With economic globalization further development and wave of cosmopolitan industrial transfer continuously flowing, the heavy chemical industry accelerated transfers to China, Southeast Asia and other regions, which pluses new science and technology revolution, port development reform as well as the industrialization, urbanization, population employment in developing countries. Many factors are intertwined, so that the spatial relationship between the port and city has become increasingly complex. How dialectically look on the separation and integration of port and city? What does the dynamic trend of their interaction show? These issues are the important subject in port geography and urban geography. Closely around the new changes of the modern seaport city’s spatial evolution in China and taking revealing the dialectical relationship and dynamic changes of interaction between port and city as mainline, this study divides the evolution process of Chinese-style port-city spatial system into 4 stages: the early formation of primitive accumulation, spatial concentration, moved outside the port city of fission, and the bidirectional network development of port-city groups’ classification interaction. It deeply analyzes and depicts the spatial characterization of port-city on various stages. It emphasizes that the inevitable trend in advanced stage of port-city system development is port relocating, and then fission to port-city bidirectional network. Secondly, this article makes a system analysis on the dynamic mechanism of port-city interaction and its spatial system evolution from 4 aspects, that is, the dialectical relationship between relationship evolution and the geographical spatial influences of port-city, the urban geographical spatial impacts on port are endogenous impetus, the impacts of port on urban geographical spatial are in the dynamic changes, as well as the ultimate aim of port-city development in the globalization era. The article considers that the interaction among three forces (action of port on city, reaction of port on city and self-growth effect of city) promotes the evolution and cycling regeneration of port-city system ,and the spatial effect of the port evolution on city is the dominant factor. Finally, the article takes empirical study by investigating some Chinese large coastal port cities to verify the proposed “port-city spatial system” evolution theory of Chinese coastal cities, in order to reflect the new changes on port-city spatial relationship in new era, perfect regional system evolution theory of port city and provide scientific reference for port city’s development.. This article points out that the port-city system of main regional hub ports in current China is in the early stage of port-city bidirectional network development.
Given two potential issues in the current studies in the production of space, i.e. the simplism in application and mysticism in implication, this article provides a concise sketch of the theories or thoughts of David Harvey and Michel Foucault in the production of space based on the existing relevant researches. It is argued that both Harvey and Foucault pay much attention to the issues of production of space and spatiality from two illuminating perspectives which are complementary with each other. Generally, this article sorts out 3 main elements in Harvey’s researches, i.e. capital, class and superstructure; by the same token, three perspectives are summarized in Foucauldian’s studies, i.e. instrumental spaces, productive spatalitis and spatial rationality. Besides the disparities in perspectives, both of them emphasize heavily on the uneven logics behind the processes of production of space and pursuit the emancipation of human beings. We also examined the necessity and feasibility to introduce these figures into the studies in China; some promising fields for future studies are provided after brief summarization and comparison; a freer and more introspective academic atmosphere of current Chinese human geography is advocated based on Foucault’s discussions on power-knowledge and truth.
Regional inequality has always been a greatly significant issue to both academic enquiry and government policy. The recent literature on regional inequality implies that both scale and spatiality have been playing significant roles in the economic geographical processes. Despite the tremendous scholars interest in regional inequality in China since the late 1970s, the current research work ignores the spatial effects in studying China's regional inequality at the county level. Based on the per capita GDP data at the county level from 1998 to 2009, this article analyzes the transition across different classes in the per capita GDP distribution, by a comprehensive application of Markov framework. For per capita GDP, this article distinguishes among 5 classes based on the average of all the 2 345 county units, computes their Markov chain matrix and spatial Markov chain matrix, and then analyzes the changing spatial patterns of the class transitions and their surrounding counterparts. The analysis concludes as follows. 1) The process of regional convergence in China has been characterized by “convergence clubs” since 1998. Furthermore, spatial polarization is discovered. The Markov chain matrix indicates that the richest and the poorest counties do not seem to change their relative position over time. The most affluent counties appear persistent—the 92.9% probability of the richest remaining richest. And 94.1% probability of the poorest remaining poorest is the largest entry in the transition matrix. 2) The robustness of per capita GDP class transitions in China differentiates across the three regional belts. The counties in East China remain the most stable in changing their relative position. By contrast, their counterparts in Central China change their relative position more easily—33.38% of the 701 counties experiencing downward mobility locate in East China, 42.8% in Central China and 23.82% in West China. Among 443 counties experiencing upward mobility, 21.67% are in the East China, 41.31% in Central China and 37.88% in West China. 3) The maps of spatial Markov transitions show that the per capita GDP class transitions in China are greatly affected by their spatial neighbors. Lower-level units are negatively influenced by being surrounded by other lower-level units. Also, higher-level neighbors tend to prevent units from falling down in the per capita GDP distribution. 4) Per capita GDP class transitions in urban agglomerations, such as Changjiang River Delta and Zhujiang River Delta, remain stable, while their surrounding counterparts are active in changing their relative position. The class distribution map also shows “core-periphery” spatial structures in the urban agglomerations and their neighboring counties. More emphases should be paid to the poor county clusters in the eastern and central China, and to the spatial dynamics underlying the changing patterns of regional inequalities in China by the policy makers.
