Table of Content

    20 January 2015, Volume 70 Issue 1 Previous Issue    Next Issue
    Orginal Article
    The contemporary glaciers in China based on the Second Chinese Glacier Inventory
    Shiyin LIU, Xiaojun YAO, Wanqin GUO, Junli XU, Donghui SHANGGUAN, Junfeng WEI, Weijia BAO, Lizong WU
    2015, 70 (1):  3-16.  doi: 10.11821/dlxb201501001
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    The Second Chinese Glacier Inventory (SCGI) was compiled based on remote sensing images after 2004 including Landsat TM/ETM+ and ASTER images, and the digital elevation models (DEMs) from SRTM. The SCGI shows that there are 48,571 glaciers with a total area of 5.18×104 km2 and ice volume of 4.3×103-4.7×103 km3 in China (including glaciers measured from 1:50,000 or 1:100,000 topographic maps made from the 1960s to the 1980s because of no high quality remote sensing images for the contemporary glacier inventories). The number of glaciers with the area below 0.5 km2 reaches 33,061 and accounts for the majority part (66.07%) of glaciers in China. Glaciers with areas between 1.0 km2 and 50.0 km2 are totaled as ~3.40×104 km2 (~2.65×103 km3 in ice volume) and constitute the main part of glaciers in China. The Yengisogat Glacier (359.05 km2), located in the Shaksgam Valley, north slope of the Karakoram Mountain, is the largest glacier in China. The glaciers are spatially distributed in 14 mountains and plateaus in western China. The Kunlun Mountains has the largest number of glaciers in China, followed by Tianshan Mountains, Nyainqêntanglha Range, the Himalayas and Karakoram. Glaciers in the above five mountains account for 72.26% of the total glacier number in China, however, over 55% of the total area of glaciers and 59% of the total ice storage in China are concentrated in the Kunlun Mountains, Nyainqêntanglha Range and Tianshan Mountains. The number and area of glaciers in Karakoram Mountains are less than those in the Himalayas, but the volume of the former is more than that of the latter because the glaciers in the Karakoram are generally larger. Some 4/5 of the total area of glaciers in China is mainly distributed in an altitudinal band between 4500-6500 m a.s.l. with regional differences depending on the general elevations of various mountains. Analogously, there is an obvious difference of glaciers in basins. The first level basin having the most glaciers is the East Asia interior drainage area (5Y) which occupies ~40% of glaciers in China. The Yellow River basin (5J) has the fewest glaciers where only 164 with an area of 126.72 km2 are distributed. Xinjiang and Xizang autonomous regions are the two provincial units rich in glaciers, with ~9/10 of the total area and ice storage of glaciers in China.

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    The changes and dynamics of coastal wetlands and reclamation areas in central Jiangsu from 1977 to 2014
    Jianguo LI, Lijie PU, Caiyao XU, Xinjian CHEN, Yunfeng ZHANG, Fangfang CAI
    2015, 70 (1):  17-28.  doi: 10.11821/dlxb201501002
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    Five remote sensing images (1977, 1984, 2000, 2007 and 2014) were obtained to study the spatial dynamics of coastal wetlands and reclamation area in central Jiangsu province. The results indicated that most of the coastal wetlands showed an accretion trend from the south of Sheyang estuary, while there still existed some erosion phenomena in the past 40 years. The mean rate of accretion/erosion of Jiangsu coastal wetlands was ±20 m per year, and the highest value was observed at Dongtai and Yangkou ports. Meanwhile, the reclamation rate was significantly higher than the accretion ones, and the former kept a level of 50 m per year. In addition, the key ecological areas of Jiangsu coastal wetlands reduced rapidly from 1977 to 2014, which can be found from the shrinkage of natural halophytic vegetation in the southern part of Sheyang County and the whole part of Dafeng County. It was found in field surveys that the evolution pattern of reclamation in coastal wetlands was in the order of bare flat → halophytic vegetation → aquaculture pond → cropland → built-up land. However, with the aid of new technology, the period of evolution pattern was shortened. Moreover, the development of coastal wetlands has been intensified due to reclamation activities. The hotspots of reclamation were presented at major ports and central towns.

