Urbanization is the right way to build a well-off society and realize modernization for China. It determines not only the future of China, but also the development process of the world's urbanization. Chinese geographers have made important contributions to the urbanization development of China over the past 35 years. This is mainly manifested in the following aspects: 1) They put forward the concept of urbanization firstly and promoted the urbanization to be national strategy. 2) They took the lead in revising the three stage theory of urbanization proposed by Northam to the four stage theory. 3) They put forward a reasonable process about the development of China's urbanization which has been adopted by National New Urbanization Plan. 4) They developed a comprehensive zoning of China’s new urbanization and set up a reasonable pattern of China's new urbanization. 5) They took the lead in developing the quantitative measure methods and system of urbanization development quality, which provided technical support to improve the quality of urbanization development. 6) They earlier issued the development report of China’s new urbanization, and put forward the general patterns and the different patterns of the new urbanization development. 7) They put forward the theory and technical drawings of the coupling circle bewteen urbanization and eco-environment for the first time. Chinese geographers often act as the organizer of urbanization research which is multidisciplinary, and undertake the following responsibilities: 1) to comprehensively analyze the problems and foreign experiences of urbanization development; 2) to explore the driving mechanism and the basic laws of urbanization development; 3) to analyze the spatial pattern of urbanization and the difference model; 4) to reveal the coupling relationship between urbanization development and resource environment; 5) to simulate a variety of scenarios and make an early warning of urbanization development; 6) to choose the sustainable development road of improving urbanization quality. In the future, Chinese geographers will have the following missions on urbanization development: 1) to innovate the theory of new type urbanization quality improvement; 2) to optimize China's urbanization spatial pattern under the background of “Belt and Road”; 3) to reveal the interactive coupling mechanism and coupling law between urbanization and eco-environment; 4) to develop the intelligent decision support system for China’s urbanization development and give the guiding policies.
公共自行车作为一种绿色低碳的交通出行方式,在国内外许多城市得到了快速发展。目前国内公共自行车相关研究多以使用特征分析为主,而与建成环境关系的研究较少。采用运营大数据与网络开放大数据相结合的方法,以南京市桥北区为案例,研究公共自行车站点使用特征及建成环境对其的影响。研究结果表明：① 公共自行车的使用存在明显的时空间差异;② 使用主要受站点300 m范围内日常服务设施网点密度、基础设施及公共交通条件等建成环境因子影响;③ 建成环境对不同时段使用的影响存在较大差异。研究结果可为片区站点的优化布局与管理建设,以及无桩型共享单车的投放与运营管理提供科学的参考依据。
In the content of sustainable and smart city development, more and more cites in the world start building Bicycle Sharing System (BSS) which is a green and low-carbon way to travel. Most previous studies on BSS focus on analysis of trip characteristics with small sample survey and simple statistical analysis in China, few studies focus on quantitatively exploring built environment factors that affecting public bicycle flows and usage employing real bicycle usage data. In this article we aim to build a method to examine the influence of the built environment attributes on arrival and departure flows at station level using real bicycle usage data and combined with internet open data. Then by taking Qiaobei area of Nanjing as study object, first we analyzed the temporal and spatial characteristics of public bicycle usage, then we examine the influence of bicycle infrastructure, daily service facilities (such as super market restaurant) and built environment attributes on arrival and departure flows at station level using the a multiple linear regression model. The results show that: 1) There are significant spatial difference between station distribution and usage. Meanwhile there are significant differences in the public bicycles usage at different periods; the use of public bicycles is mainly concentrated in the morning and evening peak stage. It indicates that bicyclists mainly use public bicycle for commuting during morning and evening peak. 2) In built environment factors that in a buffer zone of 300 m around each bike sharing station, the length of secondary road in station catchment and the distance to the closest metro station as well as the number of shopping network, restaurant, around station and the capacity of station were most important factors that influence the bike usage. There is a significant positive correlation between the usage of public bicycle and the density of nearby living facilities, including restaurants, shopping centres and metro stations etc.. The closer station of public bicycle sits from the metro station, the higher frequency of public bicycle usage will occur. Another interesting finding is that there is somewhat competition between bus and public bicycle. 3) In different time periods,there are also significant differences between the built environment factors that influencing bike usage. The developed methodology and findings provide some useful information for urban planners and BSS administrators who design or optimize BSS to improve the demand and turnover of bikes at bike stations with the goal of maximizing usage and availability. At the same time, these finds put forward scientific and reasonable reference for the operation and management of the non-pile-type shared bicycle.