Spatial structure benefits of urban agglomerations have critical impacts on the overall development of urban agglomerations. Thanks to the help of ArcGIS and basic geographic data, spatial structure benefits of urban agglomerations have been defined and expounded in this article. Then, the comparative study between Poyang Lake urban agglomeration and the Great Nanchang urban agglomeration has been conducted from 3 aspects, that is, scale merit, distance effect and spatial association benefit. The research results show that: Poyang Lake urban agglomeration has its outstanding strengths which are larger number of cities and bigger population size, however, some shortcomings of lower compactness, unobvious city hierarchical structure, poor spatial accessibility and weak spatial connection between some important cities coexist. Therefore, the Poyang Lake urban agglomeration exhibits a characteristic of “big & empty”. On the contrary, the Great Nanchang urban agglomeration which has fewer number of cities, smaller population size and poor economies of scale, presents the highlights of higher compactness, obvious urban hierarchical structure, better spatial accessibility and good spatial connection. In order to maximize the spatial structure benefits of urban agglomeration, basing on the comprehensive analysis, a programme of Nanchang urban agglomeration is put forward.
Taking main 9 cities (Changchun, Jilin, Siping, Liaoyuan, Songyuan, Baicheng, Baishan, Tonghua and Yanji) in Jilin Province, which belong to the northeast old industrial base of China as examples, , this article used the weighted mean travel times as indicators by the improved gravity model to calculate the urban accessibility and the economic linkage intensity among the 9 cities. Then, the economic linkage subordination degrees was employed to indentify the economic linkage direction of the cities. Moreover, the ranges of economic linkage scales of cities in Jilin Province were defined by use of gravity breakpoint model and GIS spatial analysis. The results showed that the accessibility level of central area is higher than other areas in Jilin Province, the circle-type spatial pattern of the accessibility level that reduces gradually from Changchun to outside has emerged, the disparity of economic linkage intensity among cities in Jilin is remarkable and the middle cities have larger economic linkage intensity than the northwestern and eastern ones. The traffic accessibility is highly related to the economic linkage intensity, and the economic linkage concentration area has been formed which is in the middle cities with an outward radiating “concentric circle” shape and Changchun as its center. In the east, Yanji has larger economic linkages with the region of Changchun and Jilin, while, in the southeast, Tonghua has larger economic linkages with Baishan. The urban economic linkages of Jilin Province conform to the law of distance attenuation.
Since China’s reform and opening up, with the rapid development of urban and rural economy, China has accelerated urbanization process. By the end of 2011, urban population accounts for 51.27% of total population in China. China has already got to a stage of urban society. Due to the low quality of fast growing urbanization, along with promoting the income growth of peasants, promoting the rural transformation and buffering the conflict between human and land in countryside, the extensive pattern of development also carries a series of negative influences to the healthy and sustainable development of city and countryside. It has been the priority task of China’s urbanization to transform the pattern and improve the quality of urbanization development. Especially on the eastern costal region which has developed economy and higher level of land urbanization, it is of more considerable realistic significance to promote the process of transformation from only pursuing speed to aiming at improving the quality, and from partial urbanization to comprehensive urbanization. Based on specifying the connotation of urbanization quality, the thesis elaborates a quality evaluation index system adapting to urbanization of Shandong Province, with considering 6 aspects, namely the economic growth, the social progress, the demographic development, the ecological environment, the urban-rural harmony, and the urbanization effectiveness. It also employs an entropy method to comprehensively measure the urbanization quality of Shandong Province. According to overall scores, the 17 cities are classified into five categories: 1) high quality urbanization regions; 2) relatively high quality urbanization regions; 3) medium quality urbanization regions; 4) relatively low quality urbanization regions; and 5) low quality urbanization regions. By summarizing the similarities of all these categories, the thesis analyses the existing problems and inadequacies of urbanization of each city in detail and discusses their future developments.
