect on NH3-N discharge, and the pollution halo effect is more prominent in the marginal areas of the YRD such as northern Jiangsu, northern Anhui, and southern Zhejiang; local fiscal decentralization has a noticeable inhibitory effect on COD discharge in the central areas of the YRD, reflecting the positive impacts on improved local environmental awareness and stronger constraints of multilevel environmental regulations in the urban agglomeration. Therefore, it is recommended to guide greener development to reduce the water pollutant discharge; to embed an environmental push-back mechanism in the fields of industrial production, capital investment, and financial income and expenditure; and to establish a high-quality development pattern of urban agglomerations systematically compatible with the carrying capacity of the water environment.

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    Spatio-temporal analysis of human wellbeing and its coupling relationship with ecosystem services in Shandong province, China
    WANG Chao, WANG Xuan, WANG Yifan, ZHAN Jinyan, CHU Xi, TENG Yanmin, LIU Wei, WANG Huihui
    Journal of Geographical Sciences    2023, 33 (2): 392-412.   DOI: 10.1007/s11442-023-2088-8
    Abstract172)   HTML15)    PDF (11049KB)(118)      

    Rapid economic and social change promotes to improve human wellbeing (HW), but poses threats to ecosystems and the environment. Studying the coupling relationship between HW and ecosystem services (ES) is crucial for informing high-quality development. Firstly, we built a comprehensive index system for HW assessment, and evaluated HW for 17 prefecture-level cities in Shandong province, China, from 2000 to 2018. Then, we quantified ES based on land use data. Finally, we assessed the coupling coordination degree and analyzed the relationships between HW and each type of ES value. The results were as follows: (1) HW values increased overall in Shandong, with the highest value in Jinan (0.8034) and the lowest value in Heze (0.4965) in 2018. (2) The total ES values for the 17 cities increased slightly. The ranking of 17 cities according to the ES value per unit area was different from the ranking according to the total ES value. (3) All 17 cities in Shandong were in the coordinated development phase after 2015, with increasing coupling coordination degrees. There were clear positive relationships between HW and ES. General and specific policy recommendations were proposed, providing scientific evidence and a reference for Shandong’s urban management and policy formulation.

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    Spatiotemporal variations of water use efficiency and its driving factors in Inner Mongolia from 2001 to 2020
    MEI Li, TONG Siqin, YIN Shan, BAO Yuhai, HUANG Xiaojun, ALATENG Tuya, WANG Yongfang, GUO Enliang, YUAN Zhihui, NASHUN Dalai, GAO Suriguga, LIU Xinyi, YE Zhigang
    Journal of Geographical Sciences    2023, 33 (1): 169-194.   DOI: 10.1007/s11442-023-2078-x
    Abstract170)   HTML11)    PDF (4015KB)(108)      

    Water use efficiency (WUE) is an important variable to explore coupled relationships in carbon and water cycles. In this study, we first compared the spatial variations of annual gross primary productivity (GPP) and evapotranspiration (ET) using four GPP and ET products. Second, we selected the products closest to the flux towers data to estimate WUE. Finally, we quantitatively analyzed the impact of climate change and soil water content on WUE. The results showed that: (1) Four GPP and ET products provided good performance, with GOSIF-GPP and FLDAS-ET exhibiting a higher correlation and the smallest errors with the flux tower data. (2) The spatial pattern of WUE is consistent with that of GPP and ET, gradually decreasing from the northeast to the southwest. Higher WUE values appeared in the northeast forest ecosystem, and lower WUE values occurred in the western Gobi Desert, with a value of 0.28 gC m?2 mm?1. The GPP and ET products showed an increasing trend, while WUE showed a decreasing trend (55.15%) from 2001 to 2020. (3) The spatial relationship between WUE and driving factors reveal the variations in WUE of Inner Mongolia are mainly affected by soil moisture between 0 and 10 cm (SM0-10cm), vapor pressure deficit (VPD), and precipitation, respectively. (4) In arid regions, VPD and precipitation exhibit a major influence on WUE. An increase in VPD and precipitation has a negative and positive effect on WUE, with threshold values of approximately 0.36 kPa and 426 mm, respectively. (5) In humid regions, SM0-10cm, VPD, SM10-40cm, and SM40-100cm exert a significant impact on WUE, especially SM0-10cm, and weakens with increasing soil depths, these differences may be related to physiological structure and living characteristics of vegetation types in different climate regimes. Our results emphasize the importance of VPD and soil moisture in regional variability in WUE.

