Table of Content

    20 November 2014, Volume 69 Issue 11 Previous Issue    Next Issue
    Orginal Article
    Influences of shrubs-herbs-arbor vegetation coverage on the runoff based on the remote sensing data in Loess Plateau
    Xiaoyan LIU, Changming LIU, Shengtian YANG, Shuangyan JIN, Yajun GAO, Yunfei GAO
    2014, 69 (11):  1595-1603.  doi: 10.11821/dlxb201411001
    Abstract ( )   HTML ( )   PDF (6027KB) ( )   Save

    The impact of vegetation coverage on flood or runoff yield in the Loess Plateau has been extensively studied, but the research has been primarily based on observations from slope runoff plots or secondary forest regions. This paper is based on vegetation information from remote sensing images, measured rainfall and runoff data and water consumed from the related basin in Loess Plateau over nearly 50 years. By introducing the concepts of runoff yield coefficient, flood yield coefficient, base flow yield coefficient, and the percentage of effective vegetation, we proposed the quantitative relation between vegetation coverage extracted from remote sensing images and runoff yield at the watershed scale. The response relations reveal that the runoff yield and flood volume will decrease with the increase of shrubs-herbs-arbor vegetation, especially in the dryer region, and the reduction of the runoff in sand-covered loess region is even more than that in the loess region with similar climate. But the flood volume will be kept at a stable level, when the percentage of effective vegetation is larger than 60%. The river's runoff will be stable at a threshold, which is more than its base-flow at last, with a further increase of vegetation.

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    Summary of the paleodrainage pattern changes in the Northeast China Plain and its neighboring areas
    Shanwen QIU, Xikui WANG, A.N. MAKHINOV, Baixing YAN, Yi LIAN, Jinhua ZHU, Fengli ZHANG, Zhenqing ZHANG
    2014, 69 (11):  1604-1614.  doi: 10.11821/dlxb201411002
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    The evolutions of Quaternary drainage pattern in the Northeast China Plain are discussed in the paper. According to analytical results of core samples, we found that during Paleogene and Neogene periods there was a large paleolake in Dalianhe-Xiangshun region that deposited more than 700 m of lacustrine-aluvial coal-bearing fragmental rocks, and proved that the upper Songhua River and the Mudan River flowed into the large paleolake at that time. Because of the rising of Yitong-Yilan rift, the lower Songhua River eroded headwards and captured upper Songhua River and Mudan River; for this reason, we believe, that the Songhua River and Mudan River had never been able to flow westwards to the Songnen Plain. The capture river systems of the Songhua River and Heilong River were formed between the end of Pliocene and beginning of the Early Pleistocene. After that period, another large paleolake was formed in the western Northeast China Plain during the Early and Middle Pleistocene, thus the surrounding rivers to flow into the paleolake to form a centripetal drainage.

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    The synchronicity and difference in the change of suspended sediment concentration in the Yangtze River Estuary
    Yunping YANG, Mingjin ZHANG, Jinyun DENG, Yitian LI, Yongyang FAN
    2014, 69 (11):  1615-1627.  doi: 10.11821/dlxb201411003
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    The sediment discharge from the Yangtze River Basin has a stepwise decreasing trend in recent years. The impounding of the Three Gorges Reservoir exacerbated this decreasing trend and affected the change of the suspended sediment concentration (SSC) in the Yangtze River Estuary through the transmission effect. The SSC data of the Yangtze River Estuary during 1959-2012 showed that: (1) The SSC in the South Branch of the Yangtze River in the estuary and in the off-shore sea area displayed decreasing trends and decreased less towards the sea. At the same time, the difference in decreasing magnitude between SSC and sediment discharge became bigger towards the sea; (2) For the North Branch the preferential flow did not change much but the SSC tended to decrease, which was mainly caused by the decrease of SSC in the south branch and East China Sea; (3) Due to the decreased runoff and the relatively strengthened tide, the peak area of the SSC in the bar shoal section in 2003-2012 moved inward for about 1/6 longitude unit compared with that in 1984-2002, and the inward-moving distance was in the order of flood season > annual average > dry season; (4) In the inlet of the South Passage, the SSC decreased mainly because the increase caused by resuspension and shore-groove exchange was less than the decrease caused by the sharp SSC decrease in the basin and the sea areas. The reverse was true in the middle section, where the SSC showed an increasing trend. (5) In the inlet of the North Passage, under the combined influence of decreased flow split and sediment split ratios, decreased SSC in the basin and the sea area and decreased amount of resuspension, the SSC displayed a decreasing trend. In the middle section, because the increased amount caused by sediment going over the dyke was more significant than the decreased amount caused by external environments, the SSC tended to increase. Holistically, the sharp decrease in sediment discharge caused synchronized SSC decreases in the Yangtze River Estuary. But there were still areas where the SSC displayed increasing trends, indicating synchronicity and difference in the response of SSC to the sharp decrease in sediment discharge from the basin.

