Table of Content

    20 May 2011, Volume 30 Issue 5 Previous Issue    Next Issue
    Earth Surface Processes
    Study on urban agglomeration: Progress and prospects
    GU Chao-lin
    2011, 30 (5):  771-784.  doi: 10.11821/yj2011050001
    Abstract ( )   PDF (977KB) ( )   Save
    Urban agglomeration is a complex with the central city as the core surrounded by two or more cities. It is the objective reflection of the economic growth and social development as well as industrial layout in a region. It has also become a main form of urbanization in developed countries. In fact, the "urban agglomeration" concept in China is the characteristics of a noun, no equivalence in foreign countries. In Western literature, the "urban agglomeration" means "urban cluster", that is, a big city and its surrounding satellite towns in remote sensing image formed the connected irregularities each other, and the spatial range includes "urbanization area (UA)" and "metropolitan area (MA)". Sometimes, some of metropolises connected each other are also called as urban agglomeration. United Nations gave a definition of urban agglomeration as follows: "Comprises a city or town proper and also the suburban fringe or thickly settled territory lying outside, but adjacent to, its boundaries. A single large urban agglomeration may comprise several cities or towns and their suburban fringes." Therefore, urban agglomeration in the Western concept includes the cities, towns and urban-region outlying areas. "Urban agglomeration" in China refers to geographical concepts of a group of major cities which are similar and interactions among administrative, transportation, economic, and social fields. In the 21st century, thanks to China's entry into the World Trade Organization, a national coastal urban agglomeration has become the main region for the national trade economy, export and the "world manufacturing bases". Urban agglomeration as an important urban spatial pattern was a unique choice to promote the process of urbanization in China. This article reviewed some progress in studies of urban agglomeration, such as the concept of urban agglomeration, overseas research of urban agglomeration, early researches of Chinese urban agglomeration and studies on Chinese urban agglomeration as a national strategy. This paper has prospects for the studies of Chinese urban agglomeration in the future. It argued that there is more complex mechanism for the rise and development of the Chinese urban agglomeration than those in Western developed countries, so that the relevant researches need innovations.
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    Hierarchical structure and distribution pattern of Chinese urban system based on railway network
    ZHONG Ye-xi, LU Yu-qi
    2011, 30 (5):  785-794.  doi: 10.11821/yj2011050002
    Abstract ( )   PDF (1105KB) ( )   Save
    The rail transportation has become an important conveyance carrying passengers and cargos. Railway network which is comprised of stations and railways influences the hierarchical structure and distribution pattern of the national urban system. This paper screens out the study objects including 186 prefectural-level cities having starting trains by timetable, and analyzes the hierarchical structure and distribution pattern of the urban system based on the data of starting trains. This paper demonstrates that the number of railway trains at starting station is positively correlated with the hierarchy of urban system. On this basis, it uses the methods of charts discriminance and the clustering analysis to classify all the 186 cities into four hierarchies. There are 3 national central cities, 8 regional central cities, 30 sub-regional central cities and 145 local central cities. From a unique perspective of railway network, the article reveals the following characteristics of the hierarchical structure and distribution pattern of Chinese urban system. (1) The urban hierarchy system presents a typical pyramidal structure, which means the higher the hierarchy of the cities is in the system, the smaller the number of the cities is. (2) The administrative, topographical and economic factors affect the railway network markedly, consequently affect the urban hierarchy system greatly. (3) The distribution of cities in eastern China is different from that in western China, which means the higher-hierarchy cities are mainly distributed in the east, and the railways of the west cities are mostly in east-west direction. (4) High-hierarchy cities are evenly distributed in eastern China, which constitutes the fundamental framework of Chinese urban railway network and coincides with the "T"-shaped development strategy of the national land. (5) Six pairs of dual-core structure of urban patterns have been formed among high-hierarchy central cities due to the close connection of railway network.
