全文下载排行

  • 一年内发表的文章
  • 两年内
  • 三年内
  • 全部
  • 最近1个月下载排行
  • 最近1年下载排行

Please wait a minute...
  • 全选
    |
  • Climate and Environmental Change
    LU Yuqi, Yehua Dennis Wei
    Journal of Geographical Sciences. 2003, 13(1): 85-96.

    The dual-nuclei spatial structure is composed of a regional central city, a port city and their spatial relations in certain regions. In general, this spatial structure could be found in most of the coastal regions or regions along big rivers. In terms of the mechanism, the dual-nuclei structure is the result of the spatial interaction and the complementary characteristics of the center city and the port city. The "marginal function" of the port city and its relationship with the central city has long been discussed in the literature. On the one hand, drainage area is the main natural geographical background of the formation of the dual-nuclei spatial structure; therefore, we can build a theoretical geographic structure that is based on the drainage area. On the other hand, vicissitude of the coastline also has important influence on the formation of the dual-nuclei spatial structure. It is especially meaningful if we can notice this when we examine deeply the research on the spatial structure of delta.

  • Climate and Environmental Change
    LIU Yansui, ZHANG Xiaoping| LI Xianwen, Jay Gao
    Journal of Geographical Sciences. 2003, 13(2): 217-224.

    Yulin district is located in the transitional zone between Mu Us Desert and Loess Plateau of northern Shaanxi Province, thus it is particularly vulnerable to degradation due to its fragile ecosystem and intense human activities there. The purpose of this study is to explore the mechanism, process and driving force of land degradation in area with vulnerable eco-environment within the context of increasing population and intensifying human economic activities, and then find out the patterns and countermeasures of how to control them using the economic and technological ways. In detail, this study includes three main sections: the first section analyzes the mechanism, causes and characteristics of land degradation, which can be achieved by the typical field investigations and systematical analysis within the regional natural, social and economic context. Based on the technologies of remote sensing and GIS, and combined with the modeling methods, the second section reveals the change characteristics of land use and its driving force from 1990 to 2000; As to the third section, feasible countermeasures of how to prevent the degradation and rehabilitate the regional ecology are proposed, which are studied from the perspective of harmony between nature and economy, and the conception of regional sustainable development.

  • Climate and Environmental Change
    GE Miao
    Journal of Geographical Sciences. 2003, 13(3): 331-338.

    A research is conducted on the relationship between the normal reference value of 20,475 examples of hemoglobin of young women and five geographical factors in 208 areas in China, the normal reference value is determined by the hemoglobincyanide method. It is found that the correlation of geographical factors and the normal reference value of hemoglobin of young women are quite significant (F=142.81). By using the method of multiple linear regression analysis, one regression equation is inferred. If geographical values are obtained in some areas, the normal reference value of hemoglobin of young women of this area can be reckoned by using the regression equation. Furthermore, depending on the geographical factors, China can be divided into six regions: Qinghai-Tibet (Qingzang) Plateau, Southwest, Northwest, Southeast, North and Northeast China.

  • Climate and Environmental Change
    WEN Xuefa, YU Guirui, SUN Xiaomin, LI Qingkang, REN Chuanyou, HAN Shijie
    Journal of Geographical Sciences. 2003, 13(4): 463-468.

    Water vapour and CO2 fluxes were measured by the eddy-covariance technique above a mixed needle and broad-leaved forest with affiliated meteorological measurements in Changbai Mountain as part of China's FLUX projects since late August in 2002. Net water vapour exchange and environmental control over the forest were examined from September 1 to October 31 in 2002. To quantify the seasonal dynamics, the transition period was separated into leafed, leaf falling and leafless stages according to the development of leaf area. The results showed that (a) seasonal variation of water vapour exchange was mainly controlled by net radiation (Rn) which could account for 78.5%, 63.4% and 56.6% for leafed, leaf falling and leafless stages, respectively, while other environmental factors' effects varied evidently; (b) magnitude of water vapour flux decreased remarkably during autumn and daily mean of water vapour exchange was 24.2 mg m-2 s-1 (100%), 14.8 mg m-2 s-1 (61.2%) and 10.3 mg m-2 s-1 (42.6%) for leafed, leaf falling and leafless stage, respectively; and (c) the budget of water vapour exchange during autumn was estimated to be 87.1 kg H2O m-2, with a mean of 1427.2 g H2O d-1 varying markedly from 3104.0 to 227.5 g H2O m-2 d-1.