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    Research framework of ecosystem services geography from spatial and regional perspectives
    Shuangcheng LI, Jue WANG, Wenbo ZHU, Jin ZHANG, Ya LIU, Yang GAO, Yang WANG, Yan LI
    2014, 69 (11):  1628-1639.  doi: 10.11821/dlxb201411004
    Abstract ( )   HTML ( )   PDF (783KB) ( )   Save

    The research on ecosystem services has become a hotspot in ecology, geography and other related disciplines at home and abroad. Through reviewing the history of ecosystem service study, it can be found that the research has been gradually transformed from rational paradigm to regional paradigm, and from natural science paradigm to integrated paradigm between natural science and social science. It was characterized by increasing attention to spatiotemporal heterogeneity, spatial flow ability and regional features, and links between ecosystem services and human welfare. Almost all the subdisciplines of geography can find their own research themes in the cascade framework of ecosystem structure and function-service-human benefits and welfare. Due to more participation in the study area of ecosystem services, the geography of ecosystem services which is being constructed as a new branch of geography, not only plays a more important role in the research of ecosystem services, but also can extend the study scope of geography. Based on reviewing the historical process and development trend of the ecosystem service research, the logical necessity, opportunities and challenges of geography in ecosystem services research were analyzed in this paper. To promote the transform of ecosystem service research into geographical context, we proposed that the geography of ecosystem service should be established and well defined as an independent branch of geography. Moreover, a preliminary framework of geography of ecosystem service was described, including the definition, research scope and contents, and the subject position in geography.

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    Disturbance impacts of land use change on biodiversity conservation priority areas across China during 1990-2010
    Guosong ZHAO, Jiyuan LIU, Wenhui KUANG, Zhiyun OUYANG
    2014, 69 (11):  1640-1650.  doi: 10.11821/dlxb201411005
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    Considering the impacts of land use change on biodiversity conservation services of varied ecosystems, the Ecosystem Comprehensive Anthropogenic Disturbance Index (ECADI) is built to assess disturbance impacts of land use change during 1990-2010 on biodiversity conservation priority areas of China at national and regional scales. Four levels of biodiversity conservation areas are categorized: generally important areas, moderately important areas, important areas, and very important areas. Results showed that: In 2010, the ECADI value is higher in Central and Eastern China than that in Western China, and the values of the moderate important, important and very important regions are lower than the average value of the whole country at all levels. Notably, in recent 20 years, the change extent of ECADI in Central and Eastern China was much greater compared with that in Western China, and the change extent of ECADI in the moderately important, important and very important biodiversity conservation regions all showed slightly increasing trends, with the increasing degree lower than that of whole China at all levels. Due to human activities such as urbanization in Eastern China and cropland reclamation in Northeast China and Xinjiang, ECADI value in the moderately important, important and very important biodiversity conservation areas showed an increasing trend, which should be given more attention. However, ECADI value in the Loess Plateau presented a decreasing trend because of the obvious effectiveness of Green for Grain Project. Furthermore, the variation was negligible in the Tibetan Plateau.

