基于非期望产出视角,采用SBM模型测度2005~2014年中国东部沿海地区53个城市（不包括港、澳、台、三沙市）的城市发展效率,并分析其时空差异特征及其影响因素。结果表明：① 考虑非期望产出的城市发展效率值低于不考虑非期望产出的城市发展效率值,并且更符合城市实际发展; ② 中国东部沿海地区城市发展效率整体水平不高,波动幅度大,阶段特征明显,整体呈先上升后下降的趋势;③ 在时空分析特征中,城市发展效率的区域差异明显,近2 a有缩小的趋势;整体城市发展效率空间呈现“北部围绕青岛市,中部围绕上海市,南部围绕深圳市”的发展格局;④ 在影响因素分析中,经济规模对城市发展效率产生正向影响,第二产业结构水平和污染处理能力对城市发展效率产生负向影响,传统的加工制造业、高耗能重污染工业和污染处理不到位是导致城市发展效率降低的主要原因。
We can grasp the distribution of resources, utilization efficiency and propulsion paths in the process of urbanization in China’s coastal areas by measuring the urban development efficiency, which can provide references for policy and experience for sustainable development. This article is based on the viewpoint of undesirable output, measuring the urban development efficiency of 53 coastal cities in China (excluding Hong Kong,Macao, Taiwan and Sansha) during 2005 to 2014 with the SBM model, and analyzing its spatial-temporal disparities and affecting factors. The main results are summarized as follows: 1) The urban development efficiency value taking consideration of undesirable output is lower than the one without consideration of undesirable output, which turns out that undesirable output has a significant effect on urban development efficiency and the development efficiency value considered it matches the actual situation of urban development better. 2) The urban development efficiency of the coastal cities is not high on the whole,it fluctuates widely and has obvious characteristic of stages, which shows a trend of rising in the first and declining then as a whole. During 2005 to 2008, the percentage of the cities with highest development efficiency increased from 15.09% to 28.30%,and the percentage of the cities with medium efficiency increased from 7.55% to 28.3%;While in 2011,the two percentages mentioned above declined to 18.87% and 22.64%,and in 2014,they went a step further in declining,there were only 9.43% of the cities with highest development efficiency and 11.32% with medium development efficiency. 3) The spatial disparity of urban development is significant though in a trend of shrinking recent two years. on the whole ,the urban development efficiency presents a development pattern of” surrounding Qingdao in the north, surrounding Shanghai in the middle and surrounding Shenzhen in the south”. Which means that Qingdao, Shanghai and Shenzhen has become the three poles in aspect of urban development efficiency. 4) The level of second industry structure and ability of pollution treatment have negative impacts on urban development efficiency,while the scale of economy has a positive impact on the efficiency of urban development. The main reasons leading to lower urban development efficiency contain traditional processing and manufacturing industry, high energy consumption, heavy pollution industry and inadequate pollution treatment. Finally, the suggestions to improve urban development efficiency for coastal cities are as follow：In order to upgrade industries, the investment of human, capital and resources should be reasonable. We can not neglect the effect of undesirable output when measuring the urban development efficiency, and we should pay more attention to environment protection and pollution treatment.
以居住为导向的北部回龙观区域和产业导向的南部亦庄为区域,以时间剖面遥感影像图为基础,综合运用土地利用数据、实地调查与深度访谈等多种方法,判别、回顾并解译物质空间的基本变化过程,凝练物质空间的演替规律与组织模式,以期为制定科学合理的交通基础设施建设和城市综合开发方案提供支撑。研究发现：① 居住导向的物质空间组织模式,以站域内居住空间持续扩大、居民数量不断增多为特征,伴随着城乡景观和生活方式的角逐。同时,却往往忽视了产业空间与公共服务设施空间配套建设,加之高密度的人口集聚,大大降低了居住舒适度。② 产业导向的物质空间组织模式以站域内产业空间持续扩大、企业数量不断增多、配套基础设施逐步完善为特征。但居住空间与公共服务设施空间建设的时滞性显著,造成了人气不足、土地利用效益低下。③ 建立和完善轨道交通站域的物质空间组织模式知识库,将为交通导向下的基础设施建设和城市综合开发方案提供科学依据。
Based on the integrated use of the land use data, remote sensing image, field survey and in-depth interviews, this article interprets the physical space change process and organization model of the northern Huilongguan area and the southern Yizhuang area in order to formulate a scientific urban development plan. 1) Living function oriented physical space is characterized by living space expanding and the number of residents increasing, along with the competition between urban and rural landscape as well as life-style. At the same time, industrial space and public service facilities are always ignored to construct, coupled with a high density of population agglomeration, which greatly leads to reduce the living comfort. 2) Industry function oriented physical space is characterized by the industrial space expanding, number of enterprises increasing and infrastructure improving. However, there is a temporal hysteresis in the construction of residential space and public service facilities, which causes the lack of popularity and poor benefit of the land use. 3) To establish and improve the organization model of the physical space so as to provide the scientific basis for traffic infrastructure construction and urban comprehensive development plan.