  • Climate and Environmental Change
    ZHANG Yunlin, QIN Boqiang, CHEN Weimin
    Journal of Geographical Sciences. 2003, 13(1): 97-104.

    The data utilized in this analysis consisted of extraterrestrial radiation, global radiation, diffuse radiation, direct radiation, total cloud cover and relative sunshine. The annual variations and trend were analyzed for monthly mean daily total global, direct, and diffuse radiation on a horizontal surface and for the relations between global, direct, diffuse radiation and relative sunshine, total cloud cover. The climatological calculation equations of global and direct radiation are put forward. The results show that global and direct radiations are characterized by decrease and diffuse radiation by increase. The main causes are due to the increase of concentration of suspended particles and atmospheric turbidities rather than cloud cover variations.

  • 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
    HAN Hui, GONG Daoyi
    Journal of Geographical Sciences. 2003, 13(4): 469-479.

    Climate extremes for agriculture-pasture transitional zone, northern China, are analyzed on the basis of daily mean temperature and precipitation observations for 31 stations in the period 1956-2001. Analysis season for precipitation is May-September, i.e., the rainy season. For temperature is the hottest three months, i.e., June through August. Heavy rain events, defined as those with daily precipitation equal to or larger than 50 mm, show no significant secular trend. A jump-like change, however, is found occurring in about 1980. For the period 1980-1993, the frequency of heavy rain events is significantly lower than the previous periods. Simultaneously, the occurring time of heavy rains expanded, commencing about one month early and ending one month later. Long dry spells are defined as those with longer than 10 days without rainfall. The frequency of long dry spells displays a significant (at the 99% confidence level) trend at the value of +8.3%/10a. That may be one of the major causes of the frequent droughts emerging over northern China during the last decades. Extremely hot and low temperature events are defined as the uppermost 10% daily temperatures and the lowest 10% daily temperatures, respectively. There is a weak and non-significant upward trend in frequency of extremely high temperatures from the 1950s to the mid-1990s. But the number of hot events increases as much as twice since 1997. That coincides well with the sudden rise in mean summer temperature for the same period. Contrary to that, the frequency of low temperature events have been decreasing steadily since the 1950s, with a significant linear trend of -15%/10a.

  • 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.

  • Climate and Environmental Change
    ZHANG Zulu, SHEN Ji, LIU Enfeng, SUN Qingyi, JIANG Luguang, WANG Lin
    Journal of Geographical Sciences. 2003, 13(2): 241-249.

    Through high-resolution research of sedimental chronology and the sediment environmental indexes, such as graininess, minerals, magnetic parameters, pigment content, organic carbon and chronology in Ds-core and Ws-core in Nansihu Lake, the authors analyze the formation cause of the Nansihu Lake and its water environmental changes. Historical documents are also analyzed here in order to reach the conclusion. Researches indicate that the Nansihu Lake came into being about 2500 aBP and its evolution succession can be divided into four stages. In this evolution process, several scattered lakes merge into one large lake in the east of China. This process is distinctively affected by the overflow of the Yellow River, the excavation of the Grand Canal and other human activities.

  • Climate and Environmental Change
    ZHANG Erfeng, CHEN Xiqing, WANG Xiaoli
    Journal of Geographical Sciences. 2003, 13(3): 355-362.

