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    Urban and Rural Studies
  • Urban and Rural Studies
    GU Chao-lin, PANG Hai-feng
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    During the past 50 years, profound changes took place in the field of spatial structure of Chinese urban system. This paper will focus on the spatial relations (including network relations and territorial relations) in the inner urban system, and classify the ranks of spatial combination areas of Chinese urban system with different values of Distance Friction Coefficients b. Concerning Chinese urban system, two major regions (1st grade urban system) and seven sub-regions (2nd grade urban system) have formed, the Southern Major Region centralized with Shanghai and the northern one with Beijing. The Southern Major Region consists of four 2nd grade regional urban systems including the Shanghai System (Shanghai, Jiangsu, Zhejiang, Anhui and Fujian), Wuhan System (Hunan, Hubei and Jiangxi), Guangzhou System (Guangdong, Guangxi and Hainan) and Chongqing System (Chongqing, Sichuan, Yunnan, Guizhou and Tibet). The Northern Major Region consists of three 2nd grade regional urban systems including the Beijing System (Beijing, Tianjin, Hebei, Henan, Shandong, Shanxi, Shaanxi and Mongolia), Shenyang-Harbin System (Liaoning, Jilin and Heilongjiang) and Lanzhou-Urumqi System (Gansu, Ningxia, Qinghai and Xinjiang). Besides, 64 local urban systems (3rd grade) have formed in the Chinese urban system, among which the 3rd Grade Shanghai System covers Wuxi, Ningbo, Hangzhou and Jinhua Systems, and the 3rd Grade Beijing System includes Beijing System and Datong System.

  • Urban and Rural Studies
    ZHU Chuan-geng, SUN Shan-shan, LI Zhi-jiang
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    The issue of population urbanization used to be a hot point in academic study, and the paper intends to discuss the problem in a new way. This paper makes a critical review about researches on the population urbanization in China since the 1990s, and then based on the data from the Fifth National Population Census in 2000 and correlative statistics, some influencing factors and spatial distribution of population urbanization are analyzed. Firstly, according to the data in China City Statistical Yearbook 2001, and using the software of Statistics Package for Social Science, the authors have conducted Factor Analysis and found out that there are four main factors having relations with the amount of urban population, including economic growth, social development, urban consumption and economic formations. Then the authors conducted Correlations Analysis and found out that economic growth, social development and urban consumption are notably relative to the size of urban population, and their relationship declines. Secondly, the data from the Fifth National Population Census in 2000, and using visualization technique of a group of geographic information system software, the authors found out that the spatial distribution of Chinese counties' population urbanization is of evident northeast-center-southwest triadic relations, and the spatial distribution of Chinese provinces' population urbanization divisions are of three clusters and three zones, which are the eastern cluster, the middle cluster, the northern cluster, the Beijing-Tianjin-Shanghai zone, and the Chongqing-Hubei zone, and the Xizang-Xinjiang zone. Thus the authors have actualized the regional planning of population urbanization in China. Finally, the authors discussed the academic and practical value of this article. On the one hand, it is an item of academic innovation. On the other hand, it can provide foundation of population policies in China and make contributions to economic and social development in China.The authors hope other experts can keep on studying the issue in new ways, and make more contributions to the development of the country.

  • Urban and Rural Studies
    XUE Jun-fei
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    The air transportation has become an important conveyance to carry passengers and cargos, and an important factor to influence the regional urban system. The status of a city in the global or national aviation network directly reflects the hierarchy of the city in the global or national urban system. The aviation network which is comprised of nodes (airports) and lines (airlines) represents the spatial accessibility of the cities, and intuitionisticly reflects the hierarchical structure and distribution pattern of the national urban system. This article collects the airline data which include 128 cities open to air traffic and 2083 airlines from China's 14 major airline companies. The correlation analysis proves that in the aviation network the number of urban airlines was positively correlative to the size of the urban population. On this basis, through the aviation network analysis based on the airline network map of Chinese cities, the article uses the methods of charts discriminance and the clustering analysis to classify all the 128 cities into four hierarchies. They are national central cities which include three cities, regional central cities which include seven cities, sub-regional central cities which include 31 cities and general local central cities which include 87 cities. Then,from a unique perspective of aviation network the article reveals the characteristics of the hierarchical structure and distribution pattern of Chinese urban system under the open conditions, including:1) the urban hierarchical system takes on a typical pyramidal structure, which means the higher the hierarchy of the cities in the system, the smaller the number of cities; 2) the administrative, economic and tourism factors affect the aviation network markedly, consequently affect the urban hierarchical system strongly; 3) the distribution of Chinese cities has obvious differences between east and west, which means the higher-hierarchical cities are mainly distribute in the east, and the aviation relation of the west cities is mostly eastward; 4)the three national central cities including Beijing, Shanghai and Guangzhou and the seven regional central cities including Shenzhen, Urumqi, Shenyang, Chengdu, Xi'an, Chongqing and Kunming constitute the foundamental framework of Chinese urban aviation network, and they are the core of the Chinese urban system. The lower hierarchical cities join in the national aviation network through connecting with the higher hierarchical cities, and in this way they become part of the Chinese urban system.

