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  • 2013 Volume 68 Issue 3
    Published: 20 March 2013
      
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  • Research on geomorphological regionalization of China
    LI Bingyuan, PAN Baotian, CHENG Weiming, HAN Jiafu, QI Deli, ZHU Che
    2013, 68(3): 291-306. https://doi.org/10.11821/xb201303001
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    According to research achievements of Chinese regional geomorphology over nearly 30 years, including landscape classification and landform mapping, this paper systematically discusses the specific steps and methods, principles and the standards for geomorphological regionalization. It is suggested that the basis and standard of geomorphological zoning at all levels not only include the similarities and differences of the combinations of geomorphology type together with the landform genesis, but also its dimension. Based on 1:4000 000 geomorphplogical map of China and the GIS technology, we made an analysis of reasons for the Chinese regional differentiation of the essential geomorphological types and their genesis and divided the whole China into six major geomorphological regions and 38 districts. Region I (eastern hilly plains) is located in the northern part of the low terrain unit of China, in which the largest plain areas of China are distributed. Plains and platforms are dominant and the fluvial accumulation landforms are well developed. This region includes seven districts. Region II (southwestern low-middle mountains) is located in the southern part of the low terrain unit of China, which is dominated by low-elevation hills and low- or middle-relief mountains with only 30% of its area occupied by plain and platforms. Fluvial geomorphologies are typical with a developed karst landform in Southwest China, which can be divided into five districts. Region III (central and northern middle mountains and plateau) is located in the northeastern part of the middle terrain unit of China, characterized by the plateau landform composed of the low- or middle-relief mountains, hills, platforms and plains. Loess landform is well developed. This region includes five districts. Region IV (northwestern middle and high mountains and basins) is located in the northwestern part of the middle terrain unit of China. It is composed of middle to high mountains interposed by flattened basins and is characterized by arid desert geomorphology, where mountains with basins are made up of plains, platforms and hills. This region can be divided into five districts. Region V (southwestern subalpine mountains) is located in the southern part of the middle terrain unit. With a typical karst landform, middle or high mountains with middle or high reliefs are widespread and are scattered by wide valley basins. This region includes five districts. Region VI (Tibetan Plateau) covers the high terrain unit of China. It is composed of plains and high mountains with elevations higher than 4000 m and 3/4 area of the region, and is characterized by glacier and periglacial landforms. This region can be divided into nine districts.
  • A primary study on scheme of soil and water conservation regionalization in China
    ZHAO Yan, WANG Zhiguo, SUN Baoping, ZHANG Chao, JI Qiang, FENG Lei, ZHAO Qiankun
    2013, 68(3): 307-317. https://doi.org/10.11821/xb201303002
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    Regionalization of soil and water conservation is the basis for the planning of soil and water conservation in China. It can provide scientific basis for constructing healthy ecological environments and regional management and development. It makes a brief review of related regionalization of study and makes clear the concept of regionalization of soil and water conservation. In this paper, based on synthetical analysis of the characteristics of ecological environments of China, the principles, indices and nomenclature of the regionalization of soil and water conservation are proposed. Through the construction of the regionalization of soil and water conservation collaboration platform and data reporting system, combined with the existing soil and water conservation research, this paper uses the top-down and bottom-up and the combination of qualitative and quantitative methods to build soil and water conservation regionalization preliminary scheme, with 8 regions, 41 subregions and 117 sections divided across the country.
  • Permafrost distribution modeling and depth estimation in the Western Qinghai-Tibet Plateau
    NAN Zhuotong, HUANG Peipei, ZHAO Lin
    2013, 68(3): 318-327. https://doi.org/10.11821/xb201303003
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    In this study, an extended surface frost number model (E-FROSTNUM) is applied to simulate the spatial distribution of permafrost in the study area combined with remotely sensed data and available field survey data from an ongoing project titled Permafrost Background Investigation over the Qinghai-Tibet Plateau. The distribution simulation is verified with the two typical areas investigated during the project. Moreover, a relationship between soil temperatures at a 10-m depth and topographic factors (latitude/longitude, elevation, aspect) and potential incoming solar radiation is found to be significant and applicable to estimate soil temperature at the 10-m depth in the study area. Based on this estimation, the permafrost depths are computed using a regressed relationship of 10 m soil temperature and permafrost bottom depth, derived from the west Kunlun borehole records. The study shows that 36.9% of the area is covered by permafrost and mainly distributed in the areas of Karakoram and western Kunlun Mountains in a range of 34°~36.5°N, and 57.5% covered by seasonally frozen soil, which includes the Tarim Basin and the area south of 34°N.