Geological heritage, one kind of important resources with aesthetic value, scientific value, and great conservation value, gets more and more attention from the fields of geonomy and tourism Science. During the protection and exploitation of the geological heritage, the contradiction between the community development and geological heritage conservation and development become increasingly prominent. It is very crucial for geological heritage conservation and development to get support of the original inhabitants. It becomes an important issue whether and how the original inhabitants can participate in geological heritage exploitation. Based on the typical case of the grand canyon geo-park in Huaying Mountain, this article investigated the situation of community participation and the wishes of the original inhabitants in the geo-park by questionnaire and interview, analyzed their attitude toward the heritage conservation and development, as well as the interest demands. The survey showed that, during the heritage conservation and development, the chances of community participation are very limited, but they show strong desires to participate in decision-making, planning, business operations, and hope to share the benefit of the resource exploitation, besides, they expect their participation to get indemnity from the government and exploitation enterprises. Under the existing management system, the article analyzed the driving mechanism of the community participation, i.e. government policies driving, the residents' willingness being respected and the interest driving. It provides a theoretical and practice reference for the study of community participation in geological heritage conservation and development.
The mechanism of coordination and adjustment of eco-ecological system are explored by using coupling degree model and coordination degree model and the neural network model as theoretical basis and factor contribution degree of eco-ecological system in Dongting Lake Area as guidance. The outcomes indicated that: 1) The variation trend of the coupling degree was smooth during 2003-2012, their coupling degrees was basically at resisting stage from 2003 to 2011, and coupling degrees during 2012 were becoming gearing stage. The annual variations order parameter were stable, and trend of development was a dynamic process from disordering to ordering but the result was clearly not ideal. 2) The coordination degrees of economy and ecological environment are lower from 2003 to 2012 in Dongting Lake Area, and transformed into moderate coordination in 2013. The coordination degree of economy and ecological environment in Dongting lake area remains to be further improved. 3) The coupling degree and coordination degrees inconsistent from 2003 to 2005. The variation trend of coupling degrees and coordination degrees are similar from 2006 to 2012. 4) The contribution degree of the evaluation factor of the ecological economic system was put further, which is reflected the impact effects of evaluation of a coupling or coordinate degree. The contribution degree of evaluation factor of ecological system was greater than economic system, which showed ecological system has a more important role than ecological system. 5) There was a positive correlation between the contribution degree and regulation degree. There was greater driving force of the coupling or coordinate when the factor contribution rate was greater.
The key to make scientific decision and to promote soundly and rapidly regional economic and social development is to optimize the urban spatial structure. Based on social and economic data of Zhoukou City, Hehan Province, from 1995 to 2010 and technical analysis such as town construction land area and urban population growth strength index, this article states the present urban development of Zhoukou City: low level of regional urbanization, under-developed urban center, equilibrium development of town layout and integrated urban built-up area of Zhoukou City and Shangshui County. Then, the study deeply analyses the mechanism of urban spatial structure evolution and the trend of center polarized and fan-shaped wild goose queue type circle-layer network evolution orientated by transport and led by characteristic industrial clusters. Finally, it puts forwards related countermeasures: to scientifically plan the regional urban system, to essentially boost the unity of Zhoukou City and Shangshui County, to rapidly form the characteristic industrial clusters, to orderly promote the circulation of rural land, to advance the coordinated development of urbanization, industrialization and agricultural modernization and to enhance the construction of ecological towns in order to optimize Zhoukou urban spatial structure.
