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  • 2011 Volume 31 Issue 9
    Published: 20 September 1997
      

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  • FANG Chuang-Lin
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    Based on the basic judgment of identification standards and spatial structure of urban agglomerations in China, this paper considered that "15+8" spatial structure system comprised of 15 compliance and 8 non-compliance of urban agglomerations was the present structure of formation and development of urban agglomerations in China. The main conclusions were as follows. Firstly, analyzing the "three high" characteristic comprised of high-density cluster, high-speed growth, high-intensity operation of urban agglomerations in China, this paper put forward: 1) "Four Low" problems containing low development degree, low input-output efficiency, low compact degree, low resources and environmental protection degree, 2) "Four Competition" problems comprised of blindly competing for national strategies regardless of own condition to strive for national pilot area, expanding their power regardless of the red line to trigger a large-scale land to construct cities, leading to the so-called high degree of integration with competing for construction repeatedly regardless of cooperation, breeding area deprivation with drawing up high goals careless for the resources and environmental capacity; 3) "Four-off" problems containing excessive intervention of government and administration, high estimated of the development prospects, dense negative effect of the clustering size, large development gap and 4) "Five Missing" problems comprised of lack of unified identification standard of urban agglomerations, lack of standardized statistical data, lack of centralized management with specific authorities, lack of accepted planning approach and implementation institution, lack of planning legal status of urban agglomerations. Secondly, this paper brought forward the overall development strategy and construction goals of urban agglomerations in China and thought that it would form national urban agglomerations spatial structure system comprised of 23 urban agglomerations, 6 urban agglomerations gathering area and "π" shaped urban agglomerations continuous band. Finally, some policy support mechanism and countermeasures suggestions for the construction of urban agglomerations in China were put forward: 1) to formate a national-level and local-level coordinated development management committee of urban agglomerations, public finance mechanisms and public financial reserve system for urban agglomerations, 2) to revise Town and Country Planning Act or to introduce Regional Planning Act which will add the content of urban agglomerations planning and draft treaty for cooperation of urban agglomerations, 3) to introduce Urban Agglomerations Planning Approval Approach and Urban Agglomerations Planning Implementation Management Ordinance and to build urban agglomerations planning implementation institution, 4) to introduce technical guide to guide scientific planning for urban agglomerations and to strengthen resources and environmental protection capacity and sustainable development capacity of urban agglomerations, 5) relying on the rapid land-axis and speeding up to construct the 7 918 national highway network and "four vertical and four horizontal" high-speed railway network for improving rapid transit system of urban agglomerations, and 6) to specify standards of statistical data and compile and publish Statistical Yearbook of Urban Agglomerations in China.
  • LU Yu-Qi, DONG Ping
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    From the angle of genology, it is confirmed that the model of regional spatial structure is composed of location theory, dual-nuclei theory and harbor theory which are put forward respectively based on the endogenetic regional development background, transitionary regional development background and exogenous regional development background. Particularly, the three spatial structure theories are put forward on the common assumption that the topography in a region is homogeneous plain, which is also a necessary condition of all regional spatial structure models, but the sufficient condition is different for different models. Because of the different regional development process, different spatial structure patterns are formed and the corresponding regional spatial structure models are put forward. Location theory was abstracted based on the endogenetic regional development process and was drived by endogenesis force. The typical regional cases in Germany in Europe are elected to prove the authentic of the model which brought out a shape of perfect hexagon spatial structure system. Harbor theory was abstracted based on exogenous regional development process in America and its colonies in Africa, which is drived by exogenous force. And the dual-nuclei theory was abstracted based on the transitionary regional development process in China which was drived by balanced endogenesis and exogenous forces. The dual-nuclei is composed of regional central place and the harbor city, such as Jinan-Qingdao, Beijing-Tianjin,Hefei-Wuhu and Chengdu-Chongqing and so on. From the angle of genology, the basic theoretical framework system of spatial structure models is constituted by the three theoretical models. And the theoretical status of dual-nuclei structure model is scientifically established in academic circles. The scholars in America had great style of preciseness, during the process of probing the central place system in America, who found that the perfect hexagon spatial structure system model disagreed with the fact of regional spatial structure in America, and the harbor spatial structure model in North America was abstracted based on the reality of regional development process. Accordingly, during the studying on the regional spatial structure system in China, not only the whole regional characteristics should be analyzed, but also the characteristics in every individual region should be analyzed deeply and comprehensively.