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    The effects of climate change and phenological variation on agricultural production and its risk pattern in the black soil area of northeast China
    GAO Jiangbo, LIU Lulu, GUO Linghui, SUN Dongqi, LIU Wanlu, HOU Wenjuan, WU Shaohong
    Journal of Geographical Sciences    2023, 33 (1): 37-58.   DOI: 10.1007/s11442-023-2073-2
    Abstract164)   HTML16)    PDF (7413KB)(105)      

    The black soil region of northeast China is a vital food base and is one of the most sensitive regions to climate change in China. However, the characteristics of the crop phenological response and the integrated impact of climate and phenological changes on agricultural productivity in the region under the background of climate change are not clear. The future agricultural risk assessment has been insufficiently quantified and the existing risk level formulation lacks a sound basis. Based on remote sensing products, climate data, and model simulations, this study integrated a logistic function fitting curvature derivation, multiple linear regression, and scenario simulation to investigate crop phenology dynamics and their climate response characteristics in the black soil region. Additionally, the compound effects of climate and phenology changes on agricultural production and possible future risks were identified. The key results were as follows: (1) From 2000 to 2017, 29.76% of the black soil region of northeast China experienced a significant delay in the start of the growing season (SOS) and 16.71% of the total area displayed a trend for the end of the growing season (EOS) to arrive earlier. The time lagged effects of the SOS in terms of the crop response to climatic factors were site and climatic parameter dependent. The influence of temperature was widespread and its effect had a longer lag time in general; (2) Both climatic and phenological changes have had a significant effect on the inter-annual variability of crop production, and the predictive ability of both increased by 70.23%, while the predictive area expanded by 85.04%, as compared to that of climate change in the same period of the growing season; (3) Under the RCP8.5 scenario, there was a risk that the future crop yield would decrease in the north and increase in the south, and the risk area was constantly expanding. With a 2.0℃ rise in global temperature, the crop yield of the southern Songnen black soil sub-region would reduce by almost 10%. This finding will improve our understanding of the mechanisms underlying climate change and vegetation productivity dynamics, and is also helpful in the promotion of the risk management of agrometeorological disasters.

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    Coordinated development of land multi-function space: An analytical framework for matching the supply of resources and environment with the use of land space for ecological protection, agricultural production and urban construction
    QU Yanbo, ZHANG Yanjun, WANG Shilei, SHANG Ran, ZONG Haining, ZHAN Lingyun
    Journal of Geographical Sciences    2023, 33 (2): 311-339.   DOI: 10.1007/s11442-023-2084-z
    Abstract164)   HTML4)    PDF (3441KB)(75)      

    Based on the carrying capacity of the resources and the environment, this article defines the connotation of the land multifunctional space (LMFS) from three aspects, ecological protection, agricultural production and urban construction, in the new era of land space planning system. Moreover, a framework is constructed for the coordinated development of the multi-functional oriented space to match the use of land space (ULS) with the supply of resources and environment (SRE). Based on this, the technology and methods of comprehensive evaluation, dominance recognition, and matching relationship division functions of the use of land space (FULS) and functions of the supply of resources and environment (FSRE) are discussed. The advantageous functions of the use of land space (AFULS) and advantageous functions of the supply of resources and environment (AFSRE) are also identified in the study area. A LMFS coordinated development system integrating “function position-comprehensive partition-regulation strategy” is proposed. Through the empirical study of Shandong province, we found that, first, the FULS of ecological protection space in the province is mainly found in high value areas, and the FSRE is mainly in low value areas, which has certain complementarity in the space. The FULS of agricultural production space is mainly observed in high value areas, the FSRE is mainly in middle value areas, and the spatial distribution is balanced and staggered. The FULS of the urban construction space and the FSRE are mainly in middle values areas, and the spatial distribution is basically similar. Second, the FULS in the study area is dominated by the single advantage of agricultural production and urban construction, while the FSRE has a relatively balanced distribution of the advantages of ecological protection, single agricultural production and compound advantages of agricultural production and urban construction, and urban construction and ecological protection. The matching between the two is mainly at high and middle levels. Specifically, 70% of the province’s land space still has a certain development and utilization potential, and 30% of ULS intensity is close to or exceeds the resource and environment carrying capacity. Third, considering the comprehensive impact of resource endowment, social and economic development and policy and institutional environment on different matching relationships, this paper constructs the land spatial development strategic pattern of “two screens-seven regions-multicore” positioning and “four regions-eight categories” hierarchical area of Shandong at the macro level, and puts forward a differentiated land space development strategy.

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    Extraction and spatiotemporal evolution analysis of tidal flats in the Bohai Rim during 1984-2019 based on remote sensing
    XU Haijue, JIA Ao, SONG Xiaolong, BAI Yuchuan
    Journal of Geographical Sciences    2023, 33 (1): 76-98.   DOI: 10.1007/s11442-023-2075-0
    Abstract159)   HTML11)    PDF (3945KB)(92)      

    Tidal flats, a precious resource that provides ecological services and land space for coastal zones, are facing threats from human activities and climate change. In this study, a robust decision tree for tidal flat extraction was developed to analyse spatiotemporal variations in the Bohai Rim region during 1984-2019 based on 9539 Landsat TM/OLI surface reflection images and the Google Earth Engine (GEE) cloud platform. The area of tidal flats significantly fluctuated downwards from 3551.22 to 1712.36 km2 in the Bohai Rim region during 1984-2019, and 51.31% of tidal flats were distributed near the Yellow River Delta and Liaohe River Delta during 2017-2019. There occurred a drastic spatial transition of tidal flats with coastline migration towards the ocean. Low-stability tidal flats were mainly distributed in reclamation regions, deltas, and bays near the estuary during 1984-2019. The main factors of tidal flat evolution in the Bohai Rim region included the direct impact of land cover changes in reclamation regions, the continuous impact of a weakening sediment supply, and the potential impact of a deteriorating sediment storage capability. The extraction process and maps herein could provide a reference for the sustainable development and conservation of coastal resources.

