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  • Orginal Article
    Zhou-ying SONG, Wei-dong LIU
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    Information and communication technologies (ICT) is a major symbol of the contemporary world, which is predominated by two interwoven tendencies, namely globalization and informatization. It is now widely accepted that the world is moving fast towards an information age, while ICT is a major channel to such a historical transformation. Indeed, no technological progress in the last several decades can match the advent of ICT in terms of its profound and extensive influences. Since 1994, the development of ICT in China has been incredibly fast, but there has been “digital divide” between provinces. Indeed, there are huge digital-divide worldwide, which would impact economic spatial distribution. It is against such a background that this article takes a close examination on the development of informatization in China and its spatio-temporal pattern. Based on the literature review, principal components analysis and fuzzy analytic hierarchy process, it established ICT development index (IDI) and then calculated IDI and CV value, in order to provide a more comprehensive explanation of ICTs trends and developments. It also tried to gauge and justify the spatial implications of ICTs development, especially the relationship between informatization and economic development, by regression analysis. The findings of this study are follows. First, there are significant regional differences in informatization, and the development of ICT declines gradually from Eastern China to Western China. From 2000 to 2010, the development of ICT in Western China and Central China are much faster than Eastern China and Northeast China, while the regional digital gap is becoming smaller. Secondly, the difference of informatization among provinces is also very remarkable. The provincial spatial pattern of informatization has changed, with lessened digital divide in 2000-2010. Finally, at provincial scale, the spatial distribution of ICT has obviously positive correlation with local GDP development. From 2000 to 2010, with the evolution towards an informatization society, the relationship between informatization and economic development has been more and more related.

  • Orginal Article
    Chang-long SUN, Nuo JIN, Xiao-lei ZHANG, Hong-ru DU
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    Urbanization and carbon emissions have attracted intensively attention. This article analyzes the impacts of the urbanization on CO2 emissions in three aspects. Then the historical data of 76 countries (regions) (1980-2007) are employed by separating them into different categories according to urbanization levels to study the correlation between the stage of urbanization and the dynamic evolution of the CO2 emissions. The main impact factors on CO2 emissions during different stages of urbanization are evaluated based on the STIRPAT model. Finally, according to analysis results, combined with the characteristics of the various elements in the development stage of urbanization, this study explores the impacts of various stages of urbanization on CO2 emissions. The results showed that: the urbanization affects the CO2 emissions mainly through changing lifestyle, production and land use, which performances a driving and restricting role. In the early stage of urbanization, the driving and restricting effect of the CO2 emissions are not obvious, showing slow development in urban system and the slow growing carbon emissions rate; in the mid-stage, the driving role of urbanization on CO2 emissions becomes to be dominant, but the restricting effect is weaker, which is characterized by the acceleration development of urbanization system, the city development in numbers and scales, the accelerated industrialization process, and a rapid growth of CO2 emissions; in latter stage, the city enters a slow phase of development, urbanization on the driving role of CO2 emissions is still dominant, but the restricting effect is gradually enhancing. In this stage, the quality of urbanization continuously improves, and household consumption reaches a high level. Meanwhile, the phenomenon of suburban urbanization and counter urbanization appear, the tertiary industry takes up most part of industrial structure, technical level increases rapidly, CO2 emissions becomes slow, but the total emissions are still increasing. Therefore, the impact of urbanization on CO2 emissions is different in various urbanization stages. In response to CO2 emission reduction mandate in the context of global climate change, countries (regions) should reasonably guide the process of urbanization and enhance the restricting effect of urbanization.