  • HENNEMANN Stefan, WANG Tao
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    The Chinese science and technology system is currently going through a period of considerable transition. Within a period of just 10 years, not only was the university system consolidated and upgraded, but the public research organizations also found themselves completely restructured in order to meet the future requirements of their country, namely the production of new knowledge. The tendency of globalization also requires the integration of the Chinese academic system into the global research system. This article aims to answer the question as to which group of universities and research organizations is most relevant for the absorbing of knowledge directly and indirectly from foreign research-related organizations. For this purpose, the international scientific publications from 1998 to 2004 with Chinese involvement were analyzed. A network constructed from the co-publication data functions as an aid to understanding the paths of knowledge exchanged between foreign and Chinese players in the scientific field. The analysis presented in this article has shown that Chinese academic knowledge network becomes larger and denser over time, showing properties of scale-free network topologies. The probability of having a 211-university in a path between any two nodes in the network doubled from 1998 to 2004. Chinese elite universities have a strong and increasingly dominant position connecting China to the global knowledge system than public research organizations. The decreasing influence of public research organizations in the knowledge network can be seen as a remarkable shift from the pre-reform period in the university and science sector. All universities apart from the 211-project universities are comparatively detached from the knowledge creation process, and this marginal position is becoming more pronounced. Furthermore, although Beijing is still as the core of the knowledge network in China, but the disparity of core-periphery shows a narrowing trend. The evolution of China's academic knowledge network should be due to the active integration effects of the elite universities and the trickle-down effect of global knowledge systems. Clearly, the integration of the Chinese system into the global scene is following a unique path, but there is still a lot to learn for other large developing economies such as India, Brazil, and Russia. Top-down political programs that foster the introduction of elements of competition produce strong guidelines for the concentration on key development sectors, suggesting the pooling of resources into these selected sectors, while comprehensive innovative talent initiatives can be used to propel these economies into a relevant position in the global science arena.
  • LIN Lin, LU Dao-Dian
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    Major transportation facilities projects implemented since 1949 have brought about significant changes in Guangzhou's urban spatial structure and urban form. There are three stages of changes. During the first 30 a after the founding of the People's Republic of China, the government has paid much attention to the construction of the major urban roads and bridges, forming a spatial structure of "stripes of dispersed groups" along the Zhujiang River in Guangzhou. After two decades of reform and openning-up, many efforts have been made to construct urban expressways, resulting in urban expansion along the Zhujiang River and the Baiyun Mountain. The spatial structure of Guangzhou thus changed into an "L" shape comprised of three major groups. During the first decade of the 21st century, Panyu County and Huadu County were merged into Guangzhou metropolis. A series of transportation facilities, such as Baiyun International Airport, South Railway Station of Guangzhou, Nansha Deep-water Port, MTR system lines, were deployed and constructed in the expanded Guangzhou metropolitan area, forming a "multi-center, multi-axis network" spatial structure. During the process, the construction of major transportation facilities has projected significant influences on Guangzhou's urban spatial structure. The road traffic framework first guided urban development into stripes shape, the rapid traffic system then adjusted the urban spatial structure into "L" shape; and large-scale facilities and track transportation facilities fundamentally altered the existing structure into a "multi-center, multi-axis network" in accordance to the spatial organization of the rapid expanding metropolitan area. The emphases of transportation facilities construction varied in different stage of urban developmen. 1) In the growing period of the city, the emphases of transport facilities construction were palced on the infrastructures, such as major urban roads and bridges. 2) During the rapid urban development period, the emphases of transportation facility constructions were rapid traffic system. And 3) in the stable development period, the emphases of transportation facilities are to foster a new growing pole and development axis through constructing regional large-scale facilities and track transportation facilities. By that, the major transportation facility construction and urban spatial structure development form a reciprocal relationship and an effective feedback loop.
