Spatial and temporal characteristics of precipitation using an extensive network of ground gauge in the Korean Peninsula     

Kyung-Ja Ha  Eun-Hee Jeon  Hyun-Mi Oh 《Atmospheric Research》2007,86(3-4):330-339

The aim of the present study is to investigate the spatial and temporal structures of precipitation over the Korean Peninsula using extensive AWS (automatic weather stations) observation network data for the summertime from May to September. Additionally TRMM/PR precipitation data in the southern part of peninsula was used to investigate the vertical structure. For the spatial and temporal scales of hourly precipitation, the e-folding threshold approach was employed to cut off the correlation in terms of distance in km and time in hours. From a correlation analysis of AWS precipitation in terms of time and space, it was found out that the e-folding distance and e-folding time in correlation coefficients ranged from 50 km–110 km and 1 h–2 h. The shortest distance and time in e-folding values were found to be in July and August. Precipitation structures in May and September tended to be isotropic, a cell-type structure, and those of July and August had an apparent band type, from the southwest to northeast. In the case of the vertical feature of precipitation, the correlation with height showed that the vertically efficient height was within 5 km as convective rain cells with a monthly difference of 1.2 km. In this study, the coastal effect tended to slightly increase threshold values.  相似文献   

Wave propagation in transversely isotropic and periodically layered isotropic media     

Joseph Ha 《Geophysical Journal International》1986,86(2):635-650

Summary. A set of stable algorithms for computing synthetic seismograms in attenuating transversely isotropic media is presented. The structures of these algorithms for anisotropic media are formally equivalent to their counterparts for isotropic media. The seismic responses of a periodically layered isotropic medium are compared with those of its long-wave equivalent transversely isotropic medium. The synthetics for the two media show observable differences in the range of frequencