Ryukyu Islands is a geographical unit that has a special geopolitical relation with China. In history, the vassal relation which was established between Ming and Qing dynasties of China and Ryukyu kingdom represented by Ryukyu Islands lasted for five hundred years. Today the geo-strategic significance of Ryukyu Islands is closely connected with the sovereignty of Diaoyu Islands of China and the maritime rights and interests of East China Sea. In fact, the forced annexation of Ryukyu Islands by Japan was not recognized by the international communities. In order to annex Ryukyu Islands “legally”, Japan implicitly eliminated Ryukyu characteristics for naming the islands, by sometimes using “Nansei Islands” which is a generalized regional appellation to remove its political properties, and sometimes applying “Satsunan Islands” which disintegrates the islands, and sometimes calling Ryukyu Islands “Okinawa islands” for concealing the history of the islands. The confusion created by Japan in appellation of Ryukyu Islands leads to a vague understanding of relevant geographical concepts of Ryukyu Islands for the international communities. Starting from the analysis of historical evolution of the appellations related to Ryukyu Islands, this article explores the geographical significance and political connotation of related appellations like “Nansei islands”, “Satsunan islands” and “Okinawa islands”. “Ryukyu Islands” is a general name for the islands ruled by Ryukyu Kingdom in history. The political significance of appellation of “Ryukyu Islands” is the denial of Japanese annexation of Ryukyu Islands and the assertion of independence of them. “Nansei islands” is a generalized regional appellation in Japanese to all the islands scattered between the southwest of Kyushu Island of Japan and the northeast of Taiwan Island of China, which means the islands to the southwest of Japan. The political significance of appellation of “Nansei islands” is manifested from two aspects: one is elimination of Ryukyu characteristics in the appellation and the other is to induce international communities to acknowledge the “sovereignty” of “Nansei Islands”. “Satsunan Islands” in Japanese refers to the combination of three groups of islands including Osumi Islands of Japan, Tokara Islands of Ryukyu kingdom and Amami Islands. The name means the islands to the south of Satsuma (Kagoshima Prefecture). The political significance of the appellation of “Satsunan Islands” is also reflected from two aspects: one is disintegration of Ryukyu Islands and the other is to claim the “sovereignty” of “Satsunan Islands”. “Okinawa Islands” is a name of the islands in Japanese which includes Ryukyu Islands (including Kerama Islands), Daito Islands and Sakishima Islands. The political significance of this appellation is, on the one hand to eliminate Ryukyu characteristics and on the other, to disintegrate Ryukyu Islands. Correct understanding of the geographical significance and political connotation of the related appellations of Ryukyu Islands is of significance on bilateral relations on Ryukyu issues for China in the future.
The Sunan model attributes the development of Sunan (Southern Jiangsu) to the local state-directed township and village enterprises (TVEs). However, with intensifying global competition in China, since the early 1990s Sunan has moved “beyond the Sunan model” through privatization and the infusion of global capital, especially Taiwanese investment. However, Sunan shows a great diversity of evolution in the development and restructuring. The research on Sunan deals largely with the development of peri-urban areas represented by national or provincial development zones, rather than the evolution of the Sunan model. This article investigates economic restructuring and industrial location in Wuxi city, especially the Nanchang district, to better understand the remaking of Sunan model and spatial change. The paper analyzed how the manufacturing firm migration and new firm locational choice influenced industrial upgrading and spatial patterns as well as the impact of the government on regional transformation. This study based on the spatial analysis of a large amount of enterprise data, and questionnaire survey and interviews of local officials and company managers. The results showed that the manufacturing industry in Nanchang had experienced changes in property rights, structure and space successively under the promotion of economic transformation and urbanization. The manufacturing industry had exhibited some characteristics of urbanization obviously, such as endogenous development chiefly through high-tech advancement and highly concentrated in industrial parks. The government applied regulatory planning and financial policies such as development zone construction, tax and so on to gradually move out the traditional manufacture with high-pollution and low-added value and attract high-tech enterprises. What governments do in this process is very different from what they did in the traditional Sunan model, which was to step in business of enterprise directly. However, there are many new challenges both the local government and manufacturing firms must face, including the shortage of highly skilled labor, the unemployment of lower skilled workers, and the relocation of the manufacturing enterprises from urban zones into industrial parks.
