Urban agglomerations are the most dynamic and potential core areas for the future economic development of China. As the key and optimal development zones of major function oriented zoning in China, urban agglomerations play the roles of strategic support points, growth poles and core nodes in national productivity layout. To begin with, the formation and development of Chinese urban agglomerations indeed dates back to the initial stage of China′s reform and opening-up in the 1980s. It has gone through three stages, namely the embryonic development stage in the 1980s, the rapid growth stage in the 1990s and the sustained development stage in the 2010s. Moreover, there are distinct government-led characteristics for the formation and development of Chinese urban agglomerations, mainly resulted from national and local macro-regulation policies and regional development policies. They involve in both the guidance of national macro-regulation policies and the propensity of key regions′ development policies. Specifically, the related supportive policies and their implementation impact on the formation and development of Chinese urban agglomerations from the 6th Five-Year Plan to the 11th Five-Year Plan can be concluded as follows. Firstly, the policy about regional cooperation and economic zone in the 6th Five-Year Plan is to be the start the construction of Chinese urban agglomerations. Secondly, the policy about three levels of economic zone network in the 7th Five-Year Plan builds the preliminary framework for the construction of Chinese urban agglomerations. Thirdly, the policy about horizontal alliance and balancing urban and rural development in the 8th Five-Year Plan puts forward the integration outlook to the construction of Chinese urban agglomerations. Fourthly, the policy to promote balanced development among regions in the 9th Five-Year Plan drives the formation and development of urban agglomerations in the central and western regions of China. Fifthly, the urbanization strategy in the 10th Five-Year Plan points out the overall direction for the construction of Chinese urban agglomerations. Finally, the policy, which first time emphasizes urban agglomerations to be a primary pattern to accelerate urbanization in the 11th Five-Year Plan, establishes the spatial layout for the construction of Chinese urban agglomerations. In addition, in view of the urban agglomerations in different regions, different spatial patterns and different development degree, national government successively implements at least 22 supported policies with the principle of adaptation to local conditions. The policies actively guide Chinese urban agglomerations to ensure their sound and steady development.
The demarcation line of China’s population geography, the Aihui-Tengchong Line or the internationally known “Hu Line” divides China into the east and west parts, based on differences in China's population, geography, climate and economy, all of which are closely associated with the aerosols over China. By using the aerosol optical depth (AOD) data of MODIS during 2000 to 2010, the geographical and climatological distributions of aerosols over China are presented, and the ‘Hu Line” is found also to describe a geographic division of aerosols over China. On the east of “Hu Line” with high population densities in the low-elevation China, the monthly AOD varies from the peak (>0.5) during March and June to the low of around 0.3 in November and December with an annual mean of about 0.45, mostly contributed by anthropogenic aerosols from the human activities. On the west of “Hu Line” with a sparse population in the high elevation regions, the AOD is dominated by the naturally emitted aerosols with an annual mean of 0.25 changing between the high (about 3.0) in the period of April to July and the low (<0.2) from October to January. The positive and negative trends in annual AOD in 2000-2010 are respectively found in the regions on the east and west of “Hu Line”. Asian monsoon has a notable impact on the interannual variability of aerosols over the east region by modulating the atmospheric transport and precipitation washout. Taking example of the AOD anomalies in July 2002 and 2003 for a weak and strong year of south Asian summer monsoon, compared to the 10-year mean value, the AOD values in a weak summer monsoon year (2002) were (0.3-0.6) higher and (0.2-0.4) lower respectively in south and north of Huaihe River. In a strong summer monsoon year (2003), the opposite AOD pattern to the weak summer monsoon year 2002 was distributed over the east region with negative (positive) AOD anomalies in south (north) of Huaihe River. The interannual aerosol variations in the west of “Hu Line” are strongly influenced by dust emission sources in the deserts. The dust weather processes control the natural dust emissions. The maximal AOD of 3.0 in the west China could be brought by the frequent dust storm events from April to July.
