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  • Ziyan YAO, Lijuan ZHANG, Shihao TANG, Xiaxiang LI, Tiantian HAO
    地理学报(英文版). 2017, 27(7): 771-785. doi: 10.1007/s11442-017-1405-5

    In this paper, we analyzed the spatial patterns of cultivated land change between 1982 and 2011 using global vector-based land use/land cover data. (1) Our analysis showed that the total global cultivated land area increased by 528.768×104 km2 with a rate of 7.920×104 km2/a, although this increasing trend was not significant. The global cultivated land increased fastest in the 1980s. Since the 1980s, the cultivated land area in North America, South America and Oceania increased by 170.854×104 km2, 107.890×104 km2, and 186.492×104 km2, respectively. In contrast, that in Asia, Europe and Africa decreased by 23.769×104 km2, 4.035×104 km2 and 86.76×104 km2, respectively. Furthermore, the cultivated land area in North America, South America and Oceania exhibited significant increasing trends of 7.236× 104 km2/a, 2.780×104 km2/a and 3.758×104 km2/a, respectively. On the other hand, that of Asia, Europe and Africa exhibited decreasing trend rates of -5.641×104 km2/a, -0.831×104 km2/a and -0.595×104 km2/a, respectively. Moreover, the decreasing trend in Asia was significant. (2) Since the 1980s, the increase in global cultivated lands was mainly due to converted grasslands and woodlands, which accounted for 53.536% and 26.148% of the total increase, respectively. The increase was found in southern and central Africa, eastern and northern Australia, southeastern South America, central US and Alaska, central Canada, western Russia, northern Finland and northern Mongolia. Among them, Botswana in southern Africa experienced an 80%-90% increase, making it the country with the highest increase worldwide. (3) Since the 1980s, the total area of cultivated lands converted to other types of land was 1071.946×104 km2. The reduction was mainly converted to grasslands and woodlands, which accounted for 57.482% and 36.000%, respectively. The reduction occurred mainly in southern Sudan in central Africa, southern and central US, southern Russia, and southern European countries including Bulgaria, Romania, Serbia and Hungary. The greatest reduction occurred in southern Africa with a 60% reduction. (4) The cultivated lands in all the continents analyzed exhibited a trend of expansion to high latitudes. Additionally, most countries displayed an expansion of newly increased cultivated lands and the reduction of the original cultivated lands.

  • Shicheng LI, Zhaofeng WANG, Yili ZHANG
    地理学报(英文版). 2017, 27(7): 786-800. doi: 10.1007/s11442-017-1406-4

    Geographically explicit historical land use and land cover datasets are increasingly required in studies of climatic and ecological effects of human activities. In this study, using historical population data as a proxy, the provincial cropland areas of Qinghai province and the Tibet Autonomous Region (TAR) for 1900, 1930, and 1950 were estimated. The cropland areas of Qinghai and the TAR for 1980 and 2000 were obtained from published statistical data with revisions. Using a land suitability for cultivation model, the provincial cropland areas for the 20th century were converted into crop cover datasets with a resolution of 1 × 1 km. Finally, changes of sediment retention due to crop cover change were assessed using the sediment delivery ratio module of the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model (version 3.3.1). There were two main results. (1) For 1950-1980 the fractional cropland area increased from 0.32% to 0.48% and land use clearly intensified in the Tibetan Plateau (TP), especially in the Yellow River-Huangshui River Valley (YHRV) and the midstream of the Yarlung Zangbo River and its two tributaries valley (YRTT). For other periods of the 20th century, stability was the main trend. (2) For 1950-1980, sediment export increased rapidly in the Minhe autonomous county of the YHRV, and in the Nianchu River and Lhasa River basins of the YRTT, which means that sediment retention clearly decreased in these regions over this period. The results of this assessment provide scientific support for conservation planning, development planning, or restoration activities.

  • Bin HE, Aifang CHEN, Weiguo JIANG, Ziyue CHEN
    地理学报(英文版). 2017, 27(7): 801-816. doi: 10.1007/s11442-017-1407-3

    Though many studies have focused on the causes of shifts in trend of temperature, whether the response of vegetation growth to temperature has changed is still not very clear. In this study, we analyzed the spatial features of the trend changes of temperature during the growing season and the response of vegetation growth in China based on observed climatic data and the normalized difference vegetation index (NDVI) from 1984 to 2011. An obvious warming to cooling shift during growing season from the period 1984-1997 to the period 1998-2011 was identified in the northern and northeastern regions of China, whereas a totally converse shift was observed in the southern and western regions, suggesting large spatial heterogeneity of changes of the trend of growing season temperature throughout China. China as a whole, a significant positive relationship between vegetation growth and temperature during 1984 to 1997 has been greatly weakened during 1998-2011. This change of response of vegetation growth to temperature has also been confirmed by Granger causality test. On regional scales, obvious shifts in relationship between vegetation growth and temperature were identified in temperate desert region and rainforest region. Furthermore, by comprehensively analyzing of the relationship between NDVI and climate variables, an overall reduction of impacts of climate factors on vegetation growth was identified over China during recent years, indicating enhanced influences from human associated activities.