    Based on hydrometric data and extensive investigations on water-extracting projects, this paper presents a preliminary study on water discharge changes between Datong and Xuliujing during dry season. The natural hydrological processes and human factors that influence the water discharge are analyzed with the help of GIS method. The investigations indicate that the water-extracting projects downstream from Datong to Xuliujing had amounted to 64 in number by the end of 2000, with a water-extracting capacity up to 4,626 m3/s averaged in a tidal cycle. The water extraction from the Changjiang River has become the most important factor influencing the water discharge downstream Datong during dry season. The potential magnitude in water discharge changes are estimated based on historical records of water extraction and a water balance model. The computational results were calibrated with the actual data. The future trend in changes of water discharge into the sea during dry season was discussed by taking into consideration of newly built hydro-engineering projects. The water extraction downstream Datong in dry season before 2000 had a great influence on discharges into the sea in the extremely dry year like 1978-1979. It produced a net decrease of more than 490 m3/s in monthly mean discharges from the Changjiang into the sea. It is expected that the water extraction will continually increase in the coming decades, especially in dry years, when the net decrease in monthly mean water discharge will increase to more than 1000 m3/s and will give a far-reaching effect on the changes of water discharge from the Changjiang into the sea.

  • Climate and Environmental Change
    HUANG Zhenguo, ZHANG Weiqiang
    Journal of Geographical Sciences. 2003, 13(4): 488-497.

    About 70 examples of Quaternary fauna in China's tropics are enumerated in this paper. Of which about 40% of the examples can be found even in cooling stages, showing the smaller amplitude of climatic fluctuation during Quaternary. According to the temporal and spatial distribution of tropical faunas, the following characters of climate variation can be evidenced: two main cycles in Early Pleistocene, three main cycles in Middle Pleistocene, two main cycles in Late Pleistocene and Holocene Megathermal. The drop in temperature during the Latest Glacial Period and Neoglaciation has not endangered the existence of tropical faunas. With influence of cooling fluctuation during historical period, some faunas have removed southwards progressively, but disappearance of these animals in China's tropics was mainly the result of artificial factors.

  • Climate and Environmental Change
    LIANG Fuyuan, SONG Linhua, TANG Tao
    Journal of Geographical Sciences. 2003, 13(2): 250-256.

    Lunan stone forest is a kind of typical karst in China, which is mainly developed under red soil. In the winter of 1999, three study sites were chosen in stone forest national park according to vegetation cover, geomorphologic location and soil types. CO2 concentration was measured with Gastec pump at different depths of soil (20, 40, 60 cm) and at the same time soil samples were gathered and soil properties such as soil moisture, pH, soil organic content were analyzed and the total number of viable microbes were counted in laboratory. In the study, dependent variable was chosen as the mean soil log (PCO2), and soil properties were chosen as the independent variables. Multiple stepwise regression analysis showed that the total amount of microbes and soil moisture are the best indicators of the CO2 production, with the equation LOG(PCO2) = - 0.039(TNM) - 0.056(Mo) + 1.215 accounting for 86% of the variation of the soil CO2 concentration, where TNM is the total number of microbes in the soil and Mo is the moisture of soil sample.

  • Climate and Environmental Change
    CHEN Rensheng, KANG Ersi, YANG Jianping, ZHANG Jishi
    Journal of Geographical Sciences. 2003, 13(3): 363-372.

    In order to predict the futuristic runoff under global warming, and to approach to the effects of vegetation on the ecological environment of the inland river mountainous watershed of Northwest China, the authors use the routine hydrometric data to create a distributed monthly model with some conceptual parameters, coupled with GIS and RS tools and data. The model takes sub-basin as the minimal confluent unit, divides the main soils of the basin into 3 layers, and identifies the vegetation types as forest and pasture. The data used in the model are precipitation, air temperature, runoff, soil weight water content, soil depth, soil bulk density, soil porosity, land cover, etc. The model holds that if the water amount is greater than the water content capacity, there will be surface runoff. The actual evaporation is proportional to the product of the potential evaporation and soil volume water content. The studied basin is Heihe mainstream mountainous basin, with a drainage area of 10,009 km2. The data used in this simulation are from Jan. 1980 to Dec. 1995, and the first 10 years' data are used to simulate, while the last 5 years' data are used to calibrate. For the simulation process, the Nash-Sutcliffe Equation, Balance Error and Explained Variance is 0.8681, 5.4008 and 0.8718 respectively, while for the calibration process, 0.8799, -0.5974 and 0.8800 respectively. The model results show that the futuristic runoff of Heihe river basin will increase a little. The snowmelt, glacier meltwater and the evaportranspiration will increase. The air temperature increment will make the permanent snow and glacier area diminish, and the snowline will rise. The vegetation, especially the forest in Heihe mountainous watershed, could lead to the evapotranspiration decrease of the watershed, adjust the runoff process, and increase the soil water content.

