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1.
土壤盐渍化是土地荒漠化的主要类型之一,是干旱、半干旱地区土地退化的主要形式,水盐运移是研究土壤盐渍化的主要内容。土壤中的水盐运移是一个集物理、化学和生物反应的复杂过程,溶质降解和生成必然对水盐运移过程产生影响,但目前对此方面的研究很少。通过利用水盐运移两区模型对不同降解系数或溶质生成系数下穿透曲线的模拟分析,研究了降解和溶质生成对水盐运移的影响。结果表明,在水盐运移过程中,土壤溶液浓度会随着土壤降解系数的增加而降低,随着土壤溶质生成系数的增大而增大。 相似文献
2.
资源环境承载能力监测预警中一项重要的内容就是资源环境耗损过程的变化趋势测度。本文从资源消耗、环境损坏和生态质量变化角度出发,提出了一种基于资源环境耗损的过程评价方法,即通过计算水土资源消耗、水气环境污染以及生态质量变化,测度资源环境耗损指数,刻画资源环境耗损趋势,并在京津冀地区开展了试评价。研究结果表明：①该评价方法以资源环境耗损变化为基础,力图客观反映区域资源环境变化趋势,从科学架构出发,结合数据可获得性和实际可操作性,综合得出一种科学合理且简单易行的评价方法,有利于资源环境耗损过程评价在全国推广。②试评价结果显示,京津冀地区水土资源利用效率提高趋势明显,近80%的区县处于资源利用高效率类别;污染物排放强度总体呈现下降趋势,但仍然有33%的区县污染物排放处于高强度状态;以林草覆盖率表征的生态质量处于逐步降低状态,年均降低速率约为1.2%。③从指标组合关系上看,水土资源利用效率同时趋于良好的县占比最高(100个,约50%);效率趋势相异的区县较少(62个),其中土地资源利用效率趋差而水资源利用效率趋良的区县个数最少(18个)。污染物排放强度变化的指标组合呈现两极分化特征。京津冀地区资源环境耗损趋缓型和加剧型评价单元数量对比为6:1,市辖区的耗损加剧程度比县略严重。 相似文献
3.
中尼口岸作为环喜马拉雅经济合作带的窗口,其贸易和交通发展是中国建设“面向南亚开放大通道”的重要支撑。论文探讨口岸贸易与跨境交通的耦合协调机理,运用评价指标体系法和可达性模型分别评估中尼口岸的贸易可持续发展水平和跨境交通可达性,运用耦合协调模型分析2010—2019年中尼口岸贸易可持续性与跨境交通可达性的耦合协调关系。研究结果表明：① 口岸贸易与跨境交通复合系统是一个具有交互耦合关系的有机整体,口岸贸易与跨境交通高水平同步发展是口岸贸易与跨境交通耦合协调的关键。② 中尼口岸贸易的整体可持续发展水平偏低,贸易流量是中尼口岸贸易可持续发展的关键要素;中尼口岸的跨境交通可达性提升缓慢,樟木口岸的跨境运输优势明显。③ 中尼口岸贸易与交通发展的耦合协调整体处于中度失调状态,贸易滞后于交通发展,交通对贸易的促进作用有限。为了推进口岸贸易与跨境交通的耦合协调发展,应当充分发挥中尼口岸的货运职能,大力发展尼泊尔转口贸易,打通南亚大市场。加快建设吉隆口岸跨境经济合作区;远期打造新通道以发挥樟木口岸大宗货物运输功能;利用直升机发展普兰(斜尔瓦)口岸的“神山圣湖”旅游经济,促进口岸贸易可持续发展。 相似文献
4.
国土资源知识库的建设与应用 总被引：2，自引：0，他引：2
为满足决策分析的需要和指导国土资源数据利用,从数据—知识—应用3个层次对国土资源数据进行了深层次的挖掘和利用,按照知识获取→知识表示→知识库设计、存储→知识利用技术流程建设国土资源知识库,包括国土资源空间知识库、国土资源影像知识库、国土资源专题知识库、国土资源元知识库,并给出知识库应用于国土资源综合分析系统的实例。 相似文献
5.