  • Zhiyuan YANG, Chao GAO, Shuying ZANG, Xiuchun YANG
    地理学报(英文版). 2017, 27(7): 817-834. doi: 10.1007/s11442-017-1408-2

    In this paper, we selected the middle and upper reaches of the Wuyuer River basin in the black soil region of Northeast China as the study area. We adopted the soil and water integrated model (SWIM) and evaluated the parameter sensitivity using partial correlation coefficient. We calibrated and validated our simulation results based on the daily runoff data from Yi’an hydrological station at the outlet of the river basin and the evaporation data recorded by various weather stations from 1961 to 1997. Following evaluation of the modeling data against the observed data, we present the applicability of SWIM in the river basin of the black soil region, and discuss the resulting errors and their probable causes. Results show that in the periods of calibration and validation, the Nash-Sutcliffe efficiency (NSE) coefficients of the monthly and daily runoffs were not less than 0.71 and 0.55, and the relative errors were less than 6.0%. Compared to daily runoffs, the simulation result of monthly runoffs was better. Additionally, the NSE coefficients of the potential monthly evaporation were not less than 0.81. Together, the results suggest that the calibrated SWIM can be utilized in various simulation analyses of runoffs on a monthly scale in the black soil region of Northeast China. On the contrary, the model had some limitations in simulating runoffs from snowmelt and frozen soil. Meanwhile, the stimulation data deviated from the measured data largely when applied to the years with spring and summer floods. The simulated annual runoffs were considerably higher than the measured data in the years with abrupt increases in annual precipitation. However, the model is capable of reproducing the changes in runoffs during flood seasons. In summary, this model can provide fundamental hydrological information for comprehensive management of the Wuyuer River basin water environment, and its application can be potentially extended to other river basins in the black soil region.

  • Degen WANG, Yu NIU, Feng SUN, Kaiyong WANG, Jia QIAN, Feng LI
    地理学报(英文版). 2017, 27(7): 835-856. doi: 10. 1007/s11442-017-1409-1

    Traffic is an indispensable prerequisite for a tourism system. The “four vertical and four horizontal” HSR network represents an important milestone of the “traffic revolution” in China. It will affect the spatial pattern of tourism accessibility in Chinese cities, thus substantially increasing their power to attract tourists and their radiation force. This paper examines the evolution and spatial characteristics of the power to attract tourism of cities linked by China’s HSR network by measuring the influence of accessibility of 338 HSR-linked cities using GIS analysis. The results show the following. (1) The accessibility of Chinese cities is optimized by the HSR network, whose spatial pattern of accessibility exhibits an obvious traffic direction and causes a high-speed rail-corridor effect. (2) The spatial pattern of tourism field strength in Chinese cities exhibits the dual characteristics of multi-center annular divergence and dendritic diffusion. Dendritic diffusion is particularly more obvious along the HSR line. The change rate of urban tourism field strength forms a high-value corridor along the HSR line and exhibits a spatial pattern of decreasing area from the center to the outer limit along the HSR line. (3) The influence of the higher and highest tourism field strength areas along the HSR line is most significant, and the number of cities that distribute into these two types of tourism field strengths significantly increases: their area expands by more than 100%. HSR enhances the tourism field strength value of regional central cities, and the radiation range of tourism attraction extends along the HSR line.

  • Weidong CAO, Yingying LI, Jianquan CHENG, MILLINGTON Steven
    地理学报(英文版). 2017, 27(7): 857-878. doi: 10.1007/s11442-017-1410-8

    China’s economy has undergone rapid transition and industrial restructuring. The term “urban industry” describes a particular type of industry within Chinese cities experiencing restructuring. Given the high percentage of industrial firms that have either closed or relocated from city centres to the urban fringe and beyond, emergent global cities such as Shanghai, are implementing strategies for local economic and urban development, which involve urban industrial upgrading numerous firms in the city centre and urban fringe. This study aims to analyze the location patterns of seven urban industrial sectors within the Shanghai urban region using 2008 micro-geography data. To avoid Modi?able Areal Unit Problem (MAUP) issue, four distance-based measures including nearest neighbourhood analysis, Kernel density estimation, K-function and co-location quotient have been extensively applied to analyze and compare the concentration and co-location between the seven sectors. The results reveal disparate patterns varying with distance and interesting co-location as well. The results are as follows: the city centre and the urban fringe have the highest intensity of urban industrial firms, but the zones with 20-30 km from the city centre is a watershed for most categories; the degree of concentration varies with distance, weaker at shorter distance, increasing up to the maximum distance of 30 km and then decreasing until 50 km; for all urban industries, there are three types of patterns, mixture of clustered, random and dispersed distribution at a varied range of distances. Consequently, this paper argues that the location pattern of urban industry reflects the stage-specific industrial restructuring and spatial transformation, conditioned by sustainability objectives.

