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1.
Although future climate change will significantly affect New Zealand's climate, how regional climates will be changed remains highly uncertain. As a consequence, pre‐screening sensitivity analysis is recommended for climate‐sensitive activities. A ‘bottom‐up’ approach intended to serve this purpose in the context of non‐irrigated pasture is developed and demonstrated in the Hawke's Bay context. This is achieved using a simple daily water balance model to simulate near‐surface hydrological processes and empirical relationships between transpiration and pasture dry matter production. The Hawke's Bay case study indicates that the methodology has merit and is worthwhile pursuing nationally (with refinements).  相似文献   

2.
安宁  蔡晓梅 《地理科学》2020,40(9):1412-1420
分析1982—2019年中国核心学术刊物和著作，梳理地理学和政治学对于“地缘政治”概念和研究范式的不同理解。研究发现：① 地理学和政治学有很多相似之处，包括对“地缘战略”等概念的关注，对“大国安全与崛起”等议题的探讨，以及在分析框架中对案例和质性分析方法的强调等；② 地理学和政治学有各具特色，地理学衍生“地缘环境”等概念，政治学也衍生“地缘安全”等概念；地理学在议题上更具空间和系统思维，对海洋地缘政治等话题更偏好，而政治学更强调时事性，侧重于分析时事政治及其地缘政治逻辑等；在分析框架上，地理学受计量革命的影响深远，对质性和定量分析都有所关注，而政治学对案例分析和质性分析的依赖度更高。这些发现说明了当前学科分工并没有改变地理学中的“地缘政治”概念和政治学中的“地缘政治”概念源出一脉的事实，同时也发现，其中的差异正是学科壁垒形成关键所在。  相似文献   

3.
The quantitative effect of climate change on fragile regions has been a hot topic in the field of responses to climate change. Previous studies have qualitatively documented the impacts of climate change on boundary shifts in the farming-pastoral ecotone (FPE); however, the quantitative methods for detecting climate contributions remain relatively limited. Based on long-term data of meteorological stations and interpretations of land use since 1970, climate and land use boundaries of the 1970s, 1980s, 1990s and 2000s were delineated. To detect climate contributions to the FPE boundary shifts, we developed two quantitative methods to explore the spatial-temporal pattern of climate and land use boundary at the east-west (or south-north) (FishNet method) and transect directions (Digital Shoreline Analysis System, DSAS method). The results indicated that significant differences were exhibited in climate boundaries, land use boundaries, as well as climate contributions in different regions during different periods. The northwest FPE had smaller variations, while the northeast FPE had greater shifts. In the northwest part of the southeast fringe of the Greater Hinggan Mountains and the Inner Mongolian Plateau, the shifts of climate boundaries were significantly related to the land use boundaries. The climate contributions at an east-west direction ranged from 10.7% to 44.4%, and those at a south-north direction varied from 4.7% to 55.9%. The majority of the results from the DSAS were consistent with those from the FishNet. The DSAS method is more accurate and suitable for precise detection at a small scale, whereas the FishNet method is simple to conduct statistical analysis rapidly and directly at a large scale. Our research will be helpful to adapt to climate change, to develop the productive potential, as well as to protect the environment of the FPE in northern China.  相似文献   

4.
王涛 《中国沙漠》2022,42(1):1-4
防沙治沙工作自新中国成立之初就是国家层面上的重要任务.随着国家大规模社会经济活动的展开,干旱半干旱区的绿洲、农田、牧场、公路、铁路、渠道、乡镇村落和一些重要基础设施都面临着风沙危害,需要积极应对,开展防沙治沙工作.而面对沙漠科学基本空白的科研工作者们,则需要在形成防沙治沙关键科技支撑的同时,发展中国沙漠科学,这就是20...  相似文献   

5.
《Urban geography》2012,33(10):1422-1442
ABSTRACT

This article argues that contested cities are inherently characterized by uncertainty and uses the interconnections between conflict, uncertainty and urban planning as a new analytical framework for investigating conflict cities. In the contested city of Jerusalem, geopolitical uncertainty stems from the Israeli occupation over East Jerusalem. Focusing on recent urban regeneration plans for West Jerusalem’s city center, the article explores how the municipality locates, plans and imagines the city center when the city’s external and internal boundaries are contested and unfixed. A two-tier analysis is employed. First, a historical analysis shows that the “city center”, as defined by authorities, is an unfixed locale that shifts in concurrence with shifts in the city’s boundaries. Then, a geopolitical analysis shows that by shifting the city center’s boundaries, the Israeli authorities decouple the city’s economic development (in the west) from Israel’s continuing ethno-national policies (in the east).  相似文献   