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    Topsoil organic carbon storage and its changes in Inner Mongolia grassland from the 1980s to 2010s
    Erfu DAI, Ruixue ZHAI, Quansheng GE, Xiuqin WU
    2014, 69 (11):  1651-1660.  doi: 10.11821/dlxb201411006
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    Soil carbon sequestration and potential has been a focal issue in global carbon research. Under the background of global change, the estimation of the extent well as its change of soil organic carbon (SOC) storage is of great importance. Based on soil data from the second soil survey of China and field survey during 2011-2012, this paper studied spatial distribution and changes of topsoil (0-20 cm) organic carbon storage in Inner Mongolia grassland between the 1980s and 2010s, by using the regression relation between soil data and remote sensing data. The results showed that (1) the SOC storage values in Inner Mongolia grassland in the 1980s and 2010s were estimated to be 2.05 and 2.17 Pg C, with an average density of 3.48 and 3.69 kg C·m-2, respectively. The SOC storage was mainly distributed in the typical steppe and meadow steppe, which accounted for over 98% of the total. The spatial distribution showed a decrease trend from the meadow steppe, typical steppe to the desert steppe, corresponding to the temperature and precipitation gradient. (2) SOC variations during 1982-2012 were estimated to be 0.12 Pg C, at 7.00 g C·m-2·yr-1, which did not show a significant change. This indicates that SOC storage in grassland ecosystem of Inner Mongolia remained relatively stable over this period. However, topsoil organic carbon of different grassland ecosystems showed different trends of carbon source/sink during the past three decades. Meadow steppe and typical steppe, as a carbon sink, had sequestered at 0.15 and 0.03 Pg C, respectively, while desert steppe, as a carbon source, had lost 0.06 Pg C. It is concluded that SOC storage in grassland ecosystem may respond differently to climate change, which is related to vegetation type, regional climate type and grazing intensity. These results will provide references for decision makers to find proper resolutions to protect grassland soil resource.

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    Spatial-temporal distribution of δD in atmospheric water vapor by using TES retrievals over middle to low latitudes in Asia
    HUANG Yimin, SUN Jia, HUANG Yibin, ZHANG Xinping
    2014, 69 (11):  1661-1672.  doi: 10.11821/dlxb201411007
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    SSpatial-temporal distribution of water vapor δD, the correlations between water vapor δD and temperature, water vapor amount, and the relationship of water vapor δD with precipitation δD at mid-latitude to low latitudes over Asia are studied by using daily retrievals of H2O, HDO, temperature from TES on NASA's Aura spacecraft and data from GNIP. In terms of the spatial distribution, both precipitation and water vapor δD decrease with the increasing latitude, and there are two regions with the highest δD values over low latitudes, one in the east of Pacific warm pool and the other in western Asia, while there are two regions with the lowest δD values over the mid latitudes (i.e., the Tibetan Plateau and the western Pacific). As for the seasonality, water vapor δD is low in the cool season and high in the warm season. This periodical change is significant over the continent but insignificant over the ocean. The highest δD values occur in summer over mid-latitude continent, while the highest δD values comes out before the monsoon season over low-latitude continent (i.e., the India Peninsula and the Indo-China Peninsula). Referring to the correlations of water vapor δD with temperature and the amount of water vapor, both temperature and the amount of water vapor show positive correlations over the mid-latitude continent and the West Asia, while the Pacific warm pool shows positive and negative correlations for temperature and amount of water vapor with water vapor δD, respectively.
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    Orginal Article
    Research on ecological effects of urban land policy based on DLS model: A case study on Shenzhen City
    Jiansheng WU, Zhe FENG, Yang GAO, Jian PENG
    2014, 69 (11):  1673-1682.  doi: 10.11821/dlxb201411008
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    Urban land ecological policy is an important management tool to enhance ecological construction and urban sustainable development. In this paper, Shenzhen was chosen as a typical case of rapid urbanization areas. A combination of land-use change and ecological effect quality models was used to evaluate the effects of two types of urban land-use policies, scale-control policy and space-control policy. The results showed that: (1) During the urbanization process, habitat fragmentation, connectivity decreasing and degradation are resources of ecological risks, which can be alleviated by the implementation of ecological policy. (2) Scale-control policy can enhance landscape connectivity and curb the trends of landscape fragmentation and habitat degradation, but it may result in an increase of the intensity of construction. (3) Space-control policy can maintain ecological land pattern, and curb the trends of landscape fragmentation and habitat quality decline, but it can play a limited role in maintaining the landscape connectivity. (4) The synergistic effect of simultaneously implementing the two policies results in better effects than separately implementing them.