  • Guoqi LI, Fengjun JIN, Yu CHEN, Jinjuan JIAO, Sijing LIU
    地理学报(英文版). 2017, 27(7): 879-896. doi: 10.1007/s11442-017-1411-7

    The logistics nodes and logistics enterprises are the core carriers and organizational subjects of the logistics space, and their location characteristics and differentiation strategies are of key importance to optimizing urban logistics spatial patterns and ensuring reasonable resource allocation. Based on Tencent Online Maps Platform from December 2014, 4396 logistics points of interest (POI) were collected in Beijing, China. By the methods of industrial concentration evaluation and kernel density analysis, the spatial distribution pattern of logistics in Beijing are explored, the interaction mechanism among the type difference, supply-demand side factors and location choice behavior are clarified, and the internal mechanism of spatial differentiation under the combined influence of transportation, land rent and assets are revealed. The following conclusions are drawn in the paper. (1) Logistics enterprises and logistics nodes exhibit the characteristic of both co-agglomeration and spatial separation in location, and logistics activities display the spatial pattern of "marginal area of downtown area, suburbs and exurban area", which have a weak coupling degree with logistics employment space. (2) The public logistics space, namely, logistics parks and logistics centers, is produced under the guidance of the government, and the terminal logistics space consisting of logistics distribution centers serving for the specific industries and terminal users is dominated by enterprises. The locational differentiation between the two modes of logistics space is significant. (3) In the formation of the logistics spatial location, the government can change the traffic condition by re-planning the transport routes and freight station locations, and control the land rent and availability of different areas by increasing or decreasing the land use of logistics, to impact the enterprise behavior and form different types of logistics space and function differentiation. In comparison, logistics enterprises meet the diverse demands of service objects through differentiation of asset allocation to promote the specialization of division and form the object differentiation of logistics space.

  • Wenchao LIU, Jiyuan LIU, Wenhui KUANG, Jia NING
    地理学报(英文版). 2017, 27(6): 643-660. doi: 10.1007/s11442-017-1398-0

    China had implemented the national strategies for Major Function-oriented Zones (MFOZs) to realize the goal of national sustainable development since 2010. This study analyzed and compared spatio-temporal characteristics and differences in built-up area for China’s MFOZs using a China’ s Land Use Database (CLUD) derived from high-resolution remotely sensed images in the periods of 2000-2010 and 2010-2013. To sum up: (1) The percentage of built-up area in each of the MFOZs was significantly different, revealing the gradient feature of national land development based on the distribution of the main functions. (2) Annual growth in built-up area in optimal development zones (ODZs) decreased significantly during 2010-2013 compared with the period 2000-2010, while annual growth in built-up area in key development zones (KDZs), agricultural production zones (APZs) and key ecological function zones (KEFZs) increased significantly. (3) In ODZs, the average annual increase in built-up area in the Yangtze River Delta region was significantly higher than in other regions; the average area increase and rate of increase of built-up area in KDZs was faster in the western region than in other regions; average annual area growth of built-up area in APZs in the northeast, central and western regions was twice as high as the previous decade on average; the annual rate of change and increase in the dynamic degree of built-up area were most notable in KEFZs in the central region. (4) The spatial pattern and characteristics of built-up area expansions in the period 2010-2013 reflected the gradient feature of the plan for MFOZs. But the rate of increase locally in built-up area in ODZs, APZs and KEFZs is fast, so the effective measures must be adopted in the implementation of national and regional policies. The conclusions indicated these methods and results were meaningful for future regulation strategies in optimizing national land development in China.

  • Xuejuan CHEN, Xingguo MO, Shi HU, Suxia LIU
    地理学报(英文版). 2017, 27(6): 661-680. doi: 10.1007/s11442-017-1399-z

    Quantifying the contributions of climate change and human activities to ecosystem evapotranspiration (ET) and gross primary productivity (GPP) changes is important for adaptation assessment and sustainable development. Spatiotemporal patterns of ET and GPP were estimated from 2000 to 2014 over North China Plain (NCP) with a physical and remote sensing-based model. The contributions of climate change and human activities to ET and GPP trends were separated and quantified by the first difference de-trending method and multivariate regression. Results showed that annual ET and GPP increased weakly, with climate change and human activities contributing 0.188 mm yr-2 and 0.466 mm yr-2 to ET trend of 0.654 mm yr-2, and -1.321 g C m-2 yr-2 and 7.542 g C m-2 yr-2 to GPP trend of 6.221 g C m-2 yr-2, respectively. In cropland, the increasing trends mainly occurred in wheat growing stage; the contributions of climate change to wheat and maize were both negative. Precipitation and sunshine duration were the major climatic factors regulating ET and GPP trends. It is concluded that human activities are the main drivers to the long term tendencies of water consumption and gross primary productivity in the NCP.

  • Yingjie LI, Liwei ZHANG, Junping YAN, Pengtao WANG, Ningke HU, Wei CHENG, Bojie FU
    地理学报(英文版). 2017, 27(6): 681-696. doi: 10.1007/s11442-017-1400-x

    Spatial-explicitly mapping of the hotspots and coldspots is a vital link in the priority setting for ecosystem services (ES) conservation. However, little research has identified and tested the compactness and efficiency of their ES hotspots and coldspots, which may weaken the effectiveness of ecological conservation. In this study, based on the RUSLE model and Getis-Ord Gi* statistics, we quantified the variation of annual soil conservation services (SC) and identified the statistically significant hotspots and coldspots in Shaanxi Province of China from 2000 to 2013. The results indicate that, 1) areas with high SC presented a significantly increasing trend as well, while areas with low SC only changed slightly; 2) SC hotspots and coldspots showed an obvious spatial differentiation—the hotspots were mainly spatially aggregated in southern Shaanxi, while the coldspots were mainly distributed in the Guanzhong Basin and Sand-windy Plateau; and 3) the identified hotspots had the highest capacity of providing SC, with 29.6% of the total area providing 59.7% of the total service. In contrast, the coldspots occupied 46.3% of the total area, but only provided 17.2% of the total SC. In addition to conserving single ES, the Getis-Ord Gi* statistics method can also help identify multi-functional priority areas for conserving multiple ES and biodiversity.