  • ZHANG Yan, CHAI Yan-Wei
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    The dramatic institutional and spatial transformation has brought great challenges for the planning and provision of public housing and transportation in terms of social sustainability. In the western cities, the urban disadvantages such as the female, the elderly, the disabled, and the low-income groups have been "entrapped" in certain spatial territory with lower level of accessibility and mobility in their daily life as a result of the urban sprawl, suburbanization of jobs and other public facilities, the institutional housing segregation, as well as the deficiency of the public transit. In China, there have been great social transformation and spatial restructuring driven by the dissolve of Danwei compound, land use separation, industrial suburbanization, and residential relocation during the process of market-oriented transition. As a consequence, individuals, especially the urban middle and low-income groups, would face great challenges of decreasing accessibility and mobility in their daily life which could in turn result in the decline of the life quality. Aiming at discovering the spatio-temporal demand of the urban middle and low-income groups and promoting the social equity in urban policy and planning, this paper explores the spatio-temporal activity pattern of the urban middle and low-income residents in Beijing from the perspectives of the temporal allocation and spatial distribution of both work and non-work activities, observed daily activity space and mobility based on the activity diary survey of 600 households, 1 119 individuals of Beijing in 2007. Aided by the GIS technique and tools, the 3D geovisualization of individual's spatio-temporal path and the spatio-temporal activity density surface are introduced to explore and compare the spatial and temporal pattern of the middle and low-income groups and their counterpart group. It is found that the social transformation and spatial restructuring in urban China has exerted obviously more negative impact on the daily life of urban middle and low-income groups than their other groups. Firstly, the whole daily activity pattern show the trend of "fragmentation" due to the existing of large amount of out-of-home, non-employment activities during the day time. Also, the middle and low-income have relatively shorter work hours than their counterparts in the workday while they have relatively longer work hours than their counterparts in the weekend. Secondly, there is no strong rhythm of their work time, and their work activities relatively dispersed in the large spatial extent. Also, most of their non-work activities are located within the 1-km distance from their home. Thirdly, the middle and low-income group has lower level of mobility than other groups. They have more single purpose trips, and more frequently use the non-motorized mode such as walk and bicycle in their daily life. Besides, they have much smaller observed activity space measured by convex polygon. Finally, it is argued that much more attention should be paid to the accessibility and mobility consequences of provision the public housings for the low-income group.
  • LI Ming-Sheng, ZHANG Jian-Hui, LUO Hai-Jiang, LIN Lan-Yu, LI Qian, ZHANG Yin-Jun
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    SO2 is one of total quality control of pollutions. It provides the theory and realistic reference meaning for pollutions reduction to investigate the changing trend and influential factors of SO2. The SO2 emission data are from China Environment Statistical Yearbook and the emission trend and reduction trend of SO2 are showed firstly in the paper. Then, Logarithmic mean weight divisia method model and reduction model are applied to analyzing the influential factors effects and SO2 reduction. The main results could be summarized as follows: 1) The industrial emission of SO2 kept rising from 2000 to 2006 and descended in recent four years. Changes in the three regions of China were similar to national trend. However, the proportion of western region in whole emission increased in the past ten years. 2) The SO2 reduction goal in "Eleventh Five-Year Plan" had been achieved. The industrial SO2 made a greater contribution for reduction. Reduction volume in east region was the most. From the view of technique, it was the main method to increase SO2 removal rate. 3) The average growth of industrial SO2 was-65?104 t. The scale of economic development, the industry structure and emission intensity had different contributions to the change, which were 315?104 t,-344?104 t,-36?104 t,respectively. 4) Conditional convergence and absolute convergence obviously exit for the SO2 emission intensity among provinces in China. The SO2 reduction potential of different regions in conditional convergence would be 738?104 t (equivalent to 1/3 of SO2 emission in 2009). 5) If the reduction goal was 8%-10%, the industrial SO2 removal rate must reach 74%-80%. The reduction situation would be severe. It was of vital importance in SO2 reduction to promote the change in the pattern of economic growth.
