In this study, we use a variety of spatial measurement model to study the spatial evolution characteristics and its driving factors of China’s listed companies’ from 2005 to 2015. It is found that: 1) China’s listed companies are mainly concentrated in the Yangtze River Delta, the Pearl River Delta and Beijing-Tianjin-Hebei Region, and are concentrated in high administrative grade cities obviously. 2) The shift of space center indicates that the listed companies in China have the stage characteristics of “fast and stable” development. Spatial association pattern shows a gradient trend which is “Hot spot to transition zone to cold spot area” from the coastal to inland. 3) The spatial evolution pattern of the three major listed companies of specialization is different, the mode of the labor intensive area evaluated from “single core” to “dual core”. Capital intensive is the polarization distribution situation of “breaking point” significantly. Technology intensive area emerges a situation of “multi-core beaded”, and it has a significant characteristics like the creep spread. 4) The regression model shows that the spatial pattern of listed companies is driven by factors such as city location grade and scale, global level, investment situation, science and education level and information level and so on.
Comprehensive evaluation of the level of regional integrated transportation development based on supply-side perspective has a great significance to promote regional transportation development, and even regional economic and social development. Based on the highway, railway, waterway, aviation and pipeline transportation, considering the difference of traffic demand at different spatial scales, the article constructs the evaluation index system of integrated transportation from national and international scales, then analyses the level of integrated transportation development of the three major urban agglomerations including the Beijing-Tianjin-Hebei region, the Yangtze River Delta and the Pearl River Delta. The results show that there is a significant difference in the level of integrated transportation development among the three major urban agglomerations: the Yangtze River Delta region is higher than the Beijing-Tianjin-Hebei region, and the Pearl River Delta region has the lowest development level. There are different gaps among three urban agglomerations on the different spatial scales and different transportation modes. The unbalanced development on national scale is lower than that on international scale. Considering different transportation modes, the unbalance among the three urban agglomerations of highway transportation is significantly lower than that of waterway, railway, aviation and pipeline transportation, but the main factors that lead to the differences of the level of integrated transportation development lie in the development unbalance of railways, aviation and waterway. The disadvantages of the development of various transportation modes, especially the development of the railway is obviously lagging behind, are the main factors which lead to the lower level of the transportation development of the Pearl River delta region. Based on the conclusions, some advices are put forward to promote the transportation development of the Pearl River Delta region.
Based on interviews and questionnaires of 1 200 more or less rural migrant workers in the city of Xi’an in the interval between 2015 and 2016, a network node model of urban space (USNN) associated with the statistical model is proposed in this research aiming to understanding the integrating principles of rural migrant workers in cities. With the combination the principle of penetration and the application of mathematical statistics method, the principle of penetration ideas is exploited to analyze the dynamic change process involving in rural migrant workers pouring into the cities and towns. Logistic regression is employed to describe the nodes in USNN of dynamic change process which is determined by the the interactions of penetration force and repulsion force each other, and the difference value between the interactions of penetration force is determined the direction of displacement in USNN. The conclusions and results can be drawn as follows: Firstly, the integration into the urban space of rural migrant workers takes on the phenomenon of penetration and migration, the influence factors involve in the interactions of penetration force and repulsion force which depends on the soft and hard difference potential strength; Secondly, the comprehensive threshold value of penetration force and repulsion force is determined by the time interval of migration and residence. In order to explicitly describe the stochastic process of rural migrant workers integrating into the cites and towns, network node model is established to analyze the data, and the principle of penetration is applied in exploring the urban spatial transition energy level of migrant workers in terms of concentric circle model; concentric circle model is consist of different levels whose value is arranged the energy value varying from the maximum to minimum centered at city logic origin. In addition, the statistical model with respect to rural migrant workers in urban space network level node permeation process is employed. Based on these, concepts of the soft and hard difference strength are defined to analyze interaction process of osmotic force and repulsive force on each node in urban space network. For any arbitrary node, concepts of the soft and hard difference strength are defined to analyze interaction process of osmotic force and repulsive force on each node in urban space network. The time of penetrating and migration; the moving routes well fitted with Poisson update process; Finally, Simulation and theoretical data test results demonstrate that the Logistic statistical model associated with nodes inside the network of urban space based on concentric circle theorem coincides with the dynamic displacement characteristics of rural migrant workers integrating into the cites and towns, which have a positive significant meaning effect on the harmonic development of urban space.