Since the 1900s, the research of human geography has changed from macro to micro perspective. Time-geography, which was born in the late 1960s, provides an effective tool for the micro-research. During the last several decades, the theory and research method of time-geography has deeply developed. As an important part of time-geography, the research of spatio-temporal structure of daily activities has made great progress, with the trend of classified individual research. At the same time, as the special phenomenon during the development of the city, village in city has been paid more and more attention by the government and scholars. Thus, the study on the migrant, which is the main body of population in village in city, is significant for the transformation of village in city. What is more, the study can also provide references for analyses of the spatio-temporal structure of daily activities from the classified individual research with questionnaire survey. Based on the daily questionnaire survey on the migrants in five villages in city of Beijing, the article gets the conclusions by clustering analysis as follow: the time allocation of migrants in village in city on weekday and weekend can be divided into six sorts, while work, recreation, and housework are the dominating activities. The characteristics of time allocation of each sort are much interrelated with the social environment and the attribute of the style. Closely correlated with the characteristics of time allocation, the spatio-temporal structure of each sort on weekday and weekend is restricted by the social environment as well. Daily path analysis shows that the migrants’ daily activities are becoming more and more distinctive, diverse and different, which results from the integrated effect of multiple factors. The change of macro-environment, living environment, and the attributes of the residents have integrated effect on the individual’s activities in mechanism, which leads to the special characteristics of spatio-temporal structure of migrants in village in city. The conclusion can be useful for the policy making of villages in city and it can provide fundamental materials for the further study on urban spatio-temporal structure and urban planning through the analysis on the regularity of individual activities.
Science and technology resources are the foundation of science and technology activity, the main factor that creating science and technology achievements and pushing the whole economic and social development. In this article, we make use of the principal composition analysis to evaluate the stock of science and technology resources between every prefecture-level city in Zhejiang Province first, and use the ArcView to analyze the science and technology resources distribute condition. Then, we use Data Envelopment Analysis (DEA) to evaluate the allocation efficiency of science and technology resources between every prefecture-level city in Zhejiang Province. Finally, Cobb-Douglas production function and the Solow residual value method were used to calculate the contribution rate of every city-level scientific and technological progress for economic development. The results showed that: 1) In the northeastern Zhejiang, science and technology resources and the contribution rate of scientific and technological progress should be significantly higher than that in southwestern Zhejiang, while cities inside the northeastern Zhejiang, southwestern Zhejiang there is also a greater difference. The amount in storage of science and technology resources of Hangzhou, Ningbo, Shaoxin was ranked front three. Lishui and Quzhou have the least resources in Zhejiang Provence. 2) The science and technology resources of Hangzhou, Jiaxing, Shaoxing, Jinhua, Lishui and Zhoushan are more efficient allocated, while Ningbo, Wenzhou, Huzhou, Quzhou, Taizhou are inefficient, and the efficiency of the management and the allocation efficiency of science and technology resources needs to be improved in these areas. 3) The contribution ratio of science and technology progress of Hangzhou is the highest-level, the second is Ningbo and the third is Shaoxing City. The lowest were Quzhou, Lishui and Zhoushan. The contribution ratio of science and technology progress in the northeast was lower visibly than the sourthwest of Zhejiang. At the same time, there was biggish discrepancy between two regions, Hangzhou was the most efficient but Zhoushan, Jiaxing and Huzhou were the most inefficient in the northeastern Zhejiang. The contribution ratios of science and technology progress of Quzhou and Lishui was far below that of Wenzhou City. At last, we make a number of advises for upgrading technological level and promoting economic development. In the first place, we should increase the input of science and technology appropriations and establish the pluralistic iuput system. Secondly, we should set up and upgrading safeguard mechanisms of introduction of talents. Thirdly, we should make the market system be perfected and energetically promote the industrialization of scientific results.