Based on investigating and interpreting the size structure characteristics of urban system, this article build a new method on analyzing the size structure of urban system. Adopting the resident population data of cities at county level and above, traditional rank-size rule and the rank cumulative size model proposed are used to measure the inter-provincial differences and their spatial distribution characteristics of city size structure at 2000 and 2014 in China, then discussed the geographic factors which have influence on size structure of regional urban system. The results show that the rank-size rule has some shortcomings in interpreting the characteristics of the size structure of regional urban system. Particularly, when the fitting result provided by the rank-size rule is not ideal, the β value provided by the rank cumulative size model given in this article can more realistically and objectively reflect the characteristics of the size structure of regional urban system. There is a big difference in the size structure type of urban system of provinces in China, and the β value ranks the top often belongs to the province with good physic-geographical conditions and developed socio-economic level. On the whole, the β value’s increase in the East is larger than in the West and its growth rate in the South is higher than in the North. Such change is similar to China’s population and economy center’s transfer trend in the past decade. Moreover, there is a close statistical relationship between the selected regional variables, such as regional population, urbanization, population density and road network density, and the value of β given by the rank cumulative size model. But with the development of the society and economy, the physic-geographical and infrastructures conditions’ impact on urban system size distribution is not significant.
Location is one of the most important ways for firms to accumulate resources, making locational choice the fundamental strategy of firm development. Using the case of Guangzhou software industry cluster and the research method of in-depth interviews, the paper analyzes the influence of start-ups’ locational choice on the spatial evolution of industrial cluster. The result shows the restructuring of industrial paradigm, including the technological and market ones, leads to the transformation of spatial change in the industrial cluster, and it proposes the argument that start-ups create space in the sense that it is able to extend the spatial boundary and shape spatial morphology of the industrial clusters. The first generation of software start-ups agglomerate in the place where there are abundant resources released from the declining state-owned sector and supportive policy environment. The start-ups have gradually build up the relational networks and identity on cluster reputation, leading to the formation of the spatial core of the Guangzhou software industry cluster. Nevertheless, the technological change and market transformation could alter the locational preferences of the start-ups and thus dampens the locational advantage of the pre-existing cores. The second generation of start-ups, established in the wave of rapidly-developed mobile internet and newly-emerged internet plus era, take more efforts in discovering niche market by diversifying into and integrating with other industries in order to avoid direct competition with mature firms in saturated software market. The new generation of start-ups are then able to break through the boundary of the spatial core of the industrial cluster and reduces the disadvantages of dislocating from the cores to a great extent by efficiently combing technological and market innovation. The research has contributed to the understanding on the spatial processes of new economic phenomenon, in this case the start-ups, and thus the broad debate in the evolutionary economic geography on the role of space in times of new technology development and new industry paradigm shift. Finally, the policy implication has been given, suggesting that local governments could intervene in nurturing new growth space for industrial clusters in particular when industry restructuring occurs.
以城市人口规模、城市间距离为指标,通过多元回归模型,定量分析辽宁中部城市群中城市规模与空间距离的关系,以及城市与“最近城市”的距离和“距离位序”之间是否存在类似“城市位序-规模律”的定量关系。研究发现：① 城市i的规模Pi与“最近城市”n的规模Pn、距离Di-n以及区域中心城市c的距离Di-c有关,与首位城市的规模和距离无关,其中Pn、Di-n为正向影响,Di-c为负向影响。就影响力而言,区域中心城市c的影响大于“最近城市”n,这一点区别于国内其他城市群。② 城市群中存在“城市距离-位序律”的定量关系。③ 利用城市规模与距离的定量关系可以测算理论人口规模和影响范围,为辽宁中部城市群的人口预测和空间结构划分提供有益参考。
The research establishes a multiple regression model according to city population and distance between cities, and quantitatively analyzes the relationship between city size and distance in urban system of Central Liaoning Urban Agglomeration to measure whether the distance between the city and the “nearest city” and the “distance order” have a similar quantitative relationship as the “Rank-Size Rule”. The results show: 1）in the Central Liaoning Urban Agglomeration, the population size of a certain city i (Pi) can be explained by the population size of the nearest city n (Pn) , the distance between n and i (Di-n), and the distance between the regional center city c and i (Di-c), but the size does not relate to the size and distance of the First city. In the relationships, Pn and Di-n have positive impacts on Pi, while Di-c has negative impact. Di-c is the most important factor, and its impact is bigger than Pn and Di-n, which is different from other urban systems in China. 2) The quantitative relationship between Di-n and ordinal number R of city n in the urban system is the same as the “Rank-Size Rule”. 3) The results indicate the quantitative relationship between population size and distance could estimate theoretical city sizes and influence range, which provides powerful evidence for population forecasts and spatial structure divisions of Central Liaoning Urban Agglomeration.