聚焦于乡村工业用地混杂及分散化特征较为显著的佛山市顺德区,系统分析乡村工业用地演化过程和用地特征,并以政府力和社会力的交互机制为分析框架,辨析珠三角半城市化地区的乡村工业用地演化的动力机制。结果表明：顺德区工业用地的发展可以分为4个阶段：① 1984~1991年,自下而上农村工业化,用地空间分散发展阶段,其驱动力主要为政府力与社会力一致。② 1992~1998年,产权制度改革,促进农村工业用地规模化发展阶段,其驱动力为政府力与社会力势均力敌。③1999~2005年,集约开发促成农村工业化集中发展阶段,其驱动力特征为政府力压制社会力。④2006年以后,农村工业化进入全面调整阶段,其驱动力特征为政府力与社会力相持。在顺德区工业用地空间演化过程中,政府力起主导作用,社会力相较于其它乡村型半城市化地区更为强大,政府力与社会力的相互作用的平衡点在于各个经济主体的利益均衡。在珠江三角洲半城市化地区,工业用地空间优化整合的前提是平衡各级政府力与自下而上的村民及村委的社会力,社会力的引导是破解农村工业化用地破碎化和混杂性的关键环节。
With the new urbanization development, land use space needs to be integrated in semi-urban areas. The land use model is changing from the traditional extension of expansion to “control by pressing” intension development. The study focuses on the Shunde District where the mixed and decentralized characteristics of rural industrial land are significant and then analyses systematically the evolution process and characteristics of the rural industrial land, adopting the analytical framework of the interaction mechanism with government forces and social forces, and analyses the dynamic mechanism of rural land use evolution for semi-urban areas in the Pearl River Delta. The research shows that the industrial land development could be divided into four stages in Shunde District. 1) During the stage of scattered development in 1984-1991, its driving force is mainly government force, and consistent with the social force; 2) During the stage of scale development in 1992- 1998, its driving force is the government forces and social forces which are evenly matched; 3) During the stage of focus development in 1999-2005, the character of driving force is the suppress by the government forces to the social forces; 4) During the stage of adjustment development after 2006, the character of driving force is the stalemate between the government forces and the social forces. In the development process of the industrial land use in Shunde District, the interaction between government force and social force has the following characteristics: the government plays a leading role, while the social forces in the Pearl River Delta are more powerful than other rural semi-urbanized areas. The interests of the various economic entities are the balance of the interaction between the government forces and the social forces. Therefore the integration of the industrial land in the semi-urban areas in the Pearl River Delta area needs to consider the interaction between the government force and the society force.
By constructing the database and Meta Model of the ecological service function of the forest ecosystem in China, the factors influencing the value evaluation and the validity of the model were analyzed. The research showed that: 1) The research method, the ecosystem ecological service function, the vegetation type, the vegetation area, the population and the agglomeration degree were the main factors affecting the change of the ecological service function of the forest ecosystem; 2) It was validly testified that the application of the transfer of value based on Meta-analysis in the evaluation of the ecological service function of the forest ecosystem was a quick and effective method; 3) In the ecological service function of the forest ecosystem, there were some characteristics such as high in the east and low in the west, and high in the north and low in the south. The value increased as the time went by. The value of water conservation was the highest, and the value of providing forest fruit products was the lowest.
以大连市内四区为例,将城镇地籍调查数据与互联网房产数据相结合作为基础数据,通过ArcGIS软件生成住宅小区点数据的空间分布图,对大连市住宅小区容积率的时间演变和空间分布进行研究,并利用锡尔指数计算住宅小区容积率的空间差异量化测度指数,最后阐述住宅小区容积率空间差异的机制。结果表明：① 1992~2016年大连市住宅小区的数量在持续发展时期最多,平均容积率展现出波动上涨的趋势。② 区：大尺度包括冷炳荣住宅小区容积率整体上呈现出不均匀性和破碎性,局部又呈现出混乱性和复杂性,东部地区小区容积率分异比西部大。③ 中山区空间差异量化测度指数最高为0.831,甘井子区最低为0.125,西岗区与四区整体格局最为相近。极低等级容积率空间分异指数最高,容积率分异指数由两极向中间递减。大连市住宅小区容积率空间差异主要体现在区域内,其对研究区容积率空间分异影响较大。④ 住宅小区容积率空间差异的主要原因为下垫面性质对住宅小区建设的限制、区位的优良性对住宅类型的指向、城市规划对土地利用的导向、极差地租与容积率的相关性、小区建设成本对容积率的影响。
Floor area ratio not only exerts great an impact on urban building density, architecture capacity and land utilization, but also has a great significance to the urban planning and the development of regional economy. In this article, taking the four districts of Dalian as an example, integrates cadastral survey data of cities and towns with Internet property data as basic data, by ArcGIS software creating the spatial distribution of residential quarter points. The research towards the time evolution and spatial distribution of residential quarters floor area ratio, utilizes the Theil index to calculate the spatial difference quantificational measurement index. Ultimately, it illustrates the mechanism of the spatial difference of floor area ratio of the residential quarters. The result shows that: 1) During 1992 to 2016, the number of resident quarter in Dalian is the largest during the period of sustainable development, the average of floor area ratio depicts the upward trend of fluctuation. 2) The floor area ratio of the residential quarters presents uniformity and fragmentation as a whole. Moreover, it partially shows chaos and complexity as well. The difference of floor area ratio of the eastern residential quarters is larger than western parts. 3) The highest quantificational measurement index of spatial difference is 0.831 in Zhongshan District, compared to the lowest one in Ganjingzi District, which is 0.125. Besides, the distribution of Xigang District is the most familiar to overall layout of four districts. The differentiation index of extremely low space of floor area ratio is the highest, the differentiation index of floor area ratio is from bipolar to the middle in descending order. The spatial difference of floor area ratio of residential quarter in Dalian mainly embodies within the area, which plays a dominate role in study area. 4) The main reasons of the spatial difference of residential quarter floor area ratio are the restrictions of the underlying surface properties on construction of residential areas; the excellent locational direction to the types of residential quarters; the orientation of urban planning to the land utilization; the relativity between the differential land rent and floor area ratio; and the influence of residential construction cost to floor area ratio.