  • JIANG Lei, JI Min-He
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    China is now claimed to be the largest energy consumer among all countries in the world, as it more than ever needs energy to sustain its consecutive two-digit annual GDP growth. The huge demand for energy has had a stronger impact on energy production and supply in the country. The distribution of energy consumption among provinces and cities may conceal significant spatial effects that each location has exerted onto its neighbors. When taken it into account in the analysis, these spatial effects may be used to rectify the estimation bias inherent in the traditional energy consumption model. This paper employed the total energy consumption as an index of environmental impacts to evaluate the spatial effect of energy consumption in China based on the STIRPAT model. The energy consumption data of all regions in China was first examined via the Moran's I index for the existence of spatial dependence. For calculating the index, a contiguity rule was employed to establish the spatial weight matrix for the regions. The exploratory analysis results in a value of 0.194 for Moran's I at the significant level of 0.05, which indicates a tendency of spatial clustering of similar consumption values. This warranted further analyses on a confirmatory nature. Two spatial econometric regression models based on spatial lag (SLM) and spatial error (SEM) respectively were then established to analyze the impact of several relevant factors on energy consumption. Results from these two models were compared on the basis of several statistical tests, and the SEM was selected to fit the data. The goodness of fit of the SEM reached 0.898, a 3% improvement over 0.871 of the adjusted R-squared resulting from the traditional OLS model. The results indicated that the average energy consumption between the years of 2006 and 2008 did present spatial interdependence to some degree among Chinese provinces, and the energy consumption behavior was collectively influenced by the internal factors of the province under investigation and its neighbors. There was a significant positive correlation between energy consumption and population, social affluence, and secondary industry. That is, the elastic coefficient of energy consumption increased gradually as these influential factors increased. A set of governmental countermeasures are necessary: moderate efforts should be made to revise birth control targets, civic investment should be increased to advocate a low-carbon lifestyle in China, and new and energy-saving technologies should be rapidly adopted in the Chinese industrial system. Above all, the strategic planning and policy making for the long-term reduction of energy consumption should consider the spatial interaction mechanism of energy consumption among different jurisdictions in the country.
  • ZHANG Hong-Yan, WANG Lei, LIU De-Ying
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    As an ethnic minority, the migration of Chinese Korean nationality has been for a long period. The formation and characteristics of Chinese Korean migration were analyzed based on Chinese Korean population data using GIS from the mid-19th century to the year 2000. The early migration from their native land to the Northeast China through Tumen River and Yalu River with a large-scale started at the late of the 19th century. Before the People’s Republic of China was founded, Chinese Korean nationality mainly distributed in the Northeast China. Just after liberation, population of them changed little, but increased after the Korean War broke out. Since China’s reform and openning-up, another large-scale Chinese Korean migration moved to South China and distributed all over the China, whose population in the early settlements decreased gradually. The migration of Chinese Korean nationality inevitably led to the population redistribution and the changes of settlements’ scale. Five main settlements formed before 1949, referred to as settlements of Nanman, Beiman, Dongman, Dongbiandao and Guannei. Almost half of the Korean Chinese lived in the Yanbian Korean Autonomous Prefecture since it was founded and the settlements kept stable there. After China’s reform and openning-up, some new Chinese Korean nationality settlements were formed with Beijing, Qingdao, Shanghai, Shenzhen as their centers. Migration of the Chinese Korean nationality and the distribution pattern promoted the coordinated development of population and society of minority migration among cities in China.
  • ZHANG Ke-Yun, FU Shuai-Xiong, ZHANG Wen-Bin
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    During the process of regional industrial transfer and industrial restructuring, the evolution of regional industrial structure sharply contradicts with decreasing of resources and lowing of environmental carrying capacity because of lacking industrial economic and ecological efficiency from the overall view. The pollution was transferred from the developed regions to the developing regions caused by the transfer of polluting industries. Similarly, in the process of development and utilization of resources, conspicuous transfer of ecological destruction exists among regions. A province uses a large number of ecological resources, but most of which are likely to rely on imports, in this case, the ecological system of this province has been protected, but the ecological system of provinces which export the resources are under great ecological stress. Through the empirical studies, this paper analyzed and compared the ecological carrying capacity of 31 provinces of China in 2008, based on the improved ecological footprint model, and discussed the problem of transfer of ecological destruction between regions. The empirical analysis shows that the ecological damage transferred clearly among the regions, the ecological system in the eastern region of China has been well protected, while the pressure of ecological system is increasing in the central and western areas of China where export resources. Therefore, the economic development mode for various areas should be further changed, and the the regional policy made by central government should be further improved.