With the rapid development of China’s marine economy, a large number of human and capital flocked to the coastal area, which also resulted in the destruction of the marine ecological environment. Despite the response measures have been taken, but still with little success. Therefore, it is of great practical significance which could guide the economic and ecological construction of coastal areas in China to explore the internal mechanism between the marine economic development and the marine ecological construction. The marine composite system has both economic and ecological attributes, which can be regarded as a community(symbiosis environment) of two “populations” including marine economy and marine ecology(symbiotic unit), and the input of human capital will change the flow of elements(symbiotic matrix) between marine economy and marine ecology when it raises the density of one “population” which leading the symbiosis theory has its rationality in the study of the interaction between marine economy and marine ecology. Compared to the grasp of marine economy and ecological coordination degree on the whole, the calculation of symbiotic pattern can not only distinguish the development model of the marine composite system on the whole, but also can analyze the influence of marine economy and ecology due to the development model of symbiosis, to clear the direction of future development. In this article, the Pressure-State-Impact-Response(PSIR) model of marine composite has been established to evaluate the level of marine ecology, marine economy, and marine environmental capacity. We find that the ecological level and economic level of eleven provinces and cities in China’s coastal area are mostly steady and rising, and the environmental capacity remains basically stable from 2004 to 2013. On this basis, the symbiosis model of marine ecology and marine economy is discussed based on the Logistic model, and the results show that Tianjin and Shanghai have been out of resource demand model, and there marine economic and ecological symbiotic coefficient is less significant; In other nine provinces, Hebei, Jiangsu, Guangxi and Hainan are in reverse symbiosis patterns, Liaoning and Shandong, are in individual development patterns, while Zhejiang and Guangdong, showing the ecological benefit of commensalism patterns, and Fujian is economic suffer partial interest symbiosis pattern. Overall, China’s marine ecology and marine economic development still remain in the restricted or isolated development stage, especially the situation which achieving the promotion of marine economy by sacrificing marine ecological development is pervasive, and marine ecological construction can not support the development of marine economy effectively. At last, this article puts forward some relevant policy suggestions according to the marine economic and ecological symbiotic model, in order to provide theoretical basis for the future economic and ecological development in coastal provinces and cities.
The issue of air pollution in China has already surged in recent years, attracting public concerns, even great anxiety. This paper employs a unique cross-sectional data set of 150 Chinese cities in 2014 and adopts air quality index (AQI), an indicator newly-developed by the ministry of environmental protection of China, to measure air quality. Then, from a spatial heterogeneity perspective it applies ordinary least square (OLS) technique and geographically weighted regression (GWR) model to analyze the impact of foreign direct investment (FDI) on air pollution controlling for other five explanatory variables, namely, per capita GDP, population density, sulfur dioxide emissions, PM2.5 concentration, and the number of vehicles. Meanwhile, it also investigates if there is an inverted U-shaped curve between per capita GDP and air quality index, specifically environmental Kuznets curve (EKC). The findings are the following. Firstly, there is no evidence of EKC, but an increasing linear relationship between income and air pollution. Secondly, the variable of FDI is found to be significant and negative, indicating that an increase of foreign capital may reduce air quality index, in other words, improve air quality. This is because foreign capital brings advanced technologies, improving air quality effectively. Besides, sulfur dioxide emissions and PM2.5 concentration are found to have significant and positive impacts on AQI while population density, as an indicator of environmental awareness, is found to have a negative impact on AQI. However, from the results of the OLS model, the variable of private cars is not statistically significant, even found to be positive. It hence was deleted from the model. Thirdly, the GWR model results suggest that the impacts of FDI of 150 cities on air pollution greatly vary from city to city. Specifically speaking, foreign capitals of the northeastern cities, Guangzhong plain urban cities and cities of the middle reaches of the Yangtze River play a more important role in reducing air pollution than those of other cities. On the contrary, the contribution of foreign capitals of Shandong peninsula cities and Sichuan-Chongqing urban cluster is found to be insignificant. Finally, from the above analysis, a series of policy handles and suggestions are given.
在深入阐明生态系统服务与区域生态安全格局之间内在联系的基础上,根据人类社会与生态系统之间以生态服务流为纽带形成的反馈机制,提出基于驱动（Driver）-压力（Pressure）-状态（State）-影响（Impact）-响应（Response）区域生态安全格局研究框架。该框架有助于深入理解区域生态安全维持和区域生态安全问题形成的机制,拓展区域生态安全评估、生态安全格局维持和提升的视野。当前,耦合生态服务的区域生态安全格局研究有3个关键的前沿议题：① 生态服务需求和生态服务供给的空间耦合及其对人类活动的响应;② 维持生态系统服务流网络结构完整性和稳定性的人类活动阈值;③ 耦合人类生态服务供给和需求的区域生态安全评估模型。
Ecosystem services (ESs) are material and spiritual benefits obtained from the composition and functions, and processes occurred in ecosystems. They are fundamental and critical for survival and development of human society. They not only reflect the status of ecological security comprehensively from the aspect of ecosystem by ecosystem services supply, but also provide an avenue for human society to perceive the changes of ecosystem composition and function through changes in ecosystem flows. ES is inherently coupling with regional ecological security. A sustainable supply and delivery of ESs indicates a well regional ecological security. Therefore, ES concept and ES evaluation are essential in assessing regional ecological security status. However, theories and methodology related to integrating ES approach into ecological security assessment are insufficient. It is necessary to give a systematic exploring of methodology for combining ES with regional ecological security pattern. In this study, the inherent connection between ES and regional ecological security pattern is revealed. According to the feedback mechanism between the ecosystem capacity on ecosystem services provision and human societies through ES flow, a Driver-Pressure-State-Impact-Response framework (DPSIR) is outlined. In this framework, ES demand of human society is the driven force; Intensity of ES extraction indicates the pressures; Ecosystem composition and function, and integrality and stability of ES delivery network are defined as state variables; ES supply capacity and capacity to deliver ES to human society are indicators for impact. ES flow is considered as a media to feedback information on ecosystem to human society. This framework is provide a map to study regional ecological security pattern, and may broaden the view of regional ecological security assessment and the regulation of ecosystem pattern for ecological security maintenance and improvement. In the end, some critical research issues that are relevant to the DPSIR framework are given. At present, 3 key issues need to be untangled for the DPSIR framework provided here: 1) response of the spatial coupling between ES demands and ES supply capacity; 2) threshold of human activity intensity for maintaining the integrity and stability of ES flow network; 3) models for regional ecological security pattern assessment and coupling ES demands and ES supply.