  • Orginal Article
    Ying GE, Guo-hui ZHU, Ye WU
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    To modify the assumed homogenerous space in the urban system model as developed by Krugman (1993), this article uses the fuzzy set theroy, together with the analytic hierarchy process (AHP) approach, and constructs a series of geographic spaces with spatial heterogeneity based on the study case on Zhejiang Province, aimed at examining the importance of economic or geographic features as determinants of the size, number, and location of cities in this province. The simulation of the Krugman’s urban system model shows geographic features indeed play an important role in the simulated broad patterns in the spatial distribution of the Zhejiang’s cities, but the urban systems in the study area evolves primarly because of economic geography features, concisely speaking, the interaction between transport costs and plant-level scale economies. After controling for other parameters, this model might predict more cities in this study case when transportation costs are higher, a share of the manufacturing sector is lower, or the elasticity of substituion is higher. Moreover, in equilibrium, the predicted cities can be found to be located according to a spaital distribution of the hexagonal lattice with the realistic economic as well as geographical enviroments. If true geography is incorporated into the model, the assumed space offers better simulating environments, and, as a consequentce, will improve the proformance behavior of the Krugman’s urban system model. The simulated patterns of city distribution can be postulated by one variant of central place theory proposed by Water Christaller (1966). Furthermore, under the surroundings of dispersed scenarios of four weights, an initial advantage in geography over all regions comes into effect leading to a variety of spatial patterns of urban system simulation in this province. Among them, for the Zhejiang urban system as a whole, cities are distributed consistent fully with those observed when these locations have a certain advantage of economic geography over the others. This might suggest that economic geography effects may dominate dynamic process of urban system development over time across space implying that high market potential might be associated with the predicted cities in this study area.

  • Orginal Article
    Xiao-li JIANG, Ping-yu ZHANG
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    Following the acceleration of the economic globalization, marine transportation has become the main way of international goods trade. As a result, the port becomes an important influence factor of the economic development which causes more attention concern. In the study, the Huff model was employed to calculate the potential-energy value of the influence which the six ports along the Liaoning coast act on the hinterland city. Then, a quantitative estimate about the spatial evolution process of the port hinterland along the Liaoning coast was performed in 1995-2009. Finally, we qualitative analyzed the driving factors of spatial evolution of the port hinterland. The result showed that: 1) The spatial distribution of the port hinterland in the study area has changed a lot during the past 15 years and the study area has been changed from the single hinterland of Dalian port to a mixed-hinterland of several ports. The hinterland ever belonged to Dalian port along the traffic line between Harbin and Dalian has converted to the hinterland of Yingkou port which caused a decrease on the extent of hinterland in Dalian port and oppositely an increase on the extent of hinterland in Yingkou port. Some local ports (such as Jinzhou port and Dandong port) mainly serving for the surrounding hinterland cities has not experienced a significantly variation on the extent of hinterland. 2) Based on the calculation result of the Huff model, the influence potential-energy value of the six ports has also changed. According the potential-energy value, the influence of Dalian port on the study area decreased in the past years, especially the influence on Liaoning Province and surrounding areas which has experienced an obviously reduction. The Yingkou port has an increased influence along and both sides of the T-shaped traffic line, which make the Yingkou port a more and more important position among the six ports. The influence of Jinzhou port on its original hinterland has become more stable than past years. In addition, there is an expanding trend on the spatial extent of Jinzhou hinterland toward to the central parts of Liaoning Province which represents a rising influence force of Jinzhou port. The Dandong port also has an increased influence on the most parts of the study area, particularly on the middle and eastern area of Northeast China. Following the improving of port infrastructure construction, Dandong port has become a new thoroughfare to the Sea of Northeast China. 3) The influence factors of the hinterland spatial evolution are various and complex. According to the qualitative analysis of the driving factors which caused the spatial structure evolution of the port hinterland along the Liaoning coast, location conditions, transportation infrastructure conditions, the rising of urban influence force and the guidance of government policies are considered as the most important factors.

  • Orginal Article
    Guo-jun ZENG, Shu-zhi SUN, Hong ZHU, Bo LIU, Xiao-mei CAI
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    The globalization is far from the displace process. However, it is the process of redefination and production of locality. On the background of globalization, the frequent migration of people and businesses makes them exceed the established boundary, forming a more and more translocality. Recently, the locality and cultural production are gotten a lot of research interests of cultural geographers. However, many questions, such as ‘paradox of cultural preservation and innovation’ and the ‘dilemma of authenticity and standardization’ faced by translocal cultural production are unresolved by scholars. This article constructs a theoretical framework of restaurants' cultural production to discuss the categories and characteristics of translocal cultural production based on four cases of foreign restaurants in Canton. The theoretical analysis reveals that there are four different kinds of cultural production of translocal restaurants: standardization of authenticity, cultural production of authenticity, cultural production of standardization, and cultural production of Heterogeneity. And the results of case study illustrate that four kinds of cultural production can be accepted by the consumers of translocal restaurants. In virtue of disciplinary integration, the conbination of translocality and cultural production would provide chances for the development of translocal cultural production. And also, it is a new exploration of the food geography with the methodology of new culture geography. This article would promote the discipline development of cultural geography. In the meanwhile, it can provide a theoretical basis for the protection and innovation of food culture, as well as diffusion of food culture and identification of place image.?