China is being at the stage of rapid urbanization. Based on the fifth census data, this paper analyzes the migration structure of China in different administrative and scale cities in the 1990s. The result shows that it is the prefecture cities that plays important role in the Chinese population migration in the 1990s, in which the big cities, especially the mega-cities, take a more significant position. It is also found that there are differences in the migration scale between county-level cities. The average migration scale of county-level city in East China is more than in West and Middle China. For the prefecture and above level cities is more important in the process of China′s urbanization at present and in the future, this article further examines the patial distribution pattern of inner-provincial and inter-provincial migration. It is showed that there are three ladder-like levels for prefecture cities in the spatial distribution pattern of inter-provincial migration: the first level includes the Zhujiang River Delta agglomeration, Changjiang River Delta city group, west bank cities, Beijing-Tianjin-Henan city agglomeration, the core cities of Liaodong Peninsula and a few of provincial capitals in middle-west area. The second level includes most of provincial capitals in middle-west area: Shandong Peninsula urban agglomeration and other eastern cities which are close to Beijing-Tianjin-Henan area, Changjiang River and Zhujiang River. The third level includes other provincial cities of middle west area and other cities which are far away from the core cities of three metropolises in the eastern area. Besides, the circle structure is obvious in the southeast coastal area, while the peak structure is more evident in the mid-west area. With regard to the spatial distribution pattern of inner-provincial migration, it shows that there are great similarities among prefecture-level in population spatial distribution pattern. The first gathering cities are each provincial capital cities. The ESDA technology is used to study the spatial distribution features of migration in cities in China. The result shows strong concentration for spatial distribution. The Zhujiang River Delta agglomeration, Changjiang River Delta city group are the main gather cities in both of inner and inter provincial migration. Furthermore, the migration gathering city range in Zhujiang River Delta area is larger than the Changjiang River Delta. On the contrary, the cities with small migration scales are located in agricultural provinces such as Anhui, Henan, and Sichuan, etc .
After Gottmann introduced the concept of Megalopolis in 1957, the urban agglomeration, as a special form of the urban system, has been the core content of urban geography. Since the reform and opening up, China's urban spatial organization has presented a new trend. Urban agglomerations are emerging as engines of Chinese economy. The State Council of China has also issued a series of important plans to take the urban agglomerations as national and regional growth poles and main form of urbanization. This article reviews the most important domestic and foreign literature on important concepts including 'Megalopolis', 'Desakota Region', 'Global City-Region', 'Polycentric Mega City-Region', 'Metropolitan Interlocking Region' and 'Urban Agglomeration'. Gottmann argued that megalopolis was the hub and incubator of national development. He pointed out there were six megalopolises around the world. Mcgee, based on the actual development of Asia, put forward different spatial pattern namely dasakota. Scott et al. paid attention to the effect of globalization and localization on city and regional development. They argued that global city-regions were the most important actors of the world. Hall et al. integrated research method of economic geography and urban geography to study the polycentric mega city-region. This study was innovative and enlightening. Zhou Yixing argued that the research on metropolitan interlocking region must be based on definition of metropolitan area. Yao Shimou introduced the concept of urban agglomeration systematicly. It is also the most popular spatial concept in China. Chinese scholars have done a lot of work on urban agglomerations, while the concept of urban agglomeration is not clearly defined. Because of confusion on definition, spatial scale of urban agglomeration is uncertain. So it is hard to establish the research paradigm of urban agglomeration in China. Regional and national planning on urban agglomeration is also impacted by this fuzzy concept. It is also necessary for State Council to launch work on definite metropolitan area and urban agglomeration in order to guideline regional and national economic development more effectively. We should follow scientific tradition of the project on Chinese Metropolitan Interlocking Regions, and use the latest sixth census data to clearly define urban agglomeration based on metropolitan area so as to strengthen urban agglomeration research in China. It is also reqired to integrate research method of economic geography and urban geography and carry out an interdisciplinary research. It is also important to study aggregation and diffusion laws of urban agglomeration from different spatial scale, establishing the research paradigm.
Stable isotopes of oxygen and hydrogen play an important role in the research on water transport and exchange. The composition of deuterium (D or 2H) and oxygen 18 (18O) in water is very stable, which would not change with time unless fractionation happens. Therefore, they are good fingerprint of water movement. The fractional process of stable isotope is the key for tracing water cycling and transfer. Fractionation leads to the heavy isotopes enrichment of water evaporation vapor. And isotope composition of plant transpiration vapor is similar to the soil water absorbed by the roots except some halophilous plants. Measurement technologies for the isotope composition are mass-spectrometric method and laser method. Water depletion structure was partitioned by the combination of isotopic method and other method like the eddy covariance system. The plant transpiration accounted for about 6%-90% in different ecosystems or for different growth periods. Isotope compositions of different water sources were compared for the judgment of main root uptake layers. The application of hydrogen, oxygen and carbon isotopes in the leaf water-carbon coupling research revealed that 18O was enriched because of the photosynthesis and transpiration. As the composition of carbon dioxide and water, isotope compositions of 18O, 2H and 13C in leaves could also be used to show the change of water use efficiency which was calculated by the carbon accumulation and water depletion. There still existed some problems in the application of this technique like the upscaling and impact factors analysis while some possible improvements were discussed.