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    Spatial pattern of urban hinterlands of cities at prefecture level or above in the Economic Zone on the Western Coast of the Taiwan Straits based on field-strength model
    QIU Yue, WEI Su-qiong, CHEN Jin-dong
    2011, 30 (5):  795-803.  doi: 10.11821/yj2011050003
    Abstract ( )   PDF (1063KB) ( )   Save
    The Economic Zone on the Western Coast of the Taiwan Straits has attracted much attention since the Central Government endorsed its construction and set it as a part of the national strategy. Regional development will depend on central cities and their hinterlands which supply resources for the economic activities of cities, so the reasonable hinterland delimitation and analysis of spatial pattern can not only present an approach for studies on urban economic region, but also provide the basis for regional decision. Based on field-strength model, the paper calculates the urban influence of 20 cities at prefecture level or above in the economic zone in 2007, identifies three strong influence circles of urban agglomeration, and finds out that the big mountains above 900 meters greatly weaken urban influence according to the overlay analysis of urban field-strength and contour line. Furthermore, this paper delimits urban hinterlands in accordance with the principle of "maximal field-strength choice". Then, the spatial pattern of urban hinterlands is discussed in two perspectives. One is the spatial relationship between urban hinterlands and administrative districts, and the other is the spatial relationship between different urban hinterlands. The result shows that Xiamen and Fuzhou in Fujian province, Wenzhou in Zhejiang province and Shantou in Guangdong province occupy much larger hinterland area in surrounding administrative districts due to their higher synthetic strength compared with other cities, so they can play a radiating and leading role in these regions. However, all of the four cities do not cover any inland region in Jiangxi province. At present, there is close relationship between urban hinterlands such as inclusion or semi-inclusion. Meanwhile, the small group and the isolated urban hinterland, geographically apart from the main part, can also be found. Generally speaking, the economic zone has a clear channel to connect the Yangtze River Delta and the Pearl River Delta, but it still needs some time to make achievement in coastal-inland urban hinterland integrity.
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    Designing of regional development strategic pattern in Zhanjiang based on Zhanjiang Archipelago
    ZHANG Yi-feng, ZHANG Wei, ZHANG Hong-ye, TAN Jie, JIA Da-meng, SUN Rui-feng
    2011, 30 (5):  804-813.  doi: 10.11821/yj2011050004
    Abstract ( )   PDF (923KB) ( )   Save
    It is a hot spot in academic studies on how to design the regional development strategic pattern and realize the sustainable development of regional economy through the integration of the regional resources. This paper, taking Zhanjiang as an example, puts forward the concept of "Zhanjiang Archipelago" for the first time on the basis of long-term investigation and discussion with the local government leaders; and then elaborates the significance of Zhanjiang Archipelago in the regional socio-economic development process of Zhanjiang. Based on this, this paper proposes an overall development strategy of "island-bay-harbor-city" . This strategy emphasizes the protection of Zhanjiang estuarine ecosystem to realize the unified management of Zhanjiang harbor, and advances the coordinated development of each island in Zhanjiang through promoting the strategic statuses of the islands, bays and harbors in the development of Zhanjiang. Furthermore, this strategy will promote the process of industrial integration, ocean-land integration, urban-rural integration in Zhanjiang, and then build Zhanjiang into a new growth pole in the Yuexi areas.