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    Spatio-temporal characteristics and typical patterns of eco-efficiency of cultivated land use in the Yangtze River Economic Belt, China
    KE Xinli, ZHANG Ying, ZHOU Ting
    Journal of Geographical Sciences    2023, 33 (2): 357-372.   DOI: 10.1007/s11442-023-2086-x
    Abstract152)   HTML7)    PDF (1188KB)(104)      

    Identifying the dynamics of the eco-efficiency of cultivated land use (ECLU) is important to balance food security and environmental protection. The Yangtze River Economic Belt (YREB) is a vital region of national strategic development in China. However, the spatio-temporal characteristics and typical patterns of the ECLU in the YREB remain unclear. This study aims to reveal the spatio-temporal characteristics of the ECLU by using the super-efficiency slack-based measure (SBM) and a spatial autocorrelation model. The typical patterns of the ECLU were classified based on a decision tree algorithm. The results indicate that the overall ECLU increased from 0.78 to 0.87 from 2000 to 2019, dropping sharply in 2003 before rising again. Different reaches had similar trends. The local indicators of spatial association (LISA) cluster reflect that the spatial distributions of high-high and low-low agglomeration varied dramatically among these years. The ECLU was divided into three typical patterns considering the restriction of agrochemicals and water resources (RAW), cultivated land and agrochemicals (RCA), as well as technology (RT). Most cities belonged to the low ECLU category in RT pattern. Fully understanding the spatio-temporal characteristics and classification of the ECLU will provide a reference for decision-makers to improve the ECLU in different regions.

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    Imbalance of inter-provincial forest carbon sequestration rate from 2010 to 2060 in China and its regulation strategy
    CAI Weixiang, XU Li, LI Mingxu, SUN Osbert Jianxin, HE Nianpeng
    Journal of Geographical Sciences    2023, 33 (1): 3-17.   DOI: 10.1007/s11442-023-2071-4
    Abstract148)   HTML241)    PDF (962KB)(166)      

    Forest ecosystem, as a predominant component of terrestrial ecosystems in view of carbon sinks, has a high potential for carbon sequestration. Accurately estimating the carbon sequestration rate in forest ecosystems at provincial level, is a prerequisite and basis for scientifically formulating the technical approaches of carbon neutrality and the associated regulatory policies in China. However, few researches on future carbon sequestration rates (CSRs) for Chinese forest ecosystems for provincial-level regions (hereafter province) have been reported, especially for forest soils. In this study, we quantitatively assessed the carbon sequestration rates of existing forest ecosystems of all the provinces from 2010 to 2060 using the Forest Carbon Sequestration model (FCS), in combination with large quantities of field-measured data in China under three future climate scenarios (RCP2.6, RCP4.5, and RCP8.5). Results showed that CSRs across provinces varied from 0.01 TgC a-1 to 36.74 TgC a-1, with a mean of 10.09 ± 0.43 TgC a-1. Inter-provincial differences have been observed in forest CSRs. Regarding the spatial variations in CSRs on a unit area basis within provinces, the eastern region provinces have a larger capacity for sequestration than the western region, while the western region has greater CSR per unit GDP and per capita. Moreover, there are significant negative correlations between the CSRs per capita in each province and the corresponding GDP per capita, under the assumption that GDP per capita is constant in the future across provinces. In summary, there is a significant regional imbalance in CSR among provinces. Special technological and policy interventions are required to realize carbon sink potential sustainably. An overlap in China’s poorer areas and areas with stronger carbon sinks has indicated that existing policies to support traditional carbon trading are insufficient. Regulatory measures such as “regional carbon compensation” must be adopted urgently in line with the Chinese characteristics, so that people in western or underdeveloped regions can consciously strengthen forest protection and enhance forest carbon sinks through coordinated regional development while ensuring that China’s forests play a greater role in carbon neutrality strategies.

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    Dynamics of the eco-environmental quality in response to land use changes in rapidly urbanizing areas:A case study of Wuhan, China from 2000 to 2018
    HU Can, SONG Min, ZHANG Anlu
    Journal of Geographical Sciences    2023, 33 (2): 245-265.   DOI: 10.1007/s11442-023-2081-2
    Abstract146)   HTML23)    PDF (3854KB)(103)      