从可达性的视角采用平均旅行时间、经济潜力、日常可达性等指标对河南“米”字形高速铁路网构建对各地市省内和省际可达性及城市空间格局的影响进行分析发现,① “米”字形高速铁路网有助于各地市省内和省际可达性水平提升,郑州的极化与集聚效应进一步增强,边界城市的交通边缘化状况明显改善,“米”字形城镇发展轴带正在形成;② 各地市省内和省际经济潜力大幅度提升,位置居中的高铁沿线城市省内区位优势显著,边界高铁沿线城市在省际联系中的门户区位优势显现;③ 以郑州中心的0.5 h核心圈、1 h紧密圈正在形成,“同城效应”显现,各地市省际2 h交流圈大幅度拓展,以郑州为中心的1.5 h省际合作圈即将形成。高铁网的构建将成为河南城市空间格局演变的重要推动因素和空间结构优化的基础支撑条件。
Following the construction of High-speed Railway (HSR) network all over the country, temporal-spatial convergence effects of HSR will make great impacts on the evolution of urban spatial pattern, which will help the regions along the HSR to promote the optimization of urban spatial structure and reconstruction of city spatial organization mode. From the accessibility perspective, the impacts of “star-type” HSR on accessibility and urban spatial pattern in Henan Province are probed deeply using the indices of average shortest travel time, economic potential and daily communication areas. Results are shown as follows: 1) Under the construction of “star-type” HSR network across Henan Province, all central cities’ interior-provincial accessibility level and exterior-provincial accessibility level will be significantly improved, polarization effect and agglomeration effect of Zhengzhou will be enhanced, the traffic marginalized condition of boundary cities are significantly improved, the “star-type” contact channel and urban development axis are established by the promotion of accessibility among the cities; 2) Each central cities’ interior-provincial and exterior-provincial economic potential will be enhanced under the “star-type” HSR network, location advantages of cities located in the middle of Henan along the HSR will be promoted, and gateway location advantages of boundary cities will become obviously in the process of inter-provincial contact; 3) As the center of Henan Province, Zhengzhou’s half an hour core communication areas and 1-hour close communication areas will be formed, one-city effect will come out between Zhengzhou and other cities surrounded Zhengzhou; Exterior-provincial 2-hour communication areas of each city are greatly expanded, Zhengzhou’s one and half an hour inter-provincial cooperation areas will be formed following the construction of HSR. The construction of “star-type” HSR network across Henan will be the main driving factors of urban spatial pattern dynamics in the future and will be the main supporting conditions of urban spatial structure optimization.
借助Bootstrap-DEA模型综合测算了环渤海地区17个城市海洋经济效率,并结合标准差椭圆和重心坐标方法,定量刻画了2000~2012年环渤海地区海洋经济效率空间格局演化特征,考察了影响空间格局演化的重要因素及其影响机制。结果表明：① 基于Bootstrap-DEA模型纠偏后的海洋经济效率更低,但准确性更高;计算得到的环渤海地区海洋经济效率总体上且呈现先上升后下降的趋势,低海洋经济效率的城市主要分布于渤海西南沿岸。② 从标准差椭圆分布来看,海洋经济效率总体呈现南（偏西）-北（偏东）的空间格局;从重心的移动轨迹来看,效率重心先向渤海西南部海洋经济区移动,再转向辽东半岛海洋经济区与渤海西部海洋经济区移动,最后转向山东半岛蓝色经济区移动。③ 针对海洋经济效率空间格局演化驱动机制的分析表明,区位优势对海洋经济效率产生正向影响,海洋产业结构和外商直接投资对海洋经济效率产生负向影响,资源消耗型海洋产业比重过大是导致海洋经济效率下降的主要原因。
By using Bootstrap-DEA model, this article first comprehensively measures and calculates the marine economic efficiency of 17 coastal cities in Bohai Sea Ring Area. Then Standard Deviation Ellipses and Barycentric Coordinates Method are applied to projecting and visualizing the evolution of spatial pattern of marine economic efficiency in Bohai Sea Ring Area from 2000 to 2012. Finally, we analyze the important factors which affect the evolution of spatial pattern and its mechanisms. Results are shown as follows: 1) Compared with the traditional DEA model, marine economic efficiency modified by Bootstrap-DEA model is lower but higher accuracy. Overall, marine economic efficiency in all the cities show a trend which first upwards and then downwards, and the cities with low marine economic efficiency are mainly located in northwestern BSRA. 2) Viewed from rotation angle of the Standard Deviational Ellipses, marine economic efficiency generally present a North (by east)-South (by west) spatial distribution pattern. Viewed from the track of the center of gravity, the center of gravity of marine economic efficiency first moves to Bohai Sea Southwest Marine Economic Zone, and then turns to Liaodong Peninsula Marine Economic Zone and Bohai Sea Western Marine Economic Zone, finally moves to Shandong Peninsula Blue Economic Zone. 3) By analyzing the evolution driving mechanism of spatial pattern of marine economic efficiency, we can find out that location advantages have positive impacts on the marine economic efficiency, while the marine industrial structure and FDI have a negative effect on marine economic efficiency. A large proportion of resource consuming marine industry is the main reason to reduce marine economic efficiency.