Environmental efficiency is an essential element of eco-efficiency because of its important role in the evaluation of the level of regional green development. Taking the heavy industrial base in Northeast China, Liaoning coastal economic belt, as the study area, this article measures its industrial environmental efficiency and identified factors′ significant function on the transformation of environmental efficiency. In this study, the data envelope analysis (DEA) and stochastic frontier analysis (SFA) are employed in the computation of industrial environmental efficiency of Liaoning costal economic belt over the period of 2001-2009. Then, this study builds a multiple linear regression using Tobit model to identify factors that influence industrial environmental efficiency. The results indicate that, in 2001-2009, Liaoning costal industrial environmental efficiency improved from 0.15 to 0.44, but there was still a gap compared with ideal production status. Industrial environmental efficiencies of the 6 cities in this area were quite different. Panjin had the highest industrial environmental efficiency and Dandong the lowest. Dalian had the best output elasticity as its industrial growth was promoted mostly by the increase of labor force, and had the least reliance upon environmental cost. However, the growth of industrial economy in the cities of Dandong, Yingkou and Huludao still had strong dependence on the increase of environmental cost. There were 4 factors acting on environmental efficiency significantly. They were proportion of heavy industry, capital-labor ratio, proportion of hi-tech industry and citizens′ living standard. The increase of heavy industrial proportion and capitalization reduced industrial environmental efficiency. The development of hi-tech industry also decreased environmental efficiency as it focused on equipment manufacturing and petrochemical industry which produce large amount of waste. Progress of citizens′ living standard increased environmental efficiency for citizens not only demanded more industrial products but also requested better surviving environment. Other factors like ownership, production scale, foreign investment, environmental management did not have significant function. The environmental efficiency did not decrease or increase with the reduction of proportion of nation-owned enterprises or large enterprises. The fast augmentation of foreign investment did not pull up environmental efficiency as expected. As the management of environmental quality did not perform continually, it is not useful in the increase of environmental efficiency. In the future industrial development, in order to raise environmental efficiency, Liaoning coastal economic belt should impair the share of heavy industry, develop the hi-tech industry scientifically without causing more severe environmental problems, introduce foreign investment more prudently without bringing in more pollution and strengthen environmental control.
The questionnaires are surveyed including the passengers’ travel destination, traffic mode choice and the travel distance, etc., in the Nanjing Station of Shanghai-Nanjing Intercity high-speed railway. Collecting the address, industry category, set-up time of 6 145 companies surrounding station within 3 000 m as the study samples, using spatial analysis methods, this article analyzes the distribution of industries and spatial clusters by high-speed railway station. The resluts are as follows. 1) Generally speaking, industry location has obvious circle structure around high-speed station. The company density shows a circle structure with the Nanjing Station as the center and 500 m as the buffer radius. The company density ascends to the top at 1 500-2 000 m, and has break in the point of 2 000 m far from the Nanjing Station. The wholesale and retail industry has the largest number, business service industry in second, science and technology service industry in third. Comparing industry proportion in each circle, we come to the conclution that business service industry, accommodation and catering industry increase gradually at 0-1 500 m, reduce significantly at 2 000 m, which confirms the high-speed railway passengers on business service industry and accommodation and catering industry needs a 1 500 m-radius concentration. 2) The trend of spatial industrial concentration is similar, decreasing with the distance. Owing to the different spatial scales, the location of wholesale and retail industry has most options; transportation industry and real estate industry tend to have a significant traffic location. The accommodation and catering industry, computer service industry, science and technology service industry as well as the resident service industry show homogeneous distribution based on the cluster distribution. 3) There is a significant difference in the spatial distribution of the industry, featured by “higher in the west and lower in the east”. The spatial distribution patterns are generally identified in three modes of concentration. The transportation industry and real estate industry have a "small scatter, large cluster" mode, that is, the spatial distribution of companies show relative concentration and form a single hotspot. The resident service industry, wholesale and retail industry as well as accommodation and catering industry present a “large scatter, large cluster” mode. Business service industry, science and technology service industry and computer service industry have a “large scatter, small cluster” mode. The results above confirm the Ripley' s K function analysis.