  • Urban and Rural Studies
    CHEN Xiu-ying, YE Hua
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    Market-communities are important power of urbanization. The formation and function of traditional special markets have changed greatly and the driving mechanisms to urbanization have also transformed. The study analyzed the new formation and new driving mechanisms to urbanization of special markets by observation and substantial evidence. The conclusions are as follows: First, the existence and development of special markets are the important ways of urbanization. Second, urbanization driven by special markets has four characteristics as community characters of spatial structure, special division of urban production, small and medium-sized cities as main parts of urbanization and rapid urbanization.Third, population and industrial agglomeration are the mechanisms of urbanization driven by market-communities and the forming of a spatial compound of market-communities-production communities-regional city systems is the way of urbanization driven by market-communities. Fourth, urbanization driven by market-communities has stage characteristics. We should combine isolated special markets into market-communities and promote single product markets to synthetical product markets because of the time limitation of traditional special markets. At the same time, we should implement and perfect the strategies of industries and commerce to promote the city construction.

  • Urban and Rural Studies
    LIU Yu, FENG Jian
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    There are great discrepancies in urbanization development among regions and provinces in China. It is the result of different natural resources, industrial structures, economic systems, regional development policies, globalization and other external environments. To some extent, the discrepancy is certain to exist. So what we should de concerned about is not the degree of discrepancy, but the characteristics and rationality of discrepancy. On the basis of this, we put forward general urbanization strategy according to local conditions. In general, coastal area and Northeast China take the lead during the course of urbanization while Central China and Western China lagging behind. Concretely, coastal area not only keeps a very high speed in the urbanization pace, but also has a perfect urban system and the much higher level of urban-rural integrity. Cultivating agglomerations and modern urban system is thus the main task for this area in the near future. Although in Northeast China, the proportion of urban population to the gross population is the highest, the quality of urbanization needs promoting in many aspects, especially in enhancing vigor of city development. Central China has a large number of rural population.Economic support should be strengthened by cultivating industrial system. At present, it is obvious that population should be drawn toward the largest cities. In fact, different scales of cities and towns should be developed to admit more and more residual labor forces that have been transferred from rural areas. Western China should lay emphasis on cities instead of towns because of their fragile environment. As in all, strategies for urban development must adequately embody great discrepancies among different regions.

  • Culture and Tourism
  • Culture and Tourism
    HUANG Zhen-fang, YUAN Lin-wang, YU Zhao-yuan, WU Jiang, ZHOU Nian-xing
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    The research of the spatio-temporal evolution discipline of tourist flow helped to reveal inter-functional course and mechanism in terms of each inner-element of tourism system, and also provided bases for tourism planning, product development, as well as marketing and tourism management. This paper adopted K-Means cluster to undertake spatio-temporal analysis of the number of tourists in Yancheng eco-tourism area for David's deer. The phrases and market division of tourist changes in eco-tourism area for David's deer were discussed from two scales, namely, inner-provincial and inter-provincial.The results showed that the tourist flow of the above-mentioned two scales could be divided into three stages between 1998 and 2005, and could be marked off four different types of customer market properly. Yancheng eco-tourism area for David's deer ought to ascertain its target market and the management strategy according to the spatio-temporal distribution characteristics of the tourist flow. The most important core tourist markets of this eco-tourism area were the fourth and the third kinds of customer market, namely, Yancheng and Nanjing city in Jiangsu Province. When it comes to domestic tourist market, the priority should be given to the fourth one—Jiangzhehu area—as the basic market to explore. Temporal characteristics of tourist flow in different stages indicated that the tourist market of Yancheng eco-tourism area for David's deer varied amid relative stability, and represented distinctive regional difference. Except effects of space distance and transportation, the diversification of tourist flow was closely related with economic development, tourist motivation and choice, as well as theme tourism activities and tourism promotion. The pressing task for eco-tourism area was how to protect its resources and environment. The increase of tourists couldn't be pursued simply. We should attach importance to the optimization of tourism market structure, and select tourist market that would be highly responsible for environmental protection in order to pursue connotative development. Owing to the trend that the tourist market concentrated on Jiangzhehu area, in short term we could give the priority to explore the above-mentioned market (especially the tourist market in southern Jiangsu and Shanghai), and provide tourism and service products to meet the demands of tourist market. However, in the long term, in the precondition of proper eco-resource and environmental protection, the tourist market should be exploited vigorously and the convergence of tourist market should be dispersed further though effective integration and deep exploration of eco-tourism products in Yancheng seashore to attract tourists with high quality on a larger scale. The research finding showed that K-Means cluster could indicate the detailed information of spatio-temporal evolution in terms of tourist market and could be regarded as an effective analysis method for the spatio-temporal distribution and evolution characteristics.