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    Erosion-accretion changes and controlled factors of the submerged delta in the Yangtze Estuary in 1982-2010
    Chengcheng SONG, Jun WANG
    2014, 69 (11):  1683-1696.  doi: 10.11821/dlxb201411009
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    This research analyzed the general erosion-deposition characteristics of submerged delta front, the spatio-temporal changing pattern in different sub-regions, the geomorphological changes in the typical cross-sections, and the geomorphological evolution and corresponding controlled factors of the four important sub-regions (i.e., the eastern tidal wetland of Chongming-CM, the Hengsha shoal-HS, the Jiuduansha wetland-JDS, and the eastern tidal wetland of Nanhui-NH). Data sources include high-resolution DEM, sediment load data at Datong Station, and corresponding estuary construction information. Major findings are: (1) in general, the study area was slightly eroded (51.83% vs. 48.17%) in the past 30 years; specifically, it experienced an "erosion-deposition-erosion" pattern in the three periods; the geomorphological change was significant both spatially and temporally in the eight sub-regions, with an exception of the North Channel staying eroded; (2) the eastern and northern parts of CM and HS, the northern part of JDS, and the region within the 5m-isobath of NH were mainly dominated by the vertical deposition, while an opposite trend in southern CM and HS, and the region within the 5m-isobath of eastern and southern JDS; (3) on the whole, the envelop areas of 2 m and 5 m isobaths of the four important sub-regions kept increasing, and the average annual growth rates reached 10.42 km2/a and 7.99 km2/a respectively in the period of 1982-2010 (however, four sub-regions exhibited disagreements); the envelop area of 10m-isobath decreased in the whole region as well as sub-regions; the envelop area of 15m-isobath changed slightly during the period and remained stable; (4) influenced by the estuarine engineering, CM was the only station whose isobaths envelop area decreased, in accordance with the decline of the sediment load at Datong Station. Major conclusions are that estuarine engineering plays an increasingly important role in affecting the geomorphological change in the submerged delta under the macro-background of the reduction of sediment load, in terms of change in the envelop areas and the distribution of isobaths in the Submerged Delta. Along with the accelerating construction of Shanghai International Shipping Centre and reclamation engineering, the geomorphological evolution of submerged delta will become more complex and thus deserves frequent monitoring in the future.

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    Degradation of Wuchang Lake wetland and its causes during 1980-2010
    Baohua ZHOU, Jian YIN, Baoshi JIN, Lei ZHU
    2014, 69 (11):  1697-1706.  doi: 10.11821/dlxb201411010
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    The lake-wetland ecological system is sensitive to climate change and human activities. This study investigated the ecological changes of Wuchang Lake wetland (located at the downstream of the Yangtze River) from 1980 to 2010, and the potential causes of wetland degradation. We first overviewed the landscape changes in the study area by analyzing the Landsat MSS/TM imageries; and then examined the dynamics of hydrometeorology during the study period. Based on the analysis of changes of landscape patterns and variations of hydrometeorological variables, the natural and anthropogenic causes of Wuchang Lake wetland ecosystem degradation were discussed and differentiated. Results show that over the past three decades the total area of Wuchang Lake has decreased by 40%. In particular, area of the Qingcao Lake at the downstream of the lake-wetland system has over 73%, from 52.76 km2 to 13.92 km2. The area of construction land, which manifests the human activity in the watershed, had increased significantly since the building of the Anjiu Road across the lake. The average annual temperature in the study area showed a significant increasing trend, while the annual rainfall and evapotranspiration were relatively stable with little variations. We concluded that the degradation of the Wuchang Lake wetland was accelerated mainly by constructions in the area and the increased temperature, while the annual rainfall and evapotranspiration had little influence.

