Flood simulation using the gauge‐adjusted radar rainfall and physics‐based distributed hydrologic model     

Byung Sik Kim  Bo Kyung Kim  Hung Soo Kim 《水文研究》2008,22(22):4400-4414

This paper reports the results of an investigation into flood simulation by areal rainfall estimated from the combination of gauged and radar rainfalls and a rainfall–runoff model on the Anseong‐cheon basin in the southern part of Korea. The spatial and temporal characteristics and behaviour of rainfall are analysed using various approaches combining radar and rain gauges: (1) using kriging of the rain gauge alone; (2) using radar data alone; (3) using mean field bias (MFB) of both radar and rain gauges; and (4) using conditional merging technique (CM) of both radar and rain gauges. To evaluate these methods, statistics and hyetograph for rain gauges and radar rainfalls were compared using hourly radar rainfall data from the Imjin‐river, Gangwha, rainfall radar site, Korea. Then, in order to evaluate the performance of flood estimates using different rainfall estimation methods, rainfall–runoff simulation was conducted using the physics‐based distributed hydrologic model, Vflo^?. The flood runoff hydrograph was used to compare the calculated hydrographs with the observed one. Results show that the rainfall field estimated by CM methods improved flood estimates, because it optimally combines rainfall fields representing actual spatial and temporal characteristics of rainfall. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Nearshore directional wave measurements by surface-following buoy and acoustic Doppler current profiler   总被引：1，自引：0，他引：1  

Paul A. Work   《Ocean Engineering》2008,35(8-9):727-737

Directional energy spectra of nearshore surface waves were measured for a 3-year period (2004–2007) at a site with mean depth 14 m and mean tidal range 2.1 m. Triaxys surface-following wave buoys reported hourly directional wave energy spectra and wave parameters near the offshore end of the Savannah River Entrance Channel, Georgia, USA. An acoustic Doppler current profiler (ADCP) was located beside the wave buoy for 3 months. Directional and non-directional surface wave energy spectra and the corresponding bulk wave parameters (height, period, and direction) are compared for the two systems. Most parameters derived from the spectra agree closely; the most significant differences were found at the upper and lower frequency measurement limits, where signal-to-noise ratios were lower. The wave buoy consistently reports a small amount of energy below 0.05 Hz that does not appear in the ADCP-derived spectra and does not appear to be related to the mooring system. This leads to larger mean and peak periods reported by the buoy. All directional spectra were computed using the Maximum Entropy Method for both instruments, but the buoy, with spectra derived from six independent time series, provides lower directional resolving power than the ADCP, which utilizes twelve time series. Both systems gave similar results defining mean and peak wave directions, with the primary difference being that the ADCP indicates energy to be more tightly concentrated around the peak direction.  相似文献   

空间碎片地基雷达探测综述     

杨朋翠  施浒立  李圣明 《天文研究与技术》2007,4(4):320-326

分析了空间碎片地基雷达探测的必要性和现实意义,介绍了国外有代表性的地基雷达工作概况,在此基础上,给出了描述空间碎片的轨道参量和物理参量,并对空间碎片地基雷达探测所需的关键技术进行了探讨。  相似文献   

基于四分量散射模型的多极化SAR图像分类   总被引：4，自引：2，他引：2  

张海剑  杨文  邹同元  孙洪 《武汉大学学报(信息科学版)》2009,34(1)

基于四分量散射模型提出了一种多极化SAR(synthetic aperture radar)图像非监督分类算法。与Freeman三分量散射模型不同,四分量散射模型在Freeman三分量的基础上增加了螺旋散射分量(helix),该分量反映了复杂地貌和不规则城市建筑的散射机理,可以用来处理复杂的场景图像。算法强调了初始分类的重要性,在初始分类中考虑了混合散射机制像素的存在,从而提高了分类结果的精确度。聚类过程中,采用由四个散射分量组成的特征向量进行迭代聚类。为了实现算法的完全非监督,利用特征向量给出了一种新的聚类终止准则。NASA/JPL实验室AIRSAR全极化数据分类实验结果表明,该算法具有较好的分类效果,并获得了较高的分类精度。  相似文献   