以广州都市区1 361个社区的第六次人口普查住房数据为基础,从住房的建成年代、建筑结构、户均建筑面积、住房生活设施4个方面构建居民住房条件评价体系,分析其空间分异格局与形成机制。结果表明：① 广州市居民住房条件由中心向外围逐渐提升,具有“圈层基础上的多核心”式空间分异结构;② 户均建筑面积和建成年代是决定其住房条件差异的2项重要指标,旧城的住房条件异质性最高;③ 城市发展的历史进程、互换效应和过滤效应、高房价和高地价影响和强化了住房条件分异格局,制度性因素、政府决策和市场力量同时起到了引导和推动作用。
The housing issues of China’s urban residents have always been the focus of academic circles. The issues regarding housing conditions in China's megalopolises are important topics of research for building livable cities, resolving the housing shortage, and solving the urban problem. The inequality of urban housing conditions is also an indispensable issue. However, to date, specific research on the differentiation pattern and spatial structure of housing conditions in China's cities is rare. Therefore, based on housing data from the newly available sixth census of 2010 for Guangzhou’s metropolitan areas, we established a comprehensive system for evaluating housing conditions that is composed of housing years, building structure, building area per household, and housing facilities and explored the spatial differentiation pattern of housing conditions. Furthermore, we analyzed the spatial cluster and heterogeneity of housing conditions by using the ESDA and GDI index. Finally, we summarized the spatial differentiation model and formation mechanism. The results are as follows: 1) The housing conditions of Guangzhou, gradually improving from the center to periphery, show significant imbalance and spatial cluster characteristics. Regions with better and worse housing conditions have specific location directions. Housing years and building area per household are two core indicators that decide the differentiation of housing conditions. 2) The housing conditions of the evaluation subsystem are distinct among different urban circles. In the old city, the scores of housing years, architectural structure, and building area per household are lower. In the core area, scores of the building area per household and housing infrastructure are higher than in other regions. In the central area, the level of the architectural structure is highest. In the suburbs, the housing years are the lowest. In addition, the heterogeneity of housing conditions in the old city is the highest. 3) The historical process of urban development, housing exchange and filtering effects, and high housing and land prices influence and enhance the spatial differentiation pattern of housing conditions in Guangzhou. Institutional factors, government decision making, and market forces also play a role in guiding and promoting the pattern. Thereto, institutional factors include the urban-rural dual-land system, housing dual-supply system, and housing demolition requisition system. Government decision making mainly refers to the urban development strategy and urban planning. Market forces reflect relationships between housing price, housing conditions, location, and household income.
With the in-depth development of economic globalization, Free Trade Zones not only play an important role in the expansion of international trade, attracting foreign investment, stimulating the development of regional economy and urbanization, but also take an essential part in promoting both the implementation of the overall economic development strategy in China and the reform of administration and economic system. Scholars in this field have introduced more about the early seedtime of Panama Free Trade Zone, while the study on the analysis and summary of current situation of Panama Free Trade Zone is weak. Thus, the article, which is on the basis of trade theory, economic geography, system evolution theory, uses the literature review, case study and other methods to summarize and review the development history, features and influence factors of Colon Free Trade Zone; then it analyses the strength and weakness, the opportunities and threats that prompt the evolution of Colon Free Trade Zone systematically; and it also makes a preliminary analysis and discussion about the influence to the construction of China’s experimental free-trade areas at the end of the article. And the experience of Colon Free Trade Zone means a lot to the development of the four free trade areas in China.
According to environmental criminology, built environment, especially land use may have some effects on the occurrence of criminal behaviour. The research on the relationship between crime and the land use can provide a new perspective on crime prevention from the angle of urban public security planning. However, most of the researches to date used the global model, and less to consider the factor of spatial differences, which can be improved by the Geographical Weighted Poisson Regression (GWPR). This article studies the effect of land use on the distribution of robbery cases happened in the urban area of H city by GWPR model. The results show that the correlation between residential land use and street robbery cases appears to be negative in traditional dwelling districts, resulting from the strong social bond between each resident; how the commercial and business land use affect the cases distribution depends on their spatial form, the individual high-rise commercial complex building attracts less street robberies because of better access control, while the street-side mode of commercial land use attracts more cases due to the convenient escaping routes for the criminal; the positive correlation between industrial land and cases only appears in the old city since the manufacturing industries have enhanced the complexity of social structure; tourism scenic spot with thorough security administration has negative effect on street robberies. But others lacking of residents and supervise tend to suffer from crimes; besides, relationship between the street robbery and transportation land use is affected by the transport-facilities, road-grades and road-network pattern. Generally, cases will gather in the regions near the faster road and those with high accessibility. And the traffic station areas have more potential criminal due to the heavy visitor flow. In addition, because of the diversified land use distribution all around the city, the primary land use factors to street robbery differ from each other in different regions. Therefore, on the basis of regression coefficients, the urban area of H city is divided into 6 parts by cluster, which are corresponding to several urban function areas, including the old city comprehensive functional areas, new city living areas, traffic station, wholesale market, urban-rural fringe areas and traditional residential district, contributing to summarizing street robbery spatial pattern. Consequently, according to the relationship between land use and street robbery discovered previous, correlative land use planning guidelines in every district are made to prevent the occurrence of criminal behaviour consciously, which may help to urban planning and police prevention.