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    Mechanism and network characteristics of industrial cluster in provincial border regions of China: A case study of wear-resisting casting industrial cluster in Ningguo of Anhui Province
    HAN Yu-gang, JIAO Hua-fu, LI Jun-feng
    2011, 30 (5):  814-826.  doi: 10.11821/yj2011050005
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    Researches on the interior enterprise network of industrial cluster is an important basis for understanding its forming law. Based on the survey data of enterprises' questionnaires, by applying the boundary effect theory and social network analysis, this article established a social network evaluation index system to make an empirical analysis of characteristics of enterprises' network and the mechanism of wear-resisting casting industrial cluster in Ningguo, one of the provincial border regions between Anhui and Zhejiang. Results can be obtained as follows. (1) The enterprise derivative network structure presents features of single-center and low-density, which states that "the same clan" phenomenon is obvious in industrial cluster and the derivative function of the seed enterprise is strong; the cooperation network's structure is featured by multi-center and medium-density, which illustrates that the enterprises' relational network is in its growing period and the level of their cooperation is low. The innovation network shows a characteristic of single-center, which indicates that the seed enterprise is the "technical leader" in the industrial cluster and the contacts of their technical innovation are weak. (2) The formation mechanism of the wear-resisting casting industrial cluster in Ningguo is the outcome of combined action of the optimized exterior industrial environment of the cluster, the strengthening of the key actor colonies' behavior and the increase of the knowledge stock in the cluster during the process in which the boundary effect transforms from shielding effects to intervening effects.
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    On the theory and practice of potential competitiveness evaluation in international tourism on the basis of resources and distance
    WAN Xu-cai, ZHONG Jing, DING Min
    2011, 30 (5):  827-834.  doi: 10.11821/yj2011050006
    Abstract ( )   PDF (909KB) ( )   Save
    Tourism competitiveness is divided into tourism competitive effect and potentiality in this paper. An index system of evaluating the potential competitiveness in international tourism is constructed on the basis of tourism resources and distance. The competitive potentiality in international tourism of China is evaluated and analyzed by comprehensive evaluation method and from the view of specific regional tourist origin. The results are obtained as follows. 1) The comprehensive appraisal value of potential competitiveness in international tourism of China is the highest compared with major tourism powers in the world. This demonstrates that China has great competitive potentiality. And China also has absolute advantage in tourism resources. However, as to the distance between tourist destination and tourist origin, China is at a disadvantage status as a whole. 2) According to the evaluation from the view of specific regional tourist origin, China can win over Asia-Pacific tourist market. In European tourist market, Chinese competitive potentiality is second only to France, and its potential is the same as that of Spain and Italy. In American tourist market, Chinese competitive potentiality is second only to the United States. This demonstrates that China has potential advantage to a certain degree in European and American tourist markets.
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    Cultural adaption and reconstruction of minority festival activities in tourism development: A case study of Hani Long-Street Banquet
    TANG Xue-qiong, QIAN Jun-xi, CHEN Lan-xue
    2011, 30 (5):  835-844.  doi: 10.11821/yj2011050007
    Abstract ( )   PDF (989KB) ( )   Save
    In a broad context of the ethnic tourism development, cultures of ethnic festivals are now continuously undergoing conflict and amalgamation between local tradition and modern development in the process of interacting with alien culture. This research focuses on the cultural evolution process of the Long-Street Banquet, an important festival activity of Hani people, in the context of tourism development. Our case studies are conducted in two areas, namely Habo and Luchun. Our empirical findings suggest that due to government-led tourism, the Long-Street Banquet of Hani is performed as a festival tourism product to adapt to the mainstream culture of modern society brought by tourists. By this, the Long-Street Banquet of Hani has gone through a process of local cultural identity, cultural adaption and cultural reconstruction. And it is staging itself from rural to urban area and from local identity to world culture.
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    Characteristics of cultural tourism resources and the modes of cultural industry development in Shanxi Province
    SUN Yu-mei, QIN Jun-li
    2011, 30 (5):  845-853.  doi: 10.11821/yj2011050008
    Abstract ( )   PDF (984KB) ( )   Save
    Currently, cultural tourism is a mainstream in the development of tourism in the world. Shanxi has rich in cultural tourism resources. It is the only wayout for Shanxi to enhance the sightseeing resources to take the lead in the development of the cultural industry so that its tourism and culture could be blended. Based on the analysis of the current situation of the development and utilization of the tourism resources in Shanxi, the authors believe that in the development of the cultural industry this province should take five different modes according to local conditions, namely, the interactive development mode of tourist industry and cultural industry based on the development of cultural tourism resources, the protective development mode focusing on ancient buildings and sites, the market development mode that is centered on movies, performing arts and folk arts, the multiple investing & financing mode focusing on the innovation of cultural systems and mechanisms and the government-guiding mode relying on policies, etc. In the process of the development and utilization of cultural resources, Shanxi should deal with the relationship between the development of cultural tourism resources and the protection of cultural tourism resources in a proper way, and promote the sustainable development of the cultural industry by means of combining government guidance with market orientation.