6.
The atmosphere may be the most valuable resource on Earth and is worth orders of magnitude more to society than it costs as a hazard. However, the atmosphere, and information about the atmosphere, are increasingly being transformed from being considered as part of a global commons to being conceived of as a global commodity to be bought and sold. There are three basic types of atmospheric commodity: firstly, the material atmosphere itself; secondly, the physical properties of the atmosphere; and thirdly, data or information or predictions about the atmosphere. The global expenditure on national meteorological and climatological services and research has now been surpassed by the value of new economic instruments such as weather derivatives and climate emissions trading. Atmospheric scientists, climatologists and physical geographers need to be critically aware of what the consequences, both positive and negative, of these developments for science and society might be. This is particularly the case as climate change is increasingly providing new discourses for companies and governments to exploit as the atmosphere becomes a tradable green resource. This paper attempts to construct an initial critical framework of analysis drawing from broader literatures on the commodification of nature.  相似文献   

7.
青海河湟谷地气候及干旱变化研究   总被引：13，自引：5，他引：8  
利用1961—2002青海河湟谷地11个气象台站气温、降水等地面观测资料,对该区气候要素的年代际变化特征及其干旱变化的成因进行了初步分析。结果表明：青海河湟谷地各季节平均气温20世纪90年比60年代偏高了0.4～0.8℃,冬季增温最显著。年平均降水量90年代比60年代偏少17.2 mm。地表蒸发量80~90年代比60~70年增多。90年代青海河湟谷地秋季和春季降水量减少,使得秋季和春季干旱发生的频次增加,导致河谷地区的径流量减少。  相似文献   

8.
地理科学是提升人类对地球表层认知、探索人地关系、解决资源、环境、发展所面临的复杂问题的重要支撑。引领科学发展,支撑领域人才队伍的建设与培育,是国家自然科学基金委员会的使命与职责。追踪地理科学领域前沿,优化学科布局并开展战略引导是基金委地理科学学科工作的重要任务。以2021年国家自然科学基金地理科学领域4 479项申请书为样本,运用词云分析方法,对申请书的关键词进行统计分析,剖析了地理科学及各分支学科的研究热点。结果表明：“深度学习”“气候变化”“生态系统服务”“高光谱遥感”“青藏高原”“可持续发展”等是2021年地理科学研究内容与方法的热点关键词。在分支学科间交叉融合方面,信息地理学与人文地理学的共现关键词主要有“空间分析模型”“地理信息系统”“遥感”“机器学习”等;自然地理学与人文地理学的共现关键词主要有“生态系统服务”“土地利用”“土地利用变化”“可持续发展”“情景分析”等;自然地理学与信息地理学的共现关键词主要有“遥感监测”“尺度效应”“机器学习”“数字土壤制图”等。未来,国家自然科学基金委员会将从关键词设置、学科间交叉融合等途径入手,进一步从战略层面优化地理科学研究布局,引导科学家聚焦地理学基础理论与热点前沿问题,服务碳中和、乡村振兴等国家重大战略需求。  相似文献   

9.
中国电子信息产业创新的集群网络模式与演化路径   总被引：1，自引：1，他引：1  
周灿  曹贤忠  曾刚 《地理研究》2019,38(9):2212-2225
流空间背景下,多空间尺度网络耦合对创新至关重要已达成学界共识。综合运用区位熵与社会网络分析,识别32个电子信息产业集群,进而基于1985—2015年合作申请发明专利数据,运用卡方检验和Infomap社区发现算法,借助Pajek和ArcGIS等软件,揭示中国电子信息产业创新合作空间模式,探讨创新网络空间组织演化规律。结果表明：① 中国电子信息产业创新合作呈现集群互联的模式,集群区域的创新主体更倾向于同本地和其他集群区域的创新主体合作,这与非集群区域的创新主体结网方式明显不同,印证了关系经济地理学者提出的全球集群网络论断。② 集群创新网络社区的空间组织从位于集群地理边界内,本地化特征显著,演化为超越集群地理边界,呈现等级差异明显的核心-边缘层级式特征,反映出地理邻近对集群主体创新结网影响程度的动态变化。  相似文献   

10.
A scientific delineation of geographical boundaries reflects the cognitive level of scientific abstraction and systematic analysis of the spatial variation of geographical objects and is a basic scientific issue of geography. From the perspective of earth system science, this study first explicates the core issues (e.g., basic concepts, scientific contents, and basic properties) of geographical boundaries. Based on the principles of scientificity and systematicness, we then classify geographical boundaries in terms of intrinsic mechanisms, extrinsic appearance and scientific attributes. Furthermore, this paper analyzes the mathematical connotation and representation methods of geographical boundaries, discusses the characteristics of and differences between traditional and modern methods for geographical boundary delineation. Finally, we present a framework for a “geographical boundary model” with an integration of qualitative, quantitative, and positioning methods. Focusing on geographical boundary (a basic theoretical problem in geography), this study engaged in concept definition and method analysis, with the findings enriching the theory and methodology of geographical information science.  相似文献   

