Place attachment is a hot topic in place study which is defined as an individual’s cognitive or emotional connection to a particular setting or milieu, which attracts a great concern of researchers in the field of human geography, urban sociology, community science, environmental psychology, and behavioral science. However, place attachment study is seldom related to event venue. A literature review shows that most researchers treated event as an attribute of event host community to study the place attachment between people and host community, but paid little attention to event venue itself. As an inductive research approach, grounded theory is appropriate for situations where no pre-existing theory exists, which indicates its usefulness for the exploratory study on place attachment in event venue. The primary purpose of this study is to document the meanings event-goers attach to a specific event venue. If those meanings are known, managers can more effectively plan for the management of venue deemed to be special by their constituents. As an exploratory research, the International Horticultural Exposition, 2011, Xi'an (Expo 2011 Xi'an, China) is taken as a case, and first-hand data are collected from observation and interviews. The task of observation and interviews is to find out what factors in venue significantly affect the cognition and emotion of event-goers. Interviewees were asked to respond to a series of instructions regarding the venue of Expo 2011 Xi'an, China. The instructions are as follows: 1) describing in a few sentences what the venue is like—for example, what the venue looks, sounds, smells, or feels like, important features presented, and so on; 2) describing the thoughts, feelings, memories, and associations that come to mind when they think about this venue; 3) why this venue is important or special to them. To ensure diversity in types of event-goers in levels of experience, a systematic sampling strategy is employed. On-site sampling is divided into six days (four week days and two weekend days) from June 5 through July 20, 2011. A total of 21 respondents provid key messages for theory construction. Then the attribute of event venue attachment is analyzed from aspects of behaviors, attitudes and emotions of event-goers. The dimensions of place attachment in event venue based on grounded theory are refined and summarized through three analytic procedures: open coding, axial coding, and selective coding. In open coding, the article extracts 68 native concepts in conceptual stage and forms 16 categories after categorization. The atudy establishes relationships among categories and forms four main categories in axial coding: person, society, place, and event (PSPE). Finally, a PSPE conceptual model of place attachment in event venue is contructed after selective coding. Person and society belong to human dimension. The perception object of people is a combination constituted by event and host community. Local factors and distinctiveness of event are integrated in the event venue. The article takes event dimension apart from place dimension, and further subdivides human dimension into person and society, which makes subjectivity and dominant nature of place attachment in event venue more clear and accurate.
Competition and cooperation of tourism destinations have been widely discussed for both academics and tourism practitioners. This article aims to examine the competition and cooperation relationship of oligopoly scenic areas from a game theory perspective. In particular, Bertrand model is firstly employed to analyze the competitive strategy of scenic areas under oligopoly environment, and the optimal ticket price under equilibrium is further identified. Secondly, boxed pigs game model is introduced to examine the cooperation of scenic areas for infrastructure investment under different scenarios. The results indicate that under the scenario that significant difference exists in the competitive power of scenic areas, the scenic areas with less competitive power are capable of increasing their tourist arrivals by free riding, whereas for other scenarios, all scenic areas involved either prefer to share the investment cost together or be not willing to invest at all. Finally, the theoretical conclusions are verified by the analysis on the two cases of Ngawa and the Southern Anhui in China. Here the Game theory is introduced to market behavior analysis of tourist attraction. Based on Bertrand equilibrium and boxed pigs game model, this artcile discusses the competition and cooperation of scenic areas under different scenarios. The results indicates that when the competitive powers among scenic areas are significantly different, then in the short term, the best competitive strategy for the scenic areas with less competitive power is to follow the prices established by the scenic areas with greater competitive powers. In the long term, tourist areas with less competitive power could improve themselves by promoting their brands, emphasizing the product difference, and being a free rider regarding with investing in infrastructure construction and promoting in potential tourist source markets. As for two scenic areas with similar competitive powers, they could enhance their competitive advantages by cooperation on branding and marketing the tourism destination as a whole, constructing internal transportation network together, and sharing human resources, information and other resources. This article analyzes the competition and cooperation under the assumption of complete market economy environment. Therefore, each scenic area is treated as an independent rational economic man and the impact of government is not considered. However in China, the governments play important roles in tourism market. For example, they are often the owners and managers of some scenic areas; they act as the supervisors and regulators of price competition in the tourism market; and they are largely involved in the cooperation amongst scenic areas, promotion of tourism destination and investment of tourism infrastructure. In the future, the impact of government on the cooperation and competition relationship between scenic areas could be further examined. Moreover, this study analyzes the competition and cooperation for the duopoly market structure. In the future other market structures should be also considered.