  • Yali TONG, Tao LIANG, Lingqing WANG,
    地理学报(英文版). 2017, 27(6): 697-710. doi: 10.1007/s11442-017-1401-9

    Since the construction of the Three Gorges Dam, the Poyang Lake hydrological characteristics obviously changed. During the impoundment period of the Three Gorges Reservoir, the hydrodynamic factors of Poyang Lake varied. Water level dropped, the velocity decreased and water exchange time lengthened, which changed the release of phosphorous from sediments. In order to investigate how the hydrodynamic factors influence the release of phosphorous from sediments, we used a two-way annular flume device to simulate the release characteristics of phosphorous from sediments under variable water levels and velocities. We found that both water level rising and velocity increasing could enhance the disturbance intensity to sediments, which caused the increase of suspended solids (SS) concentration, total phosphorus (TP) concentration in the overlying water, and the ability that phosphorus released to overlying water from sediments enhanced as well: when overlying water velocity maintained 0.3 m/s, SS concentration increased to 4035.85 mg/L at the water level 25 cm which was about 25 times compared to the minimum value and TP concentration in the overlying water also reached the maximum value at the water level 25 cm which was 1.2 times that of the value at 10 cm; when water level maintained 15 cm, SS concentration increased to 4363.35 mg/L at the velocity of 0.5 m/s which was about 28 times compared to the value of 0 m/s, and TP concentration in the overlying water increased from 0.11 mg/L to 0.44 mg/L. When the water level maintained 15 cm, the phosphorous release rate reached the maximum value of 4.86 mg/(md) at 0.4 m/s. The concentration of total dissolved phosphorous (TDP) and soluble reactive phosphate (SRP) both in overlying water and sediment-water interface were negatively correlated with pH. Using the parabolic equation, the optimum water level at a velocity of 0.3 m/s was calculated to be 0.57 cm, and the optimum velocity at water level of 15 cm was found to be 0.2 m/s.

  • Yan YANG, Limao WANG, Zhi CAO, Chufu MOU, Lei SHEN, Jianan ZHAO, Yebing FANG
    地理学报(英文版). 2017, 27(6): 711-730. doi: 10.1007/s11442-017-1402-8

    Much attention is being given to estimating cement-related CO2 emissions in China. However, scant explicit and systematical exploration is being done on regional and national CO2 emission volumes. The aim of this work is therefore to provide an improved bottom-up spatial-integration system, relevant to CO2 emissions at factory level, to allow a more accurate estimation of the CO2 emissions from cement production. Based on this system, the sampling data of cement production lines were integrated as regional- and national-level information. The integration results showed that each ton of clinker produced 883 kg CO2, of which the process, fuel, and electricity emissions accounted for 58.70%, 35.97%, and 5.33%, respectively. The volume of CO2 emissions from clinker and cement production reached 1202 Mt and 1284 Mt, respectively, in 2013. A discrepancy was identified between the clinker emission factors relevant to the two main production processes (i.e., the new suspension preheating and pre-calcining kiln (NSP) and the vertical shaft kiln (VSK)), probably relevant to the energy efficiency of the two technologies. An analysis of the spatial characteristics indicated that the spatial distribution of the clinker emission factors mainly corresponded to that of the NSP process. The discrepancy of spatial pattern largely complied with the economic and population distribution pattern of China. The study could fill the knowledge gaps and provide role players with a useful spatial integration system that should facilitate the accurate estimation of carbon and corresponding regional mitigation strategies in China.

  • Meifeng ZHAO, Shenghe LIU, Wei QI
    地理学报(英文版). 2017, 27(6): 731-751. doi: 10.1007/s11442-017-1403-7

    The floating population has become the main driver of urban population excessive growth in China’s mega cities. Urban transit system (UTS) is a significant factor in population spatial distributions within urban areas, especially rapid and high-capacity transit systems. This paper analyzes the causal effects of the extension of expressways and subways between 2000 and 2010 in the Beijing Metropolitan Area (BMA), focusing on the group differences between the local residents and the floating population. Due to the endogeneity of transportation improvements and population growth, Instrumental Variable (IV) regression model is applied to avoid this problem. The results show the local residents increased in the inner suburbs but decreased in the city center, while the floating population increased in the majority areas. IV regression results show that the extension of urban transit systems had statistically significant impacts on population growth across the BMA. The results also show that the extension of urban subway system had more effects on the floating population than the local residents across the BMA. It is mainly caused by the rather low fare of urban subway system. This implies that the excessive subsidy on urban subway system could result in excessive floating population growth and residential differentiation, even residential segregation. Hence, it is necessary to plan and design reasonable and scientific urban transit systems in order to advance reasonable population size and promote residential integration. Moreover, the regional analysis shows that the effects of urban transportation improvements on the local residents are not statistically significant in the inner suburbs. It implies that urban transportation improvements had limited effects on inducing people to move to suburban areas and controlling center city’s population in Beijing. Therefore, it should be stressed the differentiated effects of urban transportation improvements on population distribution in the process of urban planning and population control.