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    Review for the studies on sedimentation range of the Abandoned Yellow River subaqueous delta, North Jiangsu plain coast
    Fei XIA, Yongzhan ZHANG, Ruifa WANG, Paul LIU J., Zhenke ZHANG, Xiuqiang PENG
    2015, 70 (1):  29-48.  doi: 10.11821/dlxb201501003
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    Based on the published studies, this paper presented three main viewpoints of the maximum developed sedimentation range of the Abandoned Yellow River (AYR) subaqueous delta, North Jiangsu plain coast during AD 1128 to 1855: (1) its outer margin was located on the wide flat platform between the two slope belts in the nearshore and offshore areas off the AYR mouth with a water depth between -15 and -25 m; (2) its outer margin was located outside the offshore slope belt off the AYR mouth with a water depth between -25 and -45 m; (3) the AYR delta was composed of the compound clinoforms and its outer margin could extend beyond the -45 m isobath. Based on the comprehensive studies of the characteristics of topography, geomorphology, sedimentary strata and shallow seismic profiles, combined with the radiocarbon dating results and other data in the concerned areas, it could be concluded that the maximum sedimentation range of the AYR subaqueous delta should extend beyond the current -20 m isobath, however, it was hardly to exceed the offshore slope belt. The thick clinoform located in the offshore slope belt was unlikely to be the front deposits of the AYR delta. Therefore, further investigations need to be made on its definite origin, provenance, formation time and other concerned issues in future. In order to delineate the definite sedimentation range of the AYR subaqueous delta during AD 1128 to 1855, we should recover and interpret the high-quality shallow seismic profiles covering the entire concerned areas, analyze the supplementary sediment cores in the three main subaqueous topographic units (i.e., the slope belts in the nearshore and offshore areas, and the wide flat platform between these two belts), and compare the various sea charts issued since AD 1875.

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    A review on development of the Yellow River alluvial fan
    Yufeng MA, Shuangquan LI, Xinghui PAN
    2015, 70 (1):  49-62.  doi: 10.11821/dlxb201501004
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    The Yellow River alluvial fan is an alluvial fan complex composed of multi-stage sediment sequences since the Quaternary. It is a geomorphic unit formed by intensive deposition of sediments eroded from the Loess Plateau, and thus a region with frequent breach and diversion. It is also the cradle of Chinese civilization. After a historical review of the development of the Yellow River alluvial fan, this paper systematically introduces the advances of studies concerning the Yellow River alluvial fan formation age, geomorphological characteristics, deposition rate, developmental process and characteristics, overviews in detail, the influence of river diversion, geological structure, climate change and human activities on the alluvial fan formation. Due to the insufficient studies of development mechanism and incomplete temporal-spatial scale at present, the research concerning the prehistoric alluvial fan development of the Yellow River will be a challenge in the future.

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    Eolian loess- palaeosol sequence and OSL age of the first terraces within the Yunxian Basin along the upper Hanjiang River
    Jiangli PANG, Chunchang HUANG, Yali ZHOU, Xiaochun ZHA, Yuzhu ZHANG, Leibin WANG
    2015, 70 (1):  63-72.  doi: 10.11821/dlxb201501005
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    The first river terrace within the Yunxian Basin along the upper reaches of Hanjiang River was investigated in the field work. The sediment profiles were sampled systematically. The sedimentological characteristics, and physical and chemical properties were analyzed in laboratory. The samples were dated using OSL method. The results show that, the bottom age of the thick loess L1 is 25 ka BP, and the age range of the eolian loess-alluvial sand inter-beds (T1-al2) is between 55-25 ka BP. The age distribution suggests that deposition process of the loess sequence in Hanjiang River valley is essentially continuous. The first river terrace of the Hanjiang River has experienced two development stages, including the tectonic uplift and river incision (55-25 ka BP), and then the stabilized eolian loess deposition (25-0 ka BP). Around 55 ka BP, the river incision started because of the intensified tectonic uplifting. The eolian loess accumulation on the uplifted flood plain was frequently interrupted due to the overbank flooding. This process continued around 25 ka BP and the inter-beds of eolian loess and alluvial sand (T1-al2) were therefore formed. To about 25 ka BP, the first river terrace had formed and eolian loess accumulated continuously on the terrace land. At the same time, with the river incision, the last glaciation entered the maximum stage and the thickeolian loess covered the terrace because of the increased dust storms and dustfalls. Since the formation of the terrace about 25 ka BP, the eolian loess experienced varying degrees of weathering and pedogenesis in different periods because of monsoonal climate change. The stratigraphic paleosol-loess sequence on the first terrace from the bottom to the top is listed as fluvial gravel (T1-al2) → eolian loess and alluvial sand inter-beds (T1-al2) → Malan loess (L1) → transitional loess (Lt) →paleosol (S0) → recent loess (L0) → modern soil (MS). This stratigraphic sequence has recorded a monsoonal climate change model since 25 ka BP, including the gradually intensified southeast monsoon during the late glacial and early Holocene periods, the strongest monsoon in the mid-Holocene, and the monsoon recession and the climate drying during the late Holocene.