  • Culture and Tourism
    SUN Gen-nian, MA Li-jun
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    The 2008 Beijing Olympic Games is the first and large-scale celebration events that China undertakes since entering the new century; it will bring about gigantic influence on the Beijing's inbound and domestic tourism. Based on the theory of background trend line and a variety of survey data, the variation of tourists both at home and abroad and their distribution caused by Beijing Olympic Games in 2008 are forecasted. The results are as follows: ①Affected by the Olympic Games, Beijing’s international tourism will go to a super-normal increase time in the coming three years. Compared with background trend line, the statistic line will form a summit. The number of Beijing’s inbound tourists in 2007, 2008 and 2009 will reach 4.34 million respectively, 5.17 million and 4.65 million respectively. The net increase rates will reach 8%,25% and 10% compared with the number based on the background trend line.②Beijing’s domestic tourism will go to a super-normal increase time in the coming three years. The number of Beijing’s domestic tourists in 2007, 2008 and 2009 will reach 144.1 million, 173.84 million, and 162.85 million respectively. The net increase rates will reach 4%, 20% and 8% compared with the number based on the back ground trend line.③Affected by the Olympic Games, the time series variation of Beijing’s inbound and domestic tourism has a special lifestyle, it can be divided into three states of "pre-Olympic", "in Olympic" and "post-after Olympic", and separately named the breeding and generating state, the climax state and the weakening and smoothing state. Based on the monthly variation of tourists flow, tourism climate comfort, and the lifestyle of the Olympic Games, the tourists flow of each month in 2007, 2008 and 2009 is forecasted.④The Olympic Games and its facilities attract tourists both at home and abroad just like a magnetic field. Its attraction to tourists is inversely proportional to special distance and is directly proportional to the preference to physical training tourism of residents of a country or a region. Based on the survey data of tourist market in recent years, the tourist numbers of main markets both at home and abroad are forecasted. This provides a scientific basis for managing Beijing's tourism and admitting tourists during the Olympic Games.

  • Economy and Regional Development
  • Economy and Regional Development
    LIANG Jin-she
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    Whether some basic principles exist or not that could guide those who are engaged in studying economic geography is a major concern. The author of the paper holds a positive attitude and tries to conclude them as follows. The first is that people would be faced with making location choices, which implies that economic geographers must design possible selected places to reflect the cost of location decision-making. The second is that making location choices is spatial optimizations and competitions for space, which shows basic behavioral criterion of economic actor. Why would people like to select locations? The third gives an answer,that is, there are differences in space, which come from both the nature and the social-economic system. And the impacts of the latter may strengthen or weaken difference from the former. Two principles followed are that economic factors have different sensitivities to distance, and that economic systems have the substituting functions to adjust inputs for distance and for others, which voice the key points about effects of distance. The spatial market principle and spatial critical point principle, the sixth and the seventh, are related to the analytic methods in economic geography. The eighth is that local or regional competitiveness depends on its advantages of production and service cost and location advantage. The last is the location policy principle, which shows why and how to formulate regional policies. The author deems that the conclusion of nine principles helps the teachers and students to get a better understanding of the key points in economic geography for the teachers and students. And it is also in favor of establishing common language and building common acknowledged theories in the area of academic research of economic geography. In addition, in the area of applied research of economic geography, it is beneficial for researchers to find and choose important and essential economic geography variables.

  • Economy and Regional Development
    WANG Xin-sheng, YU Rui-lin, JIANG You-hua
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    In social and economic activities, people usually actualize their spatial activities on road networks. However, most research results were on the ideal condition that geographical space was a homogeneous one, and almost all spatial analysis methods are according to the metric of planar Euclidean distance, its drawback is quite obvious. This paper presents the principle and the constructing method of network Voronoi diagrams, and the application of ordinary Voronoi diagram and network Voronoi diagram to the delimitation of the market fields of 17 stores in Wuhan, Hubei Province, China. The main results are as follows: (1) The market fields in the inner city are quite small while the ones in the outer city are a little large. If the road density in a store trade region was low, its area would be small; conversely, provided the road density in a store trade region was high, its area would be quite large. (2) There is a more or less difference between the application results of the methods based on ordinary Voronoi diagram and network Voronoi diagram. If the road density of a region was high, the difference would be small; and vice versa, there was a great difference in a region with a low road density. This shows that the method of ordinary Voronoi diagram can be chosen as a substitute of network Voronoi diagram to define the market fields of a store system in case of a region with a high road density.

  • Economy and Regional Development
    MA Lin-bing, CAO Xiao-shu
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    An accessibility computing method based on grid partition and heuristic A * searching algorithms was put forward in the paper, which is used to research accessibility spatial distribution feature in the study area through computing each grid's accessibility. Traffic cost is an important element in accessibility computing. There are two approaches to stimulate grid traffic cost, one is approach of density of road network, and the other one is approach of relative spatial resistance for different land use status. The density of road network is anti-correlative with traffic cost. Land use has a close relationship with urban traffic, so grid relative traffic cost can be stimulated directly by integrating the two approaches, actual status of road and topological structure of road network was ignored. A computing formula of grid relative traffic cost was defined in the paper. The key point is how to compute traffic cost of grids path. Dijkstra algorithm makes sure to get the lowest traffic cost, but it must spend more searching space and time. Not only can A * algorithms improve searching efficiency, but also can add some heuristic searching information to make searching result more reasonable. The key of the searching process is the definition of heuristic evaluation function H, which is responsible for estimating traffic cost from intermediate grid to target grid. Usually, marching from one spot to another is constrained by two factors: distance and arrival angle. So Euclid distance and marching arrival angle are adopted to evaluate traffic cost. In application, in order to make computing result accorded with practice, more heuristic information can be imported into computing process. For verifying our research, a software package was developed with C# language under ArcEngine9 environment. A case study was implemented by using the package. Accessibility of business districts was selected as computing object in Guangzhou city. The computing result by using the method can provide a quantitative reference for urban planning of the city.