中国区域发展的资源环境协调问题 总被引：18，自引：3，他引：15
随着人口规模和经济发展水平的快速增长,社会经济发展与自然资源基础的协调状态已经成为我国区域社会经济持续发展能力建设的首要任务和基本目标。为此,本项研究选择了决定区域社会经济发展最为关键的5大“公用性资源”并建立相应模型以评价区域发展与自然资源基础协调状态。结果表明,在全国7大区中,以华北、东北、华东、华中和华南5个区条件相对较优,而西北和西南地区的状态相对较差。人地关系对应分析表明,华东、华南、华中和华北4个大区人地关系的紧张状态突出,其中华东区的情况最甚,目前当地实际人地关系压力系数接近6.8,高出全国均值水平33倍。尽管西北和西南的人地关系压力状态远低于其他地区,但是由于自身资源环境基础的脆弱性,当地资源环境大规模开发同样面临严重挑战。作为全国资源环境基础最佳的地区,目前东北区的人地关系依然保有较大演进空间,这也是全国区域发展与资源环境协调的最后希望所在。 相似文献
6.
在联合国下属的政府间气候变化专门委员会（IPCC）的4次评估报告影响下,全球变暖达到前所未有家喻户晓的程度．各国人民似乎对“气候变暖”有谈虎色变的感觉．只要是灾难,不论水灾还是旱灾,不管是降温的雪灾还是高温的热浪,各国媒体均将这些灾害与“气候变暖”紧密联系起来,IPCC第四次报告也是如此．气候真的变暖了吗？真的那么严重变暖了吗？气候变暖真的给人类带来的只是可怕灾难而没有益处吗？水灾与旱灾是一对矛盾的2个方面,如何都能够由“全球变暖”一个因素所导致？地质记录表明,气候冷暖波动是地球气候变化一般形式,过去在人类能够影响大气二氧化碳含量以前,地球气候就是一直在不断地冷暖变化着的．驱动地球冷暖变化的主要因素是地球接收太阳辐射量的变化．不变的气候是短期的,是暂时的,而变化的气候却是长期和永恒的．持续了约550年变冷小冰期于1850年结束,随后进入暖期则是正常的自然过程．人类活动最大可能只是叠加了变暖的影响．本研究综合对比分析全球变暖和全球变冷2种气候变化所产生的一系列后果,认为全球变暖给人类带来结果是利大于弊． 相似文献
7.
基于改进的SFA模型对长江经济带108个城市2004—2016年的绿色创新效率与生态治理绩效值进行测度,借助耦合协调模型及探索性空间数据分析法对两系统的耦合协调度和时空分异特征进行分析,进而运用PVAR模型考察其响应关系。结果表明：①2004—2016年两系统整体处于初级协调阶段,未来仍有较大提升空间;空间上自东向西梯度递减,高协调区集中在东部城市;②两系统的耦合协调度具有空间正关联性,低-低集聚城市数多于高-高集聚,协调发展领先城市对周边城市的辐射带动作用较弱;③生态治理绩效对绿色创新效率响应较弱,而绿色创新效率对生态治理绩效响应则较强,且二者均对自身依赖较强,未来优化其互动机制应是长江经济带高质量发展的重点。 相似文献
8.
湘澳合作是在CEPA及泛珠三角"9+2"框架下的区域合作,其在招商引资、会展、旅游、消费维权等合作方面取得了一些进展,但合作的广度和深度还不够,湖南没有充分利用好澳门的"平台"作用,自身的特色和优势没有得到充分体现.长株潭城市群被批准为两型社会试验区为湘澳合作提供了新的机遇,全球性的金融危机也为湘澳合作带来了新的挑战.通过对湘澳区域关系和合作机制的反思,认为湘澳合作应由政府推动的合作机制转变为市场引导和政府推动结合的新机制,并充分发挥民间组织的作用,以推动湘澳合作取得更大的进展. 相似文献
9.