The tourist efficiency is one of the central issues of domestic tourism research. By selecting the panel data of 31 provinces in Chinese Mainland from 2000 to 2010, this article firstly used the entropy method to calculate the superiority degree of provincial tourist resources, and then evaluated the relative efficiency of provincial tourist resources by the means of the modified DEA model, and thirdly made an spatial analysis about the evolution of various efficiency by applying the methods of Getis-Ord Gi *, gravity centre, standard deviational ellipses and fractal theory. The results are as follows: the relative efficiency of provincial tourist resources in Chinese Mainland is driven by the pure technical efficiency, which reflects that the intensive growth of tourist resources has made some progress. Generally speaking, the total efficiency of tourist resources in the eastern and middle area is driven by the pure technical efficiency, but the total efficiency in the west is driven by the scale efficiency. Through the analysis of Getis-Ord Gi*, we can find that the total efficiency of the hot-spot areas has not changed greatly, but the hot-spot areas of the pure technology efficiency has transferred from the southwest of China to the Changjiang Delta and its surroundings, and the hot-spot areas of the scale efficiency has transferred from the northwest of China to the Changjiang Delta as well as Beijing and Tianjin. All in all, the gravity centre of the total efficiency and the pure technology efficiency have shifted to the northeast, however, the gravity centre of the scale efficiency has shifted to the southwest. From the perspective of rotationθof the standard deviational ellipses, the total and pure technology efficiencies generally present a northeast-southwest spatial distribution pattern, and the scale efficiency roughly presents a east-west spatial distribution pattern. For the relative efficiency has some fractal characteristics, the various efficiency of provincial tourism resource of China will continue to show growth trend in the future. Constrained by the selected indicators and research data, this study has still some limitations. For one thing, what has been calculated in this article is a relative efficiency, and the result is just a ratio, which has not fully reflected the actual efficiency of tourist resources; for another, the efficiency of tourist resources is a complex problem, also involving in location, economic development, and even the travel mode, this study does not take into account these factors which are also directions for the future research. However, the conclusions of this study are in line with the actual situation fundamentally. As a result, we should increase the investment in capital, technology, talent and change the growth mode of tourism in order to improve the pure technology efficiency of tourist resources; in addition, due to the decrease of scale returns, we should try to avoid only pursuing the amount and preventing the idleness and waste of the tourist resources in the future.
AS the main form of the theme park, the movie and TV theme park attracts so much public attention. The development of movie and TV theme park has played an active role in promoting local tourism development and improving infrastructure construction. However, since the short history of movie and TV theme park in China, coupled with the unreasonable operation and management and so on, most of movie and TV theme park have fell. We can see that the sustainable and stable development of movie and TV theme park is worrisome. For such situation, this article analyzes primarily from the perspective of tourism experience. In experience, tourists are expecting to seek a more unique and profound tourism experience, not limited to sight seeing. The quality of tourism experience is not only an important measure of tourist satisfaction index, but also represents the development competence of movie and TV theme park. Therefore, it is necessary to analyze the movie and TV theme park from the perspective of the tourist experience to attain the better development. This article is divided into four parts. Firstly it introduces the development status of movie and TV theme park, domestic and foreign scholars’ studies about movie and TV theme park and the necessity of studying from the perspective of the tourist experience.The second part introduces Changchun Movie Wonderland, including its basic information and operating condition;the third part is the empirical analysis. This article takes Changchun Movie Wonderland as an empirical research object from the perspective of tourism experience through questionnaires, tourists’ travel network and interviews, using SPSS and EXCEL statistical software for sample analysis, reliability analysis, extraction of 14 factors IPA analysis. By analyzing we come to the conclusion that affecting tourism' experience factors are mainly high ticket,not sufficient time for traveling, low participation index and so on; The forth part is some advice on the basis of the Changchun Movie Wonderland’s analysis. The recommendations are as follows: First, to strengthen the planning and management. Second, to build brand experience. Third, to make rational ticket price from the perspective of the tourist experience. Fourth, to do experiential marketing.
Under the background of global climate change, extreme events occur frequently which can cause intensified natural disaster risk. China characterized with high population density and intensive economy in east-central areas, as one of the countries influenced frequently by typhoon events, the agriculture, population, buildings and economy are threatened significantly by typhoon disasters. The quantitative risk assessment on disaster-bearing bodies and regionally integrated zoning are not just a theory study in risk management, also can offer practical guidance on mitigation and prevention in typhoon disaster. In our study, on the basis of the typhoon disaster mechanism, the vulnerabilities of disaster-bearing bodies were evaluated according to typhoon disaster loss criteria established by applying historical typhoon loss data. In addition, the probabilities of typhoons in each country region were analyzed comprehensively using the indices of landing frequencies and track line lengths. Then applying risk assessment model, the typhoon risks caused by the different intensities were evaluated quantitatively. Synthesized on the risks of the same or the different intensity typhoons for disaster-bearing bodies, the typhoon disaster risk zone for China was divided into nine areas and belonged to three classes (respectively is high, medium and low risk). The high risk areas are located in southern part of Guangxi Province, most of Guangdong Province, coastal areas of Fujian and Zhejiang Province, Yangtz River Delta area, most of Jiangsu Province, some inland counties of Jiangxi and Anhui Province. Based on the above results, the helpful suggestions on prevention and reduction in regional typhoon disaster were put forward.