  • Yifei ZHANG, Duowen MO, Ke HU, Wenbo BAO, Wenying LI, Abuduresule Idilisi, J. STOROZUM Michael, R. KIDDER Tristram
    地理学报(英文版). 2017, 27(6): 752-768. doi: 10.1007/s11442-017-1404-6

    The Xiaohe Cemetery archaeological site (Cal. 4-3.5 ka BP) is one of the most important Bronze Age sites in Xinjiang, China. Although the surrounding environment is an extremely arid desert now, abundant archaeological remains indicate that human occupation was common during certain periods in the Holocene. Field investigations and laboratory analyses of a sediment profile near the Xiaohe Cemetery indicate that while the regional environment was arid desert throughout the Holocene there were three episodes of lake formation near the site in the periods 4.8-3.5 ka BP, 2.6-2.1 ka BP and 1.2-0.9 ka BP. Geomorphic and hydrological investigations reveal that a lake or lakes formed in a low-lying area when water was derived initially from the Kongque River and then shunted into the Xiaohe River basin. Low amounts of active chemical elements in lacustrine sediment between 4.8-3.5 ka BP indicate abundant and continuous water volume in the lake; the content of active chemical elements increased between 2.6-2.1 ka BP but was still at a relatively low level, suggesting a declining amount of water and diminished inflow. Between 1.2-0.9 ka BP there was a very high content of active elements, suggesting decreased water volume and indicating that the lake was stagnate. In contrast, the general climate condition shows that there had a warm-humid stage at 8-6 ka BP, a cool-humid stage at 6-2.9 ka BP and a warm-dry stage at 2.9-0.9 ka BP in this region. The hydrological evolutions around Xiaohe Cemetery did not have one-to-one correspondence with climate changes. Regional comparison indicates that broad-scale climatic conditions played an important role through its influences on the water volume of the Tarim River and Kongque River. But, the formation of the lakes and their level were controlled by geomorphic conditions that influenced how much water volume could be shunted to Xiaohe River from Kongque River. Human occupation of the Xiaohe Cemetery and nearby regions during the Bronze Age and Han-Jin period (202 BC-420 AD) corresponded to the two earlier lake periods, while no human activities existed in the third lake period because of the decreased water volume.

  • ZHANG Yuxin, LI Yu
    地理学报(英文版). 2022, 32(2): 195-213. doi: 10.1007/s11442-022-1942-4

    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.

  • ZENG Xueli, LIU Yu, SONG Huiming, LI Qiang, CAI Qiufang, FANG Congxi, SUN Changfeng, REN Meng
    地理学报(英文版). 2022, 32(2): 214-224. doi: 10.1007/s11442-022-1943-3

    Droughts are the most frequent natural disaster in regions at the margins of the East Asian summer monsoon (EASM), which pose threats to agriculture, the economy, and human lives. However, the limitations of only approximately 60 years of meteorological observations hamper our understanding of the characteristics and mechanisms of local hydroclimate. Trees growing in the marginal region of the EASM are usually sensitive to moisture variations and have played important roles in past hydroclimatic reconstructions. Here, a 303-year tree-ring-width chronology of Pinus tabulaeformis from Mt. Lama, which is located in the junction of the Liaoning Province and Inner Mongolia, China, was used to reconstruct the May-August Palmer drought severity index (PDSI) in the marginal region of the EASM. The transfer function explains 48.0% (or 47.2% after adjusting for the loss of the degrees of freedom) of the variance over the calibration period from 1946 to 2012. A spatial correlation analysis demonstrates that our PDSI reconstruction can represent the drought variability on the northernmost margin of the EASM. The winter Asian polar vortex area index showed a delayed impact on the summer EASM precipitation in the following year.

  • WANG Xiaodi, LI Yongsheng, ZHANG Lijuan, SONG Shuaifeng, PAN Tao, REN Chong, TAN Yulong
    地理学报(英文版). 2022, 32(2): 225-240. doi: 10.1007/s11442-022-1944-2

    With the advent of climate change, winter temperatures have been steadily increasing in the middle-to-high latitudes of the world. However, we have not found a corresponding decrease in the number of extremely cold winters. This paper, based on Climatic Research Unit (CRU) re-analysis data, and methods of trend analysis, mutation analysis, correlation analysis, reports on the effects of Arctic warming on winter temperatures in Heilongjiang Province, Northeast China. The results show that: (1) during the period 1961- 2018, winter temperatures in the Arctic increased considerably, that is, 3.5 times those of the Equator, which has led to an increasing temperature gradient between the Arctic and the Equator. An abrupt change in winter temperatures in the Arctic was observed in 2000. (2) Due to the global warming, an extremely significant warming occurred in Heilongjiang in winter, in particular, after the Arctic mutation in 2000, although there were two warm winters, more cold winters were observed and the interannual variability of winter temperature also increased. (3) Affected by the warming trend in the Arctic, the Siberian High has intensified, and both the Arctic Vortex and the Eurasian Zonal Circulation Index has weakened. This explains the decrease in winter temperatures in Heilongjiang, and why cold winters still dominate. Moreover, the increase in temperature difference between the Arctic and the Equator is another reason for the decrease in winter temperatures in Heilongjiang.