The acquisition of detailed population distribution has become an important research topic in the fields of geography and its relative disciplines. Urban population distribution is of significance in the correlation analysis among economies, environment protection, resources utilization and urban planning. In recent years, grid transformation of population data based on GIS and RS technologies has become the focus of population spatial distribution. Many transformation models (digital population model, kernel estimate model, gravity model, etc.) and high resolution RS images (ETM image, land use data and aerophotogrammetry image, etc.) are used. The existing researches mainly use the top-down models. The applications of them are limited since there are too many parameters to determine or too complex to execute. Urban population distribution is a typical bottom-up macroscopic phenomenon caused by individual migration at the microscopic level. Multi-agent technology provides a new solution for such problems. It has been widely used in the field of land-use simulation, land-use planning and residential segregation. This article analyzes the importance of spatial distribution of urban population data. To overcome the disadvantages of traditional methods, a framework based on multi-agent system and GIS is proposed to model the spatial distribution of urban population data. This framework consists of external environment controller, housing infrastructure, multi-agent and rule. Impact factors, such as traffic accessibility, education, environment and living facility have been chosen and quantified by GIS. In the framework, each agent represents a family. Within the consideration of economic conditions and school-age children, agents are divided into six categories. The impact factor weights in each category are determined by AHP. Residential land has been rasterized into regular residential cell in initial condition; each residential cell has the same amount of agents. Whether an agent migrates or not depends on the residential pressure, and the probability of leaving its current location increases monotonically with the residential pressure. Under the residential pressure of socio-economy, every agent decides whether to leave the residential location or not. If an agent decides to leave, it must select the optimal location to migrate according to the constraints such as incomes and perception of the environment. If the target location has been full of agents, the migrating agent must consult with every agent living in the target location. Exponential function is introduced to represent the probability of successful consultation, which depends on the utilities in target location of two consulting agents. The population distribution is formed by means of decision-making, consulting and migration of agents. The proposed model is applied to simulating the population distribution of two districts in Guangzhou, Guangdong Province, China. Compared with the gravity model, the model proposed in this article achieves higher accuracy and is closer to the actual distribution pattern. In a conclusion, the simulation model based on multi-agent technology can provide a new method of modeling urban population distribution.
As an important transportation facility of modern society, the expressway shortens the regional space-time distance and satisfies people's desire for speed and efficiency. It has changed the mode of production and people's lifestyle immensely and quickly becomes the artery of regional transportation network and important bridge of regional logistics. In order to give a comprehensive study of the influence situation and difference of expressway on regional development, the research designs the "indices selection-weight determination and modification-evaluation calculation" assessment process of the expressway's influence on the regional development. From economic, social and environmental perspective, it establishes index system, and structures DAEF model based on Delphi method, Analytic Hierarchy Process (AHP), Entropy method and Fuzzy Comprehensive Evaluation Approach (FCE). This assessment system is applied to the empirical study of Shandong Province in order to examine its scientificalness and practicability. The assessment system can reflect the situation of expressway's influence on the regional development accurately. The expressway has more and more important influence on the development of Shandong Province; it has a positive effect on regional economy and social development, on the contrary, has a negative effect on regional environmental change. The system also can reflect the variation of sensitivity of various index for expressway's responses. The assessment system can reflect spatial difference of expressway on the regional economy and society accurately. The expressway has a stronger influence on current area of Shandong Province than its potential one. The expressway economy and social influence in each area has a decreasing trend from east to west. There is a phenomenon that the north is more strongly influenced than the south in the middle part, namely, the influence of the expressway on the "Shandong Peninsula Blue Economic Region" and "Metropolitan circle of Jinan" is the strongest, the influence on the "Huanghe River Delta Effective Eco-Economic Region” takes the second and the "Lu-Nan Economic Belt" is the least. The expressway's environmental influence on two areas is roughly equal, even sometimes the influence on current area is weaker than that of potential area. The demonstration has been examined. The assessment system can reflect the situation of expressway's influence on the regional development and spatial difference of expressway on the regional economy and society accurately. But the assessment of regional environment influence is not ideal enough. The direct performance is that the classification effect of influence degree is not obvious. The reason is the monetization of expressway's environment externality is difficult to realize. The demonstration data is calculated out based on the statistics which uses administrative units as the basic calculation units, rather than the single calculation of each expressway's O-D volume. The monetization of expressway's environment externality will be the improved emphasis and basis of the assessment system.