  • Geo-information Science
  • Geo-information Science
    YANG Cun-jian, ZHANG Guo, CHEN Jun, DENG Li-li, WANG Xiao-yan
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    It is of great importance to the study of the dynamic extension of a city and its peripheral towns for simulating, predicting, adjusting and controlling urban extension, and for rationally protecting the farmland and using land resources. The extension of Chengdu and its peripheral towns is studied here by using LANDSAT TM satellite images respectively acquired in 1987 and 2000. Firstly, The images are registered to the GIS data. Secondly, the Different Building Index(DBI) is formulated by LANDSAT TM7-TM4 on the basis of analyzing the remote sensing image mechanism of the cities and towns and their background, which reflects the situation of construction. The model of extracting Chengdu city and its peripheral towns from DBI image is formulated by the threshold method. The spatial data of Chengdu city and its peripheral towns for the two periods is extracted from the remote sensing images of the two periods by calculating DBI and applying the model. Thirdly, the sprawl data of Chengdu city and its peripheral towns are obtained by overlaying the spatial data of the two periods. Finally, the sprawl data of each analytical unit obtained by masking or overlaying the sprawl data with the administrative boundary, the third circular road and the highway around the city are analyzed. It is shown that the spatial data of the two periods can be effectively extracted by using DBI and the extraction model. The GIS technology is especially suitable for analyzing the sprawl of the city in each unit. The sprawl area in the highway around the city is about 11132 hm2, which is 1.3 times of its original area. The sprawl area in the third circular road is about 6546 hm2, which is 0.9 hm2 of its original area, and mainly occurrs in the western, northwestern and southwestern parts, and most of which are external extensions. Between the third circular road and the highway around the city, the sprawl mainly occurs in the northwestern and southwestern parts,expanding mainly along the road. The sprawl pattern is mainly caused by the construction of high technology area and the spatial difference of investment and residential environment. In the five districts, Wuhou district is of the highest sprawl, which is 2.5 times of its original area. The sprawl area is over two times of its original area for each peripheral town, which is higher than the sprawl multiples of the city.

  • Geo-information Science
    LIU Hai-jiang, CHAI Hui-xia, CHENG Wei-ming, ZHONG De-cai, ZHOU Cheng-hu
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    Aeolian landform, mainly distributed in northern China, has important impacts on regional ecological security and socioeconomic development. Although great successes were obtained in aeolian landform research in the past decades, timely monitoring of aeolian landform still need improvement because of its inconstant characteristics.In order to investigate recent situation of sandy deserts in China, an aeolian landform dataset was built by extracting landform information from Landsat 7 ETM imageries which were acquired in 2000. In the present study, we focused on aeolian landform in northern China, which is the main aeolian landform region of China, and analyzed characteristics of different sand dune types quantitatively. The results showed that: 1)Aeolian landform is distributed mainly in eight provinces. They are Xinjiang Uygur Autonomous Region, Inner Mongolia Autonomous Region, Qinghai Province, Ningxia Hui Autonomous Region, Gansu Province, Shaanxi Province, Jilin Province and Heilongjiang Province, among them Xinjiang and Inner Mongolia have the largest area and the richest diversity of aeolian landform. 2)As for the sand dune morphology diversity, sandy deserts in arid regions are much richer than in sandy lands of semi-arid regions. Among all landform types, some types are generally distributed in all aeolian regions, while some morphologic types are only limited in specific areas, resulting from actions of specific wind velocity, wind direction, vegetation coverage. 3)In consideration of dune activity, floating dunes are prevalent in deserts except the Gurbantuggut Desert and the Ulan Buh Desert which are mainly covered by inactive and semi-fixed dunes. In contrast with deserts, sandy lands are dominant by inactive dunes and semi-fixed dunes. This analysis summarized the recent situation of aeolian landform in northern China, and the dataset is important in aeolian landform periodical monitoring and morphologic evolution research.