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    A method to forecast land demand by fusing geo-spatial indicators: Exemplified by Nanhai in Foshan
    MA Lin-bing, CAO Xiao-shu, MU Shao-jie
    2011, 30 (5):  854-860.  doi: 10.11821/yj2011050009
    Abstract ( )   PDF (899KB) ( )   Save
    The paper puts forward a method to forecast land demand by fusing several geo-spatial indicators. Traditionally, economic and social factors were regarded as the main influencing factors in forecasting land demand, hence the effects of spatial factors were neglected by researchers. However, for each type of land use, its spatial distribution and spatial shape are bound up with the other type of land use by interacting each other, so spatial factor should be introduced to forecast land use demand as a key ingredient. Several computable factors called geo-spatial factors can be used to fulfill the requirement, such as geographic standard distance, standard deviation ellipse parameters and spatial autocorrelation coefficient. These geo-spatial factors can reflect the changing trend of each type of land use and disclose some interior rule of spatial distribution and spatial spreading. It is necessary to fuse these geo-spatial factors into forecasting land use demand. Considering the influence of geo-spatial factors, the paper gives a land use demand forecasting method by fusing economic factor and geo-spatial factor. The method adopts multiple linear regressions to create a linear relation between land use demand quantity and multi-factor value from multi-years data and finally figures out target year's forecasting result. To verify the method, the paper makes a case study based on land use investigation data (from 2003 to 2009) and economic factor data (from 2002 to 2009) of Nanhai in Foshan city. By computing and analyzing, the result shows that it is more veracious to fuse geo-spatial indicators and economic indicators into land use demand than to use economic indicators only. It can be concluded that geo-spatial indicators have closer correlation with land use status and can play a more important role in forecasting land use demand. But restricted by basis data, the result in this paper should be verified by collecting more integrated data and adopting other statistic computing methods. The further work will focus on analyzing geo-spatial indicators' internal mechanism related to land use changes and selecting more reasonable indicators as forecasting factors.
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    High accuracy surface modeling of soil properties based on multi-grid
    SHI Wen-jiao, DU Zheng-ping, SONG Yin-jun, YUE Tian-xiang
    2011, 30 (5):  861-870.  doi: 10.11821/yj2011050010
    Abstract ( )   PDF (1195KB) ( )   Save
    Kriging, inverse distance weighting (IDW) and spline are three classical methods for interpolating soil properties. High accuracy surface modeling (HASM) has been developed in recent years, which is successfully used in geographic information system and ecological modeling. In order to assess its feasibility of soil property interpolation, HASM based on multi-grid (HASM-MG) was used to interpolate soil pH for a red soil hilly region of Jiangxi Province, China. A total of 150 samples of topsoil (0-20 cm) were collected in Ji'an municipal district, Ji'an County and Taihe County in October, 2007. Three different data sets were randomly created for simulation and validation to comparatively simulate performance of HASM, kriging, IDW and spline. A total of 30, 60 and 90 samples were removed as validation points, thus 120, 90 and 60 data points were selected as simulation points, respectively. The results show that HASM simulation is the closest to the measured data among the four methods. It has much smaller mean absolute error, root mean square error and much higher correlation coefficient of simulated value and measured value than the three classical methods. Soil pH values in the central and southeastern parts of the study area dominated by paddy soils are much higher than those in the red soil area. Therefore, HASM-MG can be considered as an accurate method for interpolating soil properties on the premise of improving the calculation speed, and it advances the practicability of HASM applied in soil property interpolation.