基于东北地区2009年、2012年和2015年A级旅游景区数据,采用最邻近指数、基尼系数、核密度分析、相关分析等数理和空间分析方法,基于GIS空间分析技术,从类型、均衡度和密度等方面对东北地区A级旅游景区的空间分布特征及影响因素进行研究,结果显示：① 2009年、2012年、2015年3个时段,东北地区A级旅游景区在空间上呈集聚状态,且集聚程度具有先强后弱的演变特征;② 省会城市和主要交通节点城市附近A级旅游景区核密度较大;③ 随着旅游业的快速发展,东北三省A级旅游景区核密度增强区域扩散较快,但蒙东地区变化较慢;④ 旅游资源空间分布受自然因素和人文因素影响很大,其中地形地貌、水文是影响A级旅游景区分布的内生因素,而社会经济水平、交通等是重要的外推动力,对A级旅游景区分布影响比较显著。
Based on the Northeast China’s data of level-A scenic spots in 2009, 2012 and 2015,using the nearest neighbor index, Gini coefficient, kernel density analysis, correlation analysis and other mathematical and spatial analysis methods, and based on GIS spatial analysis technology, this article studies the spatial distribution characteristics and influencing factors of level-A scenic spots in Northeast China from the aspects of type, equilibrium degree and density. The results showed that: In 2009, 2012 and 2015, level-A scenic spots in Northeast China show a agglomeration state in the spatial, and the degree of agglomeration has the characteristics of first strong and then weak. The provincial capital cities and main traffic nodes near the city have larger Nuclear Density of level-A scenic spots. With the rapid development of the tourism, the proliferation of kernel density of level-A scenic spots in Northeast China is faster, but that in eastern Inner Mongolia is changing slowly. The spatial distribution of tourism resources is greatly influenced by natural and cultural factors, topography and hydrology are important factors affecting the distribution of level-A scenic spots. On the social-economic aspect, traffic and other factors are very important power of extrapolation, and have significant influence of the distribution of level-A scenic spots.
The quantitative analysis and simulation study on the relationship between prehistoric settlement sites and natural environment has become a hot spot in the study of the relationship between human and land in the prehistoric settlement sites. This article used five indicators, landform, soil, exposure, slope and elevation, to construct the fuzzy evaluation system about prehistoric human settlement exponent in Zhengzhou-Luoyang Area, which is based on factor detection method based on geographic detector to gain the weight of every factor, according to environmental driving factors grading standard and scale value, we used trapezoid and triangle membership function to calculate the value of every factor, then we used comprehensive evaluation of the weighted average type and isometric method to gain the result of prehistoric human settlement exponent’s comprehensive level in Zhengzhou-Luoyang Area. Comprehensive level 1 for the western region of the site, the level of 2 are large number of distribution, is a Hybrid - Around the Center type, grade 3 is the northwest loess type, grade 4 is the Central Hills - Flood Alluvial Plain, grade 5 is the eastern Platform-Terrace-Plain type. Overlay them with the actual site of later period of the Yangshao distribution and distribution map of the site of the Dragon Mountain, statistics of the sites in each level, it is found that the vast majority of concentration in the middle of the class and above, the model is feasible, at the same time, the accuracy of the site was found is higher. To carry out specific analysis on comprehensive level 5 class, according to the SPSS data detection function, the nature is divided into I, II, III class, count respectively the membership degree of the five factors in the statistics of various types are calculated, and the degree of conformity and contribution of the comprehensive grade value are compared before and after the weight. It is found that the site of type I high livable degree is the highest degree of conformity with the characteristic of the slope factor of 0 degrees, and the height of the 100-200 m is the second; Type Ⅱ high degree of habitable site for elevation of 100-200 m conform to the highest degree, to high livable degree in geomorphology and soils on the coincidence degree was significantly higher than that of type I, class Ⅲ high degree livable sites representing class Ⅱ soil and topography of the highest degree of compliance. In the same livable degree, two geographical positions, in other conditions are the same, the position to meet the characteristics of II type environment than type I more new sites mining potential, and meet the needs of type III environmental features position than type II more potential. Most livable degree high or higher site distributions in the Zhengzhou-Luoyang area in northern and central regions of Yiluo river basin, is near the river interchange and along the main stream distribution.This article also respectively based on the actual site of the later period of the Yangshao and Longshan period distribution data of the level to verify the accuracy of the evaluation system. The results show that in the later period of the Yangshao, site environment index above the intermediate site ratio was 87.1%; In the period of Longshan, the site of the intermediate above proportion was 85.5%, indicated that the model of evaluation result is accurate and reliable.