The characteristics of a reflected spherical wave at a free surface are investigated by numerical methods; in particular, the polarization angles and amplitude coefficients of a reflected spherical wave are studied. The classical case of the reflection of a plane P wave from a free surface is revisited in order to establish our terminology, and the classical results are recast in a way which is more suited for the study undertaken. The polarization angle of a plane P wave, for a given angle of incidence, is shown to be 90° minus twice the angle of reflection of the reflected S wave. For a Poisson's ratio less than 1/3, there is a non-normal incident angle for which both amplification coefficients are 2 precisely; for this incident angle the direction of the particle motion at the free surface is also the direction of the incident wave. For a wave emanating from a spherical source, the polarization angle, for all angles of incidence, is always less than, or equal to, the polarization angle of a plane P wave. The vector amplification coefficient of a spherical wave, for all angles of incidence, is always greater than the vector amplification coefficient of a plane P wave. As expected, the results for a spherical wave approach the results for a plane P wave in the far field. Furthermore, there was a good agreement between the theoretical modelling and the numerical modelling using the dynamic finite element method (DFEM). 相似文献
10.
《The Professional geographer》2013,65(4):510-515
Two quite different concepts of space are important in geography and environmental psychology. One is the concept of macro-environment, of space as geographical scale. The other is the concept of form-at-a-timeless-instant: of naive geometry. Confusing these two concepts leads to serious errors. This paper examines some methodological and philosophical sources of this confusion, and points to a number of research problems in geography and psychology that can benefit from an untangling of the two concepts of space. One such problem is the need to understand the development of mapping abilities in very young children. Another is the larger question of building a body of theory to explain the development of macro-environmental cognition and behavior. 相似文献
11.
国内外耕地利用与保护的理论基础及其进展 总被引：23，自引：5，他引：23
文章较系统地总结了国内外耕地保护相关的理论及研究进展 ,分析了耕地保护的科学基础和历史演变过程。指出土地生产力是制定耕地保护数量的科学依据 ,土地评价是耕地保护规划的科学基础 ,土地规划、法规体系的落实是耕地保护顺利实施的保障。在此基础上 ,进一步分析了我国耕地利用与保护中面临的几个理论和实践问题 ,并提出相应的对策和建议。 相似文献
12.
J. Makris Z. Ben Abraham A. Behle A. Ginzburg P. Giese L. Steinmetz R. B. Whitmarsh S. Eleftheriou 《Geophysical Journal International》1983,75(3):575-591
Summary. A long seismic refraction profile was carried out between southern Israel and Cyprus. The seismic energy was generated by 33 sea shots each of 0.8 t explosives and was recorded by land stations in Israel and Cyprus and by ocean bottom seismographs deployed along the profile.
The results showed that the continental crust of southern Israel thins towards the Mediterranean underneath a northward thickening sedimentary cover. Cyprus is underlain by a 35 km thick continental crust thinning south-wards and extending to Mt Eratosthenes. Between Mt Eratosthenes and the Israel continental shelf the crystalline crust is composed of high velocity (6.5 km s-1 )material and is about 8 km thick. It is covered by 12–14 km of sediments and may represent a fossil oceanic crust. 相似文献
The results showed that the continental crust of southern Israel thins towards the Mediterranean underneath a northward thickening sedimentary cover. Cyprus is underlain by a 35 km thick continental crust thinning south-wards and extending to Mt Eratosthenes. Between Mt Eratosthenes and the Israel continental shelf the crystalline crust is composed of high velocity (6.5 km s
13.