This article listed the urban agglomeration influencing factors from on the basis of traditional disciplines, and then classified it into 3 classifications according to its characteristics of action and attribute. It explained the relationship mechanisms among of them, and then put the institution influencing factor into the mechanism analysis system of urban agglomeration formation and evolution, based on which it built the influence factor comprehensive analysis model. Secondly, this article interpreted the institution influencing factor that how to make the action to the mechanism of urban agglomeration formation and evolution on the basis of New Institutional Economics perspective. Thought that, the essence is analyzed that the institution influencing factor how to affect people's behavior, and the people's behavior how to influence the economic activities (entity factor) during the whole progress of the urban agglomeration formation and evolution. It cleared the mechanism of the institution and its changes to the urban agglomeration formation and evolution, then constructed the analysis framework of the urban agglomeration formation and evolution mechanism under the New Institutional Economics from the perspectives of the macro institutional change, meso mechanism design and the micro transaction cost.
Since the Chinese reform and opening policy, the living standards of the residents have been improved. At present, the process of aging in China is accelerating, and older residents are paying more attention to their own health. The ecology theory of aging suggests that the ability of individual body can be reduced with the increase of people’s age, and it is very sensitive to the environmental pressure. Based on the Competence-press model, using multiple logistic regression method to analyze the influence of person competence and environment press on self-rated health in five communities in Guang Zhou, and verify the model. The results show that: 1) Communities can be divided into the higher competence type, the slightly higher competence type, the equal competence-press type, the slightly larger press type. 2) The higher competence type is Zhong Da community which is located in the edge area in the model. Personal competence plays a greater role. The main factors that restrict the self-rated health of the elderly are pre-retirement occupation and education level. The slightly higher competence type is Long Kouxi community which is located in the most comfortable area. Personal competence and environment press match well. The main factors that promote the self-rated health of the elderly are the income level and the housing quality. The equal competence-press type are Li Rendong and Yao Hua communities which are located in maximum potential area. Environment press is more effective. The main factors that restrict self-rated health of the elderly are housing quality and community greening. The slightly larger press type is Xin Ji community which is located in poor adaptation area. Environmental stress has a greater impact on health. The main factors that restrict self-rated health of elderly are monthly income and whether there is a separate bedroom. 3) The relationship between competence-press status and self-rated health of the elderly is consistent with competence-press model. For the application of the theoretical model in China, we carried out an exploration.
：From the perspective of spatial autocorrelation, it is of great significance for the healthy development of the regional economy to clarify the evolution law of spatial organization relationship about high level areas and low level areas. In this article, the concepts of aggregated growth pole, isolated growth pole, the chief aggregated growth pole, the chief isolated growth pole, the subordinate aggregated growth pole, the subordinate isolated growth pole and periphery are defined, then the global and local spatial polarization structures about regional economy of Jiangsu Province are respectively constructed according to two levels and three zones structure system of “aggregated growth pole-isolated growth pole-periphery”. With the statistical analysis technique, three levels and five zones structure system of “chief aggregated growth pole, chief isolated growth pole, subordinate aggregated growth pole, subordinate isolated growth pole, periphery” is analyzed. On the basis of them, the evolution processes of regional economic spatial polarization structure in Jiangsu Province are analyzed. The results show that: First, the global spatial structure of regional economy in Jiangsu Province is made up of three parts which include aggregated growth pole, isolated growth pole and periphery, and “aggregated growth pole in South , isolated growth pole in North” , and “growth pole in South and periphery in North” is forming gradually, among them, the range of aggregated growth pole is expanding , the number of isolated growth pole is reducing , the spatial autocorrelation function strengthen gradually, the trickle-down effect is enhanced. Second, the evolutions of local spatial polarization structures are not the same, the spatial polarization structures along the Yangtze Rive and the Beijing-Hangzhou Canal are gradually upgraded, while the spatial polarization structures along the east Longhai coast are relatively deteriorated: the polarization zones along the Yangtze Rive are enlarged, upgraded and gathered, the polarization zones along the Beijing-Hangzhou Canal are reduced but upgraded and gathered to the South , the polarization zones along the Coastline are downgraded and gathered to the South, the polarization zones along the Longhai east are reduced and downgraded. On the basis of them, the phenomenons of North-South differentiation and opposite evolutions in the global and local spatial polarization structure of regional economy in Jiangsu Province is worthy of attention now, at the same time, the varied development policies are necessary to guide the spatial structure optimization according to local conditions.