Climate change is a major global issue of common concern of the international community, over the past century, the earth experienced a temperature rise, while solar radiation is an indicator of climate change. At the same time, solar radiation data is an important parameter about crop models, hydrological models and climate change models, many Artificial Neural Network ensemble models are developed to estimate solar radiation using routinely measured meteorolological variables, but it do not consider cloud, aerosol, and water vapor influence on solar radiation. In this article, we use cloud, aerosols, atmospheric precipitable water vapor from MODIS atmosphere remote sensing products and conventional meteorological data including air pressure, Air temperature, vapor pressure, relative humidity, and sunshine duration, and we analyze the relationship between solar radiation and meteorological data. In terms of conventional meteorological data, we make the selection of variables, the redundant variables are proposed. Then, BP artificial neural network model optimized by LM (Levenberg-Marquardt) algorithm (referred to as LM-BP) is used to stimulate solar radiation. This LM algorithm has fast local convergence feature about Gauss-Newton method, but also has global search feature about gradient descent method, which allows error along the direction of deterioration to search, and greatly improving the convergence rate and generalization ability of the network. Therefore, this article use LM-BP model to predict monthly mean daily global solar radiation from 2010 to 2013 about Hetian, Xining, Guyuan, Yan’an radiating station using only conventional meteorological data(referred to as A) and using MODIS atmosphere remote sensing products binding conventional meteorological data(referred to as A+) respectively. Then, we validate performance of the model with measured data about radiation station. The results show that cloud amount, cloud optical thickness, aerosol optical depth, and atmospheric precipitable water vapor these factors are added to the established model, the degree of matching simulated solar radiation and actual observations is more higher. And correlation determination (R2) for 4 radiation station are 0.90 or higher, while error indicators are small. This article showed that the use of LM-BP neural network model, combining with remote sensing data and conventional meteorological data to simulate solar radiation is a reasonable and effective way to simulate solar radiation.
It is a complex procedure to identify, record and monitor land cover change on the earth’s surface. Most of the existing Spatio-temporal methods are based on multi-temporal land cover maps or temporal trend analysis of spatial pattern indices. Change trajectory analysis explores the dynamic of landscape pattern in the temporal scale, will not separate the landscape change process, and is an effective method of spatio-temporal modelling. The rapid expansion, abandonment and mis-management of farmland would result in soil salinization and desertification in the inland river basin in the arid region, northwest China. In the countrywide context of continuous decrease of farmland, the evident increase intensifies the imbalance between supply and demand of water resources in the arid region. In order to better understand the Spatio-temporal pattern of farmland change in the middle reaches of Heihe River, this paper used change trajectory analysis and landscape metrics to explore the evolution process of farmland landscape and analyzed its socio-economic driving forces by partial least squares regression (PLSR) models. Spatial patterns of farmland change were quantified by employing distribution-related landscape metrics, such as indices of interspersion(IJI), connectivity (COHESION) and area-weighted patch fractal dimension index isolation (FRAC-AM), percentage of landscape (PLAND), Euclidean Nearest Neighbor Index (ENN-AM) to analyze characteristics of farmland change based on the remote-sensing images of 1987, 1992, 2001 and 2010. Results showed that the expansion of farmland was one of the main trends of land use change in the middle reaches of the Heihe River. The area of farmland expansion was significantly larger than that of abandonment. The proportion of farmland occupied in study area increased from 15.67% in 1987 to 19.74% in 2010, with a net increase of 43 758.9 hm2 for arable land and converted mainly from wetland and unused land. The expanded and reduced farmland exhibited a concentrated pattern, tending to distribute at the edge of the stable farmland, and farmland expanded towards the river. The total population, urbanization rate, industry development and number of electromechanical well were the primary social and economic driving factors prompting the farmland landscape evolution, but the effects of driving factors differed for different types of farmland. The interaction among driving factors influenced the dynamic of farmland landscape. The water resources exploitation directly influenced the change of social-economic factors such as total population, urbanization rate, industry development. The study showed that the proposed research method effectively visualized and quanti?ed the spatio-temporal dynamics of farmland change and its driving forces.
Based on the daily precipitation and tropical cyclones data in 728 stations from 1951 to 2014 in China, spatio-temporal patterns of extreme precipitation Generalized Extreme Value (GEV) distribution with annual and seasonal scales and potential relationships with tropical cyclones were analyzed. We examined the nonstationarity in annual and seasonal extreme precipitation and found that the frequency of stations with change point or significant temporal trend on total 728 stations was small. For stations with stationary in annual and seasonal extreme precipitation, the distribution curves of annual and seasonal extreme precipitation had thick upper tails and unbounded. And the upper tails in north of China were thicker than south of China with bigger in autumn and winter than annual and summer. However, the thick tails at annual scale were influenced by seasonal extreme precipitation. In addition, tropical cyclones play an important role in extreme precipitation generating mechanisms on China's coastal regions, which often caused precipitation with bigger magnitude. More than 60% of the ten largest annual precipitation extremes were caused by tropical cyclones. Therefore, anomalously large values of the GEV shape parameter estimates were linked to the role of tropical cyclones in controlling the upper tail of extreme precipitation distributions.