以武汉城市圈为研究区,借助ArcGIS9.3、Pajek2.7和SPSS16.0等软件,从节点重要性、可达性、集聚性3个方面定量揭示了复杂城乡道路网的空间异质性：① 高度节点重要性呈幂律分布,表现出无标度性,低度节点重要性则基本呈钟型泊松分布,呈现一定的随机性,导致整个圈域节点的重要性分布曲线既不遵循钟型泊松分布也不遵循幂律分布,出现“涌现”性;节点度值空间分布较均匀,呈现点状特征和弱集聚性,具有明显间断性和跳跃性,表现出一定的“中心–边缘”和“等级圈层”的复合结构;② 节点的可达性主要由网络平均路径长度、紧密度和介数指标表达,其中道路网平均路径长度较大,节点交通联系呈线状组织,遵循距离衰减律,成等级圈层分异,但受快速干道影响明显,空间收敛减慢,发生“摄动”变形,形成两条以南北京珠高速和东西宜黄高速为轴的城市交通走廊;节点的紧密度系数较随机网络小,但高紧密度节点在空间分布上较为集中,呈现出一定的“中心–边缘”空间格局;节点的介数指标相对较高,呈现指数分布,空间分布较均匀,但仍呈现出一定的“等级圈层”分异;③ 网络的集聚性空间差异显著,形成多个大型网络社团,网络的聚类系数近似为零,局部呈现耦合性质,高聚类系数节点集聚成“半月形”展布,低聚类系数节点分布较为离散。
Studies on the complexity and non-linearity of the spatial structure of road networks have attracted increasing attention during the past several years. However, few efforts have been devoted to the spatial and structural properties of large-scale road networks. In addition, most of current studies focused on either spatial morphology of road networks or structural pattern of road structure, while a comprehensive analysis on the spatial restriction of road network structures is ignored. To fill in the knowledge gap, this article introduces a series of approaches to uncover the spatial influences on the structural characteristics of general road networks. The road network of Wuhan Metropolitan Area (RNWMA) is taken as a case study and the spatial heterogeneity of the structure of RNWMA is analyzed from three aspects with the help of software including ArcGIS9.3, Pajek2.7 and SPSS16.0. Three aspects of spatial heterogeneity of the RNWMA are studied, which are importance of road intersections, accessibility of road intersections and clustering of road intersections. For each property, both statistic analysis and spatial distribution analysis are carried out. Results are visualized by map or chart. Possible explanations are also given. It is found that in the RNWMA: 1) the importance values of roads with high accessibilities in RNWMA follows a power-law distribution, which may indicate that the RNWMA is a scale-free network. While the importance values of roads with low accessibilities follow a Poisson distribution. The co-existence of scale-free and random properties for roads with different accessibility makes the entire road network a complex system with some “emergent” properties; 2) the average length of the shortest path between two roads is relatively large. While the traffic links between two roads in terms of topological distance follow the law distance decay and obvious hierarchy circles can be observed. The spatial convergence of the shortest path length is significantly influenced by roads with high hierarchy (e.g. expressway) and shows perturbation deformation. Two urban transportation corridors, i.e., the Beijing-Zhuhai (north-south) and Yichang-Huangshi (west-east) are observed. Besides, statistically the values of the betweenness of road intersections show exponential distribution although spatially they are relatively even; 3) The clustering coefficient for the RNWMA approaches zero, while several network communities are observed. The spatial distribution for the road intersections with large value of clustering coefficient are “crescent” like, and road intersections with low clustering coefficient values are sparsely distribution in the region. Attempt made in this study will not only help to interpret the structural organization and growth in a limited geographical space, but also shed light on visual analytic means for geographic environments. It is our hope if the findings of this article can provide any alternatives for current road network study, and give practical supports for the construction of urban-rural road network.
