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1.
One of the most impor tant factors impacting the development of today‘s private higher education in China is that there are not enough policies to support in.Then,the history of private higher educationin Nanjing Nationalist Government(1927-1749)is focused on.  相似文献   

2.
The Burhi‐Gandak river is one of the major tributaries of the Ganga River in the middle Ganga basin. The river is i known to have an oscillatory character and has changed its course in Recent times. In the present study, a variety of remote sensing data combined with surface and subsurface data have been used to delineate the fluvial palaeofeatures of this river. The palaeofeatures of the Burhi‐Gandak indicate that the river has shifted from N to S over a distance of 30 km. Further, its is observed that Burhi‐Gandak river had a larger channel width and higher discharge on earlier times and was very active. On detailed examination, a past link between the now northerly flowing Baghmati and Burhi‐Gandak rivers is detected. Based on the above features, three distinct stages of migration of the river have been identified and a summary of fluvial palaeohistory is presented.  相似文献   

3.
Geological studies in the area around Badami, Bijapur District, Karnataka, were carried out with the help of Landsat imagery and aerial photographs. The study are forms a part Kaladgi Basin which is located on the northernmost fringes of the exposed Dharwar Craton. Archaen Peninsular Gneiss and intrusive Granodiorite/Granites (≈Clospet Granite) form the basement for the Middle to Late Proterozoic Kaladgi Super Group sediments which are, in turn, overlain in the north by the Upper Cretaceous to Lower Eocene Deccan flood basalt lavas. Geological mapping of the study area and inferences about the structural setup were primarily based on interpretation of the remotely sensed data. The combined interpretative study of Landsat imagery and aerial photographs was instrumental in mapping of the lithostratigraphic units exposed in the study area along with the structures associated with them.  相似文献   

4.
Urban sustainability certifications (USCs) urge developers to exceed the local norms and regulatory requirements to attain sustainability. USCs are gaining international recognition as planning and policy support tools. This study aims to assess the relevance of four USCs (LEED for Neighborhood Development, BREAAM communities, CASBEE for Urban Development, and Pearl Community Rating System) in contexts outside their country of origin using Cairo Governorate as a case study. The study focuses on compactness, street connectivity, and walking accessibility as prominent components for sustainable mobility and urban form at the neighborhood level. The study examines 202 neighborhoods in Cairo in terms of compactness and then focuses on eight urban areas in different locations and with different characteristics to assess their connectivity and walking accessibility. Different analyses were performed with ArcGIS software using data about neighborhoods’ population, residential units, street networks, established buildings, buildings’ outlines and heights, and detailed uses. Results show that USCs’ indicators and thresholds are generally lenient and insensitive to the context of formal areas in Cairo Governorate, which are significantly more compact, mixed (horizontally and vertically), and connected. This study adds to the currently limited empirical evidence refuting the use of some USCs as global tools and questioning their utilization in different contexts either as they are or even through an adaptation process.  相似文献   

5.
The aim of the international project “Global Land Ice Measurements from Space (GLIMS)” headed by the US Geological Survey is to establish a world wide glacier inventory based on satellite imagery. This data set will form a first digital baseline study for future glacier monitoring. The presented GIS-based glacier inventory for King George Island is a case study for the area of the Antarctic Peninsula. In the database of the glacier inventory topographic information, specific glaciological parameters as well as metadata will be included. The topographic data consists of drainage basin limits, basin areas, altitudinal ranges, perimeters and mean lengths. Glaciological data sets should comprise information on glacier retreat in different periods, glacier velocities, ice thickness and bedrock topography as well as derived parameters. Modelled and measured mass balance parameters could be included as additional data layers. In particular, these metadata records must comprise background information on data accuracy and data sources and should be compatible with a future data model for the King George Island GIS (KGIS). Three examples illustrate that the GLIMS database will not only contain information valuable for glaciological applications, but also other environmental studies on the island will benefit from this standardised remote sensing data sets. Therefore, a very close link between the data models of KGIS and GLIMS has to be established to enable these synergisms. Finally, better access to historic aerial photography would enable a continuous record of glacier retreat from the beginning of the 1950's onward.  相似文献   

6.
While there is a large literature on the form of epidemic waves in the time domain, models of their structure and shape in the spatial domain remain poorly developed. This paper concentrates on the changing spatial distribution of an epidemic wave over time and presents a simple method for identifying the leading and trailing edges of the spatial advance and retreat of such waves. Analysis of edge characteristics is used to (a) disaggregate waves into ‘swash’ and ‘backwash’ stages, (b) measure the phase transitions of areas from susceptible, S, through infective, I, to recovered, R, status (SIR) as dimensionless integrals and (c) estimate a spatial version of the basic reproduction number, R 0. The methods used are illustrated by application to measles waves in Iceland over a 60-year period from 1915 to 1974. Extensions of the methods for use with more complex waves are possible through modifying the threshold values used to define the start and end points of an event.
Peter HaggettEmail:
  相似文献   