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    The sedimentary characteristics of Buxi loess profile in Shandong Province and their paleoclimatic and palaeoenvironment significance
    Shujian XU, Xinchao DING, Zhichao NI
    2014, 69 (11):  1707-1717.  doi: 10.11821/dlxb201411011
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    Field work was carried out systematically on one loess section at Buxi of Zhangqiu in Shandong Province. Grain size, magnetic susceptibility and optically stimulated luminescence (OSL) dating of Buxi loess section were conducted. Results indicate that: (1) According to Sahu's discrimination formula, it is found that the main sedimentary deposits are formed in aeolian environment. By analyzing grain-size class vs. standard deviation values method, environment-sensitive size fractions of this section are 7.08-8.91 µm and 39.81-50.12 µm respectively; (2) Changes of magnetic susceptibility and percentages of different size fractions are correlated. In this section, the quality of low-frequency and high-frequency magnetic susceptibility changes in the range of: 32.38×10-8-138.46×10-8 m3 kg-1 and 30.62×10-8-123.31×10-8 m3 kg-1 (ranges from A to B). The change of magnetic susceptibility can reflect the palaeoclimate variation information to some extent; (3) The section is divided into three loess layers and three paleosol layers, which records the information of climatic change and environmental evolution over the last interglacial stage.

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    Hou Renzhi and the research of desert historical geography
    Bingcheng LI, Fuqiang JIA
    2014, 69 (11):  1718-1724.  doi: 10.11821/dlxb201411012
    Abstract ( )   HTML ( )   PDF (458KB) ( )   Save

    As the pioneer of the whole new science field research on desert historical geography, Professor Hou Renzhi conducted many surveys into desert areas. Based on the investigations, he made systematic research on the historical changes of the geographical environment and its evolution laws, and has achieved remarkable academic achievements on the theoretical accomplishment and practical exploration. His works not only reveal the influences of human activities on the geographical environment and its evolution law in desert areas, but also provide an important scientific basis and historical reference for the national sand-control, the production development and the economic construction in desert areas of northwest China. His academic thoughts and significant achievements deserve our reverence, inheritance and emulation. The first part of the paper mainly elucidates the process of desert investigation. Part 2 elaborates his theoretical achievements on historical geography of desert. Part 3 is a specific introduction to his practical results. The conclusion of Hou's research in this field is drawn in the last part.

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    Academic influence of China's geographical journals in SCIE
    Chunli ZHANG, Chunlei SHENG, Sixiu NI
    2014, 69 (11):  1725-1733.  doi: 10.11821/dlxb201411013
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    In order to explore the academic influence of geographical journals in China, this paper selects 17 journals related to Geography in science citation index expanded (SCIE) as research objects. We analyzed the variation of the main citation index including impact factor, total citations, source items, self citation based on JCR database reported by ISI from 2009 to 2013. Furthermore, we analyzed cited frequency of average article, highest citation frequency of single article, proportion of international article using analysis tools on web of science platform. The results show that: (1) generally, the impact factor showed an upward trend and there was a slight increase of academic impact of these journals during the five years. (2) J ENVIRON SCI-CHINA, SCI CHINA EARTH SCI, ACTA GEOL SIN-ENGL, ADV ATMOS SCI, PEDOSPHERE are the top five in the overall impact factor rankings, which are in line with the actual situation of China. (3) Most of the geographical journals had a low proportion of international articles, indicating the low level of internationalization. (4) The other citation indexes including impact factor, total citations, cited frequency of average article, highest citation frequency of single article keep low within the same subject category. Factors that affect academic influence of geographical journals were discussed, and some suggestions were put forward to promote the academic influence. On one hand, the journals should focus on high quality articles and knowledge innovation so as to improve the academic quality of journals based on a larger global scale; on the other hand, the sources of manuscripts, editing and distributing should be standardized to a higher international level.

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