  • Orginal Article
    Guang-liang HOU, Hai-cheng WEI, Chong-yi E, Xiao-hao ZHAO
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    Integrated the archaeological and DEM data in the eastern Qinghai Province, using a combination of the area archaeological site and burials to estimate the regional prehistoric population, and apply the GIS tools to rebuild the regional cultivated land area of ??the prehistoric period for time and space. The results showed that regional population and cultivated land increased rapidly during the Majiayao culture of Neolithic Period, and the population had reached the peak during the late Machang culture regional of Neolithic period,in which the population had totally risen up to about 40×103 and the size of farm land was expanded to ??462 km2. The population and the farm land were mainly distributed in the valley area of the Huanghe River-Huangshui River. The population and farm land were decreased significantly during the Qijia culture period, but it was rebounded obviously during the bronze age, in which total population increased to 61 000 and the farm land was expanded to 1 076 km2, about 1/10 of the total arable land area in the region. With the changes of population and farm land, the influence of human activities on the environment began to appear. In 5-4ka B.P., human activities lead to the reduction of the arbor in the study area, the increase of Androphile, especially Gramineae have sharply increased, as agriculture is closely related with the millet. After 4 ka B.P., a shape reduce of the arbor is due to the change of climate, while strengthening of human activities accelerated the shrinking arbor cover area.

  • Orginal Article
    Wen-jie LI, Tie-hong WU, Xiao-jia LI, Li-ge JIA
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    The article took the tourist area in Xilamuren grassland of Inner Mongolia as study area, with remote sensing images of 2000, 2004, 2007 and 2009 as information source using a 1:50 000 topographic map and 1:50 000 land use map as reference. Through remote sensing image interpretation combination of remote sensing images and ground surveys, the spatial database was established. Acquiring the changes of data related landscape pattern indices using RS, GIS and the landscape pattern analysis software, the dynamic change characteristics of landscape pattern in the last ten years were analyzed. The results show that, with time going, the whole landscape pattern of tourist area in the Xilamuren grassland has taken great changes. The number of patches, patch density, the index of fragmentation and corridor density index were increasing. The mean patch area, aggregation index, the ratio of the largest patch to the landscape area decreased. Although the grass area did not significantly reduce, landscape became more and more broken, the islanding phenomenon of grassland patch intensifies obviously under anthropogenic interference, and ecological environment became more vulnerable. From the changes of landscape constitute, its trend and level of variation among landscape type were different. Under the impact of drought climate, high coverage grassland area decreased in the study area, the middle and low coverage grassland area increased, and the water and wetland area reduced. The rapid growth of tourism land area and its great number of patches as well as intensive distribution directly result in grassland landscape fragmentation. Reasonable regulation of tourist disturbance is the most important task of protecting grassland ecological environment in the future. In this article the dynamic change of landscape pattern was analyzed using remote sensing, GIS and landscape ecology method joining the tourism interference factors, to provide some reference for the ecological environment protection of grassland tourist area.