采用第六次中国人口普查数据,基于全面二孩实施背景,预测未来中国与省际城乡人口规模以及省际人口迁移规模;采用2010年人口数据和2020年预测人口数据,从对比视角分析了中国省际人口迁移格局变化及其对城镇化发展的影响。研究发现：① 城乡全面放开二孩政策不会带来区域人口数量的剧烈反弹;② 综合考虑省际人口迁移方向与强度,将中国31个省份划分为4种类型;③ 省际人口迁移促进了城镇化率的提高及省际差异的缩小,对2010~2020年中国城镇化率的增加的贡献占到了30.77%。
From the policy allowing couples to bear a second child if one parent is an only child to universal “Two-Child” policy, fertility policy in China had changed in succession, which had caused extensive social concerns and would have an influence on Chinese demographics in the future. Based on the implementation of universal “Two-child ” Policy, using the data from China 2010 censuses, the article predicts the number of urban and rural population by the age shift algorithm as well as the number of interprovincial population migration with Markov chain in 2020. From the data in 2010 and 2020, the article analyzes the change of population migration pattern in China and its impact on urbanization development from the perspective of contrast. The results are as follows: 1) The “Two-Child” policy would not bring a sharp rebound in population size in 2020. 2) According to the intensity and direction of migration, the area types of interprovincial migration can be divided into four modes: active areas have a larger migration and their immigration is much more than emigration, which is mainly located in the eastern coastal provinces; active areas have a larger migration and their emigration is much more than immigration, which is mainly located in the central and western China; active areas have a larger migration and their immigration is nearly equal to emigration; inactive area have a smaller migration, such as some provinces with a large ethnic minorities population. 3) Interprovincial population migration has a positive effect on the development of urbanization rate. It accounted for 30.77% of the augmentation of urbanization rate and it also narrows the discrepancies of urbanization rate among provinces in China, during 2010-2020. The implementation of universal “Two-Child” policy is a major adjustment of fertility policy in recent years, which will impact on the urbanization and the spatial distribution of populationto a certain extent. Because the influence has hysteresis quality, the fertility policy has not an obvious performance when it started to implement. In order to reduce long-term side effect from policy change, it is necessary to forecast and research potential social impact from the new policy.
Population and economic are the two main indicators of regional differences and their spatial distribution is closely related to the formation of regional disparities. With the change of development environmental and development pattern about the Yangtze River Delta in recent years, this article makes an in-depth temporal and spatial study on the inequality pattern of population and economic in the Yangtze River Delta by combining inconsistent index, center of gravity method and imbalance index, and the empirical analysis of the influencing factors based on the panel data regression from 2000 to 2015 was carried out. The results show that regional disparities still dominate the development pattern, with the change of the pattern of population and economy brought about by the change of regional development pattern, the overall imbalance of regional population and economy is weakened, and the regional inequality pattern about population and economy in the Yangtze River Delta is relatively stable. Then, we analysis the affecting factors of population and economic inconsistent index in different periods from the analysis of urban development, market and government in different periods, the results show that there are differences in factors of population and economic inconsistent index in different periods, and with the impact of urban development always plays an important role as well as market forces become more significant and government influences become weakened.