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    Cracking the root of the Two Theory Systems on eolian sand movement mechanism from an innovative perspective
    Xianke SUN, Xueli ZHANG
    2015, 70 (1):  73-84.  doi: 10.11821/dlxb201501006
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    This article breaks down the eolian sand movement into two parts from a geographic perspective for the first time, the inner core and the outer extension. The fluid start and the impact start of saltation are the two entities that constitute the inner core, and all transportation performance after the sand particle start can be defined as the outer extension. Drawing upon this innovative idea, this article carries out discussion on the root of how divergences arise between the two systems of theories, the eolian sand physics and the eolian sand geography. The results reveal that whether one is able to distinguish the different properties of the two entities of the inner core and whether one is able to understand the interaction mechanism correctly of the two entities lead to the formation of the cores of the two theoretical systems and are the root of many divergences. This article deepens the understanding towards the connotation of eolian sand movement and theoretically breaks through the long term leading core idea in the sand movement scholastic circle presented by Bagnold whose theory on the two types of sand particle start appreciates one and depreciates the other.

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    Phenological basis for determination of ornamental tourism season in China
    Zexing TAO, Quansheng GE, Huanjiong WANG, Junhu DAI
    2015, 70 (1):  85-96.  doi: 10.11821/dlxb201501007
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    Many plants have high ornamental value during specific phenophases, such as first leaf, flowering and leaf coloring. Thus, plant phenology correlates highly with seasonal aspects of landscape. Studying the determination of ornamental tourism season and its temporal and spatial patterns could provide tourism management departments and tourists with theoretical basis on tourism arrangement. Based on phenological data of 3 phenophases (first leaf date, full flower date, end of coloring date) and corresponding meteorological data at 12 sites in China, we divided the ornamental tourism season (including starting date, optimal tourism date and end date) by applying phenological frequency distribution method. The trend of optimal tourism date over the past 50 years was also analyzed. The results showed that: (1) The optimal tourism date, ranged from March 16 (Guilin) to May 5 (Harbin) for first leaf, April 3 (Kunming) to May 24 (Mudanjiang) for full flowering, October 1 (Mudanjiang) to November 30 (Shanghai) for leaf coloring. The optimal tourism date of first leaf and full flower was positively associated with latitude, while that of leaf coloring was negatively correlated with latitude. (2) The optimal tourism date of first leaf and full flower exhibited significant advancing trend of 1.6 days/decade over the past 50 years in Beijing and Xi'an, while that of leaf coloring showed significant delaying trend (Beijing, 1.6 days/decade; Xi'an, 2.1 days/decade). (3) The ornamental tourism season was significantly associated with temperature of each site. Optimal tourism date of first leaf and full flowering advanced by 4.02 days and 4.04 days per 1°C increase in spring (March-May) temperature, respectively. Optimal tourism date of leaf coloring showed significant positive correlation with September-November temperature and the spatial sensitivity was 2.98 days/°C.