Wetland remote sensing classification, as an important means of wetland management, monitoring and assessment, has been widely concerned. Genetic Algorithm (GA) does heuristic search optimization which references the law of biological evolution, while Support Vector Machine (SVM) is a new kind of spatial data mining method. Combination of both can develop their own advantages to do wetland remote sensing classification exactly, by searching the global optimal parameters of Support Vector Machine. Taking Honghe Nature Reserve as a case study, wetland remote sensing classification using Support Vector Machine optimized with Genetic Algorithm (GA-SVM) was explored in this paper. In comparison with wetland classification using support vector machine with parameters searched by Grid and the Maximum Likelihood Classification. The experimental results show that, the overall accuracy of Genetic Algorithm optimization has increased 7.29% compared to Grid Search method, and has increased 12.06% compared to the Maximum Likelihood Classification, by improving the discrimination among marsh, meadow and bare land. Therefore, GA-SVM is an effective tool in wetland remote sensing classification.
Based on remote sensing techniques, the land use/cover information between 1980 and 2010 was obtained and the change processes of land use/cover and landscape pattern of Kezuohouqi County in the loess plateau, China were characterized, using the statistical models to analyze the impacts of the Grain for Green Project (GGP) on both of them. The land was generally in quasi-balanced status with a slight difference between the loss and the gain of the area for most land use types, indicating that the land conversion direction was dominated by two-way transition. Transition between cropland and grassland dominated the processes of the land use/cover change and landscape pattern dynamics. The GGP together with other eco-restoration projects reversed the decline trend of natural vegetation (i.e., the woodland and grassland) and the increase trend of cropland and unused land, and reduced the fragmentation of landscape. These changes may be beneficial to the local eco-restoration.
城市化是一个“人口-经济-空间”三维一体的过程,其内在协调与否是城市可持续发展的关键所在。为此,首先通过构建人口、经济、空间城市化内在表征指标,运用均方差赋权法,以东北地区（指的是东北三省）34个地级市为研究对象,来综合测度其人口、经济、空间城市化水平;其次运用协调度评价模型对其协调程度进行评价;并在此基础上进行分类。研究结果表明：① 东北地区经济城市化主导人口、空间城市化,但整体水平不高,平均水平基本处于加速发展阶段（0.25~0.35）;② 人口、经济、空间城市化水平的空间分异明显,其中人口城市化整体呈现出由北往南递减的趋势,而经济城市化则成由南往北递减的趋势,两者“内在互补（互异）”趋势非常明显;③ 三者城市化协调度低,且区域差异明显,由南往北递减趋势非常明显;④ 依据彼此间协调度主宰程度,将其划分为综合协调导向型,人口-经济、人口-空间、经济-空间协调导向型4种类型。
Urbanization is a “population-economy-space” trine progress, and the coordination among them is the key to the sustainable development of city. In order to evaluate the coordination of the population-economy-space urbanization in Northeast China. In the article, firstly, the indexes of population urbanization, economy urbanization and space urbanization were constructed, and the standard variance method was used to make sure the weighs of eacry index, and then the 34 prefecture-level cities (mainly referring to the three in Northeastern provinces) were took as the research object, to measure the urbanization level of population, economy and space comprehensively. Secondly, the coordination estimate model was used to assess the coordination among of them, and then the coupling degrees was used to divide the 34 prefecture-level cities into several groups. The result shows that: ① The economy urbanization of Northeast China was leading the population urbanization and space urbanization and the whole level wasn’t high, basically at the average level from 0.25 to 0.35, which means it stated in the accelerating development stages.② the spatial differentiation characters of population urbanization, economy urbanization and space urbanization were very significant, in which the population urbanization showed a decreasing trend from north to south, while the economy urbanization showed a decreasing trend from south to north, between them “inner-complementary (internal difference)” character appeared very clear. ③ The coordination degree among population urbanization, economy urbanization and space urbanization was very small, and the regional differences were so significant that the degree showed decreasing trend from south to north. ④ According to the dominant coordination degrees among population-economy urbanization coordination degree, population-space urbanization coordination degree, economy-space urbanization coordination degree, the 34 prefecture-level cities were divided into 4 types.