    The dramatic land use changes that occur in rapidly urbanized areas are important inducement to changes in the eco-environmental quality. Investigating urban land use changes and their eco-environmental quality responses can provide theoretical support and a decision-making basis for sustainable and high-quality development in rapidly urbanizing areas. Taking Wuhan, China, as the study area, this paper extracts land use information using Landsat satellite remote sensing images and a support vector machine classification. Based on this, a remote sensing-based ecological index evaluation model including humidity, greenness, dryness and heat is constructed to explore the changes in land use and their eco-environmental quality responses from 2000 to 2018. The results show that (1) the structure, extent and spatial layout of land use in Wuhan from 2000 to 2018 have undergone tremendous changes under rapid urbanization, and the change of construction land is the greatest among all land use types; (2) the overall quality of eco-environment in Wuhan continues to improve as the scale of the improved eco-environment areas is greater than that of the deteriorated areas. The direction and magnitude of the impact of each indicator on the eco-environmental quality are different; (3) the improvement or deterioration of eco-environmental quality is closely related to the changes of different land use types within the study area. The eco-environmental quality shows significant spatial heterogeneity, especially between the main urban areas and the suburban areas. This paper argues that reasonably adjusting the land use structure can serve to maintain or even improve the quality of the regional eco-environment. Finally, this study puts forward suggestions for the coordinated development of land use and the eco-environment in rapidly urbanizing areas.

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    Modelling the impacts of cropland displacement on potential cereal production with four levels of China’s administrative boundaries
    YANG Bohan, SHENG Siyu, KE Xinli, DAI Xianhua, LU Xinhai
    Journal of Geographical Sciences    2023, 33 (1): 18-36.   DOI: 10.1007/s11442-023-2072-3
    Abstract144)   HTML9)    PDF (4829KB)(76)      

    Cropland displacement, as an important characteristic of cropland change, places more emphasis on changes in spatial location than on quantity. The effects of cropland displacement on global and regional food production are of general concern in the context of urban expansion. Few studies have explored scale-effects, however, where cropland is displaced not only within, but also outside, the administrative boundary of a certain region. This study used a spatially explicit model (LANDSCAPE) to simulate the potential cropland displacement caused by urban land expansion from 2020 to 2040 at four scales of the Chinese administration system (national, provincial, municipal, and county levels). The corresponding changes in potential cereal production were then assessed by combining cereal productivity data. The results show that 4700 km2 of cropland will be occupied by urban expansion by 2040, and the same amount of cropland will be supplemented by forest, grassland, wetland, and unused land. The potential loss of cropland will result in the loss of 3.838×106 tons of cereal production, and the additional cropland will bring 3.546×106 tons, 3.831×106 tons, 3.836×106 tons, and 3.528×106 tons of potential cereal production in SN (national scale), SP (provincial scale), SM (municipal scale), and SC (county scale), respectively. Both SN and SC are observed to make a huge difference in cereal productivity between the lost and the supplemented cropland. We suggest that China should focus on the spatial allocation of cropland during large-scale displacement, especially at the national level.

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    Multi-scale coupling analysis of urbanization and ecosystem services supply-demand budget in the Beijing-Tianjin-Hebei region, China
    ZHANG Fan, XU Ning, WANG Chao, GUO Mingjing, Pankaj KUMAR
    Journal of Geographical Sciences    2023, 33 (2): 340-356.   DOI: 10.1007/s11442-023-2085-y
    Abstract143)   HTML5)    PDF (12422KB)(70)      

    Rapid economic development and human activities have severely affected ecosystem function. Analysis of the spatial distribution of areas of rapid urbanization is the basis for optimizing urban-ecological spatial design. This paper evaluated the spatial distribution of urbanization in the Beijing-Tianjin-Hebei (BTH) region, and then quantified the ecosystem services (ES) budget in the region based on an ES supply and demand matrix. The results showed that (1) urbanization patterns in the BTH region were relatively stable from 2000 to 2015, with clear patterns of low levels of urbanization in the northwest and high levels in the southeast; (2) areas with positive ES budget values were found throughout the region, except in built-up areas, with high ES supply areas concentrated in the northwest, and high ES demand areas in the southeast; (3) at both the county and prefecture-city levels, urbanization had negative, positive, and negative correlations with ES supply, demand, and budget, respectively; (4) the coupling coordination degree (CCD) increased, with high CCD values in the southeast. Based on these results, policy recommendations include strengthening rational land-use planning and ecosystem management, promoting the coordinated development of the economy and ecological function, and coordinating the provision of production-life- ecological functions.

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    Simulation and prediction of multi-scenario evolution of ecological space based on FLUS model:A case study of the Yangtze River Economic Belt, China
    LIU Xiaoqiong, WANG Xu, CHEN Kunlun, LI Dan
    Journal of Geographical Sciences    2023, 33 (2): 373-391.   DOI: 10.1007/s11442-023-2087-9
    Abstract140)   HTML5)    PDF (12742KB)(66)      