Taking the administrative unit of 130 prefecture level cities and above in the Yangtze River Economic Zone in 2014 as the research object, the HR model and the coupling and coordination model were used to evaluate the coordinated development level between each ‘two modernizations’ and “five modernizations”, through exploratory spatial data analysis to explore the “five modernizations” of the coordinated development of spatial distribution characteristics, the geographical weighted regression model reveals the influential factors and spatial differences of the coordinated development of “five modernizations”. The results show that: The greening development level of the “five modernizations” index in the Yangtze River Economic Zone is the highest, and the agricultural modernization development level of the “five modernizations” index in the Yangtze River Economic Zone is the lowest. The greening index in the upstream area of the “five modernizations” Indexes is the highest, the industrialization index in the midstream area is the highest, and the informatization, urbanization and agricultural modernization index in the downstream area are the highest. The highest coordination degree index of “two modernizations” in the Yangtze River Economic Zone is urbanization and information index, the lowest coordination degree index of “two modernizations” in the Yangtze River Economic Zone is industrialization and greening index. The comprehensive development index of the “five modernizations” in the Yangtze River Economic Zone is the downstream area higher than the upstream area higher than the midstream area, the coupling index and the coordination index of the “five modernizations” in the Yangtze River Economic Zone are the downstream area higher than the midstream area higher than the upstream area, the development pattern of the comprehensive development index, the coupling index and the coordination index is east high and west low as a whole. The “five modernizations” of the coordinated development level in the Yangtze River Economic Zone had a clear spatial correlation, high-value areas and low-value areas of the coordinated development level in the Yangtze River Economic Zone tend to gather in a space, there was showing a hot east and cold west development trend of the coordinated development level in the Yangtze River Economic Zone on the whole. Finally, the article puts forward some suggestions for improving the coordinated development level in the Yangtze River Economic Zone: improving the per capita green area of the downstream area; enhancing industrial productivity in the midstream area; improving the per capita consumption index, the internet penetration rate and the degree of agricultural mechanization of the upstream area.
利用引力模型和社会网络分析法,采用网络密度、网络中心度和核心边缘指数,对2013和2016年的京津冀雄地区的旅游经济空间结构进行分析。分析发现：① 旅游经济联系度和联系量提高显著,旅游经济联系有均质化趋势。② 网络结构呈现北部和南部相对稀疏,中东部相对密集的非均质格局。③ 雄安新区是旅游网络空间的战略节点,该区将促进京津冀旅游均质化发展。④ 具有一定的核心-边缘区结构,北京和天津为核心区;邢台和雄安为边缘地区;其他区域为中间区。石家庄和邯郸将成为除京津之外的旅游经济网络结构中心。京津冀雄逐步从“两核独大”网络格局向“两核带动,多点发展”转变,区域整体网络化初步形成。
This article analyses the spatial structure of tourism economy in Beijing-Tianjin-Hebei-Xiong’an Region in 2013 and 2016, based on Gravity Model and the method of social network analysis (SNA), by the use of the network density, network centrality and Core-Periphery index. It achieves 4 conclusions: 1) The tourism economy affiliation level and affiliation quantity increased significantly, and tourism economic connection has a homogenization trend. 2) The spatial structure of the research area presented the pattern that north and south was relatively sparse, and middle east was densely. 3) Xiong’an New Area is the strategic node of the tourism network spatial structure, it will promote the homogeneous development of Beijing-Tianjin-Hebei region. 4) It has a core-periphery structure, and Beijing and Tianjin are the core districts; Xingtai and Xiong’an are on the periphery, while the others are in intermediate region. Shijiazhuang and Handan will be the tourism economy network center. The network structure of Beijing-Tianjin-Hebei-Xiong’an Region gradually changed from “two core areas domain alone” for “two core areas promotion, multi-point development”, and the regional network has basically formed.
With keeping a high-speed growth since reform policy, resource-based cities in Northeast China have encountered both social and economic changes caused by internal transition as well as external factors. As one of the main factors that effect the cities transition development, it is important to strenghen research on population distribution charateristics of resource-based cities, to provide scientific supports for both resource allocation and policy making. This article aims to reveal the population spatial distribution of the northeast resource-based cities during the transition developing process. The study constructs indicators for the population, economy, society, and environment based on the sustainable development theory with referring data. The spatial-temporal pattern and the effects of other factors are examined at the city level in resource-based cities in Northeast China from 2000 to 2014. The key conclusions of this study are as follows: 1) Nearly 75% of resource-based cities, population agglomeration levels declined in the Northeast during transition process. Yichun lost much more population than other places,while Daqing’s attracting ability kept being the strongest. According to the resource attribution, coal cities are qualitified capable of attracting population than mining cities, and the forest cities are the worst. 2) Four stages of population change can be identified according to their unbalanced coefficient values. The first stage was from 2000 to 2002, the level went smoothly without big fluctuation. In 2003-2005, the unbalanced situation accelerated with the resource-based cities’ population moving activity became stronger. During the third time, under the government financial help, the population agglomeration ability of resource-based cities decaresed slowly. However, the situation did not turn well after 2013, many people prefered to go outside searching more opportunities. 3) The development of a service industry, traffic transportation, medical treatment, social insurance and environmental quality were found to make significant contributions to the population development during the transition process in resource-based cities; however, income level and education were not found to be as effective as other factors. Overall, the population change in the resource-based cities matches with the economic transition process. In the future, applying the innovation, increasing the income, and upgrading management systems can enlarge the capacity of attracting people for the resource-based cities. Additionally, government and enterprises should also change their traditional planning models, implement well-directed measures and solve the historical problems such as laid-off workers’ social insurance gradually and moderately by taking a sufficient consideration of both inside and outside circumstances.