The Jianghuai Plain, which is located in the margin area of Chinese important climate separatrix—Qinling-Huaihe River, is sensitive to global climate and environment change. It is also located in the monsoon triangle area of China, which is under the influence of the East Asian monsoon. So the area is very important for recording the Paleoclimatic and Paleoenvironmental changes. A sediment core from Jianghuai Plain was chosen for this study. The climate history of the Jianghui Plain during the past 19 230 cal a B.P. was resumed, which based on the analyses of chronology, magnetic susceptibility and Grain Size of YZQ Core Sediments from this area. Since 19 230 cal a B.P., this region climate had a tread of humidity, although the area of Jianghuai Plain had experienced alternatons of relative cold-dry and warm-moisture period. The climate change pattern of the studied area may have global background. On the other hand, it also incarnates evident regional characteristics. During the research period, the paleoclimatic changes history was reconstructed as follows:1) 19 230-14 150 cal a B.P. (633-497 cm): The climate index of grain size and magnetic susceptibility shows the hydrodynamic conditions were too weak to carry materials. The climate environment characteristic was less precipitation in this period. Some short-term climate events occurred under the arid background condition. 2) 14 150-12 950 cal a B.P. (497-455 cm): This period is the interstadial characterized by warm and wet before the end of the Last glacial. Between the warm and wet climate, the cold and arid period must be the Older Drays climate event. 3) 12 950-11 290 cal a B.P. (455-397 cm): The climate was the most obvious dry during our study period. The regional precipitation decreased significantly. And the carrying capacity significantly weakened, resulting in substantial declining hydrodynamic force. 4) 11 290-7 450 cal a B.P. (397-262 cm): The climate index indicates that this period should be hot and humid since the Holocene. There were twice cold and dry fluctuations in 10 300 cal a B.P. and 8 250 cal a B.P. 5) 7 450-4 950 cal a B.P. (262-175 cm): In this stage, the regional precipitation reduced gradually and the climate became warm and dry. 6) 4 950-1 510 cal a B.P. (175-52 cm): This period climate environment was warm and humid. Precipitation was relatively more and hydrodynamic force was strong. During 3 500-2500 cal a B.P., the precipitation and hydrodynamic force had a certain degree of weakening. The climate had a tendency to become cold and dry.
Under the impacts of global climate change and regional rapid urbanization, the extreme high temperature events have increased in the Changjiang River Delta in recent years, which further have serious influence on regional society and economics system and residents' livings. Therefore, it is quite useful and necessary to understand the characteristics of extreme high temperature and their causes for the purpose of prevention and mitigation of disaster. Based on the daily maximum temperature data of 32 meteorological stations in the Changjiang River delta, western Pacific subtropical high (WPSH) indices from Beijing Climate Center, monthly 500 hPa geopotential height fields based on the NCEP/NCAR reanalysis data and daily synoptic situation data in recent years in Shanghai, the long time-series relation between extreme high temperature in the Changjiang River Delta and the WPSH was analyzed in spatial and temporal scales, and the results indicates that there is a significant positive correlation between high temperature days in the Changjiang River Delta and the area and intensity indices of WPSH in the whole year, winter and spring during 1959-2010, but the correlations between high temperature days and the ridge position and the west-extending ridge point position of WPSH are not statistically significant. Spatially, in the middle and southeastern parts of the Changjiang River Delta, there is a significant positive correlation between annual high temperature days and annual area and intensity indices of WPSH, and in the central coastal areas, there is a significant negative correlation between annual high temperature days and annual west-extending ridge point of WPSH. There is a better correlation between monthly high temperature days and monthly WPSH indices in August than in July as a whole, and the correlation is better during 1981-2010 than during 1959-1980 in August. There is a significant positive correlation between high temperature days and the area and intensity indices of WPSH, and a significant negative correlation between high temperature days and the west-extending ridge point position of WPSH in August during 1981-2010. In July or August, there is a positive anomaly of the area and intensity of WPSH and negative anomaly of west-extending ridge point of WPSH when monthly high temperature days are more than normal value. In July or August with more high temperature days, the west-extending ridge point position of WPSH is close to the Yangtze River delta, but in July or August with less high temperature days, the west-extending ridge point position of WPSH is located far away from the Changjiang River Delta. In Shanghai, the weathers are mainly controlled or influenced by system of WPSH during high temperature days in recent 8 years, accounting for 95% of the total high temperature days, but in days when the controlled or influenced systems are WPSH, the occurrence probability of high temperature is 67%, and most of the high temperature days have the daily maximum temperature range from 35.0℃ to 36.9℃.