  • YANG Yanfen, SHEN Lulu, WANG Bing
    地理学报(英文版). 2022, 32(2): 241-258. doi: 10.1007/s11442-022-1945-1

    Precipitation in the arid region of Northwest China (NWC) shows high spatial and temporal variability, in large part because of the region's complex topography and moisture conditions. However, rain gauges in the area are sparse, and most are located at altitudes below 2000 m, which limits our understanding of precipitation at higher altitudes. Interpolated precipitation products and satellite-based datasets with high spatiotemporal resolution can potentially be a substitute for rain gauge data. In this study, the spatial and temporal properties of precipitation in the arid region of NWC were analyzed using two gridded precipitation products: SURF_CLI_CHN_PRE_DAY_GRID_0.5 (CHN) and Tropical Rainfall Measuring Mission (TRMM) 3B43. The CHN and TRMM 3B43 data showed that in summer, precipitation was more concentrated in southern Xinjiang than in northern Xinjiang, and the opposite was true in winter. The largest difference in precipitation between mountainous areas and plains appeared in summer. High-elevation areas with high precipitation showed more stable annual precipitation. Different sub-regions showed distinctive precipitation distributions with elevation, and both datasets showed that the maximum precipitation zone appeared at high altitude.

  • ZHANG Yuan, YAO Xiaojun, ZHOU Sugang, ZHANG Dahong
    地理学报(英文版). 2022, 32(2): 259-279. doi: 10.1007/s11442-022-1946-0

    The glaciers in the Sanjiangyuan Nature Reserve of China (SNRC) are a significant water resource for the Yangtze, Yellow, and Mekong rivers. Based on Landsat Thematic Mapper (TM)/ Operational Land Imager (OLI) images acquired in 2000, 2010, and 2018, the outlines of glaciers in the SNRC were obtained by combining band ratio method with manual interpretation. There were 1714 glaciers in the SNRC in 2018, with an area of 2331.15±54.84 km2, an ice volume of 188.90±6.41 km3, and an average length of 1475.4±15 m. During 2000-2018, the corresponding values of glaciers decreased by 69, 271.95±132.06 km2, 18.59±8.83 km3, and 84.75±34 m, respectively. Glaciers in the Yangtze River source area witnessed the largest area loss (-154.45 km2), whereas glaciers in the Mekong River source area experienced the fastest area loss (-2.02%·a-1) and the maximum reduction of the average length (-125.82 m). Overall, the retreat of glaciers in the SNRC exhibited an accelerating trend. Especially, the loss rate of glacier area in the Yellow River source area in 2010-2018 was more than twice that in 2000-2010. The glacier change is primarily attributed to the significant rise in temperature during the ablation period. Some other factors including the size, orientation and terminus elevation of glaciers also contributed to the heterogeneity of glacier change.

  • Hong QIAN, ZHANG Yangjian, Robert E. RICKLEFS, Xianli WANG
    地理学报(英文版). 2022, 32(2): 280-290. doi: 10.1007/s11442-022-1947-z

    Biologists have considered both winter coldness and temperature seasonality as major determinants of the northern limits of plants and animals in the Northern Hemisphere, which in turn drive the well-known latitudinal diversity gradient. However, few studies have tested which of the two climate variables is the primary determinant. In this study, we assess whether winter coldness or temperature seasonality is more strongly associated with the northern latitudinal limits of tree species and with tree species richness in North America. Tree species were recorded in each of 1198 quadrats of 110 km × 110 km in North America. We used correlation and regression analyses to assess the relationship of the latitude of the northern boundary of each species, and of species richness per quadrat, with winter coldness and temperature seasonality. Species richness was analyzed within 38 longitudinal, i.e., north-south, bands (each being >1100 km long and 110 km wide). The latitudes of the northern range limits of tree species were three times better correlated with minimum temperatures at those latitudes than with temperature seasonality. On average, minimum temperature and temperature seasonality together explained 81.5% of the variation in the northern range limits of the tree species examined, and minimum temperature uniquely explained six-fold (33.7% versus 5.8%) more of this variation than did temperature seasonality. Correlations of tree species richness with minimum temperatures were stronger than correlations with temperature seasonality for most of the longitudinal bands analyzed. Compared to temperature seasonality, winter coldness is more strongly associated with species distributions at high latitudes, and is likely a more important driver of the latitudinal diversity gradient.

  • WANG Chenxi, LIANG Wei, YAN Jianwu, JIN Zhao, ZHANG Weibin, LI Xiaofei
    地理学报(英文版). 2022, 32(2): 291-316. doi: 10.1007/s11442-022-1948-y

    With the implementation of the Grain for Green Project, vegetation cover has experienced great changes throughout the Loess Plateau (LP). These changes substantially influence the intensity of evapotranspiration (ET), thereby regulating the local microclimate. In this study, we estimated ET based on the Penman-Monteith (PM) method and Priestley-Taylor Jet Propulsion Laboratory (PT-JPL) model and quantitatively estimated the mass of water vapor and heat absorption on the LP. We analyzed the regulatory effect of vegetation restoration on local microclimate from 2000 to 2015 and found the following: (1) Both the leaf area index (LAI) value and actual ET increased significantly across the region during the study period, and there was a significant positive correlation between them in spatial patterns and temporal trends. (2) Vegetation regulated the local microclimate through ET, which increased the absolute humidity by 2.76-3.29 g m?3, increased the relative humidity by 15.43%-19.31% and reduced the temperature by 5.38-6.43°C per day from June to September. (3) The cooling and humidifying effects of vegetation were also affected by the temperature on the LP. (4) Correlation analysis showed that LAI was significantly correlated with temperature at the monthly scale, and the response of vegetation growth to temperature had no time-lag effect. This paper presents new insights into quantitatively assessing the regulatory effect of vegetation on the local microclimate through ET and helps to objectively evaluate the ecological effects of the Grain for Green Project on the LP.