Focusing on Fujian Province with counties and cities as the basic research units, the study uses weighted average travel time as an indicator to analyze the accessibility patterns of highways within Fujian Province and those between Fujian and other provinces, as well as those of railways, ports and civil aviations respectively. Then, with the result of these patterns, the accessibility patterns of integrated transportation are elaborated. Finally, the proportionality of transportation space distribution is discussed. Basing on classification method of resources intensive, the selected 28 kinds of manufacturing industries can be classified into resources-intensive manufacturing, labor-intensive manufacturing and capital-intensive manufacturing. Then by Average Concentration Rate, industry centralization is calculated. Selecting 13 variables in the aspects of endowment factors, external economies, scale economies and policies to do regression analysis of influencing factors on the spatial distribution of manufacturing. The results indicate that: the accessibility of integrated transportation in Fujian Province decreases from the central coastal area to the periphery with the accessibility of highways within Fujian Province presenting an obvious circle structure, and the accessibility of highways between Fujian and other provinces taking the shape of "﹟", while railways, ports, and airports form a saddle-shaped pattern of high accessibility around Fuzhou-Xiamen-Quanzhou area. The integrated transportation net shows a zonal distribution. The different types of manufacturing present the different characteristics in spatial distribution: the high value area of manufacturing average concentration rate show an annular distribution and the low value area is distributed dottedly, which coincide with the "sag area" of transportation accessibility. There are strong positive correlations between transportation accessibility and manufacturing industries agglomeration, but the correlation degree is different in various types of manufacturing. For example, transportation accessibility has a low correlative rate with the resources-intensive manufacturing. In addition, the determinative factors of manufacturing industries agglomeration in Fujian Province also include agriculture abundance, natural resources endowments, knowledge spillovers and relative enterprise scale .
This article focuses on the establishment of virtual network for regional material circulation. Constrained by a variety of geographical environment factors, circulation of materials in the region with complex terrain is not so easy, which include goods, energy, and production tools. Thus, it is of great importance for regional development to establish a material circulation network with the smallest resistance. Virtual network for regional material circulation utilizes the shortest path analysis function of Geographic Information System (GIS) to generate, display and simulate the path network for regional material circulation with the smallest resistance under the influences of various geographic environment factors. In this study, GIS software is utilized as the analysis platform, Jinsha River basin (middle section) with complex terrain is taken as the case study object, factors such as geomorphology, topography, vegetation coverage, and land use types are selected as the indexes to evaluate the resistance of material circulation. And expert evaluation and grey correlation analysis are employed as the evaluation methods to establish the virtual network for regional material circulation with smallest resistance in the region. In addition, the material circulation among the various cities in the region is further analyzed based on this network. Studies and discussions are conducted to find out the method for establishing the optimum virtual network for material circulation in the region with complex terrain. As a result, the virtual network for material circulation can be provided as a scientific basis for the optimum route selection of roads, pipelines, and power grids in the region, and the analysis result of material circulation among cities can be provided as a reference for regional planning.
School is one of the important elements in the public service facilities. Its spatial distribution and accessibility will affect the chance and convenience of students to go to school. The accessibility plays an important role in the planning location of schools. On the one hand, we can use it to adjust schools which exist already, on the other hand, we can use it to choose location for new schools. So the article takes the accessibility into account in schools planning. Using MapX and Delphi, the article develops information system, by which the route can be chosen based on the shortest time and the isograms and service converge maps of schools accessibility can be generated. By this way, the time and route of any point in region to go to school can be attained. Based on traffic network, this article evaluates the accessibility of senior high schools in Yizheng City. Some conclusions and suggestions are drawn as follows. The shortest time to go to school is less than 30 min. The most accessible regions are distributed mainly around Zhenzhou Town, Chenji Town and Puxi Town whose accessibilities are less than 10 min. Outward the three towns, the accessibility weakened gradually. The worst accessible regions are distributed in Hexiang Village, Qianke Village and Shuangjian Village of Dayi Town, Lixin Village of Chenji Town, Changshan Village of Qinshan Town, Shuangqiao Village of Puxi Town, Fangqiao Village of Xinji Town, whose accessibilities are between 20 min and 30 min. As for the capacity of senior high schools, the capacities of Nanjing Normal University Affiliated 2nd Senior High School, Jingcheng Senior High School, Chenji Senior High School and Puxi Senior High School have not met present students' demands, but Yizheng Senior High School,Yizheng 2nd Senior High School and Yizheng Industry Senior High School have a surplus capability. At last, the article proposes some planning assumptions, such as combining Yizheng Senior High School and Yizheng 2nd Senior High School, improving the conditions of Chenji Senior High School, increasing investment appropriately to Nanjing Normal University Affiliated 2nd Senior High School, Jingcheng Senior High School and Puxi Senior High School.