Economic geographers have recently attempted to develop relational and evolutionary economic geographies. Production networks and network evolution are both popular in economic geographies. Local production network is a valuable tool by which we can have a better understanding of the global-local interaction. Now the research on local production networks is moving from relatively static analysis to historical and dynamic process study. But there is little writing about the evolution of local production network in the context of China. This article tries to full this gap and takes textile and apparel industry in Chaoshan Region as a case to explore the processes and dynamics of production networks in the context of China’s transition to market-oriented economy. Here social interview is employed as a research method, based on the Ucinet software data. The result indicates that the internal structure of production networks in Chaoshan’s textile and apparel industry has changed from the geographical concentration of enterprises to multi-clusters networks and then to cross-clusters production networks. This change can be well explained by the basic concepts of Evolutionary Economic Geography such as selection, retention, variation and path dependence and path creation. Network evolution is in nature relational evolution between enterprises which were influenced by external environments and different development phases. Some mechanisms including geographical proximity of spin-offs, aggregation economy of enterprise in related industries and relational dependence together make the whole local production network be relatively stable structure of the internal network, which can be called “retention”. However, market and institutional innovation and path destruction induce structural change, leading to the gradual formation of cross-clusters production networks, which can be called “variation”. Finally, this article strongly argues that the evolutionary thinking is helpful in explaining the evolution of local production networks and the evolutionary study of local production networks would offer insightful suggestions for policy-makers. Interaction of cross-border production networks and institutional innovation would be the important research topics of network evolution in the near future.
Responses to the challenge of global warming include research into scope for adoption of low-carbon approaches to resource use. Urban development is faced the transition to a low carbon eco-city, and evolution mechanisms of urban primary energy-related carbon emissions are the premise and foundation for Zhengzhou-Kaifeng metropolitan area′s low carbon eco-city research. The paper estimates carbon emissions and its influencing factors in different periods by carbon emission model and LMDI method. The various influencing factors include population size, economic development level, planting structure, crop yields, crop sown area, energy intensity, energy structure and so on. Especially, evolution mechanisms of fossil fuel-related carbon emissions from 2000 to 2009, primary energy-related carbon emissions and major crops carbon sequestration from 2004 to 2007 are explored using LMDI analysis. In addition, the low-carbon development identification function is constructed to choose the further leading industry. The conclusions can be drawn as follows. 1) Carbon emissions gradually increase per year in Zhengzhou-Kaifeng metropolitan area during the study period, with great difference in amount, speed and structure. Specifically, primary energy-related carbon emissions have a great increase while major crops' carbon sequestrations increase slowly. Coal-related carbon emissions play an important role in total emissions, and biomass energy-related carbon emissions can not be ignored compared with natural gas and crude oil. Fossil fuel-related carbon emissions and primary energy-related carbon emissions of Zhengzhou are higher than that of Kaifeng, while major crops carbon sequestrations of Kaifeng are higher than that of Zhengzhou. 2) Carbon emissions change with the interaction of factors such as economic development level, energy intensity, energy structure, population size, planting structure, crop yields, crop sown area. Economic growth is the most significant effect to promote an increase in carbon emissions. Energy intensity improvement effectively promotes a decrease in carbon emissions. And crop sown area expansion and crop yields increase are significant effect in carbon sequestration with some difference in Zhengzhou and Kaifeng. Because of the data and methods selected in this article, effects of energy structure and planting structure are not very significant. 3) The industry′s complementary development is contributed to reduce carbon emissions in Zhengzhou-Kaifeng metropolitan area, but a variety of industries′ capacity and structure needs improving and adjusting. The improvement of energy utilization technology in new industries, the upgrading and adjustment of traditional industries, the update of urban functions has brought new opportunities for low-carbon development in Zheng-Bian metropolitan area. 4) Low-carbon urban complex ecosystem is an open complex giant system, and mechanisms on carbon emissions of energy-material- information flow are the direction for further study. It is of significant importance to comprehensively analysis the interactive mechanism among different factors, such as population growth and technological progress, economic development and industrial restructuring, energy intensity and land use change. The ultimate goal is to regulate Zhengzhou-Kaifeng metropolitan area into a low-carbon eco-city by exploring the carbon emission discipline in built-up areas, expansion areas, and carbon footprint area in Zhengzhou-Kaifeng complex ecosystem.