  • ZHAO Yong, KONG Yun-Feng
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    In geography and related disciplines, spatial analysis is an important research tool or method, which has attracted increasing attention in geography and many other subjects, such as ecology, public health, environments, crimes, economics, etc. Based on the concepts, contents of spatial analysis, considering the different development stages and characteristics of spatial analysis since the 1960s, this article studies more than 40 colleges, organizations or universities' syllabus of spatial analysis at home and abroad. Together with the teaching practice of spatial analysis, the authors suggest the "Introduction to Spatial Analysis" course syllabus and the related specific contents, such as the detailed contents, the selection of practice software, class hours, etc. Accordingly, some advice on the teaching of spatial analysis in China are taken: 1) The specific syllabus should include: the introduction (including types and characteristics of spatial/attribute data, spatial autocorrelation, modifiable areal unit problem, edge effects, ecological fallacy), analysis based on maps (including overlay analysis, buffer analysis, Voronoi graph, thiessen polygon, network analysis, optimal path analysis, flow analysis and modeling, location-allocation analysis), geometry analysis (including centrography, distance/area measure, etc.), exploratory spatial data analysis (including visualization, scatter plot, stem-leaf plot, histogram, box plot), spatial point pattern analysis (including completely spatial randomness, quadrat analysis, kernel density estimation, nearest neighbor method, G function, F function, K/L function, Monte Carlo simulation, and some related test methods), area objects and spatial autocorrelation (including spatial weight matrix, global statistics, local statistics, joint count statistics, Moran's I, Geary's C and Getis'G/Gi*, local indicators of spatial association), spatial interpolation and geostatistics (including first law of geography, surface modeling, stochastic/determine modeling, inverse distance weighted interpolation, multinomial interpolation, spline interpolation, regionalized variable, semivariogram, ordinary Kriging, simple Kriging, and other Kriging methods), and new approaches, e.g. neural network (NN), evolutionary computation, cellular automata (CA), agent-based modeling (ABM), etc. in spatial analysis. 2) For the practice software, more than one type of software should be used in the class, in which ArcGIS, and free software GeoDa and R are recommend. Some other software about NN, CA, etc. may also be introduced, if time permitting. And 3) the class hours and practice hours are suggested that all the time should be at least 66 h, of which at least 12 h are practice hours with computer.
  • LI Jin-Ya, YANG Xiu-Chun, XU Bin, CAO Yun-Gang, QIN Zhi-Hao, JIN Yun-Xiang, ZHAO Li-Na
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    The six main pastoral areas (Xinjiang, Tibet, Qinghai, Sichuan, Gansu, and Inner Mongolia) are the important production base of animal husbandry in China, and also the frequent snow disaster areas. To obtain snow conditions of these pastoral areas timely and accurately is valuable for disaster prevention and reduction. With higher spatial resolution and stronger interpretation, optical remote sensing is better for snow cover identification, but it is vulnerable to cloudy weather. Microwave remote sensing is not easy affected by cloud, but identification accuracy is not high. In this paper, we integrated the two kinds of data to identify snow covers. The MODIS data (optical) are used in cloud-free areas, while AMSR-E data (microwave) are used in the rest areas. According to the method, each single day is defined as monitoring unit, and every ten days compose the image combining unit. The monitoring area covers the six main pastoral areas of China. The monitoring duration is from October 1st, 2008 to March 31st, 2009. The main conclusions are as follows: 1) The grasslands Northern Xinjiang, eastern Tibet, south-west of Qinghai, central Gansu, northern Sichuan, the Xilin Gol, and Hulunbeier of Inner Mongolia are the areas with frequent snow cover. 2) The monitoring area possesses the smallest snow cover in December 10th to 20th, while it has the biggest snow cover in January 1st to 10th. 3) During the monitoring period, the fluctuation of snow-cover area can be concluded in three types: Xinjiang and Inner Mongolia have the single peaks, Tibet and Qinghai have three peaks and three valleys, and Sichuan and Gansu are relatively stable.
  • YAN Deng-Hua, GENG Si-Min, LUO Xian-Xiang, QIN Tian-Ling
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    The spatial and temporal variation characteristics of start date, length and accumulated temperatures of the four seasons in Northern China are analyzed based on daily temperature of 1960-2009 from 56 meteorological stations. Seasons are divided by 5 days’ moving average temperatures. Climate tendency coefficients and GIS are used to analyze seasonal variation characteristics. The results show that: springs and summers are coming earlier; autumns are coming later while the start dates of winter have little changes. In most areas, springs, autumns and winters are becoming shorter while summers are longer and the proportion of severe winters reduced. Temperatures in springs are lower while autumns, winters and severe winters are warmer, and summers are much more hot.