11.
Understanding the driving forces and mechanism of land use change is a key issue in land change science, and has received much attention over the past 30 years. While many driving forces have been identified, the mechanism of land use change is still unclear, mainly because of limited knowledge of the underlying motivation for land use change. Traditionally, the underlying motivation for land use change was ascribed to people＇s pursuit of satisfying their own demands or that of profit maximization. However, those theoretical hypotheses combine all productive factors without highlighting certain predominant factor, in this paper, a case study was conducted on the variation of land productivity, capital productivity and labor productivity in agricultural land use in Xinjiang Uygur Autonomous Region of China. The case study revealed that only labor productivity presented a long-term increasing trend in regional cotton and grain production. This result implies that people＇s pursuit of increasing labor pro- ductivity is probably the underlying motivation for land use change. Additional details identi- fied in agricultural and non-agricultural land use in China support the above implication. As labor productivity is a determinant of people＇s living standards, increasing labor productivity means improving people＇s living standards. Therefore, it is concluded that land use change results from people＇s pursuit of increasing labor productivity in a changing environment.  相似文献   

12.
The EPIC (Erosion Productivity Impact Calculator) crop model, developed by scientists of the United States Department of Agriculture (USDA), has been successfully applied to the study of erosion, water pollution, crop growth and production in the US but is yet to be introduced for serious research purposes in other countries or regions. This paper reports on the applicability of the EPIC 8120 crop model for the assessment of the potential impacts of climate variability and climate change on crop productivity in sub‐Saharan West Africa, using Nigeria as the case study. Among the crops whose productivity has been successfully simulated with this model are five of West Africa's staple food crops: maize, millet, sorghum (guinea corn), rice and cassava. Thus, using the model, the sensitivities of maize, sorghum and millet to seasonal rainfall were demonstrated with coefficients of correlation significant at over 98 per cent confidence limits. The validation tests were based on a comparison of the observed and the model‐generated yields of rice and maize. The main problems of validation relate to the multiplicity of crop varieties with contrasting performances under similar field conditions. There are also the difficulties in representing micro‐environments in the model. Thus, some gaps appear between the observed and the simulated yields, arising from data or model deficiencies, or both. Based on the results of the sensitivity and validation tests, the EPIC crop model could be satisfactorily employed in assessing the impacts of and adaptations to climate variability and climate change. Its use for the estimation of production and the assessment of vulnerabilities need to be pursued with further field surveys and field experimentation.  相似文献   

13.
《The Journal of geography》2012,111(6):269-270
Abstract

The units of the Kelvin temperature scale (with an upper case K for the proper noun “Kelvin”) are incorrectly introduced in most undergraduate introductory physical geography textbooks. The internationally recognized unit of the Kelvin temperature scale is the kelvin (lower case k), abbreviated to K (upper case). However, many introductory physical geography textbooks incorrectly use units of “Kelvin,” “degrees Kelvin,” or “oK.” The errors detract from the prestige of physical geography as a natural science discipline.  相似文献   

14.
In late November 2014, while attending a science exhibition on human settlement at the National Museum, Premier Li Keqiang posed a question to society and scientists regarding the Hu Huanyong Line, which the media subsequently dubbed “the Premier’s question”. This increased awareness and interest in the Hu Huanyong Line and launched a lively debate which provoked a variety of views. In an attempt to address the Premier’s question, this paper firstly reviews the origins of the Hu Huanyong Line, named after the famous population geographer who proposed it in 1935 as part of a wider debate on domestic overpopulation. Using demographic data from China’s first, fifth and sixth censuses, as well as the ArcGIS platform, we analyze the size, proportion and density of populations in the areas southeast and northwest of the Hu Huanyong Line, showing that urbanization and migration have not changed the pattern of population distribution observed by Hu Huanyong. Based on this, we suggest that the pattern of a dense population southeast of the line and sparse population northwest of the line will not fundamentally change for a relatively long time, nor will the situation of urban agglomerations being mainly found in the southeastern region. We also argue that climate and other physical geographic conditions determine that the Hu Huanyong Line shall remain in place. We believe that the question posed by Premier Li Keqiang is solvable, and that with positive policy guidance and rational spatial organization, the northwestern region can achieve more modernization and better quality urbanization, while the same is true for the central region.  相似文献   

