近百余年上海气温变化的若干特征

本文根据1873—1990年上海的年、冬、夏平均气温资料,并利用1956—1990年其郊区气温资料,对城市热岛效应对气温的影响作了处理,重建了近118a的上海气温序列。在此基础上对上海的气温变化特征进行分析,并与同期的北半球气温变化作了比较。结果表明,上海的气温变化有其明显的阶段性、跃变性和周期性。近百余年上海气温变化的总体特征与北半球相似,呈缓慢变暖趋势,但具体的变化过程和幅度有差别,尤其近20多年来的变化与北半球不一致,没有明显的增温现象。     

黄河中下游地区旱涝分型及突变的初步分析

采用CEOF(复经验正交函数)对黄河中下游地区15个代表站点近500年来的旱涝等级指数分析结果表明,历史时期本地区的旱涝分布特点可用三种分布型表征:平均型、东西反相型和南北反相型,对上述三种旱涝分布型的时间振幅,应用Mann-Kendall方法进行突变检验,可以发现平均型和东西反相型近500年来发生旱涝突变,而南北反相型则相对比较稳定。     

黑龙江省与呼伦贝尔盟土地类型的划分及其分布规律

本文就土地研究的几个主要概念,即土地、土地分类、土地分级作了简要讨论,并结合黑龙江省及呼伦贝尔盟的具体条件,对为农、林、牧业服务的土地分类原则进行了初步探讨,还拟订了该区土地分级系统——土地类和土地型,及适合于大比例尺制图的土地组。在此基础上,将全区分为18个土地类、71个土地型。文章还从水平带性、垂直带性和土地结构三个方面,介绍了该区土地类型分布的一般规律。     

上海淤泥质潮滩潮锋作用及其形成机制初步探讨*

本文具体讨论了上海淤泥质潮滩的潮锋作用过程,定性给出了潮锋的形成机制,认为潮锋作用及其水体高含沙量现象的本质在于“潮锋带水体水流加速效应”,即,由于潮滩坡面变化平缓的特殊性,涨潮水体前锋沿程存在着一持续时间可达数十分钟的水流加速过程.最后,本文初步探讨了潮锋作用在滩面塑造过程中的地位,并重新定义了潮锋作用的内容.     

Combining AHP with GIS in synthetic evaluation of environmental suitability for living in China's 35 major cities

There are nearly 700 cities in China, each with their own particular characteristics of natural environment quality and rates of economic development. When people are able to choose a city to live in, they will take into account these characteristics in order to improve their lifestyles. Based on geographic information system technology and the analytic hierarchy process method, a model of the living environment suitability index (LESI) for the larger cities of China was designed. The LESI was constructed by using the factors of economic condition, convenience and livable degree, natural environment and natural resources. The LESI model was then applied to compare the living conditions in 35 major cities in China in 2007, including 30 provincial capitals and 5 sub-provincial cities. LESI values were higher for cities in southeast China than for cities in the northwest. The highest LESI values were mainly distributed along the Chinese southeast coast and the Yangtze River Delta. Cities with the lowest LESI values were found in the centre and north of China. Of the 35 cities, 4 had highly suitable living environments and 7 had unsuitable living environments.     

武汉城市圈城镇体系空间分形研究

基于统计学和分形理论,对武汉城市圈城镇体系的城镇规模级别分布维数、空间关联维数、空间集聚维数等分形维进行计算与分析。3项指标的相关系数都较高,武汉城市圈城镇体系空间自组织现象明显,存在空间分形结构和分形特征;武汉城市圈城镇体系具有规模分布较均衡、城市分布交通指向性明显、城市空间关联较弱、城镇体系内各城市向中心城市高度集聚等基本规律与特征。针对所存在的主要问题,最后提出武汉城市圈城镇体系相关的优化调控措施。     

Exploring space–time paths in physical and social closeness spaces: a space–time GIS approach