    Building the Yangtze River Economic Belt (YREB) is one of China’s three national development policies in the new era. The ecological environment of the Yangtze River Economic Belt must be protected not only for regional economic development but also for regional ecological security and ecological progress in this region. This paper takes the ecological space of the Yangtze River Economic Belt as the research object, based on land use data in 2010 and 2015, and uses the FLUS model to simulate and predict the ecological space of the research area in 2035. The variation of the research area’s ecological space area and its four sub-zones has remarkable stability under diverse situations. Both the production space priority scenarios (S1) and living space priority scenarios (S2) saw a fall in ecological space area, with the former experiencing the highest reduction (a total reduction of 25,212 km2). Under the ecological space priority scenarios (S3) and comprehensive space optimization scenario (S4), the ecological space area increased, and the ecological space area expanded even more under the former scenario (a total growth of 23,648 km2). In Yunnan-Guizhou, the ecological space is relatively stable, with minimal signs of change. In Sichuan-Chongqing, the Sichuan Basin, Zoige Grassland, and Longmen Mountains were significant regions of area changes in ecological space. In the middle reaches of the Yangtze River, the ecological space changes mainly occur in the Wuyi Mountains, Mufu Mountains, and Dabie Mountains, as well as the surrounding waters of Dongting Lake. The Yangtze River Delta’s changes were mainly observed in the eastern Dabie Mountains and Jianghuai Hills.

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    Divergent responses of Qinghai spruce ( Picea crassifolia) to recent warming along elevational gradients in the central Qilian Mountains, Northwest China
    ZHANG Weiguo, GOU Xiaohua, ZHANG Fen, LIU Wenhuo, ZHANG Yun, GAO Linlin
    Journal of Geographical Sciences    2023, 33 (1): 151-168.   DOI: 10.1007/s11442-023-2077-y
    Abstract127)   HTML4)    PDF (3153KB)(72)      

    Understanding the radial growth trends of trees and their response to recent warming along elevation gradients is crucial for assessing how forests will be impacted by future climate change. Here, we collected 242 tree-ring cores from five plots across the Qinghai spruce (Picea crassifolia Kom.) forest belt (2600-3350 m a.s.l.) in the central Qilian Mountains, Northwest China, to study trends in the radial growth of trees and their response to climate factors with variable elevation. All the sampled P. crassifolia chronologies showed an increasing trend in the radial growth of trees at higher altitudes (3000-3350 m), whereas the radial growth of trees at lower altitudes (2600-2800 m) has decreased in recent decades. The radial growth of trees was limited by precipitation at lower elevations (L, ML), but mainly by temperature at higher elevation sites (MH, H, TL). Climate warming has caused an unprecedented increase in the radial growth of P. crassifolia at higher elevations. Our results suggest that ongoing climate warming is beneficial to forest ecosystems at high elevations but restricts the growth of forest ecosystems at low elevations.

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    Embodied land in China’s provinces from the perspective of regional trade
    WANG Shaojian, WANG Jieyu
    Journal of Geographical Sciences    2023, 33 (1): 59-75.   DOI: 10.1007/s11442-023-2074-1
    Abstract122)   HTML7)    PDF (4184KB)(65)      

    With the continuous enhancement of regional connectivity, the indirect use of land resources through the pathways of trade in goods and services plays an increasingly important role in the overall utilization of land resources. Despite this, relevant research in this field is still in its infancy, and few papers have addressed this issue. This paper uses a multi-regional input-output model to calculate the embodied land in the 30 provinces (autonomous regions and municipalities) and eight regions of China from the perspective of regional trade and further analyzes the spatial pattern of characteristics associated with embodied land flows. The results show that the amount of embodied land occupied by China’s inter-regional trade accounts for 21.39% of the country’s total land, and an average of 38.54% of China’s provincial land demand is met by land exports from other provinces. More than 80% of land consumed by Beijing, Tianjin, and Shanghai is from other provinces. The provinces of Heilongjiang, Inner Mongolia, Xinjiang, and Hebei are the largest net exporters of cultivated land, forest and grazing and aquatic land, fishery land, and built-up land, respectively (the outflows account for 42.26%, 27.53%, 38.66%, and 35.28% of the corresponding land types in the province); and Guangdong, Shandong, and Zhejiang are the main net importers. The flow of agricultural land (cultivated land, forest land, grazing land, and aquatic land) generally shows a shift from west to east and from north to south. The regions in northeast and northwest China have the largest scale of agricultural land outflows, mainly into East and South China. In addition, 8.43% of cultivated land, 7.47% of forest land, 6.41% of grazing land, 6.88% of aquatic land, and 18.35% of built-up land in China are provided for foreign use through international trade. This paper provides feasible ideas and a theoretical basis for solving the contradiction between land use and ecological protection, which could potentially help to achieve sustainable land use in China.

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    Why are glacial lakes in the eastern Tianshan Mountains expanding at an accelerated rate?
    ZHANG Qifei, CHEN Yaning, LI Zhi, FANG Gonghuan, XIANG Yanyun, JI Huiping
    Journal of Geographical Sciences    2023, 33 (1): 121-150.   DOI: 10.1007/s11442-023-2076-z
    Abstract121)   HTML2)    PDF (11915KB)(90)      

    Monitoring alpine lakes is important for understanding the regional environmental changes caused by global warming. In this study, we provided a detailed analysis of alpine lake changes in the Tianshan Mountains (TS) and discussed their driving forces based on Landsat TM/ETM+/OLI, WorldView-2, Bing, Google Earth, and ASTER imagery, along with climatic data from 1990 to 2015. The results showed that during the study period, the total number and area of alpine lakes in the eastern TS exhibited an increasing trend, by 64.06% and 47.92%, respectively. Furthermore, the continuous expansion of glacial lakes contributed 95.12% and 94.17% to the total increase in the number and area, respectively, of alpine lakes. Non-glacial lakes exhibited only intermittent expansion. Since the 1990s, the new glacial lakes in the eastern TS have been mainly proglacial and extraglacial lakes. Over the past 25 years, eastern TS has experienced a temperature increase rate of 0.47 °C/10a, which is higher than that in other TS regions. The rapidly warming climate and glacier recession are the primary causes of the accelerated expansion of glacial lakes in the eastern TS.

