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251.
In the early stages of economic development in Korea, national territorial planning was used as a policy tool to guide spatial structure and to provide physical infrastructure for urban and industrial development. Such a top-down approach was inevitable because Korea maintained the centralized political and government system until the early 1990s. Circumstances, however, have changed recently since the 1990s with progress in democratization and localization. In addition, forces of globalization are making significant impacts on the parameters of national territorial planning. Reflecting these changes in both internal and external conditions, the Fourth National Territorial Plan (2000–2020) has adopted a different approach from the past three territorial plans. This paper reviews the socio-economic background that necessitated such changes in approaches to national territorial planning. A major thrust of the Fourth Plan, a focus on emergent or anticipated planning issues in Korea, is discussed. Finally, the paper examines the rationale for long-term strategic planning in the highly fluctuating situation facing Korean society in the new century.  相似文献   
252.
松辽盆地南部第三系可地浸砂岩型铀矿成矿条件研究   总被引:3,自引:1,他引:3  
松辽盆地第三系可地浸砂岩型铀矿成矿地质条件前人曾从区域上作过分析,从1998年起,该区投入了大量钻探工作,进行1:20万可地浸砂岩型铀矿区调。本文在钻孔编录及剖面编制、样品分析的基础上,从岩性、岩相,岩石化学、有机质、铀含量、岩石孔隙度、砂体分布、层间氧化带发育程度及水动力条件等方面,进一步分析了该区第三系铀成矿条件。  相似文献   
253.
对“3S”集成技术的一些认识   总被引:3,自引:0,他引:3  
刘文熙 《四川测绘》1996,19(3):99-103
本文从遥感,地理信息系统和全球定位系统的产生与发展过程,论述了它们走向集成化的必然趋势,说明了“3S”信息集成技术的涵意;介绍了它的应用领域,最后提出了作者对发展我国以“3S”集成技术为支撑的地理信息产业应采取的对策的建议。  相似文献   
254.
刘玉龙  陆大道 《地理科学》1996,16(4):305-311
着重讨论一种基于灰色GM(1,1)模型及国民收入决定函数模型而建立的新组合模型。该模型建模方法简单,组合性强,并且在各模型的拟合精度提高。该模型汲取了灰色GM(1,1)模型模拟国民收入变化趋势的优点和国民收入决定函数模型模拟国民收入波动的优点,使组合模型不但在趋势上符合国民收入的发展,而且也给出了在波动方面的比较一致的模拟。  相似文献   
255.
Tempos of Elderly Age and Geographical Concentration*   总被引:1,自引:0,他引:1  
This paper presents a method to measure two types of tempos: 1) the tempo of elderly age concentration, the rate of change in the elderly proportion in a region; and 2) the tempo of elderly geographical concentration, the rate of change in a region's share of the national elderly population. The two measurements are applied to historical data for the United States. The results reveal that both tempos vary spatially and temporally. Relative tempos are also introduced to compare the indices between different age groups and regions.  相似文献   
256.
四川省青川断裂的特征及形成的物理条件   总被引:3,自引:0,他引:3  
本文详细地讨论了四川省青川断裂的断裂特征及形成的物理条件。对断裂构造岩的微构造和宏观构造进行了细致的描述分析,将断裂岩分为四个带。结合区域资料,讨论了断裂的形成时代及与邻区的关系。  相似文献   
257.
石榴石是研究区内暗色镁铁质岩、麻粒岩及片麻岩的主要造岩矿物之一。成分分 析表明,它们是含钙铝榴石分子较多的镁铝一铁铝系列石榴石,红外光谱测定其近于铁铝榴石; 穆斯堡尔谱分析表明,Fe3+含量增多将引起石榴石内六配位多面体变形程度增大;:是胞参数ao 与Ca2+含量呈正相关。本区石榴石是麻粒岩相变质作用的产物,形成的温压条件为780-840℃. 0.85-1.10 GPa。形成石榴石的反应是复杂的,其中包括角闪石与斜长石的增温脱水反应以及 紫苏辉石+斜长石组合向石榴石+革斜辉石组合转化的滑动反应。  相似文献   
258.
This paper describes meandering alluvial rivers with mean annual suspended-sediment concentrations of more than 100 kgm?3 on the Loess Plateau, China, and explains their formation as caused by the effect of hyperconcentrated water flow. When the river is dominated by hyperconcentrated flow, the rate of energy expenditure required for sediment transport declines significantly. Accordingly, the river channel adjusts itself to a lower channel gradient by increasing the river length, resulting in a meandering channel. Since the stable transportation of sediment by hyperconcentrated flow is dependent on river channel boundary conditions, the latter play an important role in the formation of meanders of this kind. The paper also discusses the conditions for the discrimination of meandering and braided rivers in this area.  相似文献   
259.
ABSTRACT

This study experiments with reservoir representation schemes to improve the ability to model active water management in the National Water Model (NWM). For this purpose, we developed an integrated water management model, NWM-ResSim, by coupling the NWM with HEC-ResSim, and two reservoir representation schemes are tested: simulation of reservoir operations and retrieval of scheduled operations. The experiments focus on a pilot reservoir domain in the Russian River basin – Lake Mendocino, California – and its contributing watershed. The evaluation results suggest that the NWM-ResSim improves the simulation performance of reservoir outflow from this managed reservoir over the NWM default level pool routing scheme. The degree of this improvement depends on the suitability of the operation guidance; the reservoir operations simulation scheme could have acceptable errors for the purposes of water resources management, but not for flood operations. Results of the retrieval scheme of scheduled operations demonstrated better performance for sub-daily flood operations.  相似文献   
260.
ABSTRACT

Spatial heterogeneity represents a general characteristic of the inequitable distributions of spatial issues. The spatial stratified heterogeneity analysis investigates the heterogeneity among various strata of explanatory variables by comparing the spatial variance within strata and that between strata. The geographical detector model is a widely used technique for spatial stratified heterogeneity analysis. In the model, the spatial data discretization and spatial scale effects are fundamental issues, but they are generally determined by experience and lack accurate quantitative assessment in previous studies. To address this issue, an optimal parameters-based geographical detector (OPGD) model is developed for more accurate spatial analysis. The optimal parameters are explored as the best combination of spatial data discretization method, break number of spatial strata, and spatial scale parameter. In the study, the OPGD model is applied in three example cases with different types of spatial data, including spatial raster data, spatial point or areal statistical data, and spatial line segment data, and an R “GD” package is developed for computation. Results show that the parameter optimization process can further extract geographical characteristics and information contained in spatial explanatory variables in the geographical detector model. The improved model can be flexibly applied in both global and regional spatial analysis for various types of spatial data. Thus, the OPGD model can improve the overall capacity of spatial stratified heterogeneity analysis. The OPGD model and its diverse solutions can contribute to more accurate, flexible, and efficient spatial heterogeneity analysis, such as spatial patterns investigation and spatial factor explorations.  相似文献   
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