Based on 1990, 1995, 2000, 2005 Landsat-TM images in Panyu District of Guangzhou City as the main data source, GIS tools and Landscape Ecology methods were used to generate land cover landscape maps. On the basis of the quantitative study of LUCC, land cover change mechanism during the study period in Panyu District was reflected by landscape pattern indices, providing research basis for the effects of land cover on landscape pattern and its ecological effects. The result showed that the land use structure of Panyu District represented a period of development and adjustment from 1990 to 1995, and tends to become mature situation after 2000. The structure of land cover changed showed maturity along with the process of urbanization. The landscape fragmentation and the complexity of land use structure increased. The effects of human-induced land cover change gradually replaced the natural role in affecting land cover type.From the quantity of land use change from 1990 to 2005, land use change accompanied by urbanization and farmland quantitative changes are the largest in Panyu District. And as followed by construction land and garden, water changes are also significant. Farm land and garden are reduced while the other land type increased. Human factors induced land-cover changes played a growing role while the effect of natural factor was decreasing. The structure of agriculture and people's lifestyles are changing rapidly. The rates of land-use change rank as follows: green fields > transportation land> shrub grassland> building >garden> arable land = water. As shown in landscape changes, arable land, garden, forest land and building land have increasing patch fragmentation especially agricultural land, garden, lawn irrigation, etc. And the expansion of construction land area led to increasing degree of concentration. In addition to garden, the other land type also increases the complexity of the class.
The advantage and disadvantage condition of glacier tourism were analyzed in the paper based on China’s glacier tourism resources, glacier resource value and development process at home and abroad. In term of general idea of “highlighting the central cities, relying on the traffic lines, consolidating key areas, and forming network market”,the overall spatial strategy and planning “ten centers, three zones, five areas” were put forward. Along with the gradual implementation of the double-track project of Qing-Tibet railway, the planning and design of Chuan-Tibet and Dian-Tibet railway, the western transport and infrastructure will be further improved and enhanced in the future. In addition, under the opportunities of the implementation of Inter-provincial regional cooperation projects (e.g. Silk Road tourist belt, Qing-Tibet Rail tourist belt, and Shangri-la ecotourism zone) with rich and unique glacier tourism resources, China will have strong appeal to attract domestic and foreign tourists to visit, experience and explore.
通过对太湖流域重污染区1999年、2007年遥感影像数据解译结果的分析,获取了太湖流域重污染区主要土地利用类型的信息,分析了8 a来研究区内土地利用与覆被变化趋势,对区域土地利用类型的生态系统服务价值进行评估。结果表明, 1999~2007年,太湖流域重污染区内耕地面积从2 033.53 km2减少到1 401.04 km2,而林地、建设用地、园地、水域总体呈增加的趋势,其中减少的耕地主要转化为建设用地。1999~2007年太湖流域重污染区的生态系统服务价值呈减少趋势,土地利用变化使研究区生态资产减少了2.40亿元,除气体调节和原材料以外,各单项服务功能的价值量均呈现递减的趋势。
Change trends of land use/cover change (LUCC) in heavy polluted area of Taihu Lake Basin were analyzed based on remote sensing image from 1999 to 2007. Ecosystem service dynamic of these land use/cover was investigated. The results show that cultivated land area in study area decreased from 2 033.53km2 in 1999 to 1 401.04 km2 in 2007, while the area of forest land, construction land and water increased. Reducing cultivated land converted to construction land. Ecosystem service of heavy polluted area in Taihu Lake Basin decreased from 1999 to 2007 and the total ecosystem services value in study area decreased 2.4×108yuan. Value of different ecosystem service item presented decreased trend excluding gas regulation and raw materials.