Exploring the evolution of people’s social interactions along with their changing physical locations can help to achieve a better understanding of the processes that generate the relationships between physical distance and social interactions, which can benefit broad fields of study related to social networks. However, few studies have examined the evolving relationships between physical movements and social closeness evolution. This is partially related to the shortage of longitudinal data in both physical locations and social interactions and the lack of an exploratory analysis environment capable of effectively investigating such a process over space and time. With the increasing availability of sociospatiotemporal data in recent years, it is now feasible to examine the relationships between physical separation and social interactions at the individual level in a space–time context. This research was intended to offer a spatiotemporal exploratory analysis approach to address this challenge. The first step was to propose the concept of a social closeness space–time path, which is an extension of the space–time path concept in time geography, to represent evolving human relationships in a social closeness space. A space–time geographical information system (GIS) prototype was then designed to support the representation and analysis of space–time paths in both physical and social closeness spaces. Finally, the effectiveness of the proposed concept and design in gaining insight into the impact of physical migration on online social closeness was demonstrated through an empirical study. The contributions of this study include an extension of the time–geographic framework from physical space to social closeness space, the development of a multirepresentation approach in a GIS to integrate an individual’s space–time paths in both physical and social closeness spaces, and an exploratory analysis of the evolving relationships between physical separation and social closeness over time.     

Soil Iodine Determination in Deccan Syneclise,India: Implications for Near Surface Geochemical Hydrocarbon Prospecting

The association of iodine with organic matter in sedimentary basins is well documented. High iodine concentration in soils overlying oil and gas fields and areas with hydrocarbon microseepage has been observed and used as a geochemical exploratory tool for hydrocarbons in a few studies. In this study, we measure iodine concentration in soil samples collected from parts of Deccan Syneclise in the west central India to investigate its potential application as a geochemical indicator for hydrocarbons. The Deccan Syneclise consists of rifted depositional sites with Gondwana–Mesozoic sediments up to 3.5 km concealed under the Deccan Traps and is considered prospective for hydrocarbons. The concentration of iodine in soil samples is determined using ICP-MS and the values range between 1.1 and 19.3 ppm. High iodine values are characteristic of the northern part of the sampled region. The total organic carbon (TOC) content of the soil samples range between 0.1 and 1.3%. The TOC correlates poorly with the soil iodine (r ² < 1), indicating a lack of association of iodine with the surficial organic matter and the possibility of interaction between the seeping hydrocarbons and soil iodine. Further, the distribution pattern of iodine compares well with two surface geochemical indicators: the adsorbed light gaseous hydrocarbons (methane through butane) and the propane-oxidizing bacterial populations in the soil. The integration of geochemical observations show the occurrence of elevated values in the northern part of the study area, which is also coincident with the presence of exposed dyke swarms that probably serve as conduits for hydrocarbon microseepage. The corroboration of iodine with existing geological, geophysical, and geochemical data suggests its efficacy as one of the potential tool in surface geochemical exploration of hydrocarbons. Our study supports Deccan Syneclise to be promising in terms of its hydrocarbon prospects.     

改革开放以来中国农业政策效果的时空计量分析

Since reform and opening up, how much contribution has China’s implementation of new agricultural policy made to agricultural output? This paper is trying to establish an agricultural policy output econometric model for doing a quantitative analysis of China’s new agricultural policy. The results show that China’s agricultural policies on agricultural output have an average contribution rate of about 7% since 1978, which is consistent with the OECD’s basic forecast. There are obvious temporal and spatial differences. Generally speaking, we can divide the contribution of agricultural policy into three periods, which are the start-up phase from 1978 to 1991 (14 years), the stationary phase from 1992 to 2002 (11 years) and the rising phase from 2003 to 2008 (6 years). In space, the contribution of agricultural policy underwent a process from the all-low in the start-up phase, the gradual increase in the stationary phase to the all-high in the rising phase. Northern and western regions are more sensitive to policies. There are three major factors that can affect the contribution of regional agricultural policies, which are the process of national industrialization strategy, terrain and the level of local finance.     

Influence of air masses on particle number concentration and size distribution at Mt. Waliguan, Qinghai Province, China

Particle size distribution of 12–500 nm was measured at Mt. Waliguan, China Global Atmosphere Watch Baseline Observatory, from Aug. in 2005 to May in 2007. 72-hr back-trajectories at 100-m arrival height above ground level for the same period were calculated at 6:00, 12:00, and 21:00 (Beijing Time) for each day using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT-4) model developed by NOAA/ARL. It was found that air mass sources significantly impact particle number concentration and size distribution at Mt. Waliguan. Cluster analysis of back-trajectories show that higher Aitken mode particle number concentration was observed when air masses came from or passed by the northeastern section of Mt. Waliguan, with short trajectory length. High number concentration of nucleation mode was associated with air masses from clean regions, with long trajectory length