  • GAO Jie, BIAN Hongyan, ZHU Chongjing, TANG Shuang
    地理学报(英文版). 2022, 32(2): 317-332. doi: 10.1007/s11442-022-1949-x

    Mountainous landscapes are particularly vulnerable and sensitive to climate change and human activities, and a clear understanding of how ecosystem services (ES) and their relationships continuously change over time, across space, and along altitude is therefore essential for ecosystem management. Chongqing, a typical mountainous region, was selected to assess the long-term changes in its key ES and their relationships. From 1992 to 2018, the temporal variation in water yield (WY) revealed that the maximum and minimum WYs occurred in 1998 and 2006, which coincided with El Niño-Southern Oscillation and severe drought events, respectively. Soil export (SE) and WY were consistent with precipitation, which reached their highest values in 1998. During this period, carbon storage (CS) and habitat quality (HQ) both decreased significantly. ES in Chongqing showed large variations in altitude. Generally, WY and SE decreased with increasing altitude, while CS and HQ increased. For spatial distribution, WY and SE showed positive trends in the west and negative trends in the east. In regard to CS and HQ, negative trends dominated the area. Persistent tradeoffs between WY and soil conservation (SC) were found at all altitude gradients. The strong synergies between CS and HQ were maintained over time.

  • ZHANG Xiaolong, XU Sheng, CUI Lifeng, ZHANG Maoliang, ZHAO Zhiqi, LIU Congqiang
    地理学报(英文版). 2022, 32(2): 333-357. doi: 10.1007/s11442-022-1950-4

    Investigating topographic and climatic controls on erosion at variable spatial and temporal scales is essential to our understanding of the topographic evolution of the orogen. In this work, we quantified millennial-scale erosion rates deduced from cosmogenic 10Be and 26Al concentrations in 15 fluvial sediments from the mainstream and major tributaries of the Yarlung Zangbo River draining the southern Tibetan Plateau (TP). The measured ratios of 26Al/10Be range from 6.33 ± 0.29 to 8.96 ± 0.37, suggesting steady-state erosion processes. The resulted erosion rates vary from 20.60 ± 1.79 to 154.00 ± 13.60 m Myr-1, being spatially low in the upstream areas of the Gyaca knickpoint and high in the downstream areas. By examining the relationships between the erosion rate and topographic or climatic indices, we found that both topography and climate play significant roles in the erosion process for basins in the upstream areas of the Gyaca knickpoint. However, topography dominantly controls the erosion processes in the downstream areas of the Gyaca knickpoint, whereas variations in precipitation have only a second-order control. The marginal Himalayas and the Yarlung Zangbo River Basin (YZRB) yielded significantly higher erosion rates than the central plateau, which indicated that the landscape of the central plateau surface is remarkably stable and is being intensively consumed at its boundaries through river headward erosion. In addition, our 10Be erosion rates are comparable to present-day hydrologic erosion rates in most cases, suggesting either weak human activities or long-term steady-state erosion in this area.

  • LIU Dengke, SUN Xuefeng, HU Xuzhi, YI Liang, GUO Xiaoqi, WANG Yichao, WANG Shejiang, LU Huayu
    地理学报(英文版). 2022, 32(2): 358-374. doi: 10.1007/s11442-022-1951-3

    The Qinling Mountain Range (QMR) spans a large region in China and is an important area of hominin activities. Many Paleolithic sites are found in Bahe, South Luohe, and Hanjiang river valleys in the northern, eastern, and southern part of the range, respectively. The Danjiang River valley acts as a channel connecting these valleys and stretches from the north to the south of the QMR. The previous dating of the Paleolithic sites in the Danjiang valley mainly relied on geomorphologic comparison, stratigraphic correlation, fossil characteristics, and Paleolithic artifacts, indicating a lack of absolute data. In this study, we conducted a detailed geochronological investigation of the entire valley, and selected an ideal site—the Miaokou profile. Based on the identification of the loess-paleosol sequences, optically stimulated luminescence, and magnetostratigraphy, the Paleolithic artifacts of the Miaokou site located within the S5 and S6 layers of the profile belong to ~0.6-0.7 Ma. This suggests that the Paleolithic site is an old site in the Danjiang River valley, and this period also witnessed a rapid increase in the number of hominin sites during the Middle Pleistocene. Combining our results with previous reports across the QMR, we propose that the Danjiang River valley might have been a corridor for hominin migration, and is worthy of further investigation.

  • Climate and Environmental Change
    ZHANG Yuanming, CHEN Yaning, ZHANG Daoyuan
    Journal of Geographical Sciences. 2003, 13(2): 225-232.

    Plant communities were sampled in the lower reaches of the Tarim River, Xinjiang. The results showed that there are 23 species belonging to 21 genera in 11 families, most of which have low occurrence frequency in quadrats. The most common species is Tamarix ramosissima, which occurred in 17 sites accounting for 89.47% of the total 19 sites. Quantitative classification (TWINSPAN) and ordination (CCA) methods were used to study the distribution patterns of 23 plant species in 19 sites in this valley. TWINSPAN results showed that the plant communities in the middle reaches of the Tarim River could be divided into 3 groups and the sampling sites could be divided into 7 types in 3 groups. CCA results were consistent with TWINSPAN results, and showed species distribution patterns correlated with major environmental variables of groundwater level and soil moisture.