蒸发是水文循环的重要组成部分，精细化蒸发变化与气象要素的响应关系，对中国重要生 态过渡带水资源、生态恢复重建以及社会经济的可持续发展具有重要意义。基于 1970—2017 年 70 个气象站点观测数据，辅以趋势分析和小波相干方法，对秦岭南北气温和潜在蒸发（ET0）变化特征
进行分析，探讨气象要素与 ET0 的响应关系。结果表明：以滑动相关方法为基础，无论是滑动窗口 调整，还是去趋势序列，气温与ET0均呈现正相关关系，说明秦岭南北气温上升，ET0 增加；但是，秦 岭南北气温与ET0 相关关系存在时空差异。以 1993 年为时间节点，前期气温和 ET0相关性呈现增 加趋势，后期则逐渐减弱；空间上西秦岭地区是气温和 ET0 的弱相关区。在主导因素上，ET0对太阳 辐射变化更为敏感，风速并非区域 ET0 变化的主导因素，从而导致“蒸发悖论”现象并不突出。多因 素主导 ET0 变化，是秦岭南北 ET0 与气温响应关系存在时空差异的原因。 相似文献
14.
京津冀城市群城镇化与创新的耦合过程与机理 总被引：2，自引：1，他引：2
城市群是国家新型城镇化的主体形态,也是创新的孵化器;城市群区域的城镇化子系统与创新子系统之间理论上存在复杂交互关系。京津冀城市群是国家新型城镇化规划确定的国家级城市群,并将“全国创新驱动经济增长新引擎”作为其核心功能定位,因此有必要探索京津冀城市群的城镇化过程与创新发展之间的耦合关系,这对理解城镇化与创新之间的关系和京津冀城市群的发展问题都有裨益。通过梳理城镇化与创新两个子系统之间的内在理论关系,构建城镇化与创新的综合评价指标体系,借助耦合协调度模型和地理探测器因子探测方法,分析京津冀城市群城镇化与创新两子系统之间的耦合协调关系演变过程及作用机理。研究发现：① 京津冀城市群城镇化和创新的综合水平都呈现稳步增长的趋势,城镇化与创新的耦合协调关系总体向好的方向发展,但综合水平和耦合关系的空间差异都较大;② 创新滞后是京津冀城市群城镇化与创新耦合协调水平提升的关键阻力,近年京津冀城市群地区及多数城市表现为创新滞后的耦合协调类型;③ 京津冀城市群城镇化与创新的交互影响非常显著,特别是经济城镇化和社会城镇化对创新的影响、创新资源对城镇化的影响表现比较突出。 相似文献
15.
J.M. Blaut 《The Professional geographer》1999,51(4):510-515
Two quite different concepts of space are important in geography and environmental psychology. One is the concept of macro-environment, of space as geographical scale. The other is the concept of form-at-a-timeless-instant: of naive geometry. Confusing these two concepts leads to serious errors. This paper examines some methodological and philosophical sources of this confusion, and points to a number of research problems in geography and psychology that can benefit from an untangling of the two concepts of space. One such problem is the need to understand the development of mapping abilities in very young children. Another is the larger question of building a body of theory to explain the development of macro-environmental cognition and behavior. 相似文献
16.
Kristian Bjarnøe Brandsegg Erik Hammer Richard Sinding-Larsen 《Natural Resources Research》2010,19(1):45-62
Multivariate analysis is employed to investigate the structure of variations within highly heterogeneous data. Traditionally,
principal component analysis (PCA) is run by analyzing the entire wireline log and using PCA scores to characterize variability
within and between lithologies. In this paper, we propose a technique using only specific subsets of all well records to quantify
reservoir heterogeneity due to second order lithological variability. These subsets are chosen from uniform lithofacies parts
of the wireline log in order to reduce the variability in the correlation matrix that otherwise would cause lithological changes.
The purpose is to assess the efficiency of structured PCA in analyzing small-scale heterogeneity that is captured by wireline
logs but often masked by traditional PCA approaches. This paper shows that a structured PCA procedure based upon special lithological
units is superior to an unstructured PCA, when the focus is within lithology variations. This structured procedure is applied
to data from the Heidrun field, offshore mid-Norway. The results demonstrate clear benefits from added insight into the variability
of a complex fluviodeltaic heterolithic sequence that poses great challenges to hydrocarbon development. 相似文献
17.
