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211.
HONG‐KEY YOON 《Geographical review》2011,101(2):243-260
The geomantic idea of chosan pibo is a particular way of remedying the inadequacies of a geomantic landscape by building small mounds of earth or stones and has been a significant motivation for modifying the environment in Korea. This idea is a part of ancient Chinese geomancy, or feng shui, for determining auspicious sites. Historically, three principal geomantic means have been used to compensate for shortcomings at an auspicious site: building religious structures, such as temples; creating hills, planting trees, or changing directions of watercourses; or making other symbolic gestures, such as naming objects and places. In this article I concentrate on the second, modifying landforms to compensate for the geomantic shortcomings of a place. The quasi‐religious zeal shown by feng shui practitioners in Korea to improve the local geomantic landscape is worthy of comparing and contrasting with the European Christian idea, held by medieval monastic monks, that humanity is a partner of God in improving the environment. 相似文献
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213.
Subsurface flow plays an important role in forest catchment hydrological processes, for which a modified model is established in this paper. Firstly, by taking soil samples from Natural Preserve Forests of Changbai Mountain, two crucial parameters for subsurface flow, the saturated hydraulic conductivity and effective porosity, were measured in the laboratory. Secondly, submodels of the two parameters varying logarithmically with soil depth were established through regressive analysis. Then a modified subsurface stormflow model (Modified model) was founded by substituting the submodels into a storage–discharge model (Sloan's model), established by Sloan in 1983. Finally, to verify the Modified model, five rainfall events on a simulated hillside were carried out. The subsurface flow processes were simulated using the Modified model, Sloan's model and Robinson's model. The comparison of simulated subsurface stormflow processes using the three models respectively with measured ones showed that the Modified model obtained better accuracy for peak flow and total amount of subsurface stormflow than the other two models. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
214.
潜在蒸散发公式2种修正方法及其在闽江流域的应用研究 总被引:1,自引:0,他引:1
各类潜在蒸散发经验估算法具有区域性的特点,实际运用时需要进行修正。常用的修正方法是通过线性回归法对经验公式的计算结果进行修正,并没有将修正反映到经验公式中的系数上。本研究提出一种系数修正的方法,通过逐月误差比例校正来修正经验公式中的参数,称之为误差比例校正法。以FAO推荐的Penman-Monteith法为标准,比较经线性回归法、误差比例校正法2种方法修正前后6种经验估算法(Blaney-Criddle、Hargreaves、Hamon、Makkink、Priestley and Taylor、Rohwer)在闽江流域的计算精度,从而对误差比例校正法的修正效果及稳健性进行探讨。结果表明:逐月误差比例校正法整体上具有较好的修正效果,可以较大程度提高6种经验方法在该区域的计算精度;常用的线性回归法虽计算较误差比例校正法稍复杂,但其修正效果及稳健性略优于误差比例校正法。 相似文献
215.
基于BJ RUC系统的人影冷云催化潜力识别模式平台设计 总被引:2,自引:0,他引:2
提前准确识别冷云催化潜力,有助于提升人工影响天气作业的科学水平,是实现气象现代化的重要保障。北京市人工影响天气办公室基于BJ—RUC系统,设计研发了北京人影冷云催化潜力识别模式平台(BJ—CCSPR平台)。该平台通过后台支撑系统和前台分析系统的有机结合,具有自动处理数据监测、模式计算、人影业务产品制作与显示等功能,并能实现人机交互操作。冷云综合催化潜力指标基于BJ—RUC系统输出的三维云宏微观物理量条件、热力和动力条件设计研发,可直观地提供人影催化潜力区的空间和地域分布,具有较强的科学性和可信度。业务应用表明:该平台性能稳定,自动化程度较高,易于扩展,实用性强;与BJ—RUC系统结合,业务产品基本可以反映未来24 h内人影相关物理量场的变化情况;地基增雪和飞行增雨典型实例说明冷云综合催化潜力指标可直接服务于人影决策指挥,在实际业务中发挥重要作用。 相似文献
216.
217.
DAVID RHIND 《International journal of geographical information science》2013,27(3):229-241
Abstract This paper summarizes the numerous developments in geographical information systems (GIS) in the United Kingdom over the past few years, covering the development of systems, the creation of data bases, the elucidation of user needs, the education and training of staff and the role adopted by government. The review is organized by the different sectors now actively involved in GIS. 相似文献
218.
《自然地理学》2013,34(6):574-588
Casuarina (Casuarina equisetifolia) is a problematic invasive species within the Bahamas, associated with numerous environmental problems. Previous studies suggest casuarinas establish ecologically sterile monocultures, yet there is limited research on whether soils from casuarina-dominated sites differ physically or chemically from comparable soils under native vegetation. Because of the lack of knowledge and because this invader has the potential to be detrimental to native ecosystems, we conducted a study to examine differences in soil properties between sites where casuarinas dominated versus sites where casuarinas were absent. Soils at casuarina-dominated sites had lower potassium, phosphorus, and organic matter concentrations and had lower pH levels. But, casuarina-dominated sites had significantly higher leaf-litter abundances. No significant differences between soils were detected for calcium concentrations, magnesium concentrations, cation exchange capacity, nitrate-nitrogen concentrations, or soil moisture levels. A multivariate ordination showed that casuarina-dominated soils were more similar to one another than to non-casuarina soils. Thus, soil characteristics from casuarina-dominated areas appear to differ from comparable habitats devoid of casuarinas. There are at least two possible explanations: certain soil properties may have been more conducive to casuarina invasions, or casuarinas may have modified their soils once they became established. The results of this study provide insights into the invasion process and add to our understanding of how these invaders affect native Bahamian ecosystems. 相似文献
219.
深度衰减效应对大型地下洞室群强震响应的影响分析 总被引:1,自引:1,他引:0
介绍了大型地下洞室群强震反应分析所需要输入地震波的选用原则,重点考虑了场地的深度衰减效应,同时提出了一种假设来确定地震危险性分析提供的峰值加速度的所在位置。选用了两组攀枝花实测地震记录,同时利用三角级数叠加法综合考虑了深度衰减效应,合成了一组人工地震动,使用ABAQUS软件对某水电站大型地下洞室群进行了二维非线性强震动力时程数值计算分析。结果表明:生成的地震波能较好地模拟地下洞室群的地震响应,深度衰减对地震响应结果有明显影响,不同频谱的地震波相对位移-时程差距较大,但频谱参数的影响还有待于深入研究。研究成果对大型地下洞室群地震动输入问题研究具有一定的指导意义。 相似文献
220.
用增量动力分析方法求解人字形中心支撑钢框架的结构影响系数和位移放大系数(Ⅰ)——方法 总被引:2,自引:1,他引:1
结构影响系数是基于强度的抗震设计中确定设计地震作用的关键,也是基于性态抗震设计理论的基础。位移放大系数则是根据结构的弹性位移估算弹塑性位移的关键参数。本文采用增量动力分析方法求解结构影响系数和位移放大系数,并结合具体算例详细说明了基于增量动力分析求解结构影响系数和位移放大系数的实施步骤。该方法能反映结构的动力特征,并能考虑高阶振型对结构抗震性能的影响。 相似文献