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    The technology based on improved TAE algorithm to extract the information of urban heat island
    YANG Bo, LIU Yu-peng, MA Su, ZENG Fa-ming
    2011, 30 (5):  871-878.  doi: 10.11821/yj2011050011
    Abstract ( )   PDF (1665KB) ( )   Save
    The urban thermal anomaly extraction (U-TAE) algorithm was proposed for the study of urban heat island, which was evolved from the TAE algorithm for thermal anomalies extraction of underground coal fires. The U-TAE algorithm detects the entire thermal infrared image by moving windows with different sizes, and the key of this robust algorithm was to set up thresholds for pixels with land surface temperatures (LST) higher than mean plus standard deviation. Mean and standard deviation were calculated from all pixels and those pixels in the moving windows (scope from 5×5 to 151×151 pixels). This algorithm can distinguish UHI areas from background areas according to the cumulative times of pixels, and determine UHI intensity according to the cumulative times in UHI areas. Cumulative times of zero are background areas and the others are UHI areas. This U-TAE algorithm has dynamic thresholds and unbias characteristics. Results showed that the heat island areas were between 55.31 km2 and 68.35 km2 in Changsha in 2001. In UHI intensity analysis, the UHI studies at macro-scale should use larger moving windows to reflect the relationship between urban and rural areas. Micro-scale studies should use smaller moving windows to analyze specific distribution of UHI, underlying surface and driving factors. Compared with traditional methods, U-TAE algorithm makes the results comparable in different time periods.
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    Cumulative effects of landscape changes in coal mining area: A case study in Lu'an coal mining area, Shanxi Province
    WANG Xing-feng, WANG Yun-jia, MA Xiao-li, CHEN Ming
    2011, 30 (5):  879-892.  doi: 10.11821/yj2011050012
    Abstract ( )   PDF (1047KB) ( )   Save
    Coal resources have played an important role in social and economic development, at the same time, the ecosystem has been seriously affected by the exploitation in the coal mining area. Due to the inherent characteristic of time duration, spatial expansion and strong interference of coal exploitation, ecological cumulative effects have been caused remarkably and many ecological problems emerged including surface subsidence, vegetation degeneration, gangue stack, ground water resource withered and farming productive dropping etc. Based on the theory of cumulative effects and the principles of landscape analysis, ecological cumulative effects induced by coal exploitation are discussed in the paper. The concept of landscape ecological baseline value is proposed, and landscape spatial cumulative burdened index model is constructed using the landscape structure cumulative index, landscape disturbance cumulative and landscape ecological sensitivity degradation cumulative index. Taking Lu'an mining area as a case study, landscape ecological cumulative effect was calculated based on landscape analysis. Results show the cumulative load of mining landscape presents a significant increasing trend during the 13-year period (1993-2006). In terms of the intensity of human activities, different subareas have different accumulation levels, and since 2000, increased human disturbance has made cumulative degree change greater than before.