  • Evidences for the formation of the weathering pits and the stream potholes at Changle, Fujian Province of China
    WANG Wei, LIN Zhihai, LIU Zhipeng, HUANG Rihui, LIU Yun, LAI Yixun
    2013, 68(3): 328-342. https://doi.org/10.11821/xb201303004
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    In Sanxi river area of Changle of Fujian province, there are some pits developed in granitic rock on the top of mountains and the surface of river beds. Such pits known as mountain top glacial potholes or river valley glacial potholes have been considered to be typical glacial potholes, which were used to support the evidence that the Quaternary glacier has been extended to the area of Fujian Province, China. The field investigation for these pits we made in March 2011 shows that the pits are weathering pits or river potholes, instead of glacial potholes. In this paper, the origin and formation process, as well as the related influencing factors, of the weathering pits and the river potholes developed in this area were studied and compared from the aspects of geomorphology, sedimentology, petrochemistry and mineralogy. The studies show that the formation of the river potholes is due to the mechanical erosion of stream water while that of the weathering pits on the top of mountains has nothing to do with river water but is the water standing in rock surface depression that results in chemical weathering. The weathering pits may also be found in river valleys, but can be only developed in the positions where the river water could not be reached after a river incision. The potholes and the weathering pits are morphologically distinct with particles of different roundness and grain sizes, denoting the different formation processes generated by chemical weathering or mechanical erosion. The different CIA values and the different quartz to feldspar ratios between the particles in the weathering pits and the rock where the pits were formed could be used to indicate the results of chemical weathering and mineral differential weathering. The river potholes also have different CIA values or quartz to feldspar ratios between the particles and the rocks as the weathering pits, and then the value and the ratio could not be used to distinguish the potholes from the weathering pits. However, the river potholes have a chemical element migration between the rocks and the particles, which is very different from that of the weathering pits, reflecting the processes of the particle transportation by river water in the potholes and the chemical weathering in the weathering pits.
  • Coastal environment evolution record from Anshan coastal aeolian sand of Jinjiang, Fujian Province, based on the OSL dating
    HU Fangen, LI Zhizhong, JIN Jianhui, ZHAO Qian, ZHANG Hui, WANG Xianli, XIA Jing, CHEN Xiuling
    2013, 68(3): 343-356. https://doi.org/10.11821/xb201303005
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    Grain size characteristics of the coastal aeolian sand and their chronology potential could greatly improve the interpretation of past environmental changes and provide valuable information on the past aeolian activities. However, lacking of direct dating methods, domestic scholars mainly focus on the distribution, grain size characteristics and geomophogensis to the coastal aeolian sand research. In this paper, quartz single aliquot regenerative optically-stimulated luminescence (OSL) dating with high resolution sampling was firstly applied to coastal aeolian sand in China for the Anshan (SHA) section (24°36′32.7″ N, 118° 39′ 20.3″ E) near the Anshan archaeological site along the Jinjiang coast, southeast Fujian. Through grain-size analysis, we assume that the SHA section demonstrates typical coastal aeolian sand characteristics, and affected by the blowout and chemical weathering after coastal sand deposited, the grain size parameter and content of different sizes of fraction have a large change, the grain size become coarser, the sorting for worse. The OSL ages of the 11 samples range from 839±132a to 108±21a show that SHA section formed in nearly 1000 years, and three periods of coastal aeolian sand activity can be divided, AD1050-1300, AD1470-1600 and AD1720-1950 respectively. Especially during the little ice age (LIA), coastal aeolian sand activity is strong, the development of coastal dunes sand is prevailing, and the OSL age shows that the coastal aeolian sand deposition represents a multiphase and episodic feature. We discuss the main controls of coastal aeolian sand development in the research area based on the OSL chronology. Compared with East Asian monsoon change sequence and the history of typhoon landfalls in Fujian, the result shows that the main control is the intensity of East Asian winter monsoon, but not the precipitation, typhoon landfalls and sea level change. The phase of aeolian activity mainly corresponds to the stronger East Asian winter monsoon period, but over the last half-century, the weakened aeolian activity may be due to human activities on a large amount of mining sand beside a weakened winter monsoon.