  • Climate and Environmental Change
    LEI Kampeng, WANG Zhishi
    Journal of Geographical Sciences. 2003, 13(3): 339-347.

    Using the method of Constanza R, the annual value of ecosystem services of Macao was 3.302×106 US dollars in 1983, equivalent to 26.5250×106 MOP, when using the currently monetary valuation. The annual value of ecosystem services of Macao was 8.3340×106 US dollars in 2002, equal to 66.9472×106 MOP. The total globe annual value of ecosystem services was 3.3268×1013 US dollars in 1997, i.e., about 5,544.7 US dollars per capita. In Macao, the annual value of ecosystem services was only 18.8 US dollars per capita. The average ecosystem service per capita was 0.35% of the world average level. Comparing to the globe average ecosystem services level per capita, the deficit of ecosystem services of Macao is 2.44×109 US dollars for Macao population, which would require 1,069 km2 estuary to complement to the deficit, i.e., about 38 times of Macao to provide ecosystem services to reach the average level of world.

  • Climate and Environmental Change
    LAN Yongchao, DING Yongjiang, KANG Ersi, MA Quanjie, ZHANG Jishi
    Journal of Geographical Sciences. 2003, 13(1): 105-111.

    Firstly, the hydrological and meteorological features of the upper reaches of the Yellow River above Tangnag are analyzed based on observation data, and effects of EI Nino and La Nina events on the high and low flow in the upper Yellow River are discussed. The results show El Nino and La Nina events possess consanguineous relationship with runoff in the upper Yellow River. As a whole, the probability of low flow occurrence in the upper Yellow River is relatively great along with the occurrence of El Nino event. Moreover, the flood in the upper Yellow River occurs frequently with the occurrence of La Nina event. Besides, the results also show dissimilarity of El Nino event occurring time exerts greater impact on high flow and low flow in the upper Yellow River, that is, the probability of drought will be greater in the same year if El Nino event occurs in spring, the high-flow may happen in this year if El Nino occurs in summer or autumn; the longer the continuous period of El Nino is, the lower the runoff in the upper Yellow River is.

  • Climate and Environmental Change
    HU Xiaomeng, LI Youli, FU Jianli
    Journal of Geographical Sciences. 2003, 13(2): 233-240.

    Tectonic movements and climate changes are two main controllers on the development of landform. In order to reconstruct the history of the evolution of the landform in the Fenhe drainage basin during middle-late Quaternary comprehensively, this paper has provided a variety of geomorphological and geologic evidences to discuss how tectonic movements and climate changes worked together to influence the landform processes. According to the features of the lacustrine and alluvial terraces in this drainage basin, it is deduced that it was the three tectonic uplifts that resulted in the three great lake-regressions with an extent of about 40-60 m and the formation of the three lacustrine terraces. The times when the tectonic uplifts took place are 0.76 MaBP, 0.55 MaBP and 0.13 MaBP respectively, synchronous with the formation of paleosol units S8, S5 and S1 respectively. During the intervals between two tectonic uplifts when tectonic movement was very weak, climate changes played a major role in the evolution of the paleolakes and caused frequent fluctuations of lake levels. The changes of the features of lacustrine sediment in the grabens show the extent of such fluctuations of lake level is about 2-3 m.

  • Climate and Environmental Change
    GUO Zhigang, YANG Zuosheng, FAN Dejiang, PAN Yanjun
    Journal of Geographical Sciences. 2003, 13(3): 348-354.

    Seasonal distributions of suspended matter and their sedimentary effect on the Changjiang Estuary mud area of the East China Sea were discussed, based on three cruise data of total suspended matter, temperature and salinity collected from the Changjiang Estuary and its adjacent area in summer and winter. The results show that the basic pattern of distributions of suspended matter in the study area is almost the same in winter and in summer. Sediments from Changjiang (Yangtze River) to the sea are chiefly trapped to the west of 123o15'E due to a strong obstruction of the Taiwan Warm Current. This suggests that these sediments are mainly transported and deposited in the inner shelf. The sediment supply, Taiwan Warm Current, and Zhejiang Coastal Current show a strong seasonal variation, which results in a strong seasonal variation of the sedimentary effect on this mud area. This mud area is a "sink" of the Changjiang's sediment discharge to the sea and its sedimentation is stronger in summer and weaker in winter.

  • Climate and Environmental Change
    ZHAO Jianshi, WANG Zhongjing, WENG Wenbin
    Journal of Geographical Sciences. 2003, 13(1): 112-122.

    Complex adaptive system theory is a new and important embranchment of system science, which provides a new thought to research water resources allocation system. Based on the analysis of complexity and complex adaptive mechanism of water resources allocation system, a fire-new analysis model is presented in this paper. With the description of dynamical mechanism of system, behavior characters of agents and the evaluation method of system status, an integrity research system is built to analyse the evolvement rule of water resources allocation system. And a brief research for the impact of water resources allocation in beneficial regions of the Water Transfer from South to North China Project is conducted.