Transportation is one of the essential elements in tourism system and the precondition of tourism development. Therefore, a revolutionary mode of transport will have a profound impact on tourism. The high-speed railway (HSR), as the impetus of transportation innovation, has been expanded thought out the world. Based on the analysis on all the useful English documents, this article analyzes the impacts of HSR on other transport modes, travel modes, traveling time, regional tourism revenue, structure of tourism elements in destination and special tourism structure in destination. The conclusions can be arrived that: 1) the overseas researches attaching great importance to the tourism impact of HSR, and relevant researches are rich. 2) The overseas researches involve extensive fields, such as the impacts of HSR to other transport modes, travel modes, traveling time, and regional tourism revenue, structure of tourism elements in destination and special tourism structure in destination. 3) The overseas researches use quantitative and empirical analysis to study the impact of HSR to traveling time and travel modes. Based on the spatial region structure theory and system theory, such as “core-edge” theory, the overseas researches analyze the impact of HSR to special tourism structure by mode construction and mathematical statistics. The domestic researches about HSR are comparatively rare and narrow in China. They mostly focusd on the descriptive study but not quantitative research, and stay on the assumption level. So the empirical research is relatively less. Therefore, the overseas researches on HSR provide a valuable reference and paradigm for us. To strengthen the theoretical and practical research about the high-speed railway tourism can help predict and assess the tourism impacts of high-speed railway objectively, which affords the scientific foundation for the tourism sustainable development in the era of high-speed railway network.
While community is one of central research issues in the field of recreation geography, community involvement is essential premise of sustainable tourism development, and sense of community has been important for the existence and healthy development of tourism community. Properly understanding driving mechanism of community involvement influence on the sense of community is favorable to provide alternative measures in achieving the goal of residents' active support for tourism development in China. Using structural equation modeling (SEM) approach and introducing the two key variables of perceived tourism impacts and personal benefit from tourism, the article builds the conceptual model of community involvement-the sense of community (CI-SC), aiming at exploring the mediate effects of community involvement influence on the sense of community and their transmission mechanism. To test the conceptual model of CI-SC, an empirical survey was performed in several tourism destinations in Anji County in Zhejiang Province by use of stratified sample method. A total of 558 valid questionnaires were obtained. Employing AMOS 7.0, the conceptual model of CI-SC fitted better with the data collected. Furthermore, all the five path coefficients of the conceptual models are proved to be statistically significant at p<0.05 or p<0.001. To be specific, the results indicated that: 1) Perceived tourism impacts and personal benefit from tourism were two mediate variables of community involvement influence on the sense of community, and such of the mediate variables brought significantly partial mediate effects. 2) When perceived tourism impacts or personal benefit from tourism is alone mediate variables between community involvement and sense of community, the partial mediate effect caused by personal benefit from tourism is significantly higher than perceived tourism impacts. When they are simultaneously mediate variables, the partial mediate effect caused by perceived tourism impacts is significantly higher than personal benefit from tourism, and the partial mediate effects caused by them is the maximum. 3) Two paths existed in impact mechanism between community involvement and sense of community, one is direct while the other is indirect mediated by perceived tourism impacts and personal benefit from tourism, and the indirect is slightly lower than the direct. 4) Increase of perceived tourism impacts is not only the importance of improvement the educational level of local residents, but also considerating the situation with the stage of tourism destination development; To improve personal benefit from tourism should meet tourism community residents' desire for economic development aspects as much as possible
With the development of major economic zones (belts) in the three provinces becoming a national strategy and the successive construction of many big infrastructures recently, the economy of Northeast China has been rapidly developed, which obviously accelerates the integration process of Northeast China. Moreover, the improving international environment and increasing cooperation demand remarkably motivate the tourism development of the eastern border area in Northeast China. The eastern border area herein is defined as an area of Northeast China which is close to Russia and North Korea, including territorial ranges of Hegang, Jiamusi, Shuangyashan, Qitaihe, Jixi, Mudanjiang, Yanbian Korean Autonomous Prefecture, Baishan, Tonghua, Benxi, and Dandong. In terms of geographic location, touring resources and historical cultures, the border area definitely plays a leading role in Chinese regional touring cooperation in the northeastern Asia. Touring in the northeastern Asia presently is becoming globally popular, and tourism development will encounter a new breakthrough in regional cooperation of China. Simultaneously, the border area is a main body of Chinese regional cooperation in the northeastern Asia, which bears the reality and feasibility of all-win researching and developing tourism in the international cooperation. The cooperative activities include developing strategies and market strategies of regional tourism, planning and spreading selected touring lines, coordinating foreign negotiation to develop and exploit characteristic touring programs such as border touring and touring abroad, building regional touring network, and establishing market system and business service platform. In this article, based on the detailed investigation and systematic analysis of successful experience of border tourism in China and overseas, the critical issues on cooperative development of tourism in border area are profoundly discussed, aiming to promote the progress of touring chains in the area and the northeastern Asia. Through detailed study of tourism resources advantages, current situation and issues of tourism development, specific suggestions are proposed to regional tourism development of the eastern border area in Northeast China. The developing keys of characteristic touring products is border touring, natural-ecologic touring, ice and snow touring, and culture touring, based on which, the corresponding tourism spatial layout and regional strategic cooperation of “five regions” (i.e., Jiamusi-Fuyuan, Xingkai Lake, Mudanjiang-Suifenhe, Yanji-Changbai Mountains, and Benxi-Yanji touring areas) and “four axes” (i.e., Heilongjiang River, Wusulijiang River, Tumenjiang River, and Yalujiang River touring axes) are also constructed.