  • Key indicators and the characteristics of trans-boundary water allocation based on international treaties
    FENG Yan, HE Daming, LI Yungang
    2013, 68(3): 357-364. https://doi.org/10.11821/xb201303006
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    Based on "International Freshwater Treaties Database" (1820-2007), the publications and reports on trans-boundary water utilization and management since 1999, in the paper, 28 indicators of water allocation involved in the 49 international treaties focusing on water volume signed in 1864-2002 are divided into 6 types, and the spatial and temporal distribution of the indicators are analyzed. The major results include: there are significant regional differences on the adoption of the indicators among 5 continents; the indicators adopted at rank first and second place in North America and Europe are "minimum water volume maintenance" and "mean annual runoff", but in Asia, Africa and South America, the ranking places of the above two indicators are reversed; the major adopted indicators in the international rivers with less water are "mean annual runoff" and "minimum water volume maintenance", the ones in the international rivers with more water are "minimum water volume maintenance" and "maximum water intake"; among the four periods of the international treaties development in 1820-2002, the trend of the numbers of the signed treaties is few-more-less-flat, the regional distribution of the treaties shifts mainly from North America and Europe to Asia and Africa; the major adopted indicators on water allocation are shifted from "minimum water volume maintenance" and "mean annual runoff" before 1945, to "minimum water volume maintenance" and "maximum water intake" in 1946-1971, then to "hydraulic project operation" and "mean annual runoff" in 1972-1991, and final to "minimum water volume maintenance" and "mean annual runoff" in 1992-2002.
  • Temporal and spatial distribution and its change trend of suspended sediment transport in the Nujiang River Basin
    LIU Xinyou, HE Daming
    2013, 68(3): 365-371. https://doi.org/10.11821/xb201303007
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    Based on the long record of daily suspended sediment transport and runoff at the five hydrological gauge stations in the Nujiang River Basin, using the Mann-Kendall test and R/S (Rescaled Range Analysis) methods, this paper analyzed the spatial and temporal distributions, the change trend of sediment transport and its relationship with runoff in the basin from 1956 to 2011. The results showed that: (1) The average sediment concentration and sediment transport modulus of the Nanting tributary was much greater than those in the mainstream, and the inter-annual coefficient of variation of suspended sediment transport rate decreased with the increase of its catchment area; (2) In the Nujiang mainstream, the suspended sediment transport rate at Mucheng station is smaller than that at Daojieba station in the upstream, indicating that a part of sediment deposition in the river bed with the decline of river gradient may be one of the reasons for this phenomenon; (3) The annual distribution of suspended sediment transport in the Nujiang River was very uneven, and its concentration in the mainstream was higher than that in the Nanting tributary at the month scale but lower at the daily scale; (4) The suspended sediment transport rate showed a significantly increasing trend both in the mainstream and the Nanting tributary, and their mutagenesis started respectively in 1987 and 1980; (5) The relationship between suspended sediment transport and runoff was not significant in the upstream of Nujiang River, but significant in the middle and lower mainstream and Nanting tributary.
