Spatial analysis of public health facilities in Riyadh Governorate,Saudi Arabia: a GIS-based study to assess geographic variations of service provision and accessibility     

Shawky MANSOUR 《地球空间信息科学学报》2016,19(1):26-38

Much attention has been given to address public health policy in Saudi Arabia, particularly for the management, quality, and coverage issues. However, assessment of spatial patterns, distribution, and provision of public health services has been neglected. This paper analyzes the availability and accessibility of public health facilities across Riyadh Governorate, Saudi Arabia at the subnational level. Spatial and attribute data of public health facilities potentially have been analyzed using GIS to produce accurate measure of accessibility. The spatial pattern of service distribution was examined using average nearest neighbor. Distances from demand points (populations) to providers (facilities) were calculated for each district using near analysis. In addition, the ratios of public health facility to population were calculated to identify underserved and overserved areas. The findings clearly indicate that the spatial pattern of the distribution of public health facilities was significantly clustered (p value < 0.001) with Z-score of ?10.9. Several districts within the central parts of the governorate were identified as having a higher density of facilities, while most of districts that are located in the marginal parts exhibit very low density of health facilities. Overall, there was a considerable variation in the average distance from district centroids to health facilities. Substantially, less than half of the population (45.4%) living in 61 districts has access to public health facility within less than 1-km distance. In contrast, the greatest increase in distances was observed for 6% of population living in 38 districts. People that live in such districts need to travel long distances for public health care. The output of this analysis can assist policy-makers and authorities of Riyadh Governorate in planning public health delivery.  相似文献   

Integrated geophysical survey on the ancient Deák Ferenc Sluice of Hungary     

Ali Ismet Kanli  Zsolt Pronay  Peter Tildy  Endre Toros  Boriszlav Neducza  Peter Nagy 《Acta Geophysica》2018,66(6):1397-1411

The west channel of the ancient Deák Ferenc which was constructed in 1875 in Hungary was used for controlling the water amount and the east channel was used for the shipping. In the study, four geophysical nondestructive methods were used to this old channel which needs the restoration and reinforcement works. The high-frequency seismic and acoustic measurements were carried out, the resistivity measurements were carried out to map the resistivity distribution of the slab, the seismic direct wave method was used to map the seismic velocities for understanding the stability conditions of the walls and the ground penetrating radar measurements were carried out on the slab and on the walls. The results of integrated study showed us that voids, faults and cracks were detected and the inhomogeneous construction materials were used in the slab. The obtained results emerged that the usage of nondestructive geophysical methods is essential in all stages of restoration and reinforcement works, especially for the ancient structures.  相似文献   

The gravitational potential and its derivatives for the prism   总被引：24，自引：12，他引：12  

D. Nagy  G. Papp  J. Benedek 《Journal of Geodesy》2000,74(7-8):552-560

 As a simple building block, the right rectangular parallelepiped (prism) has an important role mostly in local gravity field modelling studies when the so called flat-Earth approximation is sufficient. Its primary (methodological) advantage follows from the simplicity of the rigorous and consistent analytical forms describing the different gravitation-related quantities. The analytical forms provide numerical values for these quantities which satisfy the functional connections existing between these quantities at the level of numerical precision applied. Closed expressions for the gravitational potential of the prism and its derivatives (up to the third order) are listed for easy reference. Received: 18 August 1999 / Accepted: 15 June 2000  相似文献   

A stability study of Kuiper Belt binaries     

I. Nagy  . Süli  B. rdi 《Astronomische Nachrichten》2007,328(8):797-800

The dynamical structure of the orbital element space of seven Kuiper Belt binary systems is studied by numerical methods in the model of the spatial elliptic restricted three‐body problem. It is shown that three systems have an extended region of stability where additional satellites could exist. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