  • Climate and Environmental Change
    CHEN Shenliang, ZHANG Guoan, YANG Shilun
    Journal of Geographical Sciences. 2003, 13(4): 498-506.

    A detailed analysis of suspended sediment concentration (SSC) variations over a year period is presented using the data from 8 stations in the Yangtze River estuary and its adjacent waters, together with a discussion of the hydrodynamic regimes of the estuary. Spatially, the SSC from Xuliujing downwards to Hangzhou Bay increases almost constantly, and the suspended sediment in the inner estuary shows higher concentration in summer than in winter, while in the outer estuary it shows higher concentration in winter than in summer, and the magnitude is greater in the outer estuary than in the inner estuary, greater in the Hangzhou Bay than in the Yangtze River estuary. The sediments discharged by the Yangtze River into the sea are resuspended by marine dynamics included tidal currents and wind waves. Temporally, the SSC shows a pronounced neap-spring tidal cycle and seasonal variations. Furthermore, through the analysis of dynamic mechanism, it is concluded that wave and tidal current are two predominant factors of sediment resuspension and control the distribution and changes of SSC, in which tidal currents control neap-spring tidal cycles, and wind waves control seasonal variations. The ratio between river discharge and marine dynamics controls spatial distribution of SSC.

  • Climate and Environmental Change
    ZHA Xiaochun, TANG Keli
    Journal of Geographical Sciences. 2003, 13(3): 373-378.

    Based on data observed from 1989 to 1998 in the Ziwuling survey station, changes of soil erosion and soil physico-mechanical properties were studied after forestland reclamation. When the man-induced factors changed the eco-environment by reclaiming forestlands, the intensity of man-made soil erosion in reclaimed lands was 1,000 times more than that of natural erosion in forestlands. From the analysis of soil physical and mechanical properties, the clay content and physical clay content decreased 2.74% and 3.01% respectively, and the >0.25 mm water stable aggregate content decreased 58.7%, the soil unit weight increased and the soil shear strength decreased, all of which were easier to cause soil erosion. The results of the correlation analysis showed that the >0.25 mm water stable aggregate content was the greatest influencing factor on soil erosion, the partial correlated coefficient was 0.9728, and then were soil coarse grain and soil shear strength, the partial correlated coefficients being 0.8879 and 0.6020 respectively. The relationships between the >0.25 mm water stable aggregate content, the soil sheer strength and the soil erosion intensity were analyzed, which showed that the first and seventh years were the turning years of the soil erosion intensity after the forestland reclamation. The degenerative eroded soil and eco-environment formed the peculiar erosion environment, which aggravated the soil erosion rapidly.

  • Climate and Environmental Change
    LI Xusheng, YANG Dayuan, KE Xiankun, ZHOU Lufu, CHEN Deji, YANG Tianmin, XUE Guofu
    Journal of Geographical Sciences. 2003, 13(4): 507-512.

    This paper describes valley bottom troughs of the Changjiang River and infers the geomorphologic development of troughs. Based on the morphology of the troughs, the following conclusions are drawn. (1) The deep troughs on the Three Gorges valley bottom are formed by river downcutting along the structural zones on the background of regional tectonic uplift at about 40-30 ka BP. (2) When river downcutting occurred in the river bed of Changjiang, the jets current (particularly eddy current) with a large number of pebbles ground and eroded the valley bottom, resulting in trough formation and deepening. Meanwhile, water currents with gravels and pebbles eroded the bank and the left wall of No.76 trough as well as the right wall of No.77 trough by striking, scouring, horizontal and vertical grinding. (3) The depth of the trough is mainly determined by the intensity of the water current and the consistency of bedrock against erosion, and is not controlled by the altitude of the sea level as the base level of erosion.