Based on the crime data in 2008 collected at the police-precinct level from the Public Security Bureau of Changchun, this article firstly analyzes the spatial pattern of property crimes in this typical city with a population around 3×106 in Northeast China. An approximate structure of layers was shown, which means more crimes in central areas and fewer crimes outside. After further investigation on the land use and function of the precincts with higher property crime rates, it is found that the busy areas such as the major commercial areas and the transport centers tend to possess higher probability of property crime occurrences. According to the routine activities theory which has been applied by western researchers in plenty of practical studies, the places where most of the opportunities of convergence in space and time of likely offenders, suitable targets and the absence of capable guardians against crime concentrate will suffer higher risks of criminal activities. The busy areas in Changchun possess more properties and usually gather more people for working, shopping, entertaining and so on, which means more opportunities for the potential offenders to commit property crimes with less chances to get arrested. The hotspots of property crime rates in Changchun are identified using spatial analysis, which provides us with statistical support for the assumption that criminal activities tend to cluster somewhere. This phenomenon may due to the existence of spatial spillover or diffusion. Finally, we conduct regression analysis to examine the relationships between property crime rates and demographic, socioeconomic as well as land use factors according to the relevant western theories. The model built in this article can explain more than 70% of the variation of property crime rates in Changchun at more than 95% confidence level. The result reveals that the property crime rates in Changchun in 2008 were affected by the factors of population density, employment activity, commercial area, service activities, transport center and the proportion of young people, which supports the basic ideas of routine activities to some extent. The fact that the population density exhibits the strongest effect on the property crime rates suggests that concentration of population increases the number of offenders which in turn increases the property crime risks in the city. As a typical city in China, Changchun displays a common structure of population distribution in the current urbanization process. The degree of concentration of population is much higher in the central areas which usually have better accessibility and more commercial or recreational land use. In combination with the positive effect of the commercial land use on property crime rates which has been indicated in the model, the structure of population distribution can provide us with a convincing explanation for the spatial pattern of property crimes in Changchun to a great degree. Though the proportion of young people shows an opposite relationship to what the western researches have found, it is understandable when we take the special context of China into account. As for the social disorganization theory which is another classic theory in criminal geography in western countries, the research does not lend enough support for it, because the variables (proportion of non-residential population and housing size per person) are not significant in the model. For further understanding, specific analyses are still needed based on the practical situation in Changchun.
Zhagana village (Diebu County, Gansu Province) is a Chinese traditional settlement. Studying Zhagana’s landscape spatial structure is of vital importance in ecological research and planning. Based on multifunctional landscape concept and “Fengshui” theory, it was analyzed on four levels: regional environment level, village group level, individual village level and individual house level. On the level of regional environment, the landscape has an ecological circle structure towards horizontal and vertical directions, taking human architecture as the center. On the level of village group, influenced by natural force and traditional idea, four natural villages generate the natural linear drifting configuration and represent a kind of cluster mode. On the level of individual natural village, there is one or two uninterrupted interface. On the level of individual house, two kinds of horizontal structures can be detected in Zhagana’s Tibetan Ta-ban buildings, which are left-right structure and front-back structure, including living area and planting or breeding area. Considering its function for living, religion and storage, the Ta-ban building usually includes two or three layers vertically. This study establishes a foundation for Zhagana settlement’s protection and development. Further planning suggestions are also proposed. Firstly, taking Zhagana settlement as an integral protection area is a better way for settlement sustainable development. Secondly, environment protection based on religion is an ingenious way for ecological protection. The third is to improve Zhagana’s settlement model by spatial ecological planning.