Based on the analysis of general variation characteristics of land price in Jiangsu Province, this article attempts to build a GWR model for residential land price in urban areas designed to study the factors responsible and the spatial variation characteristics in 1997, 2005 and 2008. The study reveals the degrees of the influential factors and regional differences on land prices, and explores the theoretical research of spatio-temporal variation laws of the factors that contribute to urban land price. The results show: 1) the distance from a central city to residential lands produces negative impacts on the land price, and the average of the absolute value of the regression coefficient increases gradually over the three years with a gradual expansion of high value areas; 2) GDP is positively correlated to residential land price, and the regions where GDP has the most powerful influences on residential land price shift gradually to the northern part of Jiangsu Province; and the number of areas with high value reduces gradually; 3) urbanization rate shows a positive correlation with residential land price, in the sense that from spatial perspective. In the areas along Changjiang River which link the central and southern parts of Jiangsu Province, urbanization rate exerts increasing impacts on residential land price, whereas, from temporal perspective, urbanization rate produces decreasing effects on residential land price; 4) outbound traffic condition shows a positive impact on residential land price, and the regression coefficient in the southern part is fairly high but gradually decreases from the south to the north; from temporal perspective, its influence shows an upward trend; 5) the number of employees is positively correlated to residential land price; the regression coefficient in the southern part of Jiangsu Province is fairly high and the absolute value of regression coefficient gradually increases from the south to the north; besides, the number of employees produces more effects on the southern part than on the northern part of Jiangsu Province; 6) the regression coefficient of the total real estate investment in the northern part is fairly high, and it gradually declines from the northern part to the southern part; the total real estate investment is more influential to the residential land price of the northern part than to that of the southern part of Jiangsu Province.
The industrial transfer theories based on cost difference analysis explain the driving forces and direction of industrial transfer at the macro level, but failed to explain in the geographical location of enterprises in the transfers. In fact, location selection of enterprises in the transfers do not only depend on economic factors such as labor cost, tariff cost, and transportation cost, but also the different social networks of the places where it migrates out and resettles in. From the perspective of the “embeddeness” social network of the enterprises, this article analyzes the role of social network in the transfer of garment industry from Shanghai to Ningbo. It finds out that the “Hong Bang Masters” working in Shanghai garment industry has been a key factor for the transfer of garment industry in Shanghai. In the early development of garment industry in Ningbo, “Hong Bang Masters” was the bridge between Shanghai and Ningbo garment enterprises. They had not only introduced processing business to the Ningbo garment enterprises, but also established networks between Shanghai and Ningbo garment enterprises, thus, helping the Ningbo garment enterprises obtain a large amount of processing businesses. Besides, these “Hong Bang Masters” had provided technical guidance to the Ningbo garment enterprises in person or by introducing other garment technicians.
Urban spatial expansion is an inevitable result of regional development. It is important to find out the expansion mechanism so that we can control the region in harmony. Based on the land use data of Shiyang River Basin, combined with a variety of models including lacunarity index, fractal correlation coefficient, expansion intensity index, spatial association measurements and semivarigram, the investigation of the process and pattern of urban spatial expansion from space and time scales was analyzed in the paper. The results showed a urban spatial expansion in Shiyang River Basin in 20 years. And it concentrated along the Shiyang River , Danla Highway 045 and State Road NO.312. There is a little change of township land. It expanded with "point - axis" mode significantly. That becomes the unique expansion of inland cities. And a reference about Shiyang River Basin of various regional planning was provided in the article.