  • Climate and Environmental Change
    LIU Huiqing, XU Jiawei, LV Xinmiao
    Journal of Geographical Sciences. 2003, 13(3): 379-384.

    The sandy land of the western part of Jilin Province is located in the ecotone of semi-humid and semi-arid area in the temperate zone of China. The sandy desertification has widely spread in the region because of the vulnerable natural conditions and the unreasonable human activity; as a result of this, the precious land resources and the economic development in the area have been seriously impacted. In this paper, the sandy land ecologic environment geographic information system is established based on the multi-spectral, multi-temporal Landsat TM images and field investigation. The comprehensive indexes of sandy desertification extent assessment which include vegetation degradation, wind erosion extent and soil depth are presented to classify the sandy land in western Jilin into three levels--slight, moderate and severe sandy desertification with the support of GIS platform. The results demonstrate that the sandy desertification has been partly controlled in the past twenty years, except some small sites. However, this doesn't necessarily mean that there is nothing for more concern. The two main causes of sandy desertification have not been eliminated yet, one is its natural factor, especially the physical and chemical characters of sandy soil and dry climate; another is the immoderate economic activity of human being that has highly accelerated the sandy desertification process.

  • Climate and Environmental Change
    LI Ying, Douglas L. Johnson, Abdelkrim Marzouk
    Journal of Geographical Sciences. 2002, 12(1): 1-14.

    Environmental degradation and other socio-economic problems are too often discerned in contemporary pastoral systems in the wake of global economic change. This paper identifies cases where pastoral people respond to external pressures and opportunities in positive ways and adapt to changes. We hope that by doing this a framework of pastoral adaptations can be developed. The first part of this paper focuses on impacts of global economic change, which are mostly negative in nature. Through an extensive literature search in geography, anthropology, range management, and development field, the second part introduces cases that we categorize as positive adaptations.

  • Climate and Environmental Change
    LIU Ji-yuan, Masataka Watanabe, YUE Tian-xiang, OUYANG Hua, DENG Xiang-zheng
    Journal of Geographical Sciences. 2002, 12(2): 127-134.

    The objectives of Integrated Ecosystem Assessment for Western Development of China includes: (1) providing scientific basis for ecosystem protection, ecosystem management and ecological construction in the western development; (2) developing complete database and analytical tools and strengthening decision-making support capacity; and (3) improving ecosystem management in China, spreading ecological knowledge to the public, serving decision-making of local and central governments, and promoting socio-economic sustainable development. The design and implementation of the project are of significance under the macro background of western development of China. By the integrated assessment of western China, we can get the first-hand data covering all the environmental factors as well as disclose the situations and their changing trends of ecosystem in the western part of China, which will benefit the decision-making for the central and local governments in the implementation of the western development strategy. In other words, the implementation of the project, to a certain extent, can guarantee the regional sustainable development of western China.

  • Climate and Environmental Change
    DENG Xiang-zheng, ZHAN Jin-yan, LIU Ji-yuan, ZHUANG Da-fang
    Journal of Geographical Sciences. 2002, 12(1): 15-22.

    The Global Rainforest Mapping (GRFM) project was initiated in 1995 and, through a dedicated data acquisition policy by the National Space Development Agency of Japan (NASDA), data acquisitions could be completed within a 1.5-year period, resulting in a spatially and temporally homogeneous coverage to contain the entire Amazon Basin from the Atlantic to the Pacific; Central America up to the Yucatan Peninsular in Mexico; equatorial Africa from Madagascar and Kenya in the east to Sierra Leone in the west; and Southeast Asia, including Papua New Guinea. To some extent, GRFM project is an international endeavor led by NASDA, with the goal of producing spatially and temporally contiguous Synthetic Aperture Radar (SAR) data sets over the tropical belt on the Earth by use of the JERS-1 L-band SAR, through the generation of semi-continental, 100m resolution, image mosaics. The GRFM project relies on extensive collaboration with the National Aeronautics and Space Administration (NASA), the Joint Research Center of the European Commission (JRC) and the Japanese Ministry of International Trade and Industry (MITI) for data acquisition, processing, validation and product generation. A science program is underway in parallel with product generation. This involves the agencies mentioned above, as well as a large number of international organizations, universities and individuals to perform field activities and data analysis at different levels.