Hydrocarbons in the surficial sediments of Lakes St. Clair,Erie, and Ontario     

E. Nagy  P. Mudroch  A. Mudroch  R. L. Thomas 《Environmental Geology》1984,6(1):31-37

Although the long-term effects and the fate of petroleum hydrocarbons in marine and freshwater environments are not fully understood, it is generally recognized that much of the oil released by accidental spills or by various land sources ends up in the sediment where it may remain for at least several years The present study was undertaken to collect some initial data on the hydrocarbon concentrations in surficial sediments of lakes St Clair, Erie, and Ontario The distribution of hydrocarbons in these lakes followed the general patterns found for a number of contaminants, in that the distribution tended to coincide with the outlines of the sedimentary basins The highest concentrations were found in the Western Basin of Lake Erie and in the inshore zone around the west end of the lake, suggesting major inputs from the Detroit River Apart from some spots of high concentration around known dumping grounds, the concentrations gradually diminish toward the east The distribution pattern in Lake Ontario may be more readily ascribed to water circulation patterns than to any specific source around the lake The hydrocarbon levels were found to be significantly lower than those in Lake Erie in Lake St Clair only trace quantities of hydrocarbons were found, suggesting either low inputs or low sedimentation/accumulation rates due to its shallowness Although the present survey was limited to the top 3 cm of the sediments, the resulting distribution patterns indicate the western end of Lake Erie as the area with the heaviest hydrocarbon loadings The results may also facilitate the selection of specific areas where core sampling coupled with more complete analysis of the extracts could yield significant information on the long-term accumulation of anthropogenic hydrocarbons, and on their persistence and transformations in Great Lakes sediments  相似文献   

A study of the upward continuation of gravity data from a plane surface     

M. K. Paul  D. Nagy 《Studia Geophysica et Geodaetica》1972,16(4):414-414

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A crustal suture and lineament in North Africa — reply     

Richard M. Nagy  Mohamed A. Ghuma  John J.W. Rogers 《Tectonophysics》1977,40(3-4):380-382

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Planning regional development: Promoting small settlements in a trans-frontier situation     

Erika Nagy  David Turnock 《GeoJournal》2000,50(2-3):255-271

Under communism local authorities tended to be largely passive bystanders in a regional development process which emerged through the central planning process through the spatial allocations of investment by government ministries. Attention was given to physical planning, but comparatively little material entered the public domain on location policy and spatial priorities generally, apart from the objective of greater equality between regions and a commitment to backward areas generally. Now that much investment is down to private enterprise and government has become more decentralised and accountable, there is a need for concepts and strategies to coordinate public sector investment and provide guidelines for the evaluation of private development proposals. At the same time, there is an open competition for investment which requires communities to promote themselves in terms of their identity and development potential. This paper offers an overview by taking two countries - Hungary and Romania - where progress can be compared and where the focus can be placed on a common frontier which is diverting attention from conventional regional planning to cross-border cooperation. In both contexts however, attention is given to the ways in which planning can divert investment away from the main centres to the peripheral areas, including action to strengthen the role of small towns and also to improve cohesion among functionally-related groups of settlements and communes. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Effects of urbanization on stream hydrology and water quality: the Florida Gulf Coast     

R. Chelsea Nagy  B. Graeme Lockaby  Latif Kalin  Chris Anderson 《水文研究》2012,26(13):2019-2030

At the global scale, the population density of coastal areas is nearly three times that of inland areas, and consequently, land development represents a threat to coastal ecosystems. It is critical to understand how increasing urbanization affects coastal watersheds. To that end, the objective of this study was to examine the influence of urban development on stream water quality and hydrology in a coastal setting, a scenario that has received less attention than other physiographic regions. Stream hydrologic, physicochemical, and microbial data were collected in watersheds near Apalachicola, Florida with a range of impervious surfaces from 0 to 15%. Watersheds with greater impervious cover exhibited higher pH, specific conductance, and temperature, elevated nutrient concentrations and loads (, and total phosphorus), higher bacterial concentrations (fecal coliform and Escherichia coli), and increased maximum flow and hydrograph flashiness. Different responses to development here compared to other physiographic regions included lower total suspended solid concentrations, higher total dissolved solid concentrations, and a lack of response of base flow to increased urbanization. Additionally, Na⁺ and Cl^? concentrations were elevated to a greater extent than is often the case in non‐coastal areas. In the coming years, urban development is projected to increase substantially in coastal zones and thus there is risk of further stream degradation in coastal watersheds. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Organic solids produced by electrical discharge in reducing atmospheres: Tholin molecular analysis     

B.N. Khare  Carl Sagan  John E. Zumberge  Deborah S. Sklarew  Bartholomew Nagy 《Icarus》1981,48(2):290-297

The complex dark brown solid of a class called tholins, produced on passage of an electrical discharge through a roughly equimolar mixture of methane and ammonia with 2.6% water vapor, is analyzed by vacuum pyrolysis followed by gas chromatography and mass spectrometry. Pyrolyzates include a wide range of aliphatic and aromatic nitriles, alkanes, aromatic hydrocarbons, pyrrole, and pyridine. This tholin is remarkably stable to 950°C. It and its degradation products are candidate constituents of planetary aerosols in the outer solar system and of the grains in the interstellar medium.  相似文献