共查询到20条相似文献,搜索用时 15 毫秒
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农村居民点耕作距离空间分布特征估测分析 总被引:8,自引:2,他引:8
基于探索性空间数据分析(ESDA)思想,提出一种耕作距离空间估测方法,定量分析农村居民点耕作距离的分布格局与分异特征。以广东省阳山县为案例,研究表明:① 耕作距离与耕地质量及地形等别存在一定的相关性,耕作半径愈小,地形愈低平的地区,居民点与较优的耕地愈集中;② 耕作距离在空间上呈现不均衡状态,随着距离尺度的增加,耕作距离的变化由低值聚类转为高值聚类状态,表明研究区耕地格局随耕作距离尺度上升变得更加分散;③ 估测方法考虑了农村居民点与耕地之间的关系,可以有效分析耕地与居民点之间的空间分布随耕作距离变化的规律,对农村居民点调整、高标准农田建设等工作的合理开展具有参照和一定指导意义。 相似文献
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In this article, we examine the use of an unconventional procedure, PETRIMES, to estimate mineral resources of mercury deposits in California. The study, which is based on the nonparametric discovery process model and Q-Q plots, suggests that a lognormal distribution is appropriate for the mercury deposits in California. The results of the assessment are summarized as follows: (1) the total number of mercury deposits in the population is approximately 165; (2) the median value of the largest undiscovered deposit size is 487 flasks; (3) the mean of the remaining mercury potential is 2,500 flasks; and (4) the population resource ranges from 1,040,000 to 4,300,000 flasks (at a 0.9 probability level). 相似文献
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Zhang Shuai Carranza Emmanuel John M. Xiao Keyan Wei Hantao Yang Fan Chen Zhenghui Li Nan Xiang Jie 《Natural Resources Research》2022,31(4):1981-1999
Natural Resources Research - Known mineralized locations and randomly chosen non-mineralized locations are used traditionally as training samples in data-driven mineral prospectivity mapping (MPM).... 相似文献
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Philip E. Steinberg Andy Walter Kathleen ShermanMorris 《The Professional geographer》2002,54(3):332-348
Geographers have long debated the superiority of regional versus thematic approaches to geographical analysis and geographic education. While most acknowledge that these two approaches are complementary, the task of implementing both approaches in a single introductory course remains challenging. “Global Change, Local Places,” an Internet–based course offered at Florida State University, attempts to fuse thematic and regional approaches using methodological and pedagogical techniques that emphasize student–centered learning and Internet technologies. Results of a student survey and analysis of student assignments suggest that this format was successful. Students expressed a high level of satisfaction with course content, and, although attainment of skills and knowledge was particularly hard to measure given the structure and goals of the course, students appear to have gained country–specific knowledge as well as skills in critical analysis using thematic concepts. 相似文献
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气候变暖影响着生态系统碳循环,碳循环的变化反馈于气候变化。这两者的相互作用影响着未来气候变化的方向和强度。野外增温试验有助于了解生态系统碳循环对气候变化的响应及其机制,因此成为近年来的研究热点。生态系统所处的地理位置及相应的气候背景影响着碳循环对增温的响应。增温后不同生态系统的碳释放和碳固定均可表现为增加、减小或者无显著变化,因而生态系统净碳收支对气候变化响应多样。增温后土壤氮矿化速率、物候、生态系统物种组成和结构的变化间接影响着生态系统净碳收支。多年冻土区储存了大量的土壤有机碳,冻土融化后冻土有机碳分解将释放大量的CO2到大气中,正反馈于气候变暖,因而是目前野外增温试验对碳循环影响研究的焦点。 相似文献
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Using high resolution satellite imagery to estimate cropped area in Guatemala and Haiti 总被引:1,自引:0,他引:1
K. Grace G.J. Husak L. Harrison D. Pedreros J. Michaelsen 《Applied geography (Sevenoaks, England)》2012,32(2):433-440
Guatemala and Haiti are two of the most food insecure nations in the Western Hemisphere. Measurements of food availability and access are instrumental in developing targeted hunger reduction strategies yet no estimates of cropped area (a critical input in the calculation of food production) at either a national or sub-national-level exist. The purpose of this research is to produce estimates of cropped area for Guatemala and Haiti using an area frame sampling approach and very high resolution (∼1 m) satellite imagery. Related research has combined livelihood data with topographic information to construct cropped area estimates in other settings using generalized additive models. We expand this approach with the inclusion of specific population variables in place of the livelihood data. We produce estimates of cropped area for the two countries and sub-national units and our results highlight the significance and complexity of incorporating explicit population characteristics into models of cropped area. 相似文献