  • Climate and Environmental Change
    ZHANG Bai-ping, CHEN Xiao-dong, LI Bao-lin, YAO Yong-hui
    Journal of Geographical Sciences. 2002, 12(2): 135-143.

    The Tibetan Plateau (Qinghai-Xizang Plateau) is a unique biogeographic region in the world, where various landscapes, altitudinal belts, alpine ecosystems, and endangered and endemic species have been developed. A total of 26 altitudinal belts, 28 spectra of altitudinal belts, 12,000 species of vascular plant, 5,000 species of epiphytes, 210 species of mammals, and 532 species of birds have been recorded. The plateau is also one of the centers of species formation and differentiation in the world. To protect the biodiversity of the plateau, about 80 nature reserves have been designated, of which 45 are national or provincial, covering about 22% of the plateau area. Most of the nature reserves are distributed in the southeastern plateau. Recently, the Chinese government has initiated the “Natural Forests Protection Project of China,” mainly in the upper reaches of the Yangtze and Yellow rivers. “No logging” policies have been made and implemented for these areas.

  • Climate and Environmental Change
    ZHANG Mingjun, REN Jiawen, CHENG Guodong, LI Zhongqin,XIAO Cunde, QIN Dahe, KANG Jiancheng, LI Jun
    Journal of Geographical Sciences. 2002, 12(4): 379-386.

    By comparing the oxygen isotopic temperatures recorded by many shallow ice cores from the coastal regions of Antarctica, this paper presents the special characteristics of the temperature variations over the Antarctic coastal regions in the past 50 years, 150 years and 250 years. In the past 50 years, the isotopic temperatures recorded in the ice cores over different sites on the Antarctic coastal regions differ greatly. For instance, although increasing isotopic temperatures have been reported for many sites studied, many sites show decreasing trends, the regional regularity in temperature variations is still insignificant. In the past 150 years, the isotopic temperature trends in the coastal regions of Antarctica show an alternate-distributing pattern. In the past 250 years, all the ice cores from the coastal regions of Antarctica have recorded the so-called Little Ice Age (LIA). The above-mentioned spatial characteristics of the temperature variations over the Antarctic coastal regions are likely to reflect the impacts of the unique Southern Hemisphere atmospheric circulation, the Antarctic Circumpolar Wave (ACW) and the special terrain (such as the large drainage basins) on the coastal regions of Antarctica. Furthermore, the impacting intensity of the unique Southern Hemisphere atmospheric circulation, the Antarctic Circumpolar Wave and the special terrain differs in terms of the temporal scale of the temperature change.

  • Climate and Environmental Change
    LIU Shenghe, Sylvia Prieler, LI Xiubin
    Journal of Geographical Sciences. 2002, 12(3): 266-274.

    By using digitized land use maps of Beijing in 1982, 1992 and 1997 and employing GIS spatial analysis techniques, this paper conducts an empirical study on the spatial differentiation and spatial patterns of urban land use growth in Beijing in the period of 1982-1997. It is observed that urban land use growth in Beijing went beyond the control of urban planning, in terms of the extraordinary high growth rate and undesired spatial pattern. The rate of urban expansion after 1982, which was predominated by growth of industrial land, was extraordinary high compared to its historical period. While its growth centers have been actively shifting toward the northern part, rather than toward the southern and eastern parts as designated by the latest General Plan (1991-2010) of Beijing, its spatial pattern of urban land use growth in general was in distinct concentric sprawl, which seriously violated the General Plan of Beijing.