  • Orginal Article
    Yan-jiao WANG, Fu-min REN, Feng YAN
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    Affected by global climate changes and human activities, regional continual high temperature event (RCHTE) shows new trends, such as increasing intensity, higher frequency and larger range. RCHTE is one of the most serious disasters in China which does great harm to production and living conditions of human beings. It is very necessary to carry out RCHTE study synthetically and identify its temporal and spatial characteristics in China. In this paper, 642 meteorological station data of China from 1961 to 2010 were used to calculate air temperature. Intensity, area and duration of temperature were adopted to identify RCHTE. Then single index and integrated index were established to show characteristics of RCHTE. Besides, typical RCHTE case was chosen to analyze and test the methodology of RCHTE identification. Test result showed that RCHTE identify method coupled with single and integrated index can identify RCHTE correctly and effectively. On the base of the method, temporal and spatial characteristics of RCHTE in China from 1961 to 2010 are analyzed and results show that: there are 291 times RCHTE occurred in the past 50 years, including extreme RCHTE 31 times, severe RCHTE 59 times, moderate RCHTE 113 times and weak RCHTE 88 times. Distribution of RCHTE in China show obvious spatial characteristic. Moreover, spatial distribution of the intensity and frequency of RCHTE shows a good consistency. Regions with higher intensity and frequency of RCHTE mainly lie in Northwest of China (including western Northwest China and western Inner Mongolia) and Southeast China (including southern Huanghuai, Jianghuai, Jianghan, Jiangnan and southern South China) while intensity and frequency of RCHTE in Northeast China and Southwest China are relatively lower. Temporal variations of RCHTE analyses show that RCHTE in China has obvious increasing trends over the past 50 years. The accumulation of intensity, frequency, duration and area indices of RCHTE are relatively higher in 1960s and 1970s, while the indices are lower in 1980s. Since the 1990s, the annual accumulations of each index increase significantly. Especially after 2000, RCHTE increases even more quickly. Trend and mutation test for each index of RCHTE by Mann-Kendall method show that intensity, frequency, area and duration indices of RCHTE all show slightly decreasing trends before the 1990s, but increase significantly after the 1990s with the global warming. Each index of RCHTE has mutation from the late 1990s to the early 21st century and the increase trend of RCHTE is more significant.

  • Orginal Article
    Zhao-feng WANG, Han YU
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    Spatial and temporal pattern of disparity of the regional tourist economy and regional response is a core content of tourism research. This article analyzes the disparity′s feature and mechanism of tourism economic development in southwest China, by indicators of standard deviation, coefficient of variation and primacy ratio based on statistic data of domestic tourism income and tourist passengers. The result indicates that it has an overally fast but not balanced development rate of domestic tourism industry in southwest China. An absolute gap in the region is rising more and more faster. Coefficient of variation is in fluctuation and being a drop trend. The five region have different response types in the same development stage with various features for each region. Meanwhile the responses of tourism income and tourist passengers is not the same too. Tourism resoures, eco-social development level and transport location are three most important factors inducing the above results. Finally, the article puts forward that the key of domestic tourism economy is to transform the mode from tourism resources dependent to tourism industry mode.

  • Orginal Article
    Yi ZHOU, Zhi-hao QIN, Gang BAO
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    Land surface temperature (LST) is a very important parameter controlling the energy and water balance between atmosphere and land surface. Since it is difficult to obtain such information from ground-based measurements, it appears to be very attractive by using satellite thermal infrared measurements to estimate LST since it can be used for estimating surface temperature at global or local scale. Moreover, the estimation of LST by using satellite remote sensing data is feasible. Cloud cover is a major obstacle to thermal infrared remote sensing applications and remote sensing quantitative retrieval of land surface temperature. Furthermore, cloud frequently exists in most time and covers roughly half the surface of the Earth even if the sky is clear. This is the case especially in some regions of high latitudes in the north hemisphere, e.g. the tropics are covered by cloud for about 60% of the time. Therefore, the influence of clouds on LST deserves more discussion and how to estimate LST of pixels covered by cloud on thermal remotely sensed imagery is one of the cutting-edge research problems. In this article, based on the theory of surface energy balance (SEB), three methods, which are spatial interpretation adjustment method, the adjustment method by correlations between LST and Vegetation Indices (VIs) and improved surface energy balance method, have been put forward for the estimation of LST when the sky is cloudy. Moreover, the lowland effect of LST spatial distribution under cloud cover and the method for the calculation of its intensity (denoted as SE) were also discussed. Generally speaking, when SE equals to 1, it means that SE reaches its maximum due to thick cloud cover .While SE equals to 0, it means that there is no lowland effect in clear sky. SE is strongly affected by the cloud and surface conditions. That is to say, SE is influenced greatly by cloud properties such as the time it appears and lasts, its shape, thickness and height and surface characteristics. In normal conditions, SE reaches the highest at the center of cloud cover, and the closer to the cloud cover margin, the less it is. Numerical simulation of the relationship between the intensity factors of the lowland effect and the image gray value, which is based on the SEB, is the key to the practice of the three methods of LST estimation under cloudy conditions.