This article analyzes the influence factors of tourist satisfaction in different types of scenic spots of Beijing by using the structural equation model, which is based on the random samples of the 16 scenic spots in Beijing. This article, through the factor analysis, gets the influenced factors of tourists in different types of scenic spots of Beijing, including 4 aspects: scenic spot main characteristics, service degree, security level and convenience, and builds a model, which has 2 exogenous latent variables, including the satisfaction and travel decision-making. This article, through structural equation confirmatory analysis, found that: different influencing factors on the degree of tourist satisfaction evaluation are different in kinds of scenic spots. 1) The service level is the most important factor of visitors’ satisfaction in the Natural scenery scenic spot and the modern cultural scenic spot, meanwhile, the traffic is the critical factor of tourist satisfaction in natural scenery scenic spot, and the diet has become the most important factor of tourist satisfaction in modern culture scenic spot. 2) The convenience to the historic scenic area has the greatest effects in the visitors' satisfaction evaluation; emergency exit and signs are the highest factor loading. 3) The main characteristics of scenic area are the most significant effect in museum visitors' satisfaction, also, tourists pay more attention to cultural educational significance of scenic spot, and visitors' satisfaction is not only affected by factors such as age, income, education level, but staff efficiency and traffic factors greatly affect the tourists’ behavior. 4) The path coefficient between the security level and tourist satisfaction is small, and security level is relatively significant influence on four types of the scenic area tourist satisfaction, reflecting that the overall safety condition of Beijing tourism is laudable. 5) The tourists' satisfaction has a positive correlation relationship on travailing decision-making. Between different types of scenic spots on tourist satisfaction and travailing decision-making path coefficient significantly different, tourist satisfaction of natural scenery and travailing decision-making path coefficient, followed by modern cultural attractions, museums scenic, path coefficient between tourist satisfaction of historic areas and travailing decision-making is lowest. Policy implications of the research are: Beijing, in the process of tourism planning and management, needs to plan the scenic spot layout scientifically, to strengthen the main characteristics of scenic spots, to perfect the function of the scenic spot tourism, to improve the classification of scenic areas, to promote the level of social services, and to enhance the visitor experience in order to make better the overall image of Beijing.
In essence, regional coordinated development is the process of the interaction of urban economy and the strengthening of economic relations between urban agglomerations. From the perspective of the economic relation, compared Beijing-Tianjin-Hebei with Shanghai-Jiangsu -Zhejiang, the article finds that Shanghai-Jiangsu-Zhejiang is superior to Beijing-Tianjin-Hebei in both the echelon structure of the economic development and economic relation with the central city. In Shanghai-Jiangsu-Zhejiang, there is the reasonable hierarchical formation: Shanghai's radiation has contributed to the rise of the surrounding subcentres, and Nanjing, Suzhou, Hangzhou, Ningbo as the subcentres, also drive the development of the surrounding cities. However, In Beijing-Tianjin-Hebei, there is obvious disparity in the urban comprehensive strength, and all cities maintain close ties with Beijing. As the core city, Beijing’ siphon effect is much greater than the diffusion effect. The polarization effect is so much that although it brings a great deal of factor supply to Beijing, it aggravates Beijing’ urban burden and weakens the radiation effect and driving capacity of other central cities such as Tianjin, Shijiazhuang and Tangshan. Changing the state of Beijing-Tianjin-Hebei urban agglomerations, simply relying on household registration restrictions or industry forced relocation, etc. is not enough. “Easing” and “cultivating”simultaneously are very important. So, taking the Xiongan New Area planning and construction as the opportunity, adjusting the Beijing-Tianjin-Hebei regional space development strategy and industry structure, fostering innovation driven development new engines, creating a new model of city management, changing the “one city dominant” development mode, enhancing the attractiveness of the urban agglomerations, is the current important route.