Natural disaster is the hotspot question in international society and academy. Coastal cities are important areas and strategic focus of people convergence, national economy and society development. However, natural disasters occur easily and frequently in these areas. Tianjin Binhai New Area (TBNA) lies in the center of the Bohai Rim Region. Following the Shenzhen Special Economic Zone and Pudong New Area, TBNA becomes a new polarization of economic development which drives regional growth. Affected by physical-geographical conditions and human activities, however, TBNA is one of the areas where the loss from natural disasters is huge and fatal in the coastal areas in China. In view of the main causing factor, the numerical model of land subsidence was established. With three groundwater extraction scenarios, the computer program was compiled to predict the land subsidence in the process of dynamic changes of groundwater level. Based on the complex dynamic multi-hazard risk assessment theory, in accordance with population planning, land use planning and socio-economic development plan of TBNA, and according to prediction of land subsidence and sea level rise, three scenarios were designed, that was the most unfavorable, moderate, and the most ideal scenarios. Pearson-Ⅲ distribution method was used to calculate intensity of the different frequency’s maximum rainstorms in 24 hours by rainstorm data of the past 40 years at 14 hydrological stations in TBNA and its nearby regions. Inverse distance weight and Disjunctive Kriging method were respectively employed to interpolate the different frequency’s maximum rainstorms in 24 hours. The calculation model of flood submerged area was therefore established by GIS. The submerged area and depth were calculated by the module of “non-source flood”. On the basis of the loss rate of different submerged depth, the submerged loss was gained. The results showed that, by 2020, under Scenario 1, the submerged area is 32.73%, 29.34% and 26.01%; inundated population accounts for 338×104, 305×104 and 264×104; and the loss of submerged is 220.89×108yuan, 181.39×108yuan and 139.12×108yuan respectively induced by torrential rain with return period of 1 000, 200, and 50 years. Under Scenario 2, the submerged area is 30.70%, 27.47% and 24.23%; inundated population accounts for 318×104, 289×104 and 248×104; and the loss of submerged is 199.68×108yuan, 150.31×108yuan and 126.03×108yuan respectively induced by torrential rain with return period of 1000, 200, and 50 years. Under Scenario 3, the submerged area is 29.06%, 25.83% and 22.58%; inundated population accounts for 300×104, 268×104 and 224×104; and the loss of submerged is 174.48×108yuan, 135.29×108yuan and 111.53×108yuan respectively induced by torrential rain with return period of 1 000, 200, and 50 years.
Qinling range has been recognized as the geo-ecological boundary between subtropical and warm-temperate zones in the eastern China, which is the advantage of regional area to study global change. This article, based on the meteorological data of the 61 meteorological stations in the northern and southern regions of the Qinling Mountains (1961-2009), selecting the contour 1 000 m in southern piedmont as the ecological boundary line, analyzed the fundamental characteristics, spatio-temporal distribution and reasons of temperature change using methods of linear regression, Mann-Kendall mutation test, analysis of wavelets, Kriging interpolation and other Climate diagnosis method. The results show that the average temperature, extreme high and low temperature in the south and north Qinling Mountains were in increase trend, but there was a certain difference in the sharp change time and range. The tilt rate of annual average temperature in the south of Qinling Mountains is the lowest (0.121℃/10 a),then is in the north of Qinling Mountains (0.203℃/10 a),and they all lower than the other regions of China (0.26±0.032℃/10 a). The temperature mutation of the north of Qinling Mountains (1995) occurred earlier than that of the sorth (1998), which was later than the other regions of China (1993). Based the climate characteristics, it was found that the influence of climate change mainly reflects nature and human activities.
One of the significant environmental consequences of urbanization is the urban heat island (UHI), which is associated with underlying land surface types and land use patterns. Selecting Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) data of Suzhou City obtained on 1986 and 2006 separately, the paper used the maximum likelihood classification method to extract underlying surface types based on raw visual and near infrared bands, normalized difference vegetation index (NDVI), modified normalized difference water index (MNDWI) and digital elevation model (DEM) data. Then landscape pattern indices changed with different grain sizes were discussed and its variation characteristics were analyzed within the optimum grain size. Furthermore, land surface temperature (LST) was retrieved from thermal infrared bands by an emissivity-modified model and then it was used to get distribution of thermal field variance indices. Lastly the paper discussed the relationship between changes of landscape pattern indices and variation of thermal environment. Research results show that landscape pattern indices depend on grain size clearly, the most appropriate spatial grain size is from 120 m to 150 m. There is an evident development of the UHI, combined with year 1986, thermal field variance index increase in 2006 as a whole. Fragmentation degree, the shape complexity of the patches and landscape diversity increase while the clustering degree decrease, and furthermore the landscape pattern indices change more clearly in regions where the thermal field variance indices increase, which indicate that change of underlying surface pattern has an effect on local thermal environment.