Climate change and variability are predicted to have dramatic impacts on weather patterns, food production, ecosystem health, species distributions, and human health. Although climate change is a global phenomenon, its impacts on developing countries will be strongest on vulnerable sectors such as agriculture and fisheries which substantially constitute rural livelihoods. Owing to higher costs and difficulty in mitigating climate change by decreasing carbon emission and promoting carbon capture and sequestration, adaptation to climate change becomes the research focus of international academia in the 21st century. As the most important stakeholders of climate change, farmers’ perceptions and adaptation to climate change are essential to human mitigation. However, this study raises many important and largely unresolved issues about farm-level climate change adaptation. Based on recent theoretical and empirical studies, this paper provides an overview of farmers’ perception and a series of adaptation strategies to combat climate change and variability at the farm-level. Based on clarifying the definitions of climate change and climate variability, the review summarizes the farmers’ perceptions of climate change and variability and finds that the extent to which farmers are aware of climate change is uneven. Some farmers are reported to gain the accurate perceptions of climate change, while others gain contradictory results. Many factors, including key extreme climatic events, magnitude of climate variability, social-cultural backgrounds, political-economic conditions, direct experience, climate information, public propaganda, and prejudice of media, household characteristics, and individual knowledge, would play an important role in shaping farmers’ perceptions. Moreover, we systematically summarize a range of strategies adopted by farmers to cope with climate change and variability. However, whether these strategies are primary adaptation to climate change is debatable. Besides climate change and variability, other socio-economic and political determinants of these strategies should not be neglected. Finally, several research prospects are put forward to promote China’s future related research.
选取云南石林红土剖面作为研究对象,探讨在岩溶盆地这一独特地貌单元中主量、稀土元素的地球化学特征。研究表明：① 云南石林土壤中主量和稀土元素的组成具有较好的一致性;② 通过对化学蚀变指数（CIA）与Na/K比值关系图以及A-CN-K（Al2O3-CaO*+Na2O-K2O）三角图分析发现：石林地区2个剖面均经历了温暖湿润环境下的强烈化学风化作用;石林地区土壤中稀土元素含量较高,其稀土元素球粒陨石标准化分布模式表现出高度相似性,且继承了基岩的特征,两者均表现为Eu处负异常,但剖面CK在Ce处表现为负异常,而剖面KP在Ce处无明显变化;③ 2个剖面元素组成及含量变化基本保持一致,表明此地土壤受外来物质影响程度较小,2个剖面的元素地球化学特征与基岩存在一定相似性。
Shilin is located in the east of Yunnan Province, where the red soil is widely distributed. The carbonate weathering profiles in Shilin are selected as the main studying objects. The study on the geochemical behaviors of the major elements and rare earth elements（REE）in the unique terrain about the karst basin may provide a reference for elements geochemical behaviors in the weathering crust. The results indicate that the composition of the main elements in the weathering crust in Shilin have good consistency. According to the analysis of the relationship between the chemical index of alteration (CIA) and the Na/K ratio, and the A-CN-K ternary diagram (Al2O3-CaO*+Na2O-K2O), it shows that the two profiles in Shilin have both experienced strong chemical weathering under the warm and humid environment. There is a wide variation range and a higher content about the REE total composition in Shilin. The REE content in the profiles is higher than that in the bedrock. The REE distribution patterns of two profiles show a high similarity and inherit the characteristics from the bedrock. The chondrite-noamalized distribution patterns in two profiles both show slight negative Eu-anomalies. However, the profile CK shows a negative Ce-anormal, where the profile KP has no obvious changes. The change of the composition and content of the two profiles is consistent, which indicates that the soil is less affected by the other material. There are some similarities about the element characteristics between the weathering crust and the bedrock, which have an important meaning in the study of source characteristics and in-situ weathering.