通过归纳、总结前人大量的研究成果,从土壤有机碳演变的尺度约束框架、滩涂土壤有机碳的核心控制因子以及演变的驱动因素3个方面进行总结。结果表明：①目前形成的监测技术约束下的碳库研究体系,其研究的结果忽视了机理性认识的未来需要,这对于应对未来气候变化条件下的滩涂湿地碳库变化风险稍显不足; ② 滩涂土壤有机碳演变的核心控制因子有泥沙、地貌与埋藏速率、植被与农业活动。滩涂围垦后的农业活动类型与方式是滩涂开发后影响土壤有机碳演变的核心要素,远远高于自然滩涂中的自然主导因子; ③ 不同因素在不同时空尺度上会对滩涂有机碳演变起到重要影响,其中,土地利用/覆被对于有机碳的影响机制是需要重点关注的核心命题; ④ 小尺度、长时间尺度有机碳循环机制的研究需要加强,同时,综合考量要素的时空尺度特性及其技术手段的提升,更加注重过程研究对于指导未来滩涂土壤有机碳研究更具有现实意义。
In this study, we collected a large number of previous researches, summarized the scale framework of soil organic carbon evolution, the core influencing factors and the driving mechanism of coastal soil organic carbon evolution. The results as shown: 1) At present, research system of soil organic carbon induced by monitoring technologies ignores the social needs in the future, which is inadequate for revealing coastal soil organic carbon change under future climate change; 2) The main influencing factors of soil organic carbon evolution are sediment, topography and burial rate, vegetation and agricultural activities. The types of agricultural activities after reclamation are the core factors influencing the evolution of soil organic carbon, which is much higher than that of natural salt marshes. 3) Different factors play an important role in the evolution of organic carbon at different spatio-temporal scales, in which land use change/cover is the core of soil organic carbon evolution. 4) The research on the organic carbon cycling mechanism at small spatial and long time scale is needed to strengthened. In addition, spatial-temporal scale characteristics of the factors and monitoring technology upgrading are integrated to conduct future studies are of practical significance to guide the study of coastal soil organic carbon in future.
基于2005~2015年近10 a面板数据,在测算重庆市沙坪坝区耕地多功能基础上,探究其时空演变规律、多功能间协同与权衡关系,据此构建耕地空间组织经营模式。结果表明：耕地生产功能、景观游憩功能、社会保障功能及建设空间储备功能时空演变特征差异显著。耕地“生产-景观游憩-社会保障”功能间存在两两协同关系,且协同度均值 “生产-景观游憩”>“社会保障-景观游憩”>“生产-社会保障”;耕地建设空间储备功能与其他3项功能间存在此消彼长的权衡关系。据此构建了“一带两区”即山地休闲农业带、郊野农业游憩区、传统农业提升区的耕地空间组织经营模式。
Taking Shapingba district which is the suburb area of Chongqing municipality as the study area, this study establishes evaluation index system of cultivated land multi-function. According to the evaluation index system, this study measuresthe cultivated land production function, the landscape and recreation function, the social security function and the construction space reserve functionbasing on the panel data from 2005 to 2015. Thereby, we explore the spatio-temporal evolution of cultivated land multi-function, reveal the relationship of synergy and trade-off among the multi-function of cultivated land, and set up the spatio organization and management pattern of cultivated land. The results show as follows: First, the spatio-temporal evolution of multi-function of cultivated land shows significantly different characteristic. Among them, the cultivated land production function and the landscape and recreation function emerge aninverted V glyph trend that rises first and falls later, and the spatial pattern characteristics which is high in the around and low in the middle; the social security function shows a sharp downward trend and the spatial pattern characteristics which generally distributes low value parts and juts out in the high value parts. Also, the construction space reserve function appears a steady upward trend and the spatial pattern characteristics which is high in the middle parts and low in the around. Second, there exist a mutual benefit synergistic relationship and “one loss and another gain”trade-off relationship among the multi-function of cultivated land. Specifically, the synergistic relationshipperforms as the cultivated land production function, the landscape and recreation function and the social security function coordinate in pair. The mean value of synergy degree of “production function-landscape and recreation function” is bigger than “social security function-landscape and recreation function” which is bigger than “production function-social security function”. Meanwhile, the trade-off relationship performs as a “one loss and another gain” kind of pattern between the construction space reserve function of cultivated land and either of the other three functions. And third, according to the spatio-temporal evolution rule of cultivated land multi-function, combining with the synergy and trade-off relationship among the multi-function, the study establishes cultivated land spatial organization and management pattern of “one belt and two area”. The “belt” means a hilly leisure agriculture belt that takes fruits and vegetables planting as the core activity, while the “two areas” includes a suburb agricultural recreation area that mainly manages flowers and fruits industry, and a traditional agricultural promotion area which takes rice production as the core activity.