Based on the 145 settlements as the research object in Xilingol pastoral area (nine counties), adapting five national population census data (1964, 1982, 1990, 2000, 2010) and data in 2015, the article analyzes the structure configuration, scale grade, feature of spatial and temporal evolution to the settlement system in study area by means of GIS spatial analysis technique, spatial statistical technique, etc. Dynamic characteristics of morphological structure show that: A degree of external force influences the balance in geographical environment base, further, critically influences Christaller landscape; Scale grade’s dynamic analysis follows rank-size rule; During 50 years, the overall change rate of settlement scale corresponds to the "big event" in history. The evolution characteristics and mechanism of Xilingol League’s settlement system show that, traditional central place system is still influenced by traditional factors in typical pastoral areas. However, the factors such as informationzation and networking, which are deeply influenced by the central land system, have not had significant influence in the pastoral area. In addition, the characteristics of driving factor that promote the evolution of the settlement system are external cause and lack of endogenous power.
采用考虑非期望产出的SBM(Slack-Based Measure)模型,结合探索性空间数据分析方法（ESDA）,对甘肃省各县（区）2000~2014年的农业生态效率及空间分布格局进行实证分析。结果表明：① 考虑非期望产出和不考虑非期望产出的农业生态效率之间存在着明显差异,而考虑非期望产出的农业生态效率结果更符合实际情况。② 在研究期内甘肃省农业生态效率呈持续上升态势,但整体效率偏低;空间变化趋势呈现自西向东、自南向北递减态势,但南北差异小于东西差异。③ 从全局空间分异来看,除2001~2003年外,甘肃省各县（区）农业生态效率呈现正相关特征,空间集聚现象显著;从局部空间分异来看,处于空间正相关地区数量在研究期内逐渐下降,区域农业生态效率的集聚现象减弱。农业生态效率高高（HH）集聚主要分布在河西走廊及甘南地区,空间上具有明显的向邻接地区扩散的趋势;低低（LL）集聚主要分布在甘肃省中部地区,空间分布较为稳定。
The evaluation of agricultural ecological efficiency will help to understand the regional agricultural economy development status. In this paper, the agricultural water footprint and agricultural grey water footprint were respectively introduced into input indexes and undesirable output indexes. Then the SBM model of considering the undesirable outputs of DEA was used to calculate the agricultural ecological efficiency, and the Exploratory Spatial Data Analysis (ESDA) was applied to analyze its spatial distribution, agglomeration and changing trend from 2000 to 2014 in all counties (districts) in Gansu Province. The results showed that: 1) The agricultural ecological efficiency values of considering undesirable outputs were lower than the values of no consideration of undesirable outputs, and the farmer were more correspond with practical situations. 2) During 2000-2014, the agricultural ecological efficiency values were low on the whole and showed an ascending tendency in Gansu. And in spatial change, the values showed a decreasing tendency from west to east and from south to north, but the difference of values from south to north was less than that of values from west to east. 3) From the global spatial difference of efficiency values, except for 2001, 2002, and 2003, the agricultural ecological efficiency values showed the positive correlation and have remarkably agglomerated in space distribution in all counties (districts) in Gansu. From the local spatial difference, the quantity of counties with positive correlation was gradually decreasing and the spatial agglomeration of the regional agricultural ecological efficiency was reduced during the period of study. The regions with High-High (HH) correlation pattern mainly located in the Hexi Corridor and Gannan areas, and they have an obvious diffusion trend toward the adjacent areas on the space. The regions with Low-Low (LL) correlation pattern mainly located in the middle area of Gansu and the spatial distribution is relatively stable. The above evaluation results could reflect well the development condition of agricultural economy of Gansu Province in the last decade, and they could provide an important guiding and reference for realizing sustainable agricultural development in Gansu Province.