  • TAN Li-Rong, CHEN Ke, WANG Jun, YU Li-Zhong
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    Firstly, the storm surge disaster vulnerability index (Storm Surge Vulnerability Index, SSVI) is built by learning form the assessment method of Coastal Vulnerability Index (Coastal Vulnerability Index, CVI. Then, physical vulnerability of storm surge is assessed using additive model, according to the storm surge disaster loss data during 1990 to 2009 of eleven provinces in the coastal region, which are Liaoning Province, Hebei Province, Tianjin City, Shandong Province, Jiangsu Province, Shanghai City, Zhejiang Province, Fujian Province, Guangdong Province, Guangxi Zhuang Autonomous Region and Hainan Province.The results show that there is a large inter-annual variation of the vulnerability of coastal storm surges; the high and very high level of physical vulnerability are mainly distributed in southeastern coastal provinces, the low and very low level, in northern coastal provinces, respectively, while distribution of the middle level changes greatly.
  • JIANG De-Juan, LI Zhi, WANG Kun
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    Based on daily precipitation data of 18 meteorological stations over Shandong Province during 1961~2008, the extreme precipitation thresholds were determined for different stations by the centesimal value method, and then, four indices including frequency, annual amount, intensity and annual daily maximum amount of extreme precipitation events were counted and their spatial characteristics and temporary trends were analyzed. The results showed that the extreme precipitation thresholds indicated the remarkable regional difference and gradually decreased from the center of the Taishan Mountain to outside. The frequency of extreme precipitation events was about 18 d/a with a sight regional difference. The spatial characteristics of annual amount, intensity and annual daily maximum amount of extreme precipitation events were similar, i.e., they were all characterized with a decrease from the southeast to northwest of Shandong Province and their high-value centers were located in the Taishan Mountain. For recent 48 years, 4 indices except intensity of extreme precipitation events showed a slight decreasing trend, which was more significant in Jiaodong peninsular, and moreover, the abruption changes in the year of about 1965 occurred for these three indices. However, the intensity of extreme precipitation events showed no obvious trend and no abruption change. Four indices of extreme precipitation events all indicated the remarkable interdecadal variability and furthermore, the qusia-11 year oscillating period existed for these four indices during 1961~2008, which were symmetrically distributed surrounding the middle-axis in the year of 1984.
  • YOU Zhen, FENG Zhi-Ming, YANG Ge-Ge, YANG Yan-Zhao
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    Based on the national earthquake catalog database,the paper sorted out more than 5.0Ms earthquake information in western region of China; using information diffusion theory,the paper assessed the seismic risk of western twelve procinces, municipalities and autonomous regions in two aspects of annual earthquake frequency and annual maximum earthquake.On this basis,curved fitting the discrete values of the risk estimate,made a systematic review for the distribution trends and differences of seismic risk in the five provinces of China which are the most earthquake-prone,revealed quantificationally?the seismic risk in western China.Provided technical support and policy recommendations for earthquake prevention and mitigation and policy recommendations in western region of China.
  • TURSUN·Hasan, TASHPOLAT·Tiyip, MAMAT·Gazat, MAMTIMIN·Mamat
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    Taking Xinjiang Weigan River irrigation district as an example, 38 observation wells’ data from 1997 to 2007 of groundwater depth and groundwater mineralization were used in the paper to analyze annual change of groundwater depth and the groundwater mineralization of Weigan River irrigation district, and their seasonal dynamics and spatial distribution. The results showed that in the 11 years period, the highest groundwater level appeared in spring. The groundwater level rose significantly from the top of irrigation district to the periphery of the oasis. The overall trend of groundwater mineralization is that groundwater mineralization is relatively low in the upper reaches of the irrigation district, and relatively high in the lower edge and downstream of the irrigation district. The annual groundwater depth and groundwater mineralization generally decreased in the irrigation district.