  • Climate and Environmental Change
    CHEN Jie, Hans-Peter Blume
    Journal of Geographical Sciences. 2002, 12(4): 387-396.

    Saxicolous species of lichens are able to induce and accelerate weathering of their rock substrate, and effects of lichens on substrate can be attributed to both physical and chemical causes. This paper is focused on biotic weathering actions of epilithic and endolithic species on the different rock types (sandstones and volcanogenic rocks) in Antarctica. The patterns, mechanisms, processes and neoformations of rock-weathering resulting from lichen colonization are expounded in detail. Furthermore, it is pointed out that, for a better understanding of the impacts of lichens on environments, the studies on the rate of biotic weathering and the comprehensive involvement of the lichen effects on weathering of natural rocks remain to be carried out in Antarctica.

  • Climate and Environmental Change
    LIU Jiyuan, LIU Mingliang, DENG Xiangzheng, Zhuang Dafang,ZHANG Zengxiang, LUO Di
    Journal of Geographical Sciences. 2002, 12(3): 275-282.

    In the mid-1990s, we established the national operative dynamic information serving systems on natural resources and environment. During building the land-use/land-cover change (LUCC) database for the mid-1990s, 520 scenes of remotely sensed images of Landsat Thematic Mapper (TM) were interpreted into land-use/land-cover categories at scale of 1:100,000 under overall digital software environment after being geo-referenced and ortho-rectified. The vector map of land-use/land-cover in China at the scale of 1:100,000 was recently converted into a 1-km raster database that captures all of the high-resolution land-use information by calculating area percentage for each kind of land use category within every cell. Being designed as an operative dynamic information serving system, monitoring the change in land-use/land-cover at national level was executed. We have completed the updating of LUCC database by comparing the TM data in the mid-1990s with new data sources received during 1999-2000 and 1989-1990. The LUCC database has supported greatly the national LUCC research program in China and some relative studies are incompletely reviewed in this paper.

  • Climate and Environmental Change
    DENG Xiangzheng, LIU Jiyuan, ZHUANG Dafang, ZHAN Jinyan, ZHAO Tao
    Journal of Geographical Sciences. 2002, 12(4): 397-404.

    This paper discusses land-use changes in the interlock area of farming and pasturing (IAFP)in northern China. It presents detailed analyses of land-use features in the IAFP, which are controlled by the macro geomorphic units and geophysical conditions-constraints or advantages. Additionally, it selects some indicators, according to the availability in acquiring and processing their quantitative data, to analyze the canonical correlations between the typical conversion of grassland and geophysical conditions. The preliminary study indicates that the physical conditions are of great advantages to the development of grassland. There exists significant correlation between land use change and some geophysical conditions.

  • DU Yunyan, TU Wenna, LIANG Fuyuan, YI Jiawei
    地理学报(英文版). 2021, 31(2): 179-194. doi: 10.1007/s11442-021-1841-0
    CSCD(1)

    Mobile internet and wireless communication technologies have produced unprecedented location-aware data. Such big geospatial data can be used as a proxy measure of the ‘digital footprints’ left by us on the planet and provide a valuable opportunity to understand the dynamic and short-term human disturbance on the nature at fine scales. This study investigated the spatiotemporal variations of human’s digital footprints on the Qinghai-Tibet Plateau using smartphone-users-generated Tencent’s location request data. The results showed that human’s digital footprints cover less than 5% of Qinghai and Tibet, exhibiting either a U-shaped or an N-shaped temporal change pattern during the major festivals. Spatial changes of the digital footprints manifested a transition process from dispersion to concentration in Xining and Lhasa. Human disturbance assessment of seven large nature reserves on the plateau showed that the Qinghai Lake is the most disturbed one as shown by 14.6% of its area is stained with human digital footprints and the areal average of footprint intensity is 1.59, and the disturbance was significantly escalated during the National Day holiday. By contrast, the Qangtang and Hoh Xil are the least affected nature reserves with the two indices less than 1% and 0.1, respectively.