利用Radarsat-2极化雷达数据探测湿地地表特征与分类   总被引：1，自引：0，他引：1  

廖静娟  王庆 《国土资源遥感》2009,(3):70-73

利用新型的Radarsat-2极化雷达数据,结合极化雷达目标分解方法提取鄱阳湖湿地不同地表类型的极化特征量,并进行了Wishart非监督和监督分类,取得了较高的精度.研究表明,Radarsat-2卫星的全天候极化雷达成像能力将在湿地监测和制图中有较大的应用潜力.  相似文献   

雷达无损检测技术及其在钢混构（物）件质量检测中的应用效果   总被引：1，自引：0，他引：1  

张虎生  兰樟松  张炎孙  沈健 《江西地质》2001,15(1):57-60

本文从检测之系统性，科学性，准确性说明了雷达技术用于工程质量检测方面具有较大优越性，在扼要阐明雷达波在混凝土介质中的传播规律与特征的基础上，详细分析了雷达技术在无损检测混凝土构（物）件质量的分辨率，以2个无损检测工程实例，说明了该项技术在无损检测混凝土构（物）件质量的有效性和实用性。  相似文献   

新技术在城市地面沉降研究中的应用：遥感卫星雷达干涉测量（InSAR）   总被引：7，自引：0，他引：7  

陈基炜 《上海国土资源》2001,(2):45-50

本文综述了遥感卫星合成孔径雷达（SAR）干涉测量及差分干涉测量的基本原理，针对近年来国外InSAR在地面沉降方面的研究成果，重点讨论了D－InSAR在国内大中城市进行地面沉降监测应用的可能性，对SAR数据的获取方法进行了阐述，并对这种方法目前的进展及未来应用前景进行了探讨。  相似文献   

地质雷达在不同岩性介质中的应用   总被引：4，自引：2，他引：4  

李伟和  邱庆程 《物探与化探》2001,25(4):312-315

通过3个勘察实例,阐述地质雷达技术在花岗岩、石灰岩及砂岩等不同岩性介质中探测断裂、岩溶和旧开采矿坑中的应用效果。  相似文献   

应用探地雷达技术检测隧道衬砌质量   总被引：9，自引：1，他引：9  

刘敦文  黄仁东  徐国元  吕苗荣 《物探与化探》2001,25(6):469-473

介绍了应用探地雷达检测隧道衬砌质量的原理及技术,阐述了该技术的基本方法及其数据图像处理过程。老木峪隧道衬砌质量检测结果表明,应用探地雷达技术检测隧道衬砌效果良好,其衬砌厚度检测误差在 5 %之内,并能准确检测出衬砌内布筋数量,对回填层密实程度也可作出粗略估计。  相似文献   

Internal structure of a trough blowout, determined from migrated ground-penetrating radar profiles   总被引：2，自引：0，他引：2  

Adrian Neal  & Clive L. Roberts 《Sedimentology》2001,48(4):791-810

Ground‐penetrating radar (GPR) was used to investigate the relationship between the geomorphological development of a large aeolian trough blowout and the stratigraphy and internal sedimentary structure of its associated deposits. Although analogous, many of the data‐processing techniques routinely applied in seismic reflection are very rarely applied in GPR studies. In this study, a simple migration program was used that significantly enhanced the quality of GPR images from a large trough blowout at Raven Meols on the Sefton coast, northwest England. These improvements aided subsequent data interpretation, which was achieved through application of the principles of radar stratigraphy. GPR shows the pre‐blowout dunes to have a complex internal structure that suggests they were formed in the presence of at least a partial vegetation cover. Subsequent to stabilization of these dunes a thin soil developed. This dune soil forms an important radar sequence boundary and delineates a complex topography beneath the depositional lobe of the blowout. The internal structure of the depositional lobe of the blowout does not conform to a model of simple radial foreset deposition, as derived from contemporary process studies reported in the literature. Instead, the pattern of deposition has been extensively modified by the antecedent dune topography and by varying spatial and temporal exposure to important sand‐transporting winds that is partly controlled by interactions between the regional wind pattern and local dune morphology. Trough blowout deposits in coastal aeolian sedimentary sequences are likely to be recognized by the presence of laterally continuous packets of relatively high‐angle cross‐strata, which often display a spatially‐variable radial dip pattern that is only very poorly or partially developed. In addition, a soil, or other surface representing a significant hiatus in dune deposition, is likely to underlie the blowout deposits, the topography of which will show a clear relationship to the dip and orientation of the overlying cross‐strata.  相似文献