  • Earth Surface Processes
  • Earth Surface Processes
    LIU Xi-qing, LIU Hong-bin
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    Islands play an important role in marine economic development,oceanic right ascription,and national defense. So,the study of the origin classification of islands is of not only theoretic significance,but is of also important applied value.Traditionally, islands are divided into continental island, oceanic island(volcanic island, coral island) and alluvial island in the ocean. This kind of classification can no longer adapt to match the new progress in the Earth Science today. According to plate tectonic theory and oceanic landforms system,the paper explains the origin of islands,and a new classification system of ocean island is proposed. We divide islands into geotectonic-geomorphic system island(continental terrace island,island of island arc,island of oceanic basin,mid-oceanic ridge island)and exoenetic force-geomorphic system island(sand island,coral island). At the same time,traditional classification is revised,and islands are divided into continental island,oceanic island(volcanic island and coral island),sand island and tectonic melange complex island. Classification Tectonic or deposition Type of islands (example) Endogenic system Continental terrace Coastal continental island( Newfoundland Is.)Swell symon continental I.(Taiwan Is.)Continental volcanic I.(Weizhou Is.) Island arc & edge oceanic basin Island arc continental island (Sumatera Is.)Island arc volcanic island(Kraktau volcano Is.)Subducting accretion island(Mentawai Is. Andaman Is.) Ocean basin & micro continental block Aseismic ridges volcanic island(Hawaii Is. Line Is.)Microplate islands(Greenland Is.)Oceanic volcanic island(Loyalty Is.) Mid-oceanic ridge Mid-oceanic ridge volcanic island (Iceland Is. Easter Is.)Structure fault island (Revillagigedo Is.) Exogenetic force-geomorphic system island Mud-sand deposition Estuary sand island (Chongming Is.)barrer island (Caofeidian Is. )erosion sand island(Dongsha Is. ) Biology deposition Coral island(Maldives Is.)

  • Earth Surface Processes
    REN Li-xiu, HE Yan, YANG Da-yuan
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    Poyang Lake, which lies to the east of Mount Lushan in Jiangxi, is the biggest fresh water lake in China. It is also one of the abandoned lakes of the Yangtze River. As it is in the eastern monsoon area, it has a line vision in winter and a vast expanse in summer. Large areas of sandy hills appear around the Poyang Lake and the riverside of the Yangtze Rriver in the Hukou-Pengze section. They are well sorted and always come to 40 to 140 m high, looking like a desert in East China. Lots of scientists have done research in these sandy hills since the mid-20th century. They started with the formation and evolution of these sandy hills, and some of them analyzed the ancient climate change by the magnetic properties of sand samples. Shaling sandy hill in Xingzi which lies on the west shore of Poyang Lake is one of those sandy hills. After field investigation and collection of 26 sandy sediment samples in March 2005, we used sifter and laser granularity to measure their grain size. We also use 14C dating and thermoluminescence dating for three samples. Based on the field investigation of the landform and physiognomy, we classified these sandy sediments in Xingzi into seven different kinds and four periods of aeolian sandy hills. Those four aeolian sandy hills periods are 95 kaB. P. Old Red Dune, 46 kaB. P. Red Dune, 27kaB. P.~15kaB. P. Yellow Dune and 250 years Modern Dune. The other three kinds of sediments are secondary deposit on valley bottom, wind-erosion residual deposit on the lake shore and loose aeolian sediments on the Yellow Dune surface. As the wind power is the main driver of sand, the grain size of these aeolian sediments can show the wind power for the time when they deposited. We compared the grain size of the sand samples and come to the conclusion that wind power in these four periods can be arranged by Yellow Dune, Modern Dune, Red Dune, and Old Red Dune in a descending order. By comparson of the sediment series with the deep-sea oxygen isotope curve change, the Old Red Dune period of Poyang Lake is in the late Wurm glaciation (MIS5b), Red Dune period is in the middle Wurm glaciation (MIS3), Yellow Dune is in the last glacial maximum (MIS2), and Modern Dune is in the Little Ice Age. This result accords with the research result of sandy hills of this area by other scientists and can be compared with the global change in stade since the last interglacial stage and show the change of winter monsoon in Poyang Lake area.

  • Earth Surface Processes
    ZHAO Rui-feng, CHEN Ya-ning, HONG Chuan-xun, LI Wei-hong, BAI Yun-gang
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    Soil properties are one of the regional variables with the properties of geological structure and the stochastics of statistics. Geostatistics, based on the regional variable theory, has been proved to be one of the most effective methods to analyze the spatial distribution and its variation law of soil properties. It is the foundation to well manage the soil and prevent the soil salinization for fully understanding the spatial distribution of soil salinity. In the present study, based on regionalized variable theory, the spatial variability of soil salinity in different soil layers were studied by means of GPS, GIS, semivariograms of geostatistics and Kriging method in Yuepuhu oasis to quantificationally analyze the spatial variation and patterns of soil salinity in the headstream area of the Tarim River, with the purpose of provideing the academic basis for the area partitioning, meliorating and utilizing salinized soil in arid oasis. In the study, 118 samples were chosen from four soil layers at depths of 0-30cm,30-60cm,60-100cm and 100-200cm.The results indicated that the salt contents in different soil layers were high with 17.44g/kg, 11.67g/kg, 9.10g/kg and 8.14g/kg in 0-30cm, 30-60cm, 60-100cm and 100-200cm, respectively. The semivariogram of soil salinity of the four depths was best described by the Exponential model, of which the 100-200cm layer was best fitted by the Spherical model. The ranges of spatial autocorrelation differ from each other among the different soil layers. From the surface to the deeper layer, the autocorrelation ranges of the soil salinity increased gradually with 56.40 km, 91.10 km, 114.10 km and 160.00 km, respectively. The analysis of spatial pattern of soil salinity indicated that high values of soil salinity were mainly distributed at the places that were under the intensive anthropogenic activities, near to the watershed or located at low-lying areas. In vertical direction, the salinity of surface soil was the highest and it decreased gradually with the increase of soil depth. In the study area, the spatial variations and patterns of soil salinity in oasis were restricted to both the structural factors and the non-structural factors. For the impact of structural factors on surface soil was relatively less, and that of non-structural factors, i.e. anthropogenic activities, was greater. Some structural factors, such as topography, soil matrix, superficial groundwater table and soil water content from headstreams, strengthened with the increase of soil depths, and the spatial variations of soil salinity increased.