  • Orginal Article
    Yuan-yuan GUO, Duo-wen MO, Long-jiang MAO, Wei-min GUO, Hai-bin GU
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    Based on detailed field survey, oxide contents analysis and optically stimulated luminescence (OSL) dating of the samples from the Yanbandang(YBD) profile in Liyang Plain, the geochemical characteristics of major elements, the weathering process and environmental change from late Pleistocene to mid-Holocene were discussed. The results showed that the content of oxide is mainly composed of SiO2, Al2O3 and TFe2O3 (Fe2O3+FeO) and their percentage are between 86% and 90.8%. Compared to the average upper continental crust composition, Na and Ca have been leached out strongly, while total Fe and Mn relatively enriched in the sediments of the YBD profile. The intensity of chemical weathering in the YBD sequence was significantly higher than that of loess and paleosol in Loess Plateau, slightly higher than Xiashu loess in Zhenjiang, almost equal to the Yucheng profile in Liyang Plain, but obviously lower than the red soil from Xuancheng profile in Anhui Province, which indicated a moderate chemical weathering intensity under warm and moist conditions. Changes of the Chemical Index of Alteration (CIA), the Eluvial Coefficient, the Coefficient of Weathering and Eluviations (BA), the Index of Compositional Variation (ICV) and the analysis of A-CN-K and A-CNK-FM ternary diagrams suggested palpable differences in weathering intensity of the strata. There are four stages of weathering process in the YBD profile: relatively stronger weathering, relatively weaker weathering, intensifying weathering, and relatively stronger weathering. The weathering intensity of the yellowish brown soil at the top and bottom of YBD profile were clearly higher than that of the black brown soil and the black soil. Since the chemical weathering intensity is sensitive to climate change, the geochemical parameters can be used to unravel the environmental change to some extent. The higher CIA value reveals that the climate is relatively warmer and wetter in the end of the MIS3a stage. It becomes cooler during the LGM, but gradually returns to be warm again in early-Holocene. The climate in the mid-Holocene was the warmest and most humid compared to the aforementioned periods.

  • Orginal Article
    Bin ZHANG, Xian-fang SONG, Dong-mei HAN, Zhan-rong GUO, Guo-qiang XIAO, Ji-long YANG
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    Analyzing the distribution map of seawater intrusion degree can increase the knowledge of seawater intrusion mechanism, which is not only the important reference for water supplies of production and daily life but also the core content of seawater intrusion survey and research. In this article, four effective indicators for seawater intrusion of Qinhuangdao Yangdai River Plain which is located in the northeast of Hebei Province were selected out according to the different hydrochemical characteristics of fresh groundwater, brackish groundwater and seawater using the method of mathematical statistics. And then, the background values and index system of those seawater intrusion indicators were built to carry on seawater intrusion degree evaluation work based on the approach of fuzzy synthetic evaluation and geographic information system. The research results can be showed as follows: The chloride ion (Cl-), electric conductivity (EC), total dissolved solids (TDS) and potential salinity are the optimal seawater intrusion indicators which can help to distinguish the intruded samples from all groundwater samples. The background value of study area for chloride ion concentration, EC, TDS and potential salinity are 83.06-243.8 mg/L,600-1 222 μs/cm,341.82-679.14 mg/L and 2.92-8.05 meq/L, respectively. The lower limit value of chloride ion concentration, EC, TDS and potential salinity are 250 mg/L, 1 250 μs/cm、700 mg/L and 8.5 meq/L, respectively, which can manifest the occurrence of seawater intrusion. The groundwater samples identified seawater intrusion degree as rank II and rank III , make up 74% of all samples , which reveals that seawater intrusion degree of study area generally belongs to the medium level. On the basis of the distribution map of seawater intrusion degree, the seawater intrusion degree of the alluvial aquifers around Pu River between the Yang River and Dai River is the highest.