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Victoria C. Morckel 《Urban geography》2017,38(1):90-111
Abandoned properties are a significant problem facing legacy cities. Given historic and ongoing population losses, many legacy cities turn to demolitions as one solution to their surplus property problems. Unfortunately, cities lack the resources needed to demolish all of the buildings that should arguably come down. Determining which properties should receive highest priority is a difficult task. Therefore, this paper presents an empirical method, based on basic suitability analysis, for prioritizing demolitions city-wide. Using Youngstown, Ohio as an example, every vacant property in the city was assigned a demolition score based on four factors: property characteristics, vacancy, neighborhood potential, and crime. Properties with higher scores were deemed stronger candidates for timely demolition. In addition to prioritizing demolitions, the proposed method can facilitate the creation of hotspot maps of proposed demolitions, and a per se strategic demolition plan. 相似文献
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PAUL A. WALKER MICHAEL D. YOUNG 《International journal of geographical information science》2013,27(7):619-632
The potential of geographical information systems for strategic policy analysis is examined and demonstrated by example. One of the necessary conditions for this potential to be realised is the development of integrated data sets that combine economic, production and physical data sets at similar scales. The paper illustrates this potential using examples from a State-wide Resource Information and Accounting System developed by CSIRO. 相似文献
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《The Journal of geography》2012,111(2):358-367
Abstract To meet national geography standards, instructional materials using issues-based inquiry are needed. This paper reports on national classroom trials of drafts of Geographic Inquiry into Global Issues (GIGI), a set of inquiry modules for secondary geography. The analysis focuses on three modules about environmental issues, tried by 480 students in 18 schools. Students made significant gains in learning the modules' cognitive and skills objectives, but they showed no change in interest toward studying geography or these environmental issues. Student comments about the modules underscored the necessity of connecting classroom materials about global issues more closely to local experiences. These findings support current models in environmental education. Reflecting this analysis, the published modules now include activities emphasizing inquiry into local issues, to complement the study of global environmental problems. The improved GIGI materials can better meet the goals of both geography and environmental education. 相似文献
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应用常规气象观测资料估算塔里木盆地水面蒸发量 总被引:2,自引:3,他引:2
根据阿克苏水平衡站1999年至2002年非冻结期(4月至10月)20m^2蒸发池的蒸发量及常规气象观测资料,采用斜率关联度分析法分析了各气象要素对水而蒸发的影响程度,建立了计算水而蒸发量的经验公式,结果表明:(1)气象要素对20m^2蒸发池月平均蒸发量的影响程度从大到小的排列顺序为饱和水汽压差、气温、水面温度、空气饱和差、风速、实际水汽压、大气压、相对湿度;(2)20m^2蒸发池蒸发量与饱和水汽压差、空气湿度饱和差、气温、水面温度、风速、水汽压成正比关系;而与气压、相对湿度成反比关系;(3)所有回归方程都达到极显著水平,可供塔里木盆地缺测资料地区选用。 相似文献
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Summary In this paper we use the example of Singapore to make two theoretical contributions to the geographical literature on local labour markets. Firstly, we suggest that the local labour market should be conceived of as an extended 'network space' that is constituted by extra-local linkages and flows as well as local interactions. The importance of certain kinds of foreign 'workers' and 'talent' in Singapore can be used to illustrate this argument. Secondly, we contend that locally constructed discourses can actively shape labour market dynamics, exemplified here by the rise of 'knowledge-based economy' rhetoric in Singapore. 相似文献
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Ramos Claudete Gindri dos Santos de Medeiros Diego Gomez Leandro Oliveira Luis Felipe Silva Schneider Ivo André Homrich Kautzmann Rubens Muller 《Natural Resources Research》2020,29(3):1583-1600
Natural Resources Research - This study was focused on physical, petrographical, mineralogical, and chemical characterization of a volcanic-rock mining by-product (dacite rock), as well as on... 相似文献