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    Variations in the oxygen isotopic composition of precipitation in the Tianshan Mountains region and their significance for the Westerly circulation
    Xiaokang LIU, Zhiguo RAO, Xiaojian ZHANG, Wei HUANG, Jianhui CHEN, Fahu CHEN
    2015, 70 (1):  97-109.  doi: 10.11821/dlxb201501008
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    Proxy records of the oxygen isotopic composition of meteorological precipitation (δ18Op) preserved in archives such as ice cores, lacustrine carbonates and stalagmite calcite are important for paleoclimatic studies. Therefore, knowledge of the variations and controlling mechanisms of modern δ18Op on different time scales is necessary. Here, we investigate the linear correlations between δ18Op and corresponding temperature and precipitation on monthly and inter-annual timescales, using data from the Urumqi (1986-2003) and Hotan stations of the Global Network of Isotopes in Precipitation (GNIP), and δ18O data from 4 ice cores in the adjacent Tianshan Mountains. Consistent with previous reported results, modern δ18Op variations on a seasonal time scale in the Tianshan region are mainly controlled by a 'temperature effect' (indicated by a significant positive correlation between δ18Op and temperature), with more positive δ18Op values occurring in summer. However, on an inter-annual timescale, there is a weak inverse correlation between weighted average annual δ18Op and annual average temperature at Urumqi. This finding is supported by the inversely varying trends of δ18O data from 4 ice cores in the central and eastern Tianshan Mountains compared to annual average temperatures in the same region during the past 40-50 years. The data from Urumqi station and the 4 ice cores demonstrate that the inverse correlation between δ18Op and temperature on inter-annual to decadal time scales is genuine. Analysis of water vapor sources and pathways for the warm year of 1997 and the cold year of 1988 reveal that more water vapor for the Tianshan area was derived from long-distance transport from high-latitude sources than during the warm year of 1997; and that more water vapor was transported from more proximal sources from mid- to low-latitude areas during the cold year of 1988. In addition, the δ18Op values are more negative in the high latitude areas than those in mid- to low-latitude areas in the Eurasian continent at the upper wind direction of Tianshan Mountains region, according to the weighted averaged warm season (May to September) δ18Op values for 14 GNIP stations in the years 1997 and 1988. Due to the distribution of δ18Op within the Eurasian continent, the relative shift of water vapor sources between warm and cold years convincingly explains the observed variations of δ18Op in the Tianshan area. Therefore, we conclude that variations in δ18Op in the Tianshan Mountains region are mainly controlled by changes in water vapor sources which are ultimately caused by northward and southward shifts in the Westerly circulation.

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    Spatial-temporal characteristics of PM2.5 in Beijing in 2013
    Zhanshan WANG, Yunting LI, Tian CHEN, Dawei ZHANG, Feng SUN, Libo PAN
    2015, 70 (1):  110-120.  doi: 10.11821/dlxb201501009
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    Data of PM2.5 from 35 automatic air quality monitoring stations of Beijing in 2013 were analyzed to examine the temporal and spatial characteristics of PM2.5 and the correlation between PM2.5 and its precursors and atmospheric oxidation. The results showed that the average concentrations of PM2.5 in different seasons decreased in the order of winter, spring, autumn and summer, which were 122.8 μg·m-3, 85.1 μg·m-3, 84.9 μg·m-3 and 79.1 μg·m-3, respectively. The average concentrations of PM2.5 at different stations decreased in the order of traffic station, urban station, suburban station and regional station, which were 102.2 μg·m-3, 91.8 μg·m-3, 89.1 μg·m-3 and 88.7 μg·m-3, respectively. Monthly average concentrations of PM2.5 showed a wavy-shaped curve, the peaks of which appeared in January, March, June and October, respectively. For the whole year, diurnal variation of PM2.5 at traffic station showed a single-peak curve, while other stations showed bimodal curves. Annual average concentrations of PM2.5 in different regions decreased in the order of southeast, southwest, center (six districts), northeast and northwest. Concentrations of PM2.5 were significantly positively correlated with those of NO2, SO2 and OX, which indicated that precursors and atmospheric oxidation had a significant impact on the concentration of PM2.5.

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    Key indicators and the thresholds of trans-boundary water allocation based on river health and international treaties
    Yan FENG, Daming HE, Wenling WANG
    2015, 70 (1):  121-130.  doi: 10.11821/dlxb201501010
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    In the paper, according to the revealed major indicators on river health assessment and of transboundary water allocation in the preliminary studies, after the correlations among them were analyzed, the key indicators of transboundary water allocation and of healthy riverwere finally confirmed, as: mean annual runoff, maximum water intake, and minimum maintained water volume. Based on 38 international treaties related to water allocation in 1864-2002 adopting the 3 key indicators, some key hydrological data of the 28 rivers covered by the treaties from various publications were looked up, the values of the 3 key indicators were standardized and calculated, and the thresholds and the regional characteristics of them were analyzed. The results were as follows: (1) Among the 3 key indicators, "minimum maintained water volume" was most widely adopted, and "maximum water intake" was the one with the lowest adoption. (2) From the adoption of mean annual runoff, for the frontier rivers, the basic scheme of water allocation was equal allocation, and the threshold was 50%; for the tributary, which was totally within one country, the threshold was 100%; for transboundary rivers, there were more schemes with a different allocation, and more ones with a greater share for an upstream country. (3) As for the indicator of “minimum maintained water volume”, its adoption showed the extending tendencies from the developed regions to the developing ones, and from maintaining water supply for downstream countries to keeping ecological water demand. When it was used for maintaining water supply, at the river scale, the average thresholds were 41.7% on transboundary rivers and 50% on frontier ones, respectively, which were obviously affected by riparian countries’ strength, while at the reach scale, the average threshold was 36.1% on transboundary rivers. When it was used for keeping water flow in watercourse, the average value of the thresholds was 14.7%, with an increasing tendency.