  • Orginal Article
    Hua ZHOU, Fu-qiang LIAO, Ming-xing XU, Sheng-lu ZHOU, Shao-hua WU
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    The Neolithic Tenghualuo Site in Lianyungang, which belongs to Longshan period, is the first prehistory city of China with both inner and outer structure ever been discovered. According to the analysis on the heavy-metal accumulation and grain size of profile(L1) and agricultural production area profile(L2) in the city residential area, respectively, it was found that anthropogenic-related accumulation of heavy metals in soil already had occurred in Longshan period, but only appeared in the city residential area. Cu, Pb and Zn accumulated the most obvious, whose enrichment factor values are 1.91, 1.35 and 1.29 respectively. Compared with the discovery of bronze archaeology, it can be sure that Tenghualuo Site has been in Chalcolithic Age. Meanwhile, the research of soil grain size based on soil source components separation method revealed that the soil in residential area had relatively unique parent material because of city protection during 4 500-4 200 a B.P., large-scale or prolonged flooding events have occurred in agricultural production area during this period, by which the proportion of diluvium was 30%, and this may destroy agricultural production condition, and causes the heavy-metal accumulation decline, eventually lead to the entire civilization disappeared. The findings above show that although the city can protect original society, the changes of natural environment still have decisive influence on original agricultural production, which finally decided the vicissitude of prehistoric civilization.

  • Orginal Article
    Guo-jie HU, Lin ZHAO, Ren LI, Tong-hua WU, Yao XIAO, Ke-qin JIAO, Yong-ping QIAO, Yong-liang JIAO
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    To study the water-heat characteristics of soil in the active layer in high altitude permafrost regions and to examine the interaction between soil and moisture under freeze-thaw cycles, a physical process by the CoupModel was used to simulate the soil temperature and moisture in the active layer, using the meteorological, the soil thermal and the moisture data on different depths in the active layer at the Tanggula test site. Comparisons between simulated and monitored data in situ showed that: 1) for soil temperature in the active layer, the simulated results fit well with the monitored, and the determination coefficient (R2) is more than 0.94 with the mean value of 0.98 while mean square deviation is relatively small, implying the CoupModel could successfully simulate the soil temperatures. 2) For soil moisture, results generally reflect water content variation in the active layer with R2 ranging from 0.88 to 0.93, the mean is 0.90 and the mean square deviation is 4.24, indicating a bit poor accuracy compared to soil temperature. 3) As to the heat flux of soil within the depth of 0-20 cm, results simulated is consistent with the monitored. The simulation accuracy is improved with depths, which may be related to the depth from the natural ground surface. The frozen depth is about 3.0 m, which is close to the observed data. It is concluded that the CoupModel can be well applied to study soil water-heat characteristics of the active layer in permafrost regions with higher elevations in Qinghai-Tibet Plateau.

  • Orginal Article
    Rui-feng ZHAO, Li-hua ZHANG, Hai-li ZHAO, Peng-hui JIANG, Jian-zhen WANG
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    Wetland ecosystem plays an important role in global carbon budget. However, the soil organic carbon (SOC) storage of wetland has been studied poorly in arid region. The distribution of SOC and its influence factors at three types of wetland vegetation (high herb vegetation, lower herb vegetation and woody vegetation) were analyzed in the middle reaches of the Heihe River. The results showed that the SOC contents at 0-10 cm, 10-20 cm and 20-40 cm depths were in the order of high herb wetland vegetation > lower herb wetland vegetation > woody wetland vegetation. The differences in organic carbon content among the three types of wetland vegetation were significant at 0-10 cm and 10-20 cm depths of soil. The coefficient of variation of SOC was greatest in the lower herb wetland vegetation, and was least in the high herb wetland vegetation and secondary in the woody wetland vegetation. There was significant difference in SOC content between 0-10 cm and 20-40 cm depths of soil in the high herb wetland vegetation, difference was not significant in other two vegetation types. In accord with the distribution of SOC content, the soil carbon density in 0-40 cm depth was 7.33 kg/m2, 5.44 kg/m2 and 4.25 kg/m2 at high herb wetland vegetation, lower herb wetland vegetation and woody wetland vegetation, respectively. At high herb wetland vegetation and lower herb wetland vegetation, the SOC content decreased with soil depth and was more concentrated in the surface layer (0-10 cm) accounting for 32% and 31% of the total in 0-40 cm depth. While organic carbon content at the woody wetland vegetation was larger at the soil depth of 10-20 cm (accounting for 33% of the total in 0-40 cm depth). The SOC content was positively correlated with soil water content (p<0.01) and phosphorus (p<0.05), and negatively correlated with soil bulk density (p < 0.01) and pH (p<0.05). Moreover, SOC content in wetland vegetation had no obvious relationships with soil salinity and altitude. The difference in organic carbon among different soil types was not significant.