通过分析三北工程区生态系统防风固沙服务量变化,进而评价工程的防风固沙效应。结果表明：① 近35 a,三北工程区林地面积持续增加、草地面积持续减少,特别是半干旱风沙区和黄土高原区。植被覆盖度在前20 a持续增加,近15 a则呈现先下降而后略微增加趋势。②土壤风蚀模数持续减少,近15 a减幅远高于前20 a,沙地、草地、其它类型转林地或转草地区域的减幅尤为明显。生态系统防风固沙服务保有率呈上升态势,干旱荒漠区增幅显著。草地和沙地为工程区生态系统防风固沙服务总量贡献了71%,且转草地区域的贡献高于转林地区域。③ 考虑到植被好转同时受气候变化和人类活动的影响,以风场减弱为主的气候变化导致土壤风蚀力减弱与三北防护林等生态工程对生态系统防风固沙服务变化的贡献率分别介于85%~89%和11%~15%之间。
In order to understand the windbreak and sand fixation effects of the Three-North Shelter Forest Program (TNSFP) in recent 35 years, this paper analyzes the amount change of ecosystem sand fixation caused by climate change and vegetation degradation or restoration in the project region, and then assesses the sand fixation effects of the Program. Based on Landsat MSS, TM/ETM+, and environmental satellite (HJ) images, the spatial-temporal datasets of land cover changes in the project region of TNSFP were analyzed in the periods of mid 1970s, 1990, 2000, 2010, 2015, especially the forest and grassland. Combining the NDVI data of AVHRR and MODIS, the vegetation coverage was estimated, and then the change of vegetation coverage in the 1982-2015 was analyzed. The soil erosion modulus were estimated at the regional scale by applying the soil erosion equation (RWEQ), and then the ecosystem services of windbreak and sand fixation were assessed using indicators of amount and retention rate of windbreak and sand fixation. Then the contribution rate of ecological program and climate change to regional ecosystem change was determined by comparing the indexes under the conditions of average climate and real climate. The results showed that: 1) In the past 35 years, the area of forest was continuously increased and grassland was decreased, especially in the semi-arid sandy area and Loess Plateau. The vegetation coverage increased continuously in the before 20 years, and then decreased in recent 15 years. 2) The soil wind erosion modulus is decreased continuously, and the decreasing rate in recent 15 years is much higher than that in the before 20 years. The decreasing rates were especially obvious in sandy land, grassland, and regions planting trees and grassland. The retention ratio of ecosystem windbreak and sand fixation service also increased continuously, especially in arid desert area. Grassland and sandy land contributed 71% of the total amount of windbreak and sand fixation. However, just 6.6% of forest land, and the contribution of conversion grassland was higher than that of conversion forest. 3) In the TNSFP, the weakening of wind erosion force due to reducing wind, and the vegetation restoration in local areas due to TNSFP and other ecological programs, both resulted in a decrease of soil wind erosion, and accounted for 85%-89% and 11%-15% of the decrease. Winter monsoon in mid-latitude Asian is weakened due to global warming. In the project region of TNSFP, the grassland played the most important role in ecosystem service of windbreak and sand fixation, which accounts for more than 63% of the total area. Therefore, the conservation of grassland and sandy land were significant in project region of TNSFP. Project planning and implementation should focus on the transfer of funds from afforestation to grassland conservation and restoration.
通过RUSLE模型对卧虎山水库流域土壤侵蚀进行全面评价验证和总结。结果表明：① 水库流域平均侵蚀模数为462 t/(km2·a),该数值与通过水库淤积等资料推算评估结果基本一致,表明本研究结果具有较高的可信度;水库流域年均侵蚀量达到2.6×106t,其中高于容许土壤流失量的面积为176 km2,占到流域总面积的31.51%。从不同侵蚀级别来看,占流域面积27.77%的轻度侵蚀,对流域侵蚀总量的贡献率为54.64%; 面积占比3.74%的中度及以上侵蚀,侵蚀量贡献率达到30.94%。② 流域内土壤侵蚀空间差异较大,回归分析发现地形因子是导致各子流域土壤侵蚀模数差异的主要因素;就土地利用类型而言,旱地和农村居民点是流域内的主要侵蚀土地利用类型;流域内土壤侵蚀模数随着坡度增加呈现相应增大趋势,8°~25°坡度段面积比例不仅最大,而且侵蚀量占比最高,是水库流域的主要侵蚀坡度段。
Soil erosion of the Wohushan Reservoir was calculated based on RUSLE(Revised Universal Soil Loss Equation). The calculated mean soil erosion modulus is 462 t/ km2·a, which is consistent with the data estimated by the deposition from both reservoir and main watercourses. This indicated that the calculation is accurate and the result is reliable. The annual average soil erosion amount is 2.6×106t. According to standards for classification and gradation of soil erosion issued by the ministry of water resources of PR China, the area above soil loss tolerance is about 176 km2, which amounts to 31.51% of total area of the Wohushan Reservoir. With reference to the erosion intensity, the slight erosion area occupies 27.77% of total area in reservoir watershed, but contribute 54.64% of the total load of soil erosion in the Wohushan Reservoir Watershed. while the moderate and above intensity erosion area only occupies 3.74% of the study area and contributes 30.94% of the total load of soil erosion. It was found that there are large spatial differences for soil erosion intensity in the reservoir watershed. Based on hydrological module in arcgis platform, we got 11 sub-basins. Their soil erosion intensity were found to have a consistent change with their geomorphology factors, which indicates that slope length and slope gradient should be the main factors leading to the difference of soil erosion modulus in each sub-basins. Compared the ratio of erosion amount with that of different land uses, it’s found that dry land and rural settlements are the main land use types which suffered serious erosion. The soil erosion intensity increases with the increase of slope gradient. The main erosion slope ranges from 8° to 25°, in which the percentage of area is not only the largest, but also the erosion rate is the highest.