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    Have China’s drylands become wetting in the past 50 years?
    ZHANG Yu, ZHANG Yangjian, CHENG Liang, CONG Nan, ZHENG Zhoutao, HUANG Ke, ZHANG Jianshuang, ZHU Yixuan, GAO Jie, SUN Yihan
    Journal of Geographical Sciences    2023, 33 (1): 99-120.   DOI: 10.1007/s11442-022-2067-5
    Abstract120)   HTML1)    PDF (15649KB)(66)      

    Recently, whether drylands of Northwest China (NW) have become wetting has been attracting surging attentions. By comparing the Standard Precipitation Evapotranspiration Indices (SPEI) derived from two different potential evapotranspiration estimates, i.e., the Thornthwaite algorithm (SPEI_th) and the Penman-Monteith equation (SPEI_pm), we try to resolve the controversy. The analysis indicated that air temperature has been warming significantly at a rate of 0.4°C decade?1 in the last five decades and the more arid areas are more prone to becoming warmer. Annual precipitation of the entire study area increased insignificantly by 3.6 mm decade?1 from 1970 to 2019 but NW presented significantly increasing trends. Further, the SPEI_th and SPEI_pm demonstrated similar wetting-drying-wetting trends (three phases) in China’s drylands during 1970-2019. The common periodical signals in the middle phase were identified both by SPEI_th and SPEI_pm wavelet analysis. Analysis with different temporal intervals can lead to divergent or even opposite results. The attribution analysis revealed that precipitation is the main climatic factor driving the drought trend transition. This study hints that the wetting trend’s direction and magnitude hinge on the targeted temporal periods and regions.

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    An overall consistent increase of global aridity in 1970-2018
    LUO Dengnan, HU Zhongmin, DAI Licong, HOU Guolong, DI Kai, LIANG Minqi, CAO Ruochen, ZENG Xiang
    Journal of Geographical Sciences    2023, 33 (3): 449-463.   DOI: 10.1007/s11442-023-2091-0
    Abstract120)   HTML20)    PDF (4980KB)(111)      

    Climate change is expected to introduce more water demand in the face of diminishing water supplies, intensifying the degree of aridity observed in terrestrial ecosystems in the 21st century. This study investigated spatiotemporal variability within global aridity index (AI) values from 1970-2018. The results revealed an overall drying trend (0.0016 yr-1, p<0.01), with humid and semi-humid regions experiencing more significant drying than other regions, including those classified as arid or semi-arid. In addition, the Qinghai-Tibet Plateau has gotten wetter, largely due to the increases in precipitation (PPT) observed in that region. Global drying is driven primarily by decreasing and increasing PPT and potential evapotranspiration (PET), respectively. Decreases in PPT alone or increases in PET also drive global aridification, though to a lesser extent. PPT and increasing potential evapotranspiration (PET), with increasing PET alone or decreasing PPT alone. Slightly less than half of the world’s land area has exhibited a wetting trend, largely owing to increases in regional PPT. In some parts of the world, the combined effects of increased PPT and decreased PET drives wetting, with decreases in PET alone explaining wetting in others. These results indicate that, without consideration of other factors (e.g., CO2 fertilization), aridity may continue to intensify, especially in humid regions.

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    Impact of cascade reservoirs on the delayed response behaviour of sedimentation in the Three Gorges Reservoir
    LI Xin, REN Jinqiu, XU Quanxi, YUAN Jing, ZHANG Wei
    Journal of Geographical Sciences    2023, 33 (3): 576-598.   DOI: 10.1007/s11442-023-2097-7
    Abstract119)   HTML6)    PDF (3269KB)(42)      