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    Analysis of inputs and environment benefit outputs of urban park green land in Guangzhou based on DEA
    CHEN Zhong-nuan, LIU Yan-ting, WANG Tao-tao, LV Yi-hong
    2011, 30 (5):  893-901.  doi: 10.11821/yj2011050013
    Abstract ( )   PDF (877KB) ( )   Save
    Following the evaluation to green land abroad and drawing lessons from domestic study on data envelopment analysis (DEA), we did some evaluations to urban park green land which have not been studied much yet. Park green land is one part of urban green land system. Based on functions of fixing carbon and releasing oxygen, purifying environment, conditioning climate and detaining dust, we calculated the environmental benefit of park green land of ten districts in Guangzhou from 2001 to 2008. Then the input-output index system was built to evaluate the eco-efficiency of park green land in 2001—2008 by DEA. The land, labor and capital were taken as the input while the environment benefit was the output of park green land. The results showed that: firstly, influenced by the input of land and labor, generally, the environmental benefit of urban park green land presented an increasing trend but sustainable increasing ability was relatively weak; secondly, the input redundancy rate and insufficient rate of output in 2008 showed that the more input of fixed assets and financing of park maintenance caused low eco-efficiency in 2008; thirdly, the comprehensive efficiency, the technique efficiency and the scale efficiency were 1 in 2001, 2003 and 2004, which indicated the optimum efficiency. In 2002 and 2007, the comprehensive efficiency, the technique efficiency and the scale efficiency were between 0.895-1 which indicated the suboptimum efficiency. It showed non-efficiency in 2005, 2006 and 2008 in spite of over 0.8 in technique efficiency and scale efficiency because the comprehensive efficiency was below 0.8. Then it could be marked into two phases: stationary highly efficient phase in 2001—2004 and fluctuation non-efficient phase in 2005-2008, which meant the efficiency of urban park green land was low and unstable; fourthly, scale efficiency had a greater impact on environment benefit than technique efficiency influenced by fixed assets mainly, while scale efficiency was influenced by labor and land. Finally, we proposed some suggestions on enhancing the eco-efficiency of urban park green land in Guangzhou according to the findings. The government should increase input in urban park green land and labors to satisfy the need of environmental benefit outputs, and then control the proportion of input and output stably, especially the inputs. What's more, the supervision mechanisms of budget and the running of funds should be perfected.
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    Study on spacial-correlation between water pollution and industrial agglomeration in the developed region of China: A case study of Wuxi City
    GAO Shuang, WEI Ye-hua, CHEN Wen, ZHAO Hai-xia
    2011, 30 (5):  902-912.  doi: 10.11821/yj2011050014
    Abstract ( )   PDF (1127KB) ( )   Save
    Agglomeration of the manufacturing industries is not only a fundamental driving force for urban development, but also may bring negative effects on regional environment. This study first estimates the degree of clustering of pollution-intensive manufacturing industries in Wuxi City by introducing the Kernel density distribution function, and then evaluates the pollution distribution pattern by dividing the study area into several environmental units according to the naturally integrated characteristics of the primary streams. We also quantitatively analyze the mechanism of the response of water environment quality to industrial distribution by utilizing the bi-variate spatial autocorrelation model. Results show that pollution-intensive manufacturing industries form clusters in suburban and non-sensitive areas. Besides, the density of pollution sources gradually decreases from the chief canals to the peripheral areas. Spatial autocorrelation analysis shows that spatial-relationship show differences according to industry categories: the agglomeration of textile, petrochemical and metallurgical industries prominently affects the spatial heterogeneity of water pollution distribution. However, the effects of food manufacturing and paper-making industry locations are not significant. Based on the spatial autocorrelation between industrial agglomeration and pollution distribution, we divide the study area into four types: high-agglomeration and high-pollution area, low-agglomeration and low-pollution area, low-agglomeration and high-pollution area, high-agglomeration and low-pollution area. Furthermore, we analyze the formation scheme and provide policy suggestions regarding industrial development. This paper provides a new perspective for the study of the interaction between industrial agglomeration and environment effects, which plays an important role in industrial allocation and sustainable urban development.