Paul Lewis Stewart Fotheringham Adam Winstanley 《International journal of geographical information science》2013,27(5):697-716
GIS elemental unit representations of spatial data are often defined in terms of points, lines and areas. However, another type of spatial data that is becoming frequently captured, but as yet is largely ignored in GIS, is that of video. While digital video recording is a commonly encountered medium in modern society and encompasses many forms, from simple personal camcorders through to sophisticated survey and surveillance systems, its geographical representation in a GIS has not been fully examined or realised. In the majority of cases the video footage is usually captured while the device and/or the objects being viewed are in motion. What is of particular interest is when video streams can be, or have been, associated with spatial data such as location and orientation to create geographically referenced videographic data, which, for simplicity, will be defined as spatial video. Fundamentally, the nature of video is to record space, so when spatial properties can be accurately acquired and associated with this footage, an important geographical element can be considered for integration and analysis within a GIS. Existing spatial video systems, both commercial and research, are predominantly used in survey or LBS roles and are usually bespoke and application specific. These systems do not model spatial video to any recognised standards that is generalised to be both data and platform independent. They do not support GIS integration and/or analysis from a purely spatial content perspective. A video-image/remote-sensing centric approach prevails where usage options range from simple visualisation interfaces to interactive computer vision systems. What has been largely overlooked is a spatial approach where the inherent geographical extent recorded in each video frame can be modelled and used in a geo-spatial analysis context. While this modelling approach has not been fully realised, it does exist in a GIS form based on Open Geospatial Consortium standards, where the spatial context of video is defined in a structure called a ViewCone. However, a ViewCone only defines a 2D model of the geographical extent of each frame and is restricted to a three-or-five sided polygon representation. Thus, this article examines the potential of modelling spatial video through the use of elemental data types within GIS; gives some examples of using this approach; describes some problems in using spatial video within GIS; and then demonstrates how these problems are being solved. This is done in three stages: Firstly, a detailed overview of spatial video in its current GIS role is provided – this is achieved through a complete introduction to the distinct elements of spatial video followed by a review of its use in both commercial and academic application areas. Secondly, a brief theoretical overview of an alternative GIS-constrained ViewCone data structure is given that defines a more flexible spatial video model for both 2D and 3D GIS analysis and visualisation. Thirdly, a selective sample of results is presented based on an implementation of this approach being applied to a constrained spatial video data source in a specific study area. 相似文献
18.
19.
B. Feng Chao 《Geophysical Journal International》1981,66(2):285-312
Summary. There is an analogy in the algebraic structure between the terrestrial spectra belonging to different earth models and the electron energy levels of some quantum mechanical systems. The reason for such an analogy is studied by means of group theory. It is shown that the structure of the spectrum is determined solely by the symmetry of the physical system under consideration. Group theory is then applied, as a unifying theory, to study terrestrial spectroscopic problems based on the theorem that each degree of degeneracy in the spectrum is equal to the dimension of one of the irreducible representations of the symmetry group of the physical system. The influence of perturbations of lower symmetry on the degeneracies in the spectrum (particularly the pattern of splitting) is also studied through group theory; and exact results are obtained. In addition, group theory provides the selection rules for perturbation matrices which determine the coupling among normal modes belonging to the unperturbed system. 相似文献
20.
内蒙古水土资源平衡及其水资源承载能力 总被引：14，自引：0，他引：14
从资源平衡关系入手,定量计算了天然状态下内蒙古的水土资源平衡,揭示了内蒙古自然降水与作物水分需求的平衡关系;采用负载指数与承载力模型,计算了内蒙古的水资源利用潜力与承载能力,揭示了调控下内蒙古水资源支撑能力和保证程度.结果表明:内蒙古高原气候干旱,水分亏缺是自然降水条件下水土资源平衡的主要特征;内蒙古水资源承载力有限,当人均综合用水量达到较高水平时,平水年全区承载力接近超载临界值,偏枯水年全区水资源超载严重;内蒙古水资源承载能力盟市差异显著,水资源普遍短缺是区域人口发展的限制性特征. 相似文献