  • Orginal Article
    Xue-jiao WU, An-xin LU, Li-hong WANG, Hua-wei ZHANG
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    Albedo determines surface absorption capability for the solar radiation and impacts the surface radiation balance. The albedo on snow and ice is higher comparing other surfaces, and the absorption of energy from the sun is little on an ice or snow field. Monitoring and researching snow and ice albedo characteristics and variation are necessary to provide accurate data and the theoretical basis for hydrological process research of snow and ice. EOS-MODIS satellite data of snow albedo (MOD10A1 on Level3)were used in the article to analyze the regional and seasonal distribution of snow albedo, as well as the inter-annual trends in the source region of the Changjiang River from 2001 to 2010 using softwares such as ArcGIS and ENVI. Based on the meteorological data of 3 stations on the source region of the Changjiang River from 2000 to 2010, the basic features of temporal changes of temperature and precipitation were investigated. The results show that: 1) Snow albedo were different with space distribution in the snow season in the source region of the Yangtze River. The snow albedo was high on the northern source region of the Yangtze River and on the southwest of the source region of the Changjiang River with 0.67 to 0.91, respectively, whereas part of the east of the source region of the Changjiang River was low (0.15 to 0.48). The distribution of snow albedo closely related to spatial distribution of snow depth and effected by altitude. 2) The seasonal spatial distributions of snow albedo changed obviously in the source region of the Changjiang River. The snow albedo for the large proportion area of study area were 0.66-1, 0.4-0.57, 0-0.4 and 0.48-0.66 in winter, spring, summer, and autumn respectively. The variation of the seasonal snow albedo between spring and summer was the largest with difference of 0.3 to 0.5. In monthly scales, the mean snow albedo of the whole source region of the Changjiang River had the largest value in January (0.6), and the lower values in July (0.41) and August (0.42). 3) For the first decade in 21th century, mean annual snow albedo during the snow season had non-significant increasing trend in the most areas of the source region of the Changjiang River, whereas it increased significantly on the high altitude regions. The rate of regional snow albedo in the source region of the Changjiang River is 0.0002/a, but it was up to 0.0012/a on the glacier areas of the study area. There were statistical significantly positive correlations between snow albedo and snow cover and precipitation (snow fall) during the snow season. This suggests that snow albedo was sensitive to snow fall through the snow season. 4)The monthly snow albedo in summer on the source region of the Changjiang River showed a decreasing trend from 2000 to 2010, which is markedly affected by summer temperature, and there was a positive feedback relationship between them.

  • Orginal Article
    Zhong-ming GUO, Ning-lian WANG, Rui-juan MAO, Xiao-bo WU, Sheng WANG, Xi JIANG
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    The 500 m resolution Moderate Resolution Imaging Spectroradiometer (MODIS) L1B scenes over Qiyi glacier, Qilian Mountain is used to estimate the snow grain size. The retrieval is based on ratios of near-infrared albedo to visible albedo which predicts snow reflectance as a function of snowpack grain size and ice absorption. “Bow-tie” effects were removed by the ENVI software. Atmospheric effects are taken into account and corrected through the MODTRAN4+ model. By this approach snow optical grain size was determined by the volume-to-surface area ratio on account of non-oriented spheroids produce the same scattering results as spheres. The time series analysis of derived grain size shows a good sensitivity to snow melting and snow precipitation events. This inversion technique has been validated using a combination of ground-based grain size measurements derived from the handle lenses which measure the snow grain size over the top 1 cm layer. The retrievals correlate well with measurements when radii is in range of -0.1-1 mm, although retrieved optical snow grain size general is lower than physical measured grain size ,the model may be need about a factor of 1.1. As part of validation analysis for the Qiyi glacier, the retrieved snow grain size from MODIS over selected sites in the period of September 7-15 in 2011 was compared to the temperature measurement of the automatic weather station near the selected sites. The relationship between the measured snow grain size, simulated snow grain size and average temperature patterns suggests that rapid destructive metamorphism of the fresh snow occurred when temperatures were near 0℃, once temperatures were higher than 0℃ and kept for a long time, the snow particle size change was evident, snow particle size increased significantly, and vice versa. But in this prossess, snow particle size also existed evolution process of deformation; snow particle size and temperature showed significantly positive correlation. The future work is to study the better cloud mask algorithm to remove the cloud effects and build the long and continuous time series of the snow grain size.