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    The study of the adaptive 3D Old Sea Level-Land Surface Change Simulation Model based on GIS
    ZHONG He-xiang, XIE Zhi-ren, LU Guo-nian, YUAN Lin-wang, XIN Zhong-bao
    2011, 30 (5):  913-920.  doi: 10.11821/yj2011050015
    Abstract ( )   PDF (1006KB) ( )   Save
    The expression and recognition of geographical environment, the recovery and reappearance of ancient geographical environment have been the focus in some research fields such as geography, cartography, cognitive science and artificial intelligence. As well, virtual geographical environment and the expression of multidimensional spatio-temporal information have become important research directions with the development of GIS. The reconstruction of sea surface change has long been a focus of geography, and in the past years the prediction of sea surface change has also received considerable interest. The recent development of GIS provides the opportunity for the dynamical simulations of sea surface change as well as for its visualizations. It is also an important research direction in the development situation to build the model with functions of forecast, influence and countermeasure, based on the research of the sea level historical change. This model can provide an effective method for sea level change research. In this paper we present an adaptive 3D Old Sea Level-Land Surface Change Simulation Model based on GIS for the above purpose. This model can be used to simulate the old sea level-land surface evolution over coastal regions. With historical records and expertise knowledge, this model automatically verifies the simulation results and adjusts the parameters which controls the simulation; and then iteratively repeats the simulations until the results become close to the recorded history of old sea level-land surface evolution. Compared with other models, this model has the following features: relatively accurately controlling calculation, easily repeating simulations, automatically verifying the calculation results and automatically/semi-automatically adjusting the parameters. We used this model to simulate the old sea level-land surface change of the Yangtze River delta in the past ten thousand years, and it demonstrated pretty good performance.
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    The effects of underlying surface change on floods in Zijingguan watershed
    LI Jian-zhu, FENG Ping
    2011, 30 (5):  921-930.  doi: 10.11821/yj2011050016
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    Flood peaks and volumes have decreased in Daqinghe River Basin in recent years. To search for the effects of underlying surface on flood decrease, Zijingguan watershed in Daqinghe River Basin was selected as a study area, and the statistical analysis of the underlying surface change was done, including land use change and soil moisture storage capacity variation. The remote sensing land use data of 1980 and 2000 were used, and the main change is forest increase, but grassland and arable land decrease. We selected several large floods to evaluate soil moisture storage capacity, and it is 110 mm before 1980, whereas 120 mm after 1980. A hydrological model was established considering underlying surface according to the hydrologic characteristics in Daqinghe Basin, in order to quantify the effects of underlying surface on floods. This model considers different types of land use, and the runoff generation was calculated for each land use type. The infiltration excess and saturation excess runoff generation mechanism was used. Finally, it was calibrated and verified by the historical hydrological data, and the Nash coefficients are about 0.70. It means that this model is consistent with the fact, and it can be used to analyze flood response to underlying surface change in the Zijingguan watershed. We simulated several floods under scenarios of 1980 and 2000, respectively. The results showed that both flood peak and volume decreased as a result of underlying surface change, and the effects are small to large floods, about 5% decrease for 10 years return period. It is shown that transfer of land use types has minor effect on floods, and the increase of soil moisture storage capacity is the main cause of decrease of flood peaks and volumes.
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    Climate risk and economy vulnerability of rice chilling damage and division in Northeast China
    MA Shu-qing, WANG Qi, WANG Chun-yi, HUO Zhi-guo
    2011, 30 (5):  931-938.  doi: 10.11821/yj2011050017
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    Applying calendar weather, rice yield data and chilling injury index of Northeast China, this paper analyzed thermal condition, occurrence frequency and risk probability of rice chilling damage, and developed an evaluation model of the climate risk index of the damage. Thus, Northeast China region is divided into five types of rice climate risk areas of highest, higher, medium, lower and lowest levels. In climate risk analysis, based on considerations the rice cold damage cut rates, total output and the area ratio and other economic loss factors, the economy vulnerability model of the damage was developed, and the region was divided into four type areas of economic vulnerability, i.e., high degree of vulnerability, vulnerability, low vulnerablility and non-vulnerability. Northern and eastern parts of Northeast China is the high climate risk area, the central part is medium risk area, and the southern part is the lower one. Eastern Jilin Province and northeastern Heilongjiang Province are high economy vulnerability areas, eastern Heilongjiang and the eastern hilly land of Jilin are medium or higher economy vulnerability areas, southwestern and central Heilongjiang and central Jilin are lower vulnerable areas, and southwestern Jilin and most parts of Liaoning Province are the non-vulnerable areas. The main technical and strategic measures to reduce the risk and vulnerability are to improve the planting structure, to adjust the rice variety and to use the cultivation technique of resisting the damage.