：The characters of changes of vegetation cover and the interaction between vegetation and the atmosphere is important in geosciences and has become a research focus in recent years. As a sensitive indicator of surface vegetation coverage and vegetation growth status, the Normalized Difference Vegetation Index (NDVI) has been widely used in environmental, ecological, and agricultural studies. Climate change and human activities are both responsible for the improvement and degradation of vegetation cover to a certain degree. Especially, since it was initiated by the government since 1999, the "Grain for Green Projects" is an important contributor to the vegetation restoration in the ecosystem fragile zone of western China. Constituting 85% of the Three Gorges Reservoir area, Chongqing City is in an important ecological, hydrological and wildlife conservation area in Southwestern China. Examining the vegetation dynamics and environmental changes over this region plays a critical role in studying the environment and ecosystems in China. Based on SPOT-4 NDVI data, the spatial and temporal changes of vegetation coverage and correlation analysis were analyzed to distinguish its relationship with temperature, precipitation and human activities. The results show that: vegetation cover changes in Chongqing showed a continued increasing during 1999-2010; vegetation cover increased rapidly during 1999-2004; vegetation cover changes came into a relative steady phase with fluctuations after that; and vegetation cover declined rapidly in drought years like 2005, 2006 and 2010. The vegetation cover changes showed a notable spatial difference. The vegetation cover has obviously increased in the Three Gorges Reservoir area and area along the Yangtze River and the Jialing River. Area of vegetation cover decreased evidently which concentrated in the drowned area of the Three Gorges Reservoir and around the city area. The spatiotemporal variations of vegetation cover are the outcome of climate factors and human activities. Temperature is a control factor of the seasonal change of vegetation growth. There are significant correlations between ten-day vegetation cover and ten-day precipitation and between ten-day vegetation cover and ten-day temperature. Thus, the changes in precipitation, especially the changes in temperature are important factors for seasonal vegetation variation. On the other side, the human factors, such as agricultural production, farmland protection and the implementation of large-scale vegetation construction, have resulted in the increase of annual NDVI and have brought some beneficial effect on ecology.
Due to the presence of same object with different spectra and different objects with same spectrum, the accuracy of remote sensing classification is limited, which is especially obvious in arid region. Turpan Basin, which is the typical oasis-desert interlaced area in eastern Xinjiang, is selected to be the typical research area in this article. The data set in this study includes SPOT images with a resolution of 10 m, DEM and field data. At first, the classification system was built according to land use/cover characteristics of research area. Then common methods such as principal component transformation, tasseled cap transformation and minimum noise fraction transformation were used to extract spectral feature. Vegetation index and wetness index were also calculated based on SPOT image, and 12 spectral features were built using these methods. Finally a classification framework which contains 14 features was implemented by combining DEM and slope. Inter-class separability method was applied to choose the optimum feature combination. Based on spectral and spatial characteristics of different mixed ground objects, and combined with supervised classification results, a decision tree model was built to abstract the land use/cover information. The results showed that decision tree classification based on multi-parameters of land surface could make full use of terrain spectral information and spatial information, and distinguished confusion features effectively, such as different types of desertification land and urban construction land. Accuracy of the method is 88% and the kappa coefficient is 0.76. Its accuracy has been improved significantly compared with traditional classification methods, which have increased by 7%, 10% and 11% than maximum likelihood method, markov distance method and the minimum distance method. The whole process may provide reference for land use/cover real-time monitoring in oasis of arid areas, and it also has certain significance to desertification study. The novel of this article is that the classification system was built according to land use/cover characteristics of oasis. That is different type and different level desertification land was contained in classification system. So wind erosion desertification and salinization information were classified at the same time with other land types. It has certain significance for desertification prevention and control. Due to time restrictions, we only used traditional classification methods to classify spot raw data, and compared its accuracy with the results of multi-parameters decision classification. In the future studies, texture features and other features may be added, and different feature selection approaches can be adopted to compare the influence of different features on classification accuracy.