7.
ABSTRACT

Permafrost is one of the largest elements of the terrestrial cryosphere and is extremely sensitive to climate change. Based on mean annual ground temperature (MAGT) data from 189 boreholes on the Qinghai–Tibet Plateau (QTP), terrain factors, and climate data from China Meteorological Forcing Dataset, we propose a new mean annual ground air temperature (MAGAT) statistical model between meteorological parameters with subsurface temperatures to simulate permafrost distribution and variation of MAGT on the QTP over the past three decades (1981–2010). Validation of the model with MAGT data from 13 boreholes and permafrost maps of the QTP indicated that the MAGAT model is applicable to simulate the distribution and evolution of permafrost on the QTP. Simulation results show that the spatiotemporal MAGT of permafrost significantly increased by 0.37°C, or 0.25°C/10 yr, and the total area of permafrost decreased by 2.48?×?105?km2 on the QTP over the past three decades. Regionally, the changes of permafrost in the southwestern QTP were greater than other regions of the QTP.  相似文献   

8.
A technique is proposed for Earths gravity field modeling on the basis of satellite accelerations that are derived from precise orbit data. The functional model rests on Newtons second law. The computational procedure is based on the pre-conditioned conjugate-gradient (PCCG) method. The data are treated as weighted average accelerations rather than as point-wise ones. As a result, a simple three-point numerical differentiation scheme can be used to derive them. Noise in the orbit-derived accelerations is strongly dependent on frequency. Therefore, the key element of the proposed technique is frequency-dependent data weighting. Fast convergence of the PCCG procedure is ensured by a block-diagonal pre-conditioner (approximation of the normal matrix), which is derived under the so-called Colombo assumptions. Both uninterrupted data sets and data with gaps can be handled. The developed technique is compared with other approaches: (1) the energy balance approach (based on the energy conservation law) and (2) the traditional approach (based on the integration of variational equations). Theoretical considerations, supported by a numerical study, show that the proposed technique is more accurate than the energy balance approach and leads to approximately the same results as the traditional one. The former finding is explained by the fact that the energy balance approach is only sensitive to the along-track force component. Information about the cross-track and the radial component of the gravitational potential gradient is lost because the corresponding force components do no work and do not contribute to the energy balance. Furthermore, it is shown that the proposed technique is much (possibly, orders of magnitude) faster than the traditional one because it does not require the computation of the normal matrix. Hints are given on how the proposed technique can be adapted to the explicit assembling of the normal matrix if the latter is needed for the computation of the model covariance matrix.Acknowledgments. Professor R. Klees is thanked for support of the project and for numerous fruitful discussions. The authors are also thankful to Dr. J. Kusche for useful remarks and to Dr. E. Schrama, his solid background in satellite geodesy proved to be very helpful. A large number of valuable comments were made by Dr. S.-C. Han, Dr. P. Schwintzer, and an anonymous reviewer; their contribution is greatly acknowledged. The satellite orbits used in the numerical study were kindly provided by Dr. P. Visser (Aerospace Department, Delft University of Technology). Access to the SGI Origin 3800 computer was provided by Stichting Nationale Computerfaciliteiten (NCF), grant SG-027.  相似文献   

9.
Some GPS points were set up and occupied and reoccupied along the traverse route from Zhongshan Station to Dome-A.The result analysis for the GPS data processed by GAMIT/GLOBK package was presented in this paper.It was indicated that the ice along the traverse route flowed with an 8-25 m/a velocity to the northwest in the last three years,which was the direction of the edge of the ice sheet.The maximum horizontal flow velocity is about 100 m/a.Moreove,due to the ice flow,a 0.2-1 m/a sedimentation rate is achieved.finally,a 1-5m/a^2 horizontal acceleration is achieved from the GPS data of the three different stages.  相似文献   

10.
《The Cartographic journal》2013,50(3):260-261
Abstract

A dealer in second-hand maps, mostly Ordnance Survey maps, looks to the future of map dealers in the light of technological advances and the digital age.  相似文献   

11.
《The Cartographic journal》2013,50(3):222-226
Abstract

The ETH-Bibliothek (the Library of the Swiss Federal Institute of Technology) in Zurich has employed electronic resources to vastly enhance access to its collections. This article examines how ETH has set about the task of incorporating electronic data into the map collection, and then explores how access to hard copy map materials has been revolutionized by electronic means.  相似文献   

12.
IntroductionIf let roadway entities be denoted by arcs and in-tersections be denoted by nodes, then a road net-work can be represented with node-arc model. Be-cause the designation of nodes can be determinedby arcs according to the definition of node-arc mod-el, howto designate arcs becomes the key of repre-senting a road network. As described in the firstpaper of the series, all four kinds of roadway enti-ties (i.e., streets, road segments, carriageways,and lanes) can be represented by arcs. …  相似文献   