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    Monitoring glacial variations based on remote sensing in the Luozha region, eastern Himalayas, 1980-2007
    LI Zhi-guo, YAO Tan-dong, YE Qing-hua, TIAN Li-de, LI Chao-liu
    2011, 30 (5):  939-952.  doi: 10.11821/yj2011050018
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    Based on the topographic maps in 1980, 1988/1990 Landsat TM, 2000 Landsat ETM+ and 2007 ALOS AVNIR-2 remote sensing data, the glacier boundaries in the Luozha region of eastern Himalayas in the four periods were manually mapped in the false-color image by on-screen digitizing. Spatial-temporal distribution chara and changes of glaciers were analyzed by means of geographical information system and remote sensing technologies. Moreover, the reasons for glacial changes were investigated with the aid of temperature and precipitation data covering that period. The results showed that: (1) From 1980 to 2007, the total glacier area decreased from 491.64 km2 to 410.87 km2. The overall loss was 80.76 km2, or 16.4% of the whole glacial area in 1980. (2) The inverse relationship between initial area and change rate indicated that small glaciers receded faster than big ones. As the number of glaciers with area less than 1 km2 was 236, accounting for 71.7% of the total number of glaciers, the glacier system of Luozha region may be very sensitive to climate change. (3) Glacier melt mainly occurred at area below 6500 m, accounting for 98.8% of the area loss of all the glaciers in the study area. (4) During 1980-2007, the glacier areas reduced on all slopes, while the larger area loss happened on the lower slopes. (5) The area reduction of glaciers facing east, southeast, south and southeast was larger than that of glaciers facing north, northeast, west and northwest during this period. (6) The retreat rate of eastern Himalayan glaciers was faster than that of central and western Himalayas, and the Himalayan glaciers retreated faster than those in the hinterland of the Tibetan Plateau. (7) Finally, rising temperature along with little change in the precipitation in the Luozha region was the main factors that caused glacier retreat.
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    Seasonal variations of stable oxygen isotope in surface snow and vapor transportation at the headwaters of Urumqi River, Tianshan Mountains
    LI Ya-ju, ZHANG Ming-jun, LI Zhong-qin, WANG Sheng-jie, WANG Fei-teng
    2011, 30 (5):  953-962.  doi: 10.11821/yj2011050019
    Abstract ( )   PDF (1113KB) ( )   Save
    Discussion on δ18O values in 40 samples of surface snow collected from September 2002 to December 2005 on the east branch of Glacier No. 1 at the headwaters of Urumqi River, eastern Tianshan Mountains (43°06'N, 86°49'E, 4130 m a.s.l.) is presented. Seasonality of δ18O values in surface snow is analyzed, as well as the effects of different moisture transportation on δ18O values in atmospheric precipitation. The research result indicates that a significant seasonal variation of δ18O values is found in surface snow, which is similar to air temperature in tendency; δ18O values in wet season is generally above that in dry season, with the range of 12.59‰. There is a positive correlation between air temperature and δ18O values. However, many factors may contribute to the variation of δ18O values during post-depositional process (e.g.snow drifting, seasonal snow melt water, surface snow refreezing and mass-exchange between snow and atmosphere), and alter the significant relationship between air temperature and δ18O values in surface snow. And the coefficient is high in wet season (0.76) and low in dry season (0.57). Different transmission source of moisture is another main factor affecting the seasonal variation of δ18O values in precipitation. Transportation distance and characteristic of vapor have a certain influence on variation of δ18O values in precipitation. Based on the HYSPLIT air trajectory model, vapor source in dry season is closely related to water transmission controlled by Westerlies, while that in wet season is strongly influenced by regional and local air mass. And at the junction for different seasons, both the two sources have effect on this area.
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