    Delayed response behaviour commonly occurs in conjunction with changes in riverbed scouring and sediment deposition and is a key component in understanding the intrinsic behaviour of reservoir siltation. Due to the complexity of the riverbed siltation process, the variability in the factors that influence siltation and the limitations of available research methods, the understanding of the delayed response behaviour of the sedimentation process in the Three Gorges Reservoir (TGR) is currently merely qualitative, and there is a lack of quantitative in-depth understanding. In addition, the effects of changes in water and sediment conditions on sedimentation in the TGR before and after cascade reservoir impoundment have not been quantified, so further studies are needed to provide a reference for better understanding the intrinsic behaviour of sedimentation in the TGR and the implications for the long-term use of the reservoir. Based on measured water and sediment data from 2003 to 2020 and topographic data from 2003 to 2018, a delayed response model for sedimentation in the TGR is constructed and combined with theoretical derivation to analyse the changes in the delayed response behaviour of the TGR before and after the impoundment of the cascade reservoirs and the associated causes. Then, the influence of changes in water and sediment conditions in previous years on sedimentation in the reservoir area is determined. The results show that (1) the improved delayed response model of sedimentation, which considers variations in external water and sediment conditions, reservoir scheduling, and riverbed adjustment rates, can effectively reflect the sedimentation process in the TGR, especially after the impoundment of the cascade reservoirs. Additionally, the typical section elevation delayed response model can simulate the section elevation adjustment process. (2) After the impoundment of the cascade reservoirs, the decreased variation in incoming water and sediment and more concentrated incoming sediment in the flood season increased the adjustment rate of the riverbed, and the delayed response time of TGR sedimentation was shortened from the previous 5 years to the previous 3 years. The impact of the previous water and sediment conditions is not negligible for the sedimentation process in the TGR, and the cumulative proportion of the previous influence reaches more than 60%. (3) The influence of incoming sediment on the sedimentation process and typical section adjustment process in the reservoir area increased after the impoundment of the cascade reservoirs, and the influence of the water level in front of the dam on sedimentation remained the largest.

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    Considering time-lag effects can improve the accuracy of NPP simulation using a light use efficiency model
    LI Chuanhua, LIU Yunfan, ZHU Tongbin, ZHOU Min, DOU Tianbao, LIU Lihui, WU Xiaodong
    Journal of Geographical Sciences    2023, 33 (5): 961-979.   DOI: 10.1007/s11442-023-2115-9
    Abstract111)   HTML10)    PDF (15493KB)(106)      

    Most terrestrial models synchronously calculate net primary productivity (NPP) using the input climate variable, without the consideration of time-lag effects, which may increase the uncertainty of NPP simulation. Based on Normalized Difference Vegetation Index (NDVI) and climate data, we used the time lag cross-correlation method to investigate the time-lag effects of temperature, precipitation, and solar radiation in different seasons on NDVI values. Then, we selected the Carnegie-Ames-Stanford approach (CASA) model to estimate the NPP of China from 2002 to 2017. The results showed that the response of vegetation growth to climate factors had an obvious lag effect, with the longest time lag in solar radiation and the shortest time lag in temperature. The time lag of vegetation to the climate variable showed great tempo-spatial heterogeneities among vegetation types, climate types, and vegetation growth periods. Based on the validation using eddy covariance data, the results showed that the simulation accuracy of the CASA model considering the time-lag effects was effectively improved. By considering the time-lag effects, the average total amount of NPP modeled by CASA during 2001-2017 in China was 3.977 PgC a-1, which is 11.37% higher than that of the original model. This study highlights the importance of considering the time lag for the simulation of vegetation growth, and provides a useful tool for the improvement of the vegetation productivity model.

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    The spatiotemporal scale effect on vegetation interannual trend estimates based on satellite products over Qinghai-Tibet Plateau
    MA Dujuan, WU Xiaodan, WANG Jingping, MU Cuicui
    Journal of Geographical Sciences    2023, 33 (5): 924-944.   DOI: 10.1007/s11442-023-2113-y
    Abstract109)   HTML18)    PDF (9315KB)(87)      

    The trend estimate of vegetation change is essential to understand the change rule of the ecosystem. Previous studies were mainly focused on quantifying trends or analyzing their spatial distribution characteristics. Nevertheless, the uncertainties of trend estimates caused by spatiotemporal scale effects have rarely been studied. In response to this challenge, this study aims to investigate spatiotemporal scale effects on trend estimates using Moderate-Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) and Gross Primary Productivity (GPP) products from 2001 to 2019 in the Qinghai-Tibet Plateau (QTP). Moreover, the possible influencing factors on spatiotemporal scale effect, including spatial heterogeneity, topography, and vegetation types, were explored. The results indicate that the spatial scale effect depends more on the dataset with a coarser spatial resolution, and temporal scale effects depend on the time span of datasets. Unexpectedly, the trend estimates on the 8-day and yearly scale are much closer than that on the monthly scale. In addition, in areas with low spatial heterogeneity, low topography variability, and sparse vegetation, the spatiotemporal scale effect can be ignored, and vice versa. The results in this study help deepen the consciousness and understanding of spatiotemporal scale effects on trend detection.