Landslide is one of the most damaging natural hazards in China, thus landslide susceptibility mapping plays an important role in disaster prevention. Probability-based analysis is the most popular method to evaluate a wide range of natural slope instability risk. But the applications of it are limiting factor for lack of landslides data. In order to evaluate a wide range of natural slope instability risk effectively and quantitatively, this article presents a new method which evaluate regional slope instability risk, combining with two-dimensional mechanical analysis model and Geographic Information System (GIS) method. Firstly, a region is divided into a group of slope zones according to the terrain condition by using watershed hydrology analysis method in GIS. The location of main section line of each slope zone is set according to its average slope inclination and angle. A series of possible sliding surfaces are formed and the minimum safety factor of every slope zone is calculated based on two-dimensional mechanical analysis model. On the basis of calculation results, slope risk zoning map is drawn. A loess gully region in Jintai District of Baoji City, Shaanxi Province, China, is selected as the study area. The proposed method is verified. First of all, the topographic map is changed into a digital elevation model, with the planar range is 3 km×4 km and grid size is 10 m. According to the process mentioned above, the area is divided into 76 zones using hydrology tools. Secondly, the grid layers of strata interfaces are interpolated with the data of stratums, which is obtained from drilling and investigation. And then, geologic model of this area is set up using multi grid layers method. Thirdly, a regional stability evaluation program is developed according to the stability factor of each unit. It can read files in GIS formats, extract sections automatically, access stability, and convert the results into GIS data. Finally, with this program, calculation profile of every zone is generated automatically and the minimum safety factor of every profile is figured out by using 2D Bishop simplified method. The coefficients of the zones are sorted into four groups. According to the groups, regional slope risk zoning map is drawn. The method proposed in this paper is based on two-dimensional limit equilibrium method, which is the most commonly used in engineering. It can obtain not only the distribution map of safety coefficient, but also the scale and location of most dangerous slip surface. The method and program are used in seismic geological disasters assessment in Baoji City, and good results have been obtained. This study provides a new way to evaluate natural slope risk of large area.
Wetland is one of the most important ecosystems, and it has high social benefit, economic benefit and scientific research value. However, wetland resources are taking on a heavy pressure because of various natural and anthropogenic factors. The degradation of the wetland quality and quantity has aroused widespread concerns. To conserve and manage wetland resources, it is important to monitor wetlands and their adjacent uplands. Satellite remote sensing has several advantages,such as saving time and labor, multi-temporal, multi-platform, containing large amount of information and so on,for monitoring wetland resources, especially for large geographic areas. This review summarizes the literature on satellite remote sensing of wetlands, including the data source of remote sensing images used in wetland study, remote sensing classification methods of wetland, the survey of wetland, wetlands ecology and the survey of wetlands environment. Nowadays, Landsat TM, Landsat MSS, and SPOT images are the major satellite images that have been used in wetlands research; Other images including NOAA AVHRR, IRS-1B LISS-II, MODIS images and radar images, and JERS-1, ERS-1 and RADARSAT images. Early work with satellite imagery used visual interpretation for classification, which is still used widely today. The most commonly used computer classification methods are unsupervised classification and supervised classification. It is difficult to make great progress on improving the accuracy of remote sensing classification because of “the same things with different spectrums” and “different things with the same spectrums”. However, the appearance of some new algorithms(decision tree, support vectormachine, BP neural network) as well as the use of ancillary data (soil data, elevation or topography data) improve the satellite remote sensing classification of wetlands to some extent. Also the integrated use of multiple classifications becomes a new trend, which can also increase the accuracy of the satellite remote sensing classification to some extent. Remote sensing is also used widely in the surveying of wetland resources, estimating vegetation biomass of wetland, assessmenting wetland ecosystem health and so on, which can save time and labor greatly. At the same time, this paper points out five shortcomings existed in wetland research by remote sensing technology and prospects its future development from six aspects.