  • Influence of vegetation restoration models on soil nutrient of coal gangue pile: A case study of No.1 Coal Gangue Pile in Hedong, Shanxi
    WANG Shangyi, SHI Ying, NIU Junjie, FAN Lanying
    2013, 68(3): 372-379. https://doi.org/10.11821/xb201303008
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    The soil nutrients and influencing factors of vegetation restoration in Hedong coal gangue pile were studied from 2009 to 2011. The results showed that species diversity, vegetation coverage and biomass in coal gangue pile increased with the time of vegetation restoration while ground temperature decreased significantly. Contents of available phosphorus and available potassium in soil reached the third level according to the national soil gradation, and contents of alkali-hydro nitrogen and organic matter were 11.94 mg kg-1 and 7.69 g kg-1, respectively. Model of Amorpha fruticosa helped to improve the content of available phosphorus while the content of alkali-hydro nitrogen was the most under Model of Amorpha fruticosa, Festuca elata and Medicago sativa and the improvement of available potassium and organic matters under Model of Festuca elata and Medicago sativa was the best. Slope degree and surface temperature had significantly negative correlation with soil nutrient; the average biomass and Festuca elata coverage influenced significantly the soil nutrient; Medicago sativa coverage had significantly positive correlation with alkali-hydro nitrogen, available potassium and organic matters. Combination model of herb, shrub and tree were used when the eco-environment condition improved after herb was planted in the early stage of vegetation restoration of coal gangue pile.
  • Human activities and environmental change in Holocene in the northeastern margin of Qinghai-Tibet Plateau: A case study of JXG2 relic site in Qinghai Lake
    HOU Guangliang, WEI Haicheng, E Chongyi, SUN Yongjuan
    2013, 68(3): 380-388. https://doi.org/10.11821/xb201303009
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    Jiangxigou archaeological site is located in northeastern margin of the Qinghai-Tibet Plateau (QTP). This section is an important Microlith relic site with consecutive strata. Here we present an integrated study on multi-proxy including human activities index (stone, animal bones and pottery shreds) and environmental index (magnetic susceptibility, color and pollen) of this section. The results show that the occurrence of Microlith has a close relationship with environmental change. In the Holocene, Microlith hunters lived in an Artemisia dominant environment. Before 9 ka BP, human activities initiated to appear on the QTP due to the increasing improvement of the early Holocene climate. After 9 ka BP, steppe vegetation was well developed under the optimal climate of this time, which supplied abundant foods for hunters, and thus promoting Microlith culture into the prosperous period. Since 6 ka BP, as the deterioration of the climate, the Microlith culture began to decay. Pollen analysis indicates that relatively high content of Poaceae and the attendent weedy plants might relate to the human activities. The proportion of Poaceae reached its highest level during 6.7-4 ka BP, which was corresponding to the stage when pottery shreds were widely used. We suggest that these facts would relate to the crop cultivation during this time. The occurrence of pottery shreds was probably associated with the farming activities of ancient people. Based on these records, we conclude that the culture in the northeastern margin of the QTP was Microlith culture before 6 ka BP and has changed since then. After 6 ka BP, the Microlith hunters lived at higher elevations of the plateau while the farmers occupied the valley regions at relatively low altitudes.
  • Spatial distribution of heavy metal concentrations and pollution assessment in the bed loads of the Lancang River System
    SONG Jingyi, FU Kaidao, SU Bin, HUANG Qisheng, Huang Jiangcheng, Zhang Jilai
    2013, 68(3): 389-397. https://doi.org/10.11821/xb201303010
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    Mining-induced heavy metal pollution in river system is one of the main environmental problems in the process of watershed development and resource utilization. This research investigated that the bed loads of the mainstream and its 11 tributaries in the Lancang River, aiming to examine the spatial distribution of heavy metal contents (Cu, As, Pb, Zn and Cr), as well as to assess the heavy metal contamination status with the methods of Single Factor Index and Potential Ecological Risk Index. The results are shown as follows: (1) Heavy metal contents in sediments present a decreasing trend from upstream to downstream of the Lancang River system, while the heavy metal contents contained in the tributaries' bed sands are distinctly different. (2) The results of Single Factor Index indicate that sands at the Jiuzhou are seriously contaminated by As and Pb due to their high regional geological background. The two tributaries, the Heihui and Mengjia rivers, have been heavily polluted by As and Cu respectively. Especially, the single factor indexes of Pb and As are the highest with massive pollution in the Bijiang River. The other sampling sites, except for a few heavy metal elements with moderate pollution, present a pollution-free status in the main stream and tributaries. (3) The results of Potential Ecological Risk Index suggest that potential ecological risk factors ( Eri ) of the mainstream at Jiuzhou with As and the Bijiang tributary with Pb are relatively high, while the values in the other samples are below 40, and risk indices for all the tributaries investigated are less than 150, so the potential ecological risk of heavy metals is significantly low. Thus this work devotes to inspect and evaluate the spatial distribution of heavy metals in the bed loads throughout the river system of the Lancang River, in association with analyses of the pollution sources of the main stream from tributaries. So our conclusions could provide a scientific reference for pollution control during the basin development.