以河南省封丘县树莓产业为例,基于实地调查,从特色种植的空间扩散网络、村域种植规模变化、不同类型村空间分布特征、整体参与村空间集聚特征4方面对特色种植的空间持续性进行分析发现：特色种植空间扩散网络密度低,空间持续性不强,但其变化的空间范围一定,集聚特征明显。运用AMOS21.0对以上现象的影响因素进行分析发现：① 农户自身特性,尤其是冒险性精神对其持续种植时长影响较大;② 资金、技术、信息等生产条件获取越便利,农户持续种植时间越长;③ 政府推动对农户持续种植具有正向作用;④ 资源环境,尤其是土壤特性和能人带动对村域种植规模影响深刻;⑤ 距离区位对村域持续种植的影响弱于基础设施条件。
Regionally specialized agriculture could be promoted by its continuous spatial diffusion of a specific crop in a certain area, which not only improves the efficiency of agricultural production, but also pushes the rapid development of agricultural economy. The spatial distribution of specialized plantation indicates its developing status to some extent. In this article, the spatial continuity of specialized plantation means that the cultivated area of this featured crop spatially continues to extend or shrink. Continuously expansion of this featured crop’s planting within a specific area leads to the regionalized and specialized production of this crop, on the contrary, spatially shrinking of this featured crop’s planting illustrates that its relevant industrial development potential is lack. Therefore, studying on the spatial continuity of specialized plantation and its determinants could explore the formation mechanism of regional specialization in specialized plantation and examine its development problems. Taking the raspberry planting in Fengqiu County, Henan Province, China as an example, based on the survey data and ArcGIS technique, this article analyzes the spatial continuity of specialized plantation from four aspects, that is, spatial diffusion network, the varieties of planting scale in villages, spatial distribution characteristics of different types of villages and spatial agglomeration characteristics of all planting villages. It is shown that, the number of raspberry planting villages, the planting scale and professional degree varied across raspberry planting villages. These findings indicate that the spatial coherence of raspberry planting in Fengqiu County was not strong. The villages which planting raspberry lasting for short-term, for example less than 3 years, were scattered in space, whereas the villages which planting raspberry with a long history were concentrated spatially. In addition, the planting villages which cooperated with different companies or social organizations had different duration in raspberry planting. The villages establishing settled connections with the leading processing enterprises had longer time in planting raspberry. As a whole, all planting villages were concentrated in a limited area. Further more, the Structural Equation Model(SEM) and AMOS 21.0 software were used to explore the influencing factors on the spatial continuity of specialized plantation. It is found that: 1) The individual characteristics of farmers, especially their spirit of adventure had a critical impact on their duration of planting; 2) Farmers with high accessibility to capital, technology, information and other production conditions continuously cultivated this crop longer; 3) Government had a positive effect on the decision of farmers' sustainable planting; 4) Resource environment, especially the fertility of soil, and the able persons significantly impacted on the planting size of the village; 5) The influence of village’s geographic location was weaker than that of infrastructure condition on the sustainable planting of featured crops. Finally, this article puts forward some corresponding policy recommendations for the regional sustainable development of raspberry industry in Fengqiu County and other regionalized industries, such as, cultivating the innovation consciousness of farmers by providing more learning resources for them, improving the agricultural infrastructure conditions, for example, water conservancy facilities, field road and communication facilities and so on, perfecting the agricultural financial service system, encouraging local governments to appropriately intervene their specialization and regionalization of agricultural development.
China is a nation with numerous lakes; tracer studies of 239+240Pu have been carried out in 14 lakes. According to the research status of 239+240Pu in Chinese lakes, this article summarizes the source, the migration behavior of 239+240Pu and the age of the maximum accumulation peaks of 239+240Pu. The results show that 239+240Pu in lacustrine sediment cores of Chinese lakes are mainly derived from the global atmospheric nuclear tests, the mean value of 240Pu/239Pu was 0.177±0.019 in the surface sediments, the mean value 240Pu/239Pu was 0.177±0.008 in the all sediment cores. Because of the difference of lake sedimentary environment and latitude changes, the range of the 239+240Pu inventories of was 7.45-240.6 MBq/km2. The distribution characteristic of 239+240Pu in lacustrine sediment cores of Chinese lakes are mostly unimodal, and the migration of 239+240Pu in sediment cores can be neglected and the maximum accumulation peak of 239+240Pu has time scale value.
Remote sensing is the effective technology for estimation evapotranspiration (ET). In recent years, many remote sensing ET methods have been developed, and great progress has been made in ET estimation research. While accurate estimation of the satellite-based global terrestrial ET at high spatial and temporal scales remains a major challenge. A review of the commonly applied ET models using remotely sensed data, including the simplified empirical regression method, empirical statistical model for global ET, Penmen-Monteith-based remote sensing model, complementary relationship model, Priestley-Taylor model, triangle or trapezoidal feature space method, residual method of surface energy balance with one-source and two-source framework, three temperature method, nonparametric approach, semiempirical Penman algorithm, and Bayesian model averaging method were presented in this article. Beside the generally used remotely sensed multi-spectral data from visible to thermal infrared bands, these models varied greatly in inputs, main assumptions and accuracy of results, etc. Most remotely sensed ET models, from simplified equations models to the more complex physically based two-source energy balance models, relied to a certain degree on ground-based auxiliary measurements in order to derive the turbulent heat fluxes on a regional scale. The main inputs, assumptions, theories, advantages and drawbacks of each model were discussed. Moreover, the advantages and disadvantages of remote sensing, conventional calculation formula and process model simulation were analyzed. The data assimilation approaches based on the remotely sensed data to the extrapolation of instantaneous ET to the continuous values are also presented. The data assimilation approaches were divided into surface energy balance-based method and complex process model-based method. The principles, cases and common assimilation algorithms of the two types of methods were reviewed. In the final part, the problems currently and possible solutions such as efficiency, uncertainty, validation and scale in the estimation of regional ET based on remotely sensed data and ground-based measurements were discussed.