  • LI Xun-Gui, WEI Xia
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    Rainstorm flood is one important factor resulting in soil and water loss of watershed. The soil and water loss can cause the increase of sediment concentration in runoff, which will add more surplus flood in flood season and consequently become an important reason for the occurrence of flood disaster. A factor of binding information (BI) was presented based on the information entropy theory. The BI is able to describe the uncertainty degree (i.e., risk value) hiding in system before events happen. According to the BI values of different controllable-observable objectives (COOs), the changing situations of uncertainty degree that events evolve from a COO to another one can be uncovered. So the BI is convenient to test risk changing of soil and water loss and reflect its evolution trend. In addition, the Universal Soil Loss Equation (USLE) has a preferable merit to describe and maintain the details of soil and water loss. Considering these characteristics of the USLE and BI, a notion of risk, coupling risk of soil and water loss, was proposed. The coupling risk is defined as the superposition results multiplied the BI by the factors in USLE. It can not only maintain the details of soil and water loss, but also describe the evolution processes of soil and water loss risk. On the basis of the presented coupling risk, a function relationship between sediment concentration in runoff and coupling risk grade of soil and water loss is established. A maximum rating method is employed to calculate the coefficient of surplus floodwater in flood season based on the independent variable of sediment concentration in runoff. Therefore, the relation between the coefficient of surplus floodwater and the coupling risk grade of soil and water loss is achieved with the intermediate variable of sediment concentration in runoff. A case study related to Jinghe River Basin with representative characteristics of floodwater resources utilization and soil and water loss has been performed. Results demonstrate that: 1) the coupling risk grades of soil and water loss for 1986, 1995 and 2000 at the upper watershed of the controlled section of Zhangjiashan Station are 2.5437, 2.5421 and 2.4722, respectively, which shows a total decrease trend of the coupling risk of soil and water loss in the basin; 2) there is a prominent relationship at the confidence level of 0.01 between sediment concentration in runoff (y) and coupling risk grade of soil and water loss (x) as y=0.0108exp(2.4211x). The square of correlation coefficient R is equal to 0.4037 (R2= 0.4037). The higher the coupling risk grade (x) is, the larger the sediment concentration in runoff (y) is, vice versa; and 3) a prominent function relationship at 0.01 confidence level exists between the coefficient of surplus floodwater in flood season (y) and the coupling risk grade of soil and water loss (x) as y =0.0229exp(0.9937x)R2=0.3878. The bigger the coupling risk (x) is, the larger the coefficient of surplus floodwater (y) is, the larger the amount of surplus floodwater in flood season is, and the greater the flood disaster risk is. The results can provide a reference for analysis on relationship between the risks of watershed soil and water loss and flood disaster.
  • DU Hai-Bo, WU Zheng-Fang, LI Ming
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    Hydrothermal changes caused by climate change are one of the important causes for eco-system change, whose long-term changes and short-term fluctuations are essential causes of formation, distribution and change of eco-geographical boundaries. In this paper, the changes of the four main eco-geographical boundaries were quantitatively studied based on the heat index (warmth index WI and coldness index CI) firstly developed by Kira and the humidity index HI put forward by Xu Wenduo for each 10 years of Northeast China in 1961–2007. Then their responses to climate change were analyzed in Northeast China. The results indicated that zonal eco-geographical boundaries have been moving to higher latitude (shifting upwards vertical zone) and meridional eco-geographical boundaries have been moving eastward in the whole sequence, but the movements of stages were volatility. The changes of eco-geographical boundaries expressed in distribution and moving speed responded to climate change well, not only in the whole sequence but also in the stages. They are very sensitive to the basic elements of eco-climatic such as hydrothermal, etc., and it may be a new idea to research climate change by the changes of eco-geographical boundaries.
  • ZHANG Chong, ZHAO Jing-Bo, ZHANG Shu-Yuan
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    Based on the historical data, this paper studied the disaster grade, temporal change and the causes of disasters of Weihe River watershed during the Han Dynasty (202 a B.C.-220 A.D.). The results showed that during the 423 years of the Han Dynasty, the floods happened 109 times in Weihe River, with averagely once every 3.9 years. Mild floods, middle floods, great floods and serious floods respectively accounted for 44.0%, 24.8%, 22.9% and 8.3% in the total numbers of floods. There were two flood-prone periods in Weihe River watershed of the Han Dynasty, i.e. from 49 a B.C. to 10 a B.C. and from 91 A.D. to 130 A.D.. Mild flood and the middle flood disasters happened once 3-4 years in Weihe River watershed during the Han Dynasty, great flood did once about 20 years, and serious flood did once 60-70 years.