  • Earth Surface Processes
    ZHANG Yong-guang, WU Yong-qiu, WANG Yan-zai, LIU Bao-yuan
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    Ephemeral gully erosion can be a major sediment source serving as main conduits to convey runoff and sediment from most farmland. Ephemeral gully erosion is similar to but differ from both rill and classical gully erosion.But ephemeral gully erosion is often overlooked, and it is also not estimated with rill-interrill erosion prediction models such as the Revised Universal Soil Loss Equation. Soil erosion is increasingly severe in Northeast China with black soils, in which ephemeral gully erosion is an important type of water erosion. However, the existing literature indicated that little research on ephemeral gully erosion has been done in this area.In this paper, ephemeral gully erosion was investigated in spring and summer of 2005 in black soil regions of two small catchments on Heshan Farm of Heilongjiang Province.The aim of the study was to present the characteristics of ephemeral gullies and their seasonal discrepancies and controlling factors. The results show that soil losses due to ephemeral gully erosion fluctuate along the slope, and the high erosivity belts alternate with the low belt.There are also great differences in the morphology, the erosion intensity and controlling factors of ephemeral gully erosion between spring and summer. Ephemeral gully erosion in spring is mainly resulted from snow storm and is significantly influenced by freeze-thaw and snowmelt runoff. Ephemeral gully erosion in spring is slightly severer than that in summer. Ephemeral gully erosion was caused by storm. Compared with that in spring, ephemeral gullies in summer were shorter and shallower, but wider due to the storm characterized by high intensity and low duration. Furthermore, the depth and distribution of ephemeral gully are significantly influenced by tillage practice and crop type, especially in summer.

  • Climate and Global Change
  • Climate and Global Change
    WANG She-jiao
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    Through overall reviewing and analyzing History Draft of Qing Dynasty, Actual Annals of Qing Dynasty, local chronicles and other historical books about Northwest China compiled in periods of the Qing Dynasty and the Republic of China, it is concluded that during the Qing Dynasty, there were 62 dust weather events confirmed from historical books about the study area.Through analyzing these 62 dust weather events, it is found that the occurrence of dust weather in Northwest China fluctuated obviously with time. From 1650 to 1710 and from 1810 to 1910, the dust weather occurred frequently but with less frequency from 1710 to 1810 in Northwest China.In terms of season, the dust weather mainly occurred in spring; and in terms of spatial distribution, there were four dust weather frequently occurred regions, including the Guanzhong Plain region, centered around Xi'an and Weinan, the Loess Plateau region Zhenyuan and Qingyang in eastern Gansu , the Hexi Corridor region, Centered around Zhongwei, Gulang, Yongdeng and Shandan, and the Loess Plateau region, Mizhi and Zichang in northern Shaanxi. The occurrence of dust weather in Northwest China during the Qing Dynasty was connected closely with temperature change, but insignificant with precipitation change.

  • Climate and Global Change
    LI Lin, WANG Zhen-yu, WANG Qing-chun, ZHU Xi-de
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    Based on the mathematical statistic method of correlation analysis, the impact of natural factors of climate and topography upon spatial-temporal distribution of seasonal tjale is analyzed, and the response of tjale to air temperature, precipitation and cloudiness is also simulated. The results show that the topography and climate factor have a significant influence on the distribution and evolution of seasonal tjale in Qinghai, the topographic factors include altitude, longitude, latitude, slope, direction of inclination and so on. Since atmosphere is most active and sensitive compared with the others in the climate system, the climate factor and its change have significant effect on the seasonal tjale, at the same time, in that the tjale's response upon the temperature variation is most sensitive, so it is considered that global warming is the primary factor to cause seasonal tjale degeneration. The variation of local climate effect of the increasing of heat island effect brought by the urbanization in Xining and the decreasing of water effect caused by the descending of water level in Qinghai lake intensify the response of seasonal tjale upon climate change to some extent, the seasonal tjale has an evident time-delay upon the response of the air temperature variation at dekad and month scale, while it is not so significant on the interannual scale. At the same time, the response of surface temperature upon the temperature change is delayed gradually with the depth increasing, it shows : more deeper, the delay effect is more obvious.