The Songhua River area was listed as one of the key areas of “China’s Plan for Expansion of Grain Production Capacity”. The grain production will increase 30% in 10 years according to this plan, this means that grain production will reach 6.5x1010kg in 2020. However, this plan will undoubtedly present a challenge to the local water resources development. In order to evaluate the impact of water development in this area, ten indexes, which were selected base on the analysis of relevant indicators including Socio-economic indicator, water use index, bearing capacity index of water and land resources to population, water supply and demand index and water quality indicators, were used to set up the comprehensive evaluation model of Water Resources Bearing Capacity (WRBC) using Cluster Analysis, Analytic Hierarchy Process (AHP) and Fuzzy Matrix. Firstly the AHP analyses of the indicators provide the weight of each indicator. Five clusters are thus classified to these 10 indicators as follows: water demand and supply 0.229 2, water and land capacity 0.225 7, water quality 0.199 3, water use 0.185 8, and social economic index 0.159 9. Secondly modeling analysis is undertaken to the water resource capacity status in different years. The year 1999 was set as reference year while 2007 was set as present situation. The result demonstrated that the water resources bearing capacity in every year was in the safe condition. Furthermore the influencing factors of the WRBC were analyzed in combination with the specific situation of the research area. Thirdly, the variation trends of WRBC under the condition of increasing grain production were also predicted. In the condition of water use index is 0.6 or less and the better water quality control, the WRBC in the year of 2020 will be safe in the rainfall frequency of 50% as well as in 75%. Further analysis shows that another important indicator-social economic indicator-will contribute greatly on the future water safe to the grain expansion plan. This research proves that it is reasonable to implement the plan for the expansion of grain production capacity in the Songhua River area. Also based on this result, we can draw resolutions that there are still grain increment potential in Songhua River area in the view of water capacity itself.
Intense tropic cyclones, one of the major natural hazards prevailing in Shanghai, cause significant social and economic losses almost every year. In this paper, probabilistic community-based risk assessment is carried out, taking Fululi community of Yangpu District, Shanghai, for an example. The annual exceedance probabilities of the maximum wind speed and accumulated rainfall are calculated based on Shanghai tropic cyclone meteorological data in 1949-2008. Combined with the data interpreted from 4 m resolution aerial photograph acquired in 2006, relief altitude difference data measured by leveling, and damage and loss data by tropic cyclones from in situ investigations, questionnaires and interviews in Fululi, the hazards, elements at risk, and risk under specific scenarios are assessed. The result shows: 1) The annual exceedance probability of maximum wind speed 17.2 m/s is 12%. The largest accumulated rainfall during one typhoon process is 306 mm, and its annual exceedance probability is 1.8%. 2) On the scenario of 12% AEP of maximum wind speed, there are 52 (or 15.3%) buildings with losses in Fululi. 34 of the 52 buildings have losses between 0-100 yuan (RMB), 11 buildings have losses between 150- 200 yuan, 4 have loss of 300 yuan, 1 has loss of 500 yuan, and 2 have loss of 600 yuan. 47 of these, covering more than 90%, are residence buildings. There are 7 buildings with strong wind losses larger than 250 yuan, of which 5 belong to old masonry-timber structure and other 2 buildings belong to old brick-masonry structure. 3) On the scenario of accumulated rainfall AEP equal to 1.8%, the deepest inundation depth is 0.61 m in Fululi. There are 115 (or 33.8 %) buildings that have losses by rainstore, and all these buildings are for residence. Of the 115 buildings, 11 have losses between 0-200 RMB yuan; 55 have losses between 200-500 yuan; 31, 500-1 000 yuan; 13, 1000-1500 yuan; and 5, around 2000 yuan. Most of the buildings, covering 77.8 %, with losses larger than 500 yuan are old brick-masonry structure and old masonry-timber structure. According to the investigations, the water depth less than 5 cm causes little damage and loss of the resident properties. When the water depth reaches 15 cm, it will lead to some losses, and if the water depth is larger than 30 cm, it will cause relatively larger losses. Though the strong wind and accumulated rainfall induced losses are not as serious as a big disaster to the residents there, i.e., the risk is acceptable, but it is necessary to make emergency planning to cope with more serious extreme events in future.