  • Relationship between surface pollen assemblage and the vegetation in Luonan Basin, eastern Qinling Mountains, Central China
    ZHANG Wenchao, LI Chunhai, LU Huayu, TIAN Xianhua, ZHANG Hongyan, LEI Fang, TANG Lingyu
    2013, 68(3): 398-413. https://doi.org/10.11821/xb201303011
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    The catchment of South Luohe River in Central China is a major region for investigating modern pollen-environment relationship because it is an environment transitional zone which is sensitive to the climatic change. In this study, 40 surface sediment samples under 10 vegetation types in Luonan Basin, upper catchment of South Luohe River were taken to investigate the relationship between pollen assemblage and plant vegetation. The results show that the surface pollen compositions reflect the vegetation quite well, with unique features among different vegetation types. In the forest topsoils, the average of arboreal pollen percentage is greater than 40%, and the Selaginella sinensis spore content is higher. As to woodland shrubs and shrubs, the tree pollen average is 13.2% and 16.6% respectively, and the shrub pollen is higher than grass samples. And the grass and farmland topsoils are characterized by the low percentages of tree and shrub pollen (<10% and <1%), and high percentages of herb pollen (>80%). Pinus, Quercus and some other tree pollens can indicate the regional vegetation in terms of their dispersal ability. Quercus pollen is under-representative and so is to Pinus, which is quite different from general. Artemisia pollen is significantly over-represented, has poor correlation with plant coverage, and may reflect human disturbance. Gramineae can indicate plants quite well, but with low representation. High percentages of Chenopodiaceae component probably suggest human activities and predominant Selaginella sinensis may be a significant indication of forest environment. Cluster analysis (CA) and principal components analysis (PCA) can distinguish forest and non-forest vegetation well. The former one is better at separating pine and mixed forests, while the latter one at farmland and other non-forest and more stable than that of the cluster analysis. The first axis of PCA analysis is likely to mainly reflect the humidity. The average of surface pollen concentration in Luonan Basin is 1.42 × 105 grains/g. The pollen concentration does not correlate with vegetation coverage, but may help to distinguish vegetation types.
  • Impacts of climate changes on parameters of weather generator BCC/RCG-WG for daily non-precipitation variables simulation in China
    LIAO Yaoming, CHEN Deliang, XIE Yun
    2013, 68(3): 414-427. https://doi.org/10.11821/xb201303012
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    Parameters of daily non-precipitation variables including maximum temperature, minimum temperature and sunshine hours simulation at 699 stations in China of weather generator BCC/RCG-WG are estimated using historical daily records from 1951 to 1978 and from 1979 to 2007 respectively. The two sets of parameters for the two periods are compared to explore the impact of climate change on these parameters. The results show that the parameters of non-precipitation variables have experienced different changes, while the annual means and the amplitudes of the seasonal cycle show a significant change, and the interannual variability, seasonal timing and temporal correlations for each variable remain practically unchanged. This indicates that climate change in China in terms of these variables are mainly reflected in changes in the means and in the strength of the seasonal cycles. The changed parameters have implications for the stationarity assumption implied in the parameter estimation and use of the weather generator.