  • Climate and Global Change
    WANG Ling, ZHEN Lin, LIU Xue-lin, Ochirbat Batkhishig, WANG Qinxue
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    Mongolian Plateau Region is facing many problems in environment and sustainable development including land degradation, soil erosion, water pollution, solid and hazardous waste disposal, land use conflicts and desertification, which have led to social consequences such as urban unemployment and poverty. Those issues are very serious in central part of the region where population density is relatively high and intensive economic activities have caused several problems such as climate change. The central Mongolian Plateau Region covers seven provinces (municipalities) of Mongolia including Selenge, Darhan-Uul, Ulaanbaatar, Govisumber, Tov, Dundgovi and Dornogovi and four sub-provinces of Inner Mongolian Autonomous Region of China like Huhhot, Baotou, XilinGol, and Ulan Qab. The study aims at comparative analysis of climate changes, impacts on major economic activities and affecting factors in Mongolia and Inner Mongolia using temperature and precipitation data extending from 1940 to 2004 from six stations of Mongolia and 1951~2004 from six stations of Inner Mongolia of China. The results show that in comparison with temperature data in the 1960s, the average temperature has risen by 1.35℃ in the 1990s in Inner Mongolia of China, while it is 1.13℃ in Mongolia. In the period of 2000-2004, the average temperature increase was 1.89℃ in Inner Mongolia and 1.37℃ in Mongolia in comparison with the 1960s, showing a faster temperature increase in Inner Mongolia than that in Mongolia. Mutation test of the changing trend of temperature indicates that temperature mutation usually occurs in the areas with high latitude followed by those of low latitude, and big cities followed by small and medium-sized towns. However, significant change of precipitation was not observed, but periodic changes instead. For instance, duration of precipitation in Inner Mongolia is 2.8 years, while it is 4 and 8 years in Mongolia, and those results reach 95% level of correction test. The climate change has brought about significant impacts on agricultural production, livestock raising and environment, which have been considered as important components of sustainable development of the region in a long run. The results are significant for understanding interaction between climate change, impacts and driving factors, and identifying most important areas for policy intervention, and finally for sustainable use and management of fragile natural resources.

  • Environment and Ecology
  • Environment and Ecology
    ZHANG Li-ren
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    The inadequacy in understanding human behavior spatial characteristics is a main obstacle for studying the theories and practice of relationship between man and land in geography. This paper regards human behavioral humanities in influencing culture, customs and policy. factors as to correspond to order, making use of the time-space section analysis method to study the basic mindset of the spatial behavior chosen by flowing people in the Qing Dynasty in southern Shaanxi.The result shows that the human space choice behavior follows the close by principle in customs, rather than superior principle in geographic environment. The general trend of flowing people's behavior chosen is to seek unit time result maximization. The human spatial behavioral choice enhanced the exterior connection of the human behavioral result in different districts and the nature difference in grade and level, and indicated the defect of simple "man-land" cause and effect relation seeking only from the interior of a district or a certain kind of human behavior in a traditional way. Investigating mutually affected relations of the human environmental behavior from the point of view of system or a drainage basin is an important way to uuderstand and grasp the essence and the mechanism of man-land relations.

  • Environment and Ecology
    ZHU Guang-yao, ZHU Cheng, MA Chun-mei, WANG Ji-huai, KAN Xu-hang, MA Cai-xia
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    The stoneware excavated not only represent the Neolithic productive level but also indicate a relation between mankind and environment. Nevertheless, we did not give enough attention to them before. Because of the above reason, we discuss the relationship between human and environment from evolvement of stoneware excavated through the unearthed stoneware of the early Neolithic sites in Shuangdun and Yuchisi of the middle-reaches of the Huaihe River, supplemented with evidence of other relics, environmental magnetism and element geochemistry from the archaeological profiles as well. We found if the degree of productive contents would be reflected according to the quantity and the functional combination of stone implements, the order of Shuangdun Site in the early Neolithic age would be tree felling, hunting, cereal grinding, wooden tools processing and grain production, whereas, those of Yuchisi Site were grain production, hunting, wooden tools processing, tools grinding and tree felling. The unearthed stoneware shown that ancient people of Shuangdun Site used sling and other manifold hunting quomodo and got abundant meat during the Holocene Optimum. During the Yuchisi period, hunting level improved, but abrupt climate change and population boom led to the decrease of take.Seen from the wooden implements that the felled trees, during Shuangdun period, were rather small and combined in bundles, and people at that time knew little about the advantage of Maosun structure and built the sheds with sharpened roof. While during the Yuchisi period, the felled trees were relatively bulky and were used for buildings in Maosun structure. It is in the period that ancient people had more negative effects on the natural environment in the middle reaches of the Huaihe River. As far as the production instruments of agriculture were concerned, during Shuandun period, paddy planting appeared, but collection agriculture still occupied a greater proportion.Nevertheless, agriculture during the Yuchisi period was mainly planting complemented with collection agriculture when the unearthed stone implements were obviously related to types of farming and environmental evolution.

  • Environment and Ecology
    XIAO Xi-yuan, CHEN Tong-bin, LIAO Xiao-yong, WU Bin, YAN Xiu-lan, ZHAI Li-mei, XIE Hua, WANG Li-xia
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    Arsenic reserves, mineral resources distribution and arsenic mining induced environmental pollution in China were analyzed. The known arsenic reserves were 3977 kt, and preserved reserves were 2796 kt,of which 87.1% existed in paragenetic or associated ores up to the end of 2003. The total arsenic preserved reserves owned by the provinces including Guangxi, Yunnan and Hunan accounted for 58.0% of the country's total reserves. Moreover, the arsenic preserved reserves in Nandan County, Guangxi Province and Gejiu County, Yunnan province accounted for 17.0% and 10.2% of the total reserves in China, respectively. Large amount of arsenic had been released to the environment in the process of mining and utilizing ore deposits. Up to 2003, the mined amount of arsenic reached 1392 kt in China. The exploited quantity of arsenic in Guangxi, Yunnan and Hunan provinces was 733,342 and 153 kt, respectively, so the environmental arsenic pollution in those areas was at high risk. The amount of arsenic discharged in the form of mining tailings accounted for about 70% of the total mined. A lot of arsenic pollution events had shown that the arsenic sources released from mining, smelting, and processing threatened people's health through contaminated soils, foods and atmosphere. Furthermore, the arsenic calamities often took place in Southwest China where there were rich arsenic resources and intense mining activities.