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Eric Neumayer 《Area》2008,40(2):228-236
Sending diplomatic missions abroad and receiving foreign missions at home is in the political and economic interests of countries. But such missions depend on domestic and foreign political will and they also cost scarce resources. This article demonstrates that the global pattern of diplomatic representation is significantly determined by geographical distance between countries, by the power of both sending and recipient countries and by the degree of their ideological affinity. The pattern of diplomatic representation is both a reflection of and a contributor to a world of nation-states dominated by geographical distance, unequal power and ideological division. 相似文献
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中国交通流的衰减函数模拟及特征 总被引:3,自引:1,他引:3
交通流具有随距离延伸而不断衰减的空间属性,距离衰减规律是交通地理学的重要议题.基于空间"流"距离衰减研究进展的评述,本文构筑了交通流距离衰减规律的主要可能函数模型.包括指数模型、Pareto模型、常对数模型、平方指数模型、开方指数模型,采用中国城际交通流包括公路客流、铁路客流、铁路货流和航空客流,分别对5种距离衰减模型进行了模拟并对比分析,从中识别出最佳的距离衰减函数是Pareto模型.然后,重点分析了各种交通流距离衰减函数的参数差异和地理内涵,并采用时间序列的交通流进行模拟,考察距离衰减函数的主要参数变化,并解释其地理内涵,同时绘制了交通流累计率曲线和分配率曲线,对各种交通方式的距离衰减函数模型、主要函数参数和距离衰减规律进行论证和解释. 相似文献
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Eakta Jain Susan K. Jacobson Pallavi Raiturkar Nia A. Morales Archana Nagarajan Beida Chen 《社会与自然资源》2019,32(10):1092-1098
AbstractWe used heart rate change as a tool to study how positive and negative wildlife conservation messaging impacts a viewer, and which types of animal images stimulate greatest reaction. We used scenes from five wildlife conservation videos available from environmental organization websites and YouTube, with positive and negative messaging. We found both very positive and very negative messaging in videos may be similarly effective in engaging viewers. A trend in greater changes in heart rate when insects, mammals, and birds appear on the screen suggests generally high human interest in these taxa, potentially due to avoidance and attraction responses. The number of scenes (N?=?54) in which various taxa appear reflects bias toward mammals (65%) and birds (17%) to capture viewers’ attention. Arousal is a primary step in engaging an audience to attend to a message. Physiological research offers innovative new techniques to evaluate public responses to communications about biodiversity conservation. 相似文献
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Pip Wallace 《New Zealand geographer》2005,61(2):124-130
Abstract: The focus of this article is on examining how resource management plans prepared under the Resource Management Act 1991 can be used to control the effects of activities for the purpose of preserving the integrity of an organic farm. The article examines effects that can potentially threaten an organic farm and identifies methods that could be employed in a District or Regional Plan to avoid or mitigate those effects. It concludes that the use of resource management plans represents a substantial opportunity to secure the position of the organic farm in New Zealand. 相似文献
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J.F. Conley 《International journal of geographical information science》2013,27(4):657-680
Although there are many algorithms and statistical tests to detect clustering of geographical phenomena, such as disease cases, the follow-up task of analyzing the cluster to explain its existence and mitigate the cluster is generally left to the researcher. These cluster detection methods are useful only for part of the process of identifying, understanding, and mitigating disease clusters. This research develops and presents a computer program that uses the information about the shape of the cluster to evaluate the hypotheses about potential causes. To achieve this, the shapes of the clusters are represented by image moment invariant statistics developed in the field of computer vision, and these shape statistics are compared against a database of moment invariants of shapes representative of several geographical processes, such as diffusion along roads and wind diffusion. Experiments using simulated data of different types of disease transmission were carried out, and the ability of the program to accurately classify the different types of diffusion demonstrates the viability of this approach to automated cluster analysis. 相似文献