Based on the daily maximum air temperature data from 90 meteorological stations in the period 1960-2009, the climatic characteristics and the spatio-temporal variation of high temperature days (HTDs) in North China were analyzed by using the statistical methods including trend analysis. The results show that the HTDs are more in the south and less in the north on conditions that 800-meters elevation contour serves the boundary. There exist two high value centers, which is located in the south of Hebei Province and the regions from southwest of Shanxi Province to Zhengzhou and Xuchang of Henan Province respectively. The most annual mean HTDs reach 25.7d, which occurs in Yuncheng of Shanxi Province. The HTDs are mainly on the decrease in the south of North China and on the increase in the north. The most obvious decrease in HTDs occurs in Kaifeng of Henan Province and the linear trend is -2.8d/10a. The most obvious increase in HTDs occurs in Hequ of Shanxi Province and the linear trend is 1.51d/10a. The HTDs in recent 50 years has a distinct decadal evolution of increasing-decreasing-increasing. The high temperature mainly occurs during May to August, especially in June and July. Compared with the HTDs in the 1960s, those in the 2000s are slightly on the increase during July and on the decrease during May and August. The accumulated high temperature process (HTP) is on the detectable decrease, while the moderate HTP is on the detectable increase. As far as the HTP lasting day number more than 5 days is concerned, the number in Beijing is less than Erenhot and the number in Zhengzhou is 3.3 times as many as that in Beijing. There exist some difference in the era and month of HTP between the south and the north .
Based on soil relative moisture data in ten days from 16 observation stations of Hengduan Mountainous Region in 1992-2010, spatial and temporal changes of soil relative moisture were analyzed in the paper with Kriging interpolation method. The results showed that the soil relative moisture in Hengduan Mountainous Region had been in a increasing tendency since 1992 with the inclination rate of 0.51%/a. The soil relative moisture were high relatively in the southwest and the northeast of Hengduan Mountains whereas low in the southeast and the northwest. The values of soil relative moisture in deep soils were higher than that in shallow soil. As far as the seasonal change, the increasing trend of soil relative moisture in spring and summer were greater than that in autumn and winter.
Six AMS radiocarbon ages combined with the concentration and distribution of element Rb, Sr and Ti, Rb/Sr ratio and magnetic susceptibility are utilized to reconstruct the moisture evolution in the Jianghan Plain during the last 12.76 ka. The multi-proxy integrated indicators of the regional moisture conditions turned from dry to wet after the Late Glacial and progressively became better and reached its optimum period until the mid-Holocene, however, punctuated by several humidity decrease phases. Begin with the severe dry event around 4.42-4.00 cal.kaBP, the environment was dry again in the Jianghan Plain as a whole. It can be inferred that the evolution of moisture condition in the study area was dominated by the East Asian monsoon system which likely be driven by the solar insolation changes on the Northern Hemisphere. As the first time to apply the Rb/Sr ratio and Ti concentration in tracing moisture evolution in a region with typical subtropical humid climate, this study highlights the different effects and consequences of the proxies throughout the paleoenvironment process. Also the regional characteristics of continuously subsided since the Cretaceous period as well as the topography opening down to southeast. What’s more the variations of magnetic susceptibility are well coincided with the transition of Neolithic culture of the Jianghan Plain.