  • Hydrology and Water Resources
  • Hydrology and Water Resources
    FENG Ping, LI Jian-zhu, XU Xian
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    In recent years, the water resources of Luanhe River Basin have changed significantly with a sharp decrease of runoff flowing into the Panjiakou Reservoir which may affect the water supply management of the water transfer project from Luanhe River into Tianjin city. So in this paper, auto-regressed method and moving average method were adopted to research the variation trend of the annual runoff reservoir inflow.The results show that the annual runoff presented a periodicity and a general decreasing trend on a long time series from 1956 to 2003, especially from the 1990s, the annual runoff decreased obviously. To seek the factors that affect the annual runoff, precipitation, water consumption and the underlying surface were analyzed. We found that the annual precipitation just changed slightly. Although the water consumption increases each year, it only occupies a small proportion of the runoff reduction. To quantify the impact of precipitation factor and human activity factor on runoff change, the method is derived based on the relationship between precipitation and runoff. We calculated the impacts of precipitation and non-precipitation factors on runoff change and found the contribution rate of non-precipitation is the main cause for runoff reduction, which means land cover change plays an important role in runoff reduction with a contribution rate to runoff change exceeding 70%. From the rainfall runoff correlation, the conclusion can be drawn that the runoff generation depth was lower after the 1980s than that before the 1980s under the same annual precipitation regime. It was also discovered that the decadal runoff change was affected greatly by the precipitation amount, but as to the general decreasing trend the precipitation's contribution is only about 7%; and the increasing water consumption is not the main influencing factor to the decadal mutative runoff but to the general decreasing trend its contribution is about 23%. The evapotransporation is a fuzzy factor influencing the runoff. The observed pan evaporation can not represent the actual evapotransporation, so it must be studied further. The results will have some reference values to the programming of Luanhe River Basin and the utilization of water resource transferred from Luanhe River.

  • Hydrology and Water Resources
    JIANG Shi-zhong
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    The paper puts forward an analytical method of part time period to predict and analyze the long time series variation trend, and analyzes and predicts the multi-time scale variation features of natural runoff as well as the future variation trend, based on long time series data measured with instruments about the long time series runoff volume from the headwaters of the Yellow River in the Dari to Maqu section during 1956-2000, through field tests. The study area, located in the northeast of the Qinghai-Tibet Plateau and being one of the most sensitive areas to global climate change, is an important water conservation area in the upper Yellow River. With sustainable development of the regional economy the requirement for the exploreation of the river's hydrologic features in the study area is becoming increasingly important. The results indicate that: ①the runoff series has the characteristic of multi-time series changes, with the existence of major periods of 3.2a, 7.5a, 19.5a and 36.5a; ②the variation trend of runoff volume is as follows: it was relatively insufficient in 1969~1975, 1986~2004 , relatively excessive in 1956~1969, 1975~1986, 2004~2017, and will come to a normal period in 2017~2020. The low-flow period appeared since 1986 was supposed to be improved around 2004; ③the annual change of runoff is mainly caused by changes of climate, and has little to do with human activities; and ④the major period has time limitation, that only takes effects in certain periods of time.

  • Hydrology and Water Resources
    XIA Fu-qiang, KANG Xiang-wu, WU Shao-hong, YANG Qin-ye, MA Xin, LI Xiao-dong
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    The influencing factors of dike beach risk of the hanging reach in the lower Yellow River should involve four aspects, the locomotion of incoming water and sediment load, the regional crustal stability, the evolvement of river regime and the stability of river dikes. The evaluation indexes system of dike breach risk and synthetic model are established from the four aspects. With the support of GIS technology, the evaluation indexes system and the model of multi-hierarchical fuzzy synthetic judgment are applied to estimating the dike breach risk in the lower Yellow River under different flood conditions. The evaluation results show the following distributing regularities: (1) The dike breach risk increases with the increase of flood discharge. (2) Dike breach risk decreases with the channel pattern changes along the river. (3) The reaches with greater dike breach risk are mainly distributed in wandering reaches where the south bank is relativly high. (4) The dike breach risk of the north bank is higher than the south bank in winding reaches.These conclusions can be applied to the practice of flood control and channel regulation in the lower Yellow River.Simultaneously, the evaluation results manifest that the evaluation indexes system and the method can preferably resolve the problem of dike breach risk evaluation. The spatial analysis functions of GIS technology make the dike beach risk in different spatial locations qualified, and reflect the difference of dike beach risk in different spatial locations in the lower Yellow River. It has important practical meaning to direct the practice of flood control and channel regulation.