13.
Improving crop area and/or crop yields in agricultural regions is one of the foremost scientific challenges for the next decades. This is especially true in irrigated areas because sustainable intensification of irrigated crop production is virtually the sole means to enhance food supply and contribute to meeting food demands of a growing population. Yet, irrigated crop production worldwide is suffering from soil degradation and salinity, reduced soil fertility, and water scarcity rendering the performance of irrigation schemes often below potential. On the other hand, the scope for improving irrigated agricultural productivity remains obscure also due to the lack of spatial data on agricultural production (e.g. crop acreage and yield). To fill this gap, satellite earth observations and a replicable methodology were used to estimate crop yields at the field level for the period 2010/2014 in the Fergana Valley, Central Asia, to understand the response of agricultural productivity to factors related to the irrigation and drainage infrastructure and environment. The results showed that cropping pattern, i.e. the presence or absence of multi-annual crop rotations, and spatial diversity of crops had the most persistent effects on crop yields across observation years suggesting the need for introducing sustainable cropping systems. On the other hand, areas with a lower crop diversity or abundance of crop rotation tended to have lower crop yields, with differences of partly more than one t/ha yield. It is argued that factors related to the infrastructure, for example, the distance of farms to the next settlement or the density of roads, had a persistent effect on crop yield dynamics over time. The improvement potential of cotton and wheat yields were estimated at 5%, compared to crop yields of farms in the direct vicinity of settlements or roads. In this study it is highlighted how remotely sensed estimates of crop production in combination with geospatial technologies provide a unique perspective that, when combined with field surveys, can support planners to identify management priorities for improving regional production and/or reducing environmental impacts.  相似文献   

14.
15.
Coastal zone is very dynamic, being the meeting place of land and sea water. The development in coastal area and subsequent population growth have given rise to problems such as erosion, sedimentation, saltwater intrusion, degradation of natural resources, etc. Satellite data has proved to be more appropriate for change detections quantifying and monitoring coastal zones compared to conventional sources. An attempt is being made to elucidate the effect of shoreline changes with reference to the spatial and field data observed along the Tharangampadi area. The base map was prepared on 1:50,000 scale for delineation and identification of shoreline changes. The spatial variability of shoreline changes are studied using IRS 1B LISS-II 1991, IRS 1C LISS-III 2004 and IRS P6 LISS-IV and IRS 1D PAN merge data 2006. The corresponding Survey of India toposheets of 1852, 1972 and survey and land record village map of 1918 also supplemented for this study. The kind and extent of shoreline changes were investigated by using GPS during ground truth verification. The results are analyzed and presented in this paper. The study results revealed that 180 m receding of the shoreline occurred in the past 155 years.  相似文献   

16.
17.
Abstract

The organization lineage of the UK Defence Geographic and Imagery Intelligence Agency can be traced back to the seventeenth century. For much of this time the organization, bearing a succession of different titles, formed only a very small section of the armed forces, and, until the World War of 1914–1918, its main duties were the creation and maintenance of a map collection and the acquisition of geographical data of foreign countries. The survey and mapping innovations made during the war greatly enlarged the remit of what was now termed the Geographical Section General Staff (MI4). This paper outlines the work of MI4 in the inter-war years taking account of the principal personalities involved, and traces the controversial background to the creation in 1943 of the Directorate of Military Survey — the immediate predecessor of the DGIA.  相似文献   

18.
1 IntroductionAtpresent,KingGeorgeIsland (KGI)isoneofthemostfrequentedsitesinAntarctica .Intotal,9permanentresearchstationsareinoperationandseveralresearchcabinshavebeenconstructed .DuetotheeasyaccessviatheChileanairstripthenum beroftheisland’sinhabitantsr…  相似文献   

19.
The objective of the present study, developed in a mountainous region in Brazil where many landslides occur, is to present a method for detecting landslide scars that couples image processing techniques with spatial analysis tools. An IKONOS image was initially segmented, and then classified through a Batthacharrya classifier, with an acceptance limit of 99%, resulting in 216 polygons identified with a spectral response similar to landslide scars. After making use of some spatial analysis tools that took into account a susceptibility map, a map of local drainage channels and highways, and the maximum expected size of scars in the study area, some features misinterpreted as scars were excluded. The 43 resulting features were then compared with visually interpreted landslide scars and field observations. The proposed method can be reproduced and enhanced by adding filtering criteria and was able to find new scars on the image, with a final error rate of 2.3%.  相似文献   

20.
The British Cartographic Society has been in existence for 50 years. During that time it has sought to pursue its central aim of promoting the art and science of cartography through a variety of publications and events to its members and beyond. The Society has been on a journey of continual development in response to the way maps are created and used. In this short history we touch on some of the factors that have influenced its evolution and what the future may hold.  相似文献   

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