The Wenchuan earthquake caused numerous landslides and collapses that provided abundant loose solid materials for future mobilization as debris flows. The formation conditions for debris flows were changed consequently. Debris flows will be very active for a long time in the affected area. Their secondary disaster, barrier lake, is beginning to appear. Therefore, it is urgent to identify those debris flow gullies which are potential to form barrier lakes following the environmental changes caused by the earthquake. This paper selected the upper Min River from Yinxiu to Wenchuan as study area, analyzed the changed formation conditions of debris flows and the damages of a typical debris flow barrier lake, and interpreted the loose solid materials from TM satellite images and aerial photographs. Then, the identification factors were selected and classified based on the factor independence analysis. At last, the fuzzy matter-element extension theory was used to construct a model to identify potential barrier lakes. The potential future increase in debris flow activity relates directly to the great increase in loose materials. The interpretation results indicated that the area of the landslides and collapses caused by the earthquake is 39.40 km2, accounting for 6.97% of the total study area. Assuming 55% of the landslide and collapse area were their deposition area and the average deposition depth was 10 m, the volume of the loose solid materials can be estimated as 2.13×108m3 which was sufficient for debris flow formation. Based on the factor independence analysis, the volume of the loose solid materials per unit area, the discharge ratio between the debris flow gully and the main river, the slope gradient of debris flow channel, the main river width, and the included angle between the debris flow gully and the main river were determined as identification factors. According to the multi-factor comprehensive identification, among the 55 first-grade gullies, 17 gullies have high probabilities for potential debris flow barrier lakes, 15 have moderate probabilities, and 23 gullies have low probabilities. The most likely debris flow gullies for forming barrier lakes mainly distribute in the middle-to-lower reaches of the study area (Yingxiu Town to Caopo Town), and those with moderate and low probabilities are mainly distributed in the upper reaches of the study area (Caopo Town to Wenchuan County). In addition, among the 17 potential debris flow gullies with high probabilities, 4 gullies already yielded barrier lakes during the 2008-2010 rainy seasons. The remaining debris flow gullies will produce barrier lakes in the future with high probability.
In order to study the vertical distribution function of the sand transport rate of wind-sand flow at different height above the barchan dune surface, the sand transport rates of the isolated barchan dune within 100 cm height with 1 cm division in the interior of the Taklimakan Desert were measured. The piecewise fitting results show that: 1) the vertical distribution pattern of sand transport rate at the windward slope base of the dune did not entirely abide by the exponential function but exhibited an “elephant nose effect” similar to the structural characteristics of the wind-sand flow over the Gobi desert surface. The sand transport rate showed a gradually increased trend in the height of 0-3 cm, but above 3 cm it exhibited an exponential function reduction with the height; 2) The sand transport rate within 0-10 cm above the dune crest exhibited an exponential function reduction with the height ,but above 10 cm it showed a quadratic function reduction; 3) The sand transport rate at the left-wing end of the dune showed a power function distribution with the height, but in 0-20 cm at the right-wing end it showed an exponential function reduction and above 20 cm it showed a cubic function reduction; 4) The sand transport rate of wind-sand flow in 0-60 cm height and above 60 cm over the leeward slope base of the dune exhibited a different forms of cubic function distribution respectively and the sand transport rate showed a parabola-shaped vertical distribution. both the dune shapes and the dynamic character of the wind-sand flow affected the vertical distribution of the sand transport rate of wind-sand flow over the barchan dune surface. Since the windward slope base and surrounding zone were a net erosion zone, sand grains were coarse and sand supply was relatively insufficient, unsaturated wind-sand flow formed and the increase in sand transport rate with height did not entirely show an exponential function reduction. The distribution of sand transport rate at the ends of the two wings of the dune was asymmetric, this is mainly because the asymmetric shapes resulted in different proportional saltating and suspending sand amounts and the difference in wind velocity pulse in the horizontal and vertical directions. The difference in wind velocity at the leeward slope base and the crest of the barchan dune resulted in eddy flow and caused part of sand particles from the dune crest to deposit at the leeward slope, part of sand particles was transported in suspension and the transport rate gradually increased with increasing height, when the height reached a threhold (determined by both the dune height and the dynamic intensity of wind-sand flow) the sand transport rate reached a maximum value, and then it gradually decreased, exhibiting a parabolic distribution.
Based on data and information from newly set-up and original permafrost boreholes, the permafrost temperature and thickness in the Source Area of the Huanghe River were analyzed. The lowest permafrost temperature at depth of zero annual amplitude (DZZA) (so-called the MAGT) in-situ is -1.81℃, and deepest permafrost is 74 m, both are located on the north slope of the Bayan Har Mountains. Most permafrost along the National Highway No.214 (K445-K604) is warm permafrost (with the MAGT>-1℃). However, with altitude higher than 4 520 m in the north slope of the Bayan Har Mountains, and higher than 4 300 m in the Buqing Mountains, the MAGT is lower than -0.5℃. With altitude higher than 4 610 m in the north slope of the Bayan Har Mountains, and higher than 4 420 m in the Buqing Mountains, the MAGT is lower than -1℃. In the Bayan Har Mountains, the MAGT decreases with altitude at rates of 0.47-0.75℃/100 m, and permafrost thickness increase 16-25 m/100 m. Besides, the MAGT decreases with latitude at rates of 0.85℃ and permafrost thickness increase about 20-30 m per degree.