基于2000年和2010年土地利用遥感数据,从自然、区位、交通、人口和经济4个角度选取驱动因子,利用Logistic-CA-Markov土地利用综合模型预测赣南森林有林地、灌木林、疏林地和其它林地4种林地类型在当前模式、规划模式和保护模式3种情景下的空间演变格局。结果表明：① 到2020年,在当前模式和规划模式,林地总面积将减少,在保护模式则出现增加,3种情景都体现出有林地和其它林地增加、疏林地和灌木林缩减的趋势,只是增减幅度不同,但不论何种情形林地的组成结构都将发生较大程度的变化;② 3种情景都是以疏林地→有林地、有林地→其它林地和灌木林→有林地这3种类型的转化为主,向有林地的转化分布都比较分散,而向其它林地的转化却集中在安远、信丰、于都、赣县四县交界处;③ 相较于当前模式,在规划模式下集中在安远县及其周边的有林地向其它林地的转化出现大量缩减,在保护模式下这种缩减更加明显。
Gannan forest is an important safety barrier in southeast China. It belongs to Nanling Mountain forest and biodiversity reserve of China. To analyze the evolution trend of Gannan forest, driving factors is chosen from the perspectives of natural, geographic, geographic traffic and economic and a Logistic-CA-Markov model is constructed based on land use of the year 2000 and 2010. According to the development status and existing issues in Gannan, three scenes are set to predict the spatial transfer pattern of closed forest land, shrubbery, open forest land and other forest land, which are current pattern, land use planning and forest protecting. The results show that: 1) Key driving forces for forest land use change are human activities, society and economy. Location and environment variables are secondary causes. For the change of closed forest land, shrubbery and other forest land, GDP and population are key explaining variables. For open forest land, the key driving force of its change is gradients. 2) In 2020, the area of total forest land will decrease under current trend scenario and land use planning scenario, while under forest protecting scenario there is an augment. No matter in which scenario, the increase of closed forest land and other forest land and the decline of open forest land and shrubbery are obvious, and the construction of forest land will definitely change a lot. 3) The main transfer trend in 3 scenarios are open forest land to closed forest land, closed forest land to other forest land and shrubbery to closed forest land. The transfer to closed forest land is dispersedly distributed, while the transfer to other forest land is concentrated in Anyuan County and its circum. 4) Compared to current trend scenario, the transfer from closed forest land use to other forest land will have a big shrinkage in land use planning scenario and the shrinkage will be lager in forest protecting scenario. In all, on one hand, the natural forest and planted forest of high canopy density is in a recovery increase, which shows that policies and regulation to protect forest resource has achieved initial success. On the other hand, with the development of urbanization and economic construction, the social and economic factors are posing greater influence to forest. The economy rise will accelerate forest land expansion structural adjustment of agriculture mobilized by forestry and fruit growing leads to rapid expansion of economic forest. But the farmland and construction land will erode the forest land in unavoidable way under urbanization background. The contradiction between forestry development and peasant’s life demand is becoming obvious.
基于1960~2015年西安气象站点逐日最高温、最低温数据,采用RHtest软件对非均一化气温序列进行订正,进而选取16项极端气温指数,对西安极端气温变化特征进行分析。结果表明：① 由于气象站点迁移,西安气温资料存在非均一性,导致极端气温变化趋势被低估;② 全球变暖背景下,西安极端气温变化表现出：“快速增温与平稳波动并存,冷暖变化趋势相反,夜晚增暖趋势比白天明显,白天波动变化明显于夜晚,持续性高温事件变化不大,持续性低温事件大幅下降”的变化特征;③ 通过不同区域趋势变化对比、冷暖、昼夜变化关系对比发现,受城市热岛影响,西安极端低温事件减少更为突出,远高于中国其他对比区域（秦岭南北、黄土高原、东北地区等）;④ 在昼夜变化上,西安极端气温变化与中国、全球变化具有一致性,但是通过冷暖指标对比发现,西安极端气温变化具有区域性,表现为冷昼日数下降高于暖昼日数上升,冷夜日数下降高于暖夜日数上升,冷持续日数和暖持续日数共同表现为下降趋势。
Based on daily maximum and minimum temperatures observed by the China Meteorological Administration at the Xi’an meteorological station during the period 1960-2015, the series exhibiting breakpoints are adjusted using RH test software. Temporal trends of 16 extreme temperature indices are evaluated by least-squares linear regression and moving average methods; the linear trends are significant for 11 of these 16 indices. The trends of extreme temperature indices for Xi’an, China, the globe, and other regions in China are compared. Further, trends of the relative magnitudes of cold versus warm indices and day versus night indices are compared. The results are as follows: 1) Due to the migration of the meteorological station, the value of the temperature series is lower than the original meteorological station data. The warming trends of extreme temperatures are underestimated based on the in-homogeneity dataset. 2) In the context of global warming, extreme temperature variation presents its own characteristics in Xi’an. First, the extreme temperature trends show rapid warming with stable fluctuation, but the opposite trends occur in warm and cold indices; warm indices increase while cold indices decrease. Second, the warming trends are faster during the nighttime than the daytime, whereas the amplitudes of fluctuations are greater during the daytime than the nighttime. Third, warm spell events increase slowly, but cold spell events decrease rapidly. 3) Extreme temperature indices are compared between Xi’an and other regions (the southern and northern regions of the Qinling Mountains, the Loess Plateau, northeast China, etc.). Due to the impact of the urban heat island phenomenon, the decrease of extreme low temperature events is more pronounced in Xi’an than in the other regions compared. 4) With regard to daytime versus nighttime indices, the nighttime indices in all regions show the characteristic of warming faster than the daytime indices. In the case of cold versus warm indices, Xi’an exhibits its regional features: the warming magnitude is faster on cold days than on warm days, and a similar trend is seen on cold nights and warm nights; indices of cold and warm spell durations show a downward trend. Overall, this study indicates that the trends of temperature extremes in Xi’an are in accordance with global warming during 1960-2015.