Using the meteorological, geographical, agricultural and socio-economical data, the four indexes, including the danger of disaster-causing factors, the sensitivity of disaster-formative environments, the vulnerability of disaster-bearing body and the capability of disaster prevention, were presented and used to analyze the regional difference of cold disaster in Anhui Province based on the natural disaster risk theory. Furthermore, a comprehensive risk index model of cold disaster was constructed to zone the risk of cold disaster in Anhui Province using the above four disaster risk indexes and GIS. Finally, the zonation results were validated by the historical disaster data. The results showed that the cold disaster risk assessment model of Anhui Province was reasonable and objective, and its assessment results were relatively suitable for the fact of clod disaster risk in Anhui Province. Particularly, the high risk zones of cold disaster were mainly located in the northern areas of Anhui Province and the some mountainous areas, and the low risk of cold disaster zones were mainly located near water and cities areas in Anhui Province. Comparing with the historical disaster data, the zonation of cold disaster results were in accordance with the actual distributions. This work provided convincing evidences to assess, prevent and reduce natural cold disaster.
Based on remote sensing data, and combined with groundwater level observation data, the study do an quantitative research for the relationship between soil salinization and groundwater , and explore the salinization reversal evolvement of Wei-ku oasis. The results show that: 1) the annual ground water lowered 0.05 meters in the study area, with a downward trend from 1997 to 2001 year; there was obviously declined in ground water from 2002 to 2007 year, the rate was 0.175 meters every year, which was mainly caused by human activity, human land cultivation, a lot of drilling and utilization of groundwater resources, and the rise and fall of groundwater caused soil salinization.2) the middle-mild saline land has declined by 63.1 km2 from 1989 to 2001 year; while the severe saline land has increased by 342.47 km2 ;the total area of salt-affected ??land increased 279.37 km2,the average annual increase of 23.28 km2. From 2001 to 2007 year, the middle- mild saline land has decreased by 155.42 km2;the severe saline land area has increased by 70.80 km2; the total saline area was obviously decreased by 84.62 km2, at an average annual decrease rate of 14.1 km2. 3) the proportion of salinized land area is relatively high when the ground water level is in the range from 2.3 to 2.7 meters, there was a biggish value in 2.4 to 2.5 meters; the proportion is relatively low when the ground water level is in the range from 2.7 to 3.4 meters; 4) Some parts of Wei-ku oasis has already in a reversal evolvement circumstance which is valuable for soil salinization, the ground water table is below threshold(4.66 meters),which would affect the surface salt accumulation, the groundwater mineralization degree is lower than 3 g/L; 5) Salinization reversal evolvement presents temporal and spatial characters ,and gradually occurs from the upper to the lower,and from the inside to the outside of Oasis.
Geomorphology is one of the most important parts which constitute the elements of physical geography. Based on the GDEM of 1:100000 ASTER, the optimum analysis window was verified and topographic factors were extracted in the unit of drainage area. With GIS spatial analysis and unsupervised classification, the general geomorphologic types in Karst Region were auto-classified. The study results indicate: (1) DEM at the scale of 1:100000 can fill the requirements to express the configuration of earth surface on meso-scale. (2) It confirms the basic regulation to select the analysis window and extract topographic factors taking the drainage area as a unit. Topographic factors extracted can reflect the actual configuration of earth surface more impersonally. (3) Multi-spectral image is combined with topographic factors. With the method of ISODATA unsupervised classification, it can implement the quantification of the general geomorphologic types and automatic classification effectively on meso-scale. The precision of the data extracted can meet the demands of computer automatic classification. These experimental results improve the application of ISODATA unsupervised classification in the automatic classification of geomorphology.