基于侵蚀过程会导致树木生长环境变化,进而改变根系生长生理特征的基本研究思想,以金沙江干热河谷龙川江流域为典型区,从树根细胞解剖结构和组合特征的变异中提取土壤侵蚀信息,探索和发展了基于树木生理生态的土壤侵蚀研究新方法与技术。结果表明,不同侵蚀强度下根系的年轮分布特征不一致,其中偏心率大小顺序为：局部暴露根系>浅埋根系>完全暴露根系,且偏心率与根系以上土层厚度、暴露程度存在显著性相关;根系导管面积是反演侵蚀过程的敏感指标,早材导管面积的变异是确定根系暴露时间的重要依据之一;龙川江流域土壤流失厚度为1.47~4.47 mm/a,平均侵蚀模数约为3 692 t/（km2·a）。
Based on physiological responses of tree growth to environmental changes, the paper developed a new method to extract information of soil erosion from tree-root anatomical structures and cell features. A case study has been carried out in the Longchuanjiang Watershed, Dry-hot Valley of Jinsha River. The study results showed: ① Soil erosion led to eccentric growth of Eucalyptus roots. The samples are divided into roots exposed partially, roots buried shallowly, roots exposed absolutely, based on the erosion degrees. The eccentricity ratio of tree ring is 0.461±0.133、0.218±0.096、0.158±0.121 and the order is roots exposed partially>roots buried shallowly>roots exposed absolutely. There is significant correlation bewteen soil depth and the eccentricity of tree tring. ② Vessel area was a sensitive indicator for reconstructing soil erosion process, and abrupt variations of earlywood vessels size was one of the important evidences to date the first year of exposure. The area of vessel decreases in latewood, whereas there is no significant change in earlywood, fiber wall thickness increases (decrease of fiber volume). ③ The soil loss thickness is 1.47~4.47 mm/a, and the average erosion modulus is about (3692±1710) t/(km2·a), in Longchuanjiang Watershed. It is serious erosion based on the standards for classification and gradtion of soil erosion.
在“湿地临界”概念的基础上,定性分析了湿地利用与保护的平衡状态,探讨了不同利用方式下的湿地临界的研究步骤,并从基于耕地和河蟹养殖地两种土地利用方式入手,对七里海湿地临界进行了评价。研究表明,通过建立湿地临界模型,从经济效益评价和生态效益的评估入手,对湿地资源利用与保护进行临界分析,可以较好的反映湿地利用的临界状态;采用该方法,七里海湿地耕地利用的年净收益为9 5941.42元/ hm2,净损耗为18 072.75元/ hm2,临界效益（△B）值为77 868.67元/hm2;养殖河蟹的年净效益为21 622.68元/ hm2,净损耗为2 0274元/ hm2,△B值为1 348.68元/ hm2,说明在目前的社会经济发展水平下,耕地和养殖河蟹两种利用方式尚未超出开发利用的临界准则,七里海湿地仍然具有开发潜力。
Based on the concept of “wetland criticality” , the qualitative analysis was made in this paper to research on wetland exploitation and reservation optimization, and then the research procedures on the critical criteria of different kinds of used wetland. On the basis of the analyses of the use of cultivated land and the farming of river crab, the paper makes an assessment on criteria of Qilihai Wetland. The theory of exploitation and preservation of Qilihai Wetland means that the net marginal earnings of wetland should not be less than the net marginal losses when wetland is exploited. It can be defined as the equilibrium of utilization and reservation. This theory consists of ecological criteria,economical criteria and social criteria. Ecological criteria means that the basic constraint of economical and social criterion is usually seen as the dynamic constraint. The three aspects are not independent but interactive and restricted mutually, so they form an entirety that should not be separated. This passage also made a preliminary study of utilization and protection criticality of Qilihai Wetland from the perspective that the wetland was used as cultivation and raising crabs. By estimating the value of ecosystem service, the outcome of earnings and losses were calculated by means of the analysis on compatibility of each ecosystem service. The result showed that the way to establish a critical model of wetland and the analysis of economical benefit and ecological benefit could reflect the situation of wetland (utilization of critical situation by analyzing the criticality of wetland used and reserved resource). The net earnings of farmland were 2 231 798.42 yuan/hm2 and the net losses were 18 072.75 yuan/hm2, so the value of ΔB, which was the criteria of exploitation and preservation limitation, was 2 213 725.67 yuan/hm2. The net earnings of crab were 21 622.68 yuan/hm2 and the net losses were 20 274 yuan/hm2, so the value of ΔB, was 1 348.68 yuan/hm2.The preliminary study showed that Qilihai Wetland, exploited as cultivation and raising crab, is not overstepped under the circumstances of current social and economic development and Qilihai Wetland could be exploited potentially in the future.