利用1960~2014年中国西南地区141个气象台站的逐日气象资料,引入一个新的干旱指数——逐日标准化降水蒸散指数（日SPEI）,对极端干旱事件的年代际、年际、季节内变化及持续性特征进行了分析,结果表明：空间上,近55 a西南春季和年极端干旱程度呈一致的减弱趋势,重庆、四川与贵州的交界处及四川西北部极端干旱程度明显缓解,而夏、秋两季极端干旱表现出增强的趋势并有一定的区域性特征。时间上,春季和全年极端干旱频率、强度和持续天数逐渐减少,春季极端干旱的减弱程度较全年明显;夏、秋两季极端干旱频率、强度和持续天数呈增加趋势,夏季极端干旱的加重趋势比秋季明显。从极端干旱事件的持续性来看,20世纪60年代和21世纪初（2000~2014年）西南遭受的极端干旱最严重,持续期达60 d以上的站点分别占到站点总数的60%和73%。
The quantification of drought frequency, duration, intensity, and changes in areal-extent over time is not only essential in the drought risk management making process, but also combat of extreme drought hazard making. However, the current common drought indices can only identify average drought severity over a drought period and cannot indentify drought characteristics at short time scales. The climatic condition in southwestern China, largely an agricultural region, has been considerably variable in the past several decades. Drought has occurred more frequently and has become one of the most serious hazards in the last and current century in Southwest China. The extreme drought events frequently occur, as drought events have taken place in Southwest China. The present study aims to assess the changes in Southwest China's extreme drought events in 1960-2014. Using daily meteorological data collected from 141 stations across the Southwest China from 1960 to 2014, the daily Standardized Precipitation Evapotranspiration Index(daily SPEI) is developed based on daily meteorological data in this study. Latency evaporation is calculated by Penman-Monteith method, from inter-decadal, inter-annual, inter-seasonal variability, persistent characteristic of extreme drought events analyzed over Southwest China in past 55 years by daily SPEI index. The results showed that: From the point of view of space trends to see, it displayed consistent decreased extreme drought trend in spring and whole year over Southwest China in past 55 years. The Chongqing, on the border between Sichuan and Guizhou, northwest of Sichuan are the areas in which severity of extreme drought events has significantly decreased in the past 55 years. But it displayed increased extreme drought trend along with regional extreme drought trend feature in summer and autumn. The frequency, intensity and duration of extreme drought events have significantly increased on the border among of Sichuan, Guizhou, Yunnan, and Chongqing in summer and autumn. From the point of view of time evolution to see, frequency, intensity, duration of extreme drought events is decreasing in spring and whole year, and frequency, intensity, duration of extreme drought events is growing in summer and autumn over Southwest China in past 55 years. The tendency rates of frequency, intensity, duration are -0.01, -0.3, -0.18 d per decades in whole year. The frequency, intensity, duration of extreme drought events in spring showed decreasing trends at rates of -0.02, -1.15,-0.45 d per decades. The intensity, duration of extreme drought events in summer have increased by 0.5, 0.14 d per decades, respectively. The frequency, intensity, duration of extreme drought events in autumn showed increasing trends at rates of -0.01, 0.36, 0.1d per decades. By comparison, spring extreme drought lessen trend is evident than that of whole year, summer extreme drought is stronger than autumn. As a whole, extreme drought degree is strongest in summer, but it is weakest in spring. From inter-decadal scales of view of extreme drought events to see, the severity of extreme drought events was higher in 1960-1969 and in 2000-2014 during the past 55 years. From the point of view of persistent characteristic to see, duration of persistent drought event is longest in 1960-1969 and in 2000-2014 during 1960-2014. Of the two stages, about 60% and 73% meteorological stations have suffered extreme drought lasting more than 60 days.