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    Characteristics of landscape dynamic changes in Zhalong Wetland
    Yuhong ZHANG, Liying SU, Wanhui YU, Hongyun ZHANG
    2015, 70 (1):  131-142.  doi: 10.11821/dlxb201501011
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    As an internationally well known and ecological zone, Zhalong Wetland has undergone tremendous landscape changes based on hydrological pattern in recent decades. We defined a set of wetland classification system to describe the landscape changes by using Landsat TM images during 1979-2013, and analyzed the changes of landscape transition magnitude by landscape transition coefficient on a 5-year time scale. Four types of landscape dynamics were identified at Zhalong Wetland: stable landscape with regular and little magnitude, unstable landscape with irregular and normal magnitude; stable landscape with degraded and regular magnitude; unstable landscape with irregular and huge magnitude. The results show that: wetland landscape tended to be wet before 1989 with smaller magnitude, and tended to dry after 1989. In terms of dynamics, the area of A landscape (973.60 km2) is mainly distributed in the core area and farmland; the area of D landscape (311.92 km2) is mainly in the sites of human disturbance, such as on both sides of large ditches and dams.

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    Geographical distribution, diffusion and subsistence variation of prehistoric cultures in Nanyang Basin, Henan Province
    Zhongxuan LI, Cheng ZHU, Shengyuan YUAN, Jiajia XU, Guoxi WU, Hong WANG, Zhiyong GUO
    2015, 70 (1):  143-156.  doi: 10.11821/dlxb201501012
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    The Neolithic cultures of the Zhongyuan type played a leading role in the Nanyang Basin since the Holocene, yet the exotic cultures (e.g. the Qujialing culture and the Shijiahe culture) from the middle and lower reaches of the Hanjiang River exerted influences on the contents and forms in cultural evolution processes. Apart from the sites in the Shijiahe period, which were clustered in the southern margin of the basin, the sites of the Yangshao, Qujialing and Longshan periods were settled in northern highland areas with an elevation of 100-200 m. Impetus of inter-cultural rivalry derived from the rise and fall of various primitive agriculture. Therefore, the dry farming climax corresponded with southward expansion of the northern cultures (i.e. the Yangshao and Longshan cultures), and the rice-farming boom years consisted with the period of northward advance of the southern cultures (i.e. the Qujialing and Shijiahe cultures). In time sequence, the subsistence model of the study area experienced three stages: (i) collecting-hunting in the early Yangshao period; (ii) millet-farming in the middle and late Yangshao period and (iii) millet-rice mixed farming in the Qujialing and Shijiahe periods. In the transformation process, it was by advance of production instruments, handicraft industry and animal husbandry that the cultures could make great leaps. Besides, variable footprints of cultural fronts for the northern and southern types demonstrated complicated landscape of prehistoric cultures, and reflected mutual relationships between cultural evolution and environmental changes.

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    Paper writing related to the interactions of geographical factors
    Shujin HE, Xin ZHAO, Lufeng YAO
    2015, 70 (1):  157-166.  doi: 10.11821/dlxb201501013
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    The main types of studies on the interactions of geographical factors include: the impact of multi-factor on single factor, the influence of single factor on single factor and the effect of single factor on multi-factor. Geographical writing on interactions of elements should focus on data selection, reliability verification, mechanism analysis, process analysis, environmental background, influence extent, regional differences, and time difference. The methods commonly used in this type of studies are curve analysis, map-related analysis, table-related analysis.

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