The spatial and temporal characteristics and meteorological conditions for fog formation were analyzed based on the fog data from 80 stations in the period 1971-2005 in Anhui Province. The results show that fogs were concentrated in the Dabie Mountain and the southern Anhui Province. Fog days were of obvious seasonal and inter-monthly variation with wide areas in autumn and winter (maximum), narrow areas in spring and summer (minimum), and most concentrated in October, December and January in most parts of Anhui. Fog usually began at 23:00-08:00 LST and ended at 05:00-12:00 LST (maximum both at 08:00 LST), with duration 1-3 h and maximum 1 h. The yearly variation trend of fog days, different in the spatial distribution, was overall decreasing after increasing in the recent 50 years. Moist air with high relative humidity, weak wind and appropriate temperature benifits the formation of fog.
Based on the daily maximum and minimum temperature data of 1959~2009 at ten meteorological stations in Ningxia Hui Autonomous Region, and using percentile method defined extreme high and low temperature threshold of different stations year by year, this paper studied nearly 51 years extreme temperature variation features in Ningxia Hui Autonomous Region, obtained temperature mutated years in the meteorological stations by Mann-Kendall test, and then applied Pearson correlation coefficient to analyze the correlation between the extreme temperature threshold and the AO index. The result showed that: (1) Both extreme high temperature threshold and extreme low temperature threshold in Ningxia showed very significant upward trend. The increase amplitudes were 0.199℃/10a and 0.62℃/10a for the extreme high and low temperature threshold respectively and the upward trend of extreme low temperature threshold was more significant, so the upward of extreme low temperature was the main character and trend of the temperature change in the nearly 51 years in Ningxia Hui Autonomous Region. (2) Extreme high temperature threshold was high in north and low in south while extreme low temperature threshold was low in north and high in south of Ningxia Hui Autonomous Region. The difference value between the extreme high temperature and the extreme low temperature showed that the temperature changing range of temperature was high in north and low in south of Ningxia Hui Autonomous Region. (3) The mutation time of extreme low temperature threshold in Ningxia Hui Autonomous Region concentrated in the 1980s or so, and the mutation time of extreme high temperature threshold relatively late. The mutation time of the extreme temperature showed that the global climate change had the more influence on the low temperature. The mutation time of Guyuan was large far later than other regions, and the result meant that the mountains around Guyuan would block the cold and warm atmosphere and reduce the global climate change influence on the extreme temperature. (4) From 1959 to 2009, the annual average values, the summer average values and the winter average values of the AO index had rising trend, and the maximum increase amplitudes of the AO index appeared in the winter. The correlation of extreme high temperature threshold and the summer AO index was not significant in Ningxia Hui Autonomous Region, and there had significant positive correlation between the extreme low temperature threshold of the north, centre and the whole area of Ningxia Hui Autonomous Region and the winter AO index. The Arctic Oscillation had little influence on the extreme high temperature while had great impact on winter low temperature in Ningxia Hui Autonomous Region. The high mountains reduced the influence of the Arctic Oscillation on the south of Ningxia Hui Autonomous Region by the block of cold atmosphere, so there had no significant correlation between the extreme low temperature of south of Ningxia Hui Autonomous Region and the AO index.
The spatio-temporal change characteristics of flood disasters in the southern Xinjiang were analyzed using data of the break-down houses, the total area of disaster-suffered farmland, the economic loss and the total amount of death beast in 1949-2008. The situations of flood disaster in each places of the southern Xinjiang were evaluated using grey correlation disaster evaluating model. The results of the study showed that: 1) The frequency and accumulative durations of flood disaster in the southern Xinjiang were obviously increased. The frequency of flood disaster was low within the 1950s and the 1970s, but increased from 1980s. The flood disaster occurred mainly from March to September each year. The frequency of flood disaster in July was most, which was 7.8 times. The second main month for flood disaster was June, which happened 6 times in June. Flood disaster by snow melt happens in spring, while flood disaster by rain storm, snow melt and rainstorm happens in summer, and flood disaster by ice emphraxis happens in winter. 2) The frequency of flood disasters in Aksu and Kashgar were the most, and the duration of flood disaster by rainstorm was the longest. The speed of the increase of flood disaster by rainstorm was fastest. 3) The southern Xinjiang could be divided into strong flood disaster area, moderate flood disaster area and slight flood disaster area, thereinto, Aksu and Kashgar were strong flood disaster areas, Bayinholin was moderate flood disaster area and Kizilsu and Hotan were slight flood disaster areas. 4) The economic loss from flood disaster was gradually increased with the increase of the total value of industrial and agricultural production, and the speed of the increase of economic loss was faster than the economic increase. The paper suggested that the investment for disaster prevention should be increased, and the disaster relief systems should be established so that to strengthen the disaster prevention and control.