15.
Abstract

The Institute of Terrestrial Ecology (ITE) Digital Cartographic Service provides a range of services to the scientists of ITE (and others) including various techniques within the field of geographical information systems (GIS). This paper discusses work of this type as it is applied to specific ITE projects. The emphasis is very much on GIS applications to ‘real ecological science’ such as the ‘acid water’ problem and the change of forest areas into heathland. Some comments are made on fundamental GIS techniques, their use and limitations. At ITE, GIS applications are growing out of an existing use of digital mapping and remote sensing technologies; they have not purchased a GIS system ‘off the shelf.’  相似文献   

16.
 依据秦岭南北地区80个站点1980-2009年气象数据,主要应用空间分析方法对半干旱与湿润区、暖温带与亚热带界限的位置变动特征进行了分析。结果表明：（1）近30 a来,秦岭南北地区的气候干燥度呈明显的纬向分布,由北向南湿度依次增加,其线性趋势除商洛东北部,和西安中部地区呈增加变湿的趋势外,其余部分呈减少趋势;≥10 ℃积温天数呈纬向分布,由北向南依次增加,其线性趋势均为增加趋势,空间分布特征呈同心分布;（2）半干旱与湿润界限在20世纪80年代位置最北,在90年代最南,21世纪前10 a次之;暖温带与亚热带界限在20世纪80年代的位置最南、 90年代略有北移,且在21世纪前10 a位置最北;（3）秦岭南北地区的半干旱与湿润、暖温带与亚热带界限最大波动分别为1.2、0.5 个纬度,且两者30 a平均位置均在34 °N附近;（4）秦岭南北地区近30 a气候暖干化趋势明显,该区的半干旱与湿润区、暖温带与亚热带界限的北移可能会对该地区的种植制度产生较大影响。  相似文献   

17.
During the late 1980s and early 1990s, cognitive science was included as one of the key disciplines in the emerging multidisciplinary field of geographic information science (GIScience). One of the key proponents and popularizers of the study of human cognition as part of GIScience – and one of its major researchers – has been Andrew U. Frank. In this essay, we review the history of Andrew Frank’s role as an innovator and champion for cognitive GIScience, and summarize some of his research contributions in this domain. Taken along with his contributions to other areas of GIScience, this review shows that Andrew Frank has been one of the primary figures in modern GIScience, and among its very broadest and intellectually-diverse contributors.  相似文献   

18.
Country roads are an important social, economic and ecological component of agricultural landscapes in many parts of New South Wales. Using the Lockhart Shire Council area as a case study, this paper describes how present-day rural road networks are a historical vestige of past land-use decisions; a collection of Travelling Stock Routes, pastoral boundaries of early squatters, rail reserves, county and parish boundaries, and an ad hoc collection of mostly 1 chain (20.12 m) roads surveyed during the late 1800s. Road reserves were allocated across the landscape at the discretion of early surveyors, so new land titles could access vital water resources. Nineteenth-century surveyors faced many difficulties in surveying the extent of NSW, sometimes resulting in misalignments which today give ‘character’ to many country roads. Road reserves were often surveyed 2 or 3 chains wide to allow for predicted usage and provide materials for road construction. In the 1870s, Travelling Stock Routes of varying widths from 1 to 80 chains wide (one mile) were gazetted, which often form an integral part of many country road networks. In this way, present-day conservation values of many road reserves is a direct legacy of land policies, administrators and surveyors on the landscape today.  相似文献   

19.
气候变化对中国植被可能影响的模拟   总被引：46，自引：0，他引：46  
依据我国植被和气候的关系对生物地理模式MAPSS中的某些参数和过程进行了调整。将改进后MAPSS模拟的当前气候状况下潜在植被类型及叶面积指数的分布与我国植被区划图和多年平均的NDVI（NOAA／AVHRR）比较，发现结果有了很大的改进。将大气环流模式HadCM2对未来气候变化的预测结果应用于改进后的MAPSS对我国植被未来的变化进行了模拟。考虑到未来大气升高的CO2浓度对植物水分利用率（WUE）的可能影响，进行了WUE变化和不变化2种预测。结果发现未来气候变化可能导致我国东部森林植被带的北移，尤其是北方的落叶针叶林的面积减少很大，以至可能移出我国境内；华北地区和东北辽河流域未来可能草原化；西部的沙漠和草原可能略有退缩，相应被草原和灌丛取代；高寒草甸的分布可能略有缩小，将被萨瓦纳和常绿针叶林取代。同时模拟的结果表明模型对WUE非常敏感。最后对结果的不确定性进行了讨论。  相似文献   

20.
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