Based on high resolution remote sensing data-SPOT images of Turpan Oasis, by using of decision tree classification method, desertification information was abstracted and desertification evolution, development as well as conversion characteristics were analyzed in the paper. The results showed that wind erosion desertification and salinization were the main desertification types in research area. Moderate wind erosion desertification occupied the highest proportion, which accounted 64.05 % of the total in research area. Because of the reclamation of mild wind erosion desertification land, the total desertification land area decreased by 9.77% from 1986 to 2004. At the same time, part mild wind erosion desertification land converted to more serious desertification land. Severe desertification land and salinization land enlarged 2 and 12 times respectively. Speed of desertification reversal was higher than that of development, whereas the later period desertification development speed were accelerated, both showing that when desertification were harnessed, the desertification degree in part of the area was deepen. The development of desertification has brought enormous pressure on local environment.
土壤表层含水率是影响土壤风蚀的一个重要参数。在塔里木河下游土壤风蚀期间对0~15 cm层土壤水分进行调查,发现0~15 cm层土壤含水率极低,平均含水率仅0.84%,含水率>2%的区域主要分布在绿洲边缘和河道边缘。进一步探讨植被盖度、风沙活动强度和土壤结皮对0~15 cm层土壤含水率分布的影响,结果表明：① 0~15 cm层土壤含水率与植被盖度的相关性不显著;② 0~15 cm层土壤含水率与风沙活动强度呈显著指数负相关;③ 土壤结皮能够有效保护表层土壤水分,抑制土壤风蚀。
Surface soil moisture is one of the most important parameters influencing soil drifting. The moisture in 0-15 cm soil is investigated during the soil drifting in the lower reach of Tarim River. It was found that the soil moisture (0-15 cm) is very low, the average of the soil water content is only 0.84%, and the regions of the soil moisture more than 2% are concentrated in the edge of oasis and river. The relationships between the soil moisture and the vegetation coverage, the intensity of soil drifting, and the soil crust were analyzed. It shows that the correlation between the soil moisture (0-15 cm) and the vegetation coverage is not evident. The correlation between the soil moisture content and the intensity of soil drifting is significant exponential negative correlation. The soil crust can protect the surface soil moisture availably, and can restrain the soil drifting.
Natural disaster risk assessment is a process or application of a methodology for quantitatively analyzing and evaluating the possibility of different intensity disasters and the possible consequence of the disasters. On the background of multi-disasters, the eight ports, namely Dalian port, Tianjin port, Qingdao port, Shanghai port, Ningbo-Zhoushan port, Xiamen port, Shenzhen port, Guangzhou port, which are the important infrastructure in the coastal cities of China, are selected as the study area. Based on the natural and social characteristics of the study area, three factors have been selected as indices for a quantitative evaluation, including the hazard, the exposure and the vulnerability. At last, this paper establishes natural disaster risk assessment index system and evaluation model of the coastal ports. The analysis result shows that the integrated risk of coastal ports in China presents spatial disparities evidently, which can be rank as Yangtze River Delta>Pearl River Delta>annulus Bohai Sea. Qingdao Port, Shanghai Port and Ningbo-Zhoushan Port should protect themselves from the wind caused by typhoon. Xiamen Port and Shenzhen Port should pay attention to the typhoon wind and typhoon storm surge. Tianjin Port and Guangzhou Port should give attention to the typhoon storm surge, because that both of them are seriously affected by the storm surge. The exposure of container and goods is high in Tianjin, Shanghai, Qingdao, Xiamen, Shenzhen and Guangzhou Port. When natural disaster is coming, they must move the container and goods in time. The goods and the passengers highly exposed to the natural disaster in Dalian and Ningbo-Zhoushan Port. This must be concerned by related departments. At the same time, the disaster prevention facilities should be strengthened. When maintaining and expanding ports scale, administration departments should increase the number of anchorages and lighthouses to improve the ship's navigation according to relevant disaster prevention and mitigation requirements. The results which have important scientific value and practical significance, agrees with the reality.