基于黑龙江省1960~2010年的土地利用变化,采用自然正交分解（EOF）、气候倾向率及Observation Minus Reanalysis (OMR)等方法,分析了土地利用变化对黑龙江省气温的影响。研究发现：① 1960~2010年黑龙江省耕地、建设用地、水域面积依次增加,沼泽、草地和林地依次减少。土地利用变化区域性较明显,沼泽转变为耕地集中在东部,草地转为耕地集中分布在黑龙江省西部,沼泽转为林地和林地转为耕地集中在北部,建设用地增加主要集中在南部;② 黑龙江省1960~2010年土地利用变化对年平均气温及各个季节平均气温均产生升高效应,但并不显著,对年气温的影响趋势为0.053℃/10a,贡献率为12.1%;③ 1960~2010年土地利用变化产生气温空间变化异质性,但没有改变气温纬向性空间分布特征;④ 1960~2010年,林地和沼泽的气温影响效应为升温,草地和耕地为降温,但各个季节有所差异,夏季和秋季表现出降温效应,建设用地全年及各个季节均表现出升温效应,冬季最强;林地转耕地、草地转耕地均以升温效应为主,沼泽转耕地为降温效应。
The article used Empirical Orthogonal Function (EOF), climate trend rate, OMR and other methods to analyze the impact of land use and land change on temperature in Heilongjiang Province from 1960 to 2010. Results showed that: 1) Arable land, construction land, and the water area of Heilongjiang Province were increased, and the swamp, grassland and forest land decreased in turn from 1960 to 2010. Regional land use change was dramatic. Marshes in the east, grasslands in the west, and woodlands and swamps in the north part of Heilongjiang Province were converted into arable land. Construction land increased mainly in the south of the province. 2) Land use change of Heilongjiang Province from 1960 to 2010 caused a rise in the annual average temperature and all season’s average temperature. However, the impact is not significant, since the impact on the annual temperature trend was 0.053℃/10a, and the contribution rate of 12.10%. 3) Land use change generated spatial heterogeneity of temperature change, but did not change the temperature zonal spatial distribution. 4) Woodlands and marshes caused increasing temperature effects, while grasslands and farmlands caused decreasing temperature effects. However, each season is different. Summer and autumn showed cooling temperatures. Annual construction lands and all seasons showed warming temperatures with the highest value in winter. Forests converted into cropland and grassland showed warming temperature effect. Swamps converted to farmlands showed cooling temperature effect. Compared with existing research, the main contribution of this article is to highlight the corresponding relationship of land use and spatial temperature effect.
通过野外实地考察和实验分析,在巴丹吉林沙漠的呼和吉林湖东沙山、呼和吉林湖西沙山和伊利克敖包沙山斜坡上发现了高含量薄膜水和带状分布的灌木植被。分析表明：① 沙山沙层中出现了含量在3％~5％之间、占据厚度为0.5~3.0 m之间的高含量薄膜水,并出现了一部分水分含量大于5％的重力水,这在极端干旱的沙山斜坡沙层中是非常少见的。② 沙层中的含水量垂向分布与重力水的存在指示,在当年雨季末期,大气降水就完全能够通过沙层入渗达到2~4 m或更大深度,从而避免了蒸发作用的消耗,确保了沙层水分能够通过入渗向深层运移。③ 沙山沙层中高含量薄膜水和重力水的存在以及灌木植被带的发育充分证明,该区大气降水在经过蒸发与蒸腾消耗之后,仍有剩余的水分渗入地下,显示了沙山区沙层水分为明显的正平衡。高含量薄膜水的存在和带状植被的发育的表明大气降水至少是该区地下水和湖水的重要补给来源之一。④ 沙山表层1~4 m深度范围有时存在含量大于5%的重力水,表明沙山表层水分运移动力很强。沙层入渗率高,沙层水受蒸发影响的深度小,利于大气降水向地下水的转化,这也是该区大气降水能够补给地下水的重要原因。
Through field investigations and experimental analysis, film moisture with high content and zonal distribution of vegetation were discovered on the slope of megadunes of eastern Huhejilin lake, western Huhejilin lake and Yilikeaobao megadune in the Badain Jaran Desert. The experimental results show that the sand layer has appeared film moisture with high content from 3% to 5% and with about 0.5-3 m a thick, even appeared the gravity water with a content above 5% in a small part of sand layers, which in extreme arid desert area is rare in sand layer on slope of mega-dune. The vertical distribution of moisture content and the presence of gravity water indicate that, at the end of rainy season, precipitation infiltration will be able to reach through the sand layer about 2-4 m at least or more than that, thus avoiding the evaporation effect, to ensure that the sand layer water can reach to deep megadune through infiltration. The existence of the film moisture with high content, gravity water in sand layer and zonal distribution of vegetation prove sufficiently that there are still remaining water infiltrations into underground after evaporation and transpiration, which shows that the water in sand layer of the megadune area is a significant positive balance. The film moisture with high content in sand layer and zonal distribution of vegetation indicates that precipitation is at least an important supply source of groundwater and lake water. The water film pressure difference between film water with high content and film water with low content in adjacent underlying sand layer is the driving force of atmospheric precipitation infiltration into groundwater. Content and distributive thickness of film water with high content indicate that and its migration force is stronger and can effectively supply the groundwater in this area. Sometimes there is gravity water with content of more than 5% in 1-4 m deep in the surface layer of megadune, indicating that migration force is very strong in the surface layer of the megadune. The rainy season is the supply period of sand layer water. Rapid infiltration and small depth affected by evaporating in sand layers are beneficial to the conversion of precipitation to groundwater, which also is an important reason for the precipitation can supply groundwater.