以黄河青藏高原阿万仓和采日玛两段主河道50 km与65 km长的网状河段为研究对象,利用2013年3期遥感影像绘制了不同流量下（176 m3/s,978 m3/s,1 610 m3/s）网状河段活动河道的分布变化图,结合DEM数据分析了现有河道在流量增加过程中的空间分布格局和潜在定量关系。研究结果表明：根据流量大小划分出的3类活动河道,其分布规律基本是后者位于前者的两侧,据此可以推断,网状河分支河道基本是从主河道向两侧逐渐发展的。对于阿万仓河段,在河谷和河间地相对宽阔处,每个河道断面上3类活动河道数的比值为1:1.67:2.25;而在河谷较窄的地方,该比值为1:1.22:1.33。在采日玛河段,该比值分别为1:1.3:1.4和1:0.95:1.16。在宽阔的草原湿地河段,当网状河的主河道发生弯曲时,弯道内侧的活动河道数要大于弯道外侧的活动河道数。在平坦开阔的河谷地带,断面上的活动河道线密度与河谷宽度之间呈现出极好的线性负相关关系;而峡谷地带由于两侧高地形的限制,河谷宽窄不一,活动河道的线密度相对较大、且差别也较大。
As an anastomosing river pattern located in the Qinghai-Tibetan Plateau, the Awancang and Cairima anastomosing channel reaches of the Yellow River were selected to be revealed the distribution features of the active channels in this study. The main channel length of the two anastomosing river reaches is 50 km and 65 km, respectively. Based on DEM data, three remote sensing images under different discharge conditions (176 m3/s,978 m3/s,1 610 m3/s) in 2013, and established series of cross-sections with a interval about 2 km which perpendicular to the anastomosing channel belt, the active channels are classified into three kinds and the number of them and distance from active channel to the main channel on every cross-section were obtained. Furthermore, the spatial distribution characteristics of the active channels under the different discharge conditions were revealed. The results show that distribution rule of the three kinds of the active channels is the latter is on both sides of the former basically. From this we can infer that the branching channels in the anastomosing river reaches develop from the main channel to its both sides. For the Awancang anastomosing river reach, the ratio of the three kinds of the active channels on average of all cross-sections is 1:1.67:2.25 in the broader floodplain and grassland, while is 1:1.22:1.33 in the narrower valley section. For the Cairima anastomosing river reach, the ratio is 1:1.3:1.4 and 1:0.95:1.16, respectively. This phenomenon is beneficial to maintain the spatial balanced distribution and stability of the anastomosing channel system. In the reach of grassland without restrictions of valley, when the main channel occurs bends, the number of the active channels in the inner side of the curves is larger than that in the outside of the curves. In the reach of well-developed anastomosing morphology, there is an excellent linear negative correlation between the line density and valley width. While the line density of the active channels in valley reach is relatively larger so do the difference among them.