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    Regulation factors driving vegetation changes in China during the past 20 years
    ZHAO Haixia, GU Binjie, LINDLEY Sarah, ZHU Tianyuan, FAN Jinding
    Journal of Geographical Sciences    2023, 33 (3): 508-528.   DOI: 10.1007/s11442-023-2094-x
    Abstract109)   HTML12)    PDF (3984KB)(163)      

    Vegetation change is of significant concern because it plays a crucial role in the global carbon cycle and climate. Many studies have examined recent changes in vegetation growth and the associated drivers. These drivers include both natural and human activities, but few studies have identified the regulation factors. By employing normalized difference vegetation index (NDVI) data, we analyzed the spatiotemporal pattern of vegetation change in China and then explored the driving factors. It was found that the overall greening of China has improved significantly, especially in the Loess Plateau and southwest China. The Yangtze River Delta and Bohai Rim, however, have not seen as much growth. Natural conditions are conducive to vegetation growth. Although socioeconomic development will be more beneficial for vegetation restoration, the current level and speed of development have a negative effect on vegetation. The regulation factors are considered separately since they affect both directly and indirectly. Regulation factors have accelerated vegetation growth. By understanding the factors affecting the current vegetation growth, we can provide a guide for future vegetation recovery in China and other similar countries.

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    OSL chronology reveals Late Pleistocene floods and their impact on landform evolution in the lower reaches of the Keriya River in the Taklimakan Desert
    ZHANG Feng, WANG Jiao, MA Li, Dilibaier TUERSUN
    Journal of Geographical Sciences    2023, 33 (5): 945-960.   DOI: 10.1007/s11442-023-2114-x
    Abstract107)   HTML9)    PDF (18891KB)(83)      

    The impacts of climate change on the relationship between fluvial processes and dune landform evolution have been studied. However, the chronology data used to examine this relationship are deficient. The Keriya River has a glacial origin in the Kunlun Mountains on the south margin of the Tarim Basin. The river flows into the Taklimakan Desert, the second largest shifting-dune desert in the world. The dry channels and shifting dunes in this area provide an ideal opportunity to investigate fluvial and aeolian landform evolution processes and their relationship with climate change. We investigated this area during 2008-2011 and obtained 18 fluvial sediment samples from 16 sections for optically stimulated luminescence (OSL) dating. The results show that the ages ranged from 3.4-44.1 ka. Most of the samples (13) were Holocene in age, around 11 ka, 8-9 ka, 5-6.5 ka, 4.6 ka, and 3.4-3.7 ka and were distributed along ancient river channels around sites of Yuansha and Karadun. Two samples close to the Hotan River (38-47 ka) fall within the Marine Isotope Stage 3 (MIS3). Three samples (from one section) were located near ancient channels flowing towards the Yuansha Site and had ages of around 14.5 ka, i.e., during the Last Glacial Maximum (LGM). The analyses of the sediment samples and OSL ages suggest that the Keriya River flooded in the Holocene, the LGM, and MIS3. Fluvial sediments provided the source material for the dunes, and fluvial processes affected the landform evolution in the lower Keriya River. Our results suggest that most of the dunes covered in fluvial sediments in the lower reaches and the area west of the Keriya River developed since the Holocene. This differs from the results of previous studies, which suggested that they developed since the Han (202BC-220AD) and Tang (618-907AD) dynasties. The OSL ages of the fluvial sediments are consistent with the reported deglaciation (after glacial advance) ages in the alpine mountains surrounding the Tarim Basin. This suggests that climate fluctuations may have affected the occurrence of floods and the formation of dunes in the Taklimakan Desert.

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    Spatiotemporal variations in remote sensing phenology of vegetation and its responses to temperature change of boreal forest in tundra- taiga transitional zone in the Eastern Siberia
    LI Cheng, ZHUANG Dafang, HE Jianfeng, WEN Kege
    Journal of Geographical Sciences    2023, 33 (3): 464-482.   DOI: 10.1007/s11442-023-2092-z
    Abstract105)   HTML13)    PDF (16758KB)(103)      

    Phenology is an important indicator of climate change. Studying spatiotemporal variations in remote sensing phenology of vegetation can provide a basis for further analysis of global climate change. Based on time series data of MODIS-NDVI from 2000 to 2017, we extracted and analyzed four remote sensing phenological parameters of vegetation, including the Start of Season (SOS), the End of Season (EOS), the Middle of Season (MOS) and the Length of Season (LOS), in tundra-taiga transitional zone in the East Siberia, using asymmetric Gaussian function and dynamic threshold methods. Meanwhile, we analyzed the responses of the four phenological parameters to the temperature change based on the temperature change data from Climate Research Unit (CRU). The results show that: in regions south of 64°N, with the rise of temperature in April and May, the SOS in the corresponding area was 5-15 days ahead of schedule; in the area between 64°N and 72°N, with the rise of temperature in May and June, the SOS in the corresponding area was 10-25 days ahead of schedule; in the northernmost of the study area on the coast of the Arctic Ocean, with the drop of temperature in May and June, the SOS in the corresponding area was 15-25 days behind schedule; in the northwest of the study area in August and the southwest in September, with the drop of temperature, the EOS in the corresponding areas was 15-30 days ahead of schedule; in regions south of 67°N, with the rise of temperature in September and October, the EOS in the corresponding area was 5-30 days behind schedule; the change of the EOS in autumn was more sensitive to the change of the SOS in spring, because the smaller temperature fluctuation can cause the larger change of the EOS; the growth season of vegetation in the study area was generally moving forward, and the LOS in the northwest was shortened, while the LOS in the middle and south of the study area was prolonged.

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