选取10.55~2.7 kaBP Qunf洞的Q5石笋δ18O记录作为印度夏季风的代用指标,集合经验模态分解（EEMD）多尺度分析结果揭示了印度夏季风的强弱变化和与亚洲季风减弱事件的一致性,进一步讨论了11 kaBP以来印度夏季风的逐渐增强而后减弱的发展态势。选用同时期的古树年轮14C记录作为太阳活动代用指标,调频、调幅分析结果发现印度夏季风的31 a、70 a和7 860 a尺度分量受太阳活动相应分量的调频胁迫较为显著;同时又揭示出“太阳活动71 a周期-印度夏季风31 a周期”“太阳活动1 379 a周期-印度夏季风142 a周期”和“太阳活动2 376 a周期-印度夏季风733 a周期”三对调幅胁迫。
Recent analysis of the multi-scale incidence relation between the Indian summer monsoon(ISM) and the solar activity is relatively poor, which makes the research on the driving mechanism of the ISM cannot go further. To solve this problem, the multi-scale fluctuation characteristics of the ISM was analyzed based on the Ensemble Empirical Mode Decomposition (EEMD) method. Furthermore, based on the amplitude modulation method, the frequency modulation and amplitude modulation forcing by solar activity on ISM is analyzed. Finally, the driving mechanism of ISM was discussed. We selected the δ18O record of Q5 stalagmite from Qunf cave which covers 10.55-2.7 kaBP period as proxy of ISM, the EEMD multi-scale analysis results reveals that the weakened event of ISM is correlated with the Asian monsoon, furthermore, the trend component shows that the development procedure of ISM increased first and then decreased gradually since 11 kaBP. The 14C records of ancient tree rings was selected as solar activity proxy, frequency modulation and amplitude modulation analysis results showed that the ISM components on the scale of 31 years, 70 years and 7 860 years were significantly forced by the frequency modulation of solar activity components on the corresponding scale. Meanwhile, it revealed that there were three pairs of amplitude modulations: the cycles between 71 years of solar activity and 31 years of ISM, the cycles between 1 379 years of solar activity and 142 years of ISM, and the cycles between 2 376 years of solar activity and 733 years of ISM.
综合环境风险区划是变化环境下开展综合防灾减灾工作的基础,对于综合风险防范措施的制定具有指导意义。以农业、生态和人群3个系统为主要受灾体,从作物产量、生态系统变迁、高温热浪对人群的影响3个方面综合评估了4种典型浓度路径（Representative Concentration Pathways）RCP2.6、RCP4.5、RCP6.0和RCP8.5情景下21世纪末期（2071~2099年）的中国综合环境风险,并以RCP8.5情景为例编制了未来综合环境风险区划。结果表明,该时期中国综合环境风险主要出现在黄淮海地区、华南部分地区和青藏高原部分地区。综合环境风险区划共分为6个一级区和43个二级区;一级区分别为西北低风险区、东北生态较低风险区、青藏高原生态中度风险区、晋陕生态-农业中度风险区、华南农业高风险区、黄淮海农业-热浪高风险区。
Environmental risks, such as crop failure, mortality and vegetation deterioration caused by warming, drought, flood, heatwave, etc., tend to be more complex and interactive with each other. Integrated Environmental Risk Regionalization becomes the fundament for multi-hazard prevention and reduction under a changing environment. Regarding potential large losses from the agricultural system, ecosystem, and human being caused by climate change, we assessed the integrated environmental risk based on the crop yield changes, ecosystem shift and mortality by heatwave in China during the late 21st century (2071-2099) under four Representative Concentration Pathways (RCP2.6, RCP4.5, RCP6.0, and RCP8.5). Bias-corrected projections of future climate change were derived from five generic circulation model. Four major crops (rice, wheat, maize, and soybean) were considered, and the crop yield changes were projected by four global gridded crop models. The changes of crop yield during 2071-2099 compared to the period of 1980-2010 were computed to identify the risk in agricultural system. The Γ metric was used to assess the risk of ecosystem shift under climate change. The Γ metric describes the ecosystem state and its changes based on a set of macroscopic variables derived from four global gridded vegetation models. The larger Γ, changes in ecosystem state variables, indicates the larger risk of ecosystem shift in future. A heatwave event was identified by three successive days of high temperature that >35 °C. The mortality rate caused by heatwave events was estimated by the difference of mortality rate in a period with high-temperature and that in non-high-temperature days of the year. Regression was established between heatwave events and mortality rates. It was then used for estimation of mortality rate in the 2071-2099 period. These environmental risks were combined by a multi-risk index (IERI) to illustrate the integrated environmental risk in the future. In this study, the same weights were set for all environmental risks in the IERI calculation. The IERI was calculated at a spatial resolution of 0.5° for the 2071-2099 period under the four RCPs. The results showed that high integrated environmental risks will appear in the Huang-Huai-Hai region, relatively high integrated environmental risks will appear in the South China, and moderate integrated environmental risks will occur in the Tibet region. The integrated environmental risk regions (IERR) were then delineated based on the assessment. Six IERRs were identified for China, i.e., Northwest-Low-Risk region, Northeast-Relatively-Low-Risk region, Tibet-Moderate-Risk region, Jin-Shaan-Moderate-Risk region, South-China-High-Risk region, and Huang-Huai-Hai-High-Risk region. Fourty-two sub regions were further divided upon the six IERRs. Due to largely different environmental conditions of the six IERRs, they include quite different numbers of sub regions, namely 2, 6, 8, 7, 10, and 9 subregions, respectively. Though many environmental risks caused by climate change were not included in this assessment, the preliminary integrated environmental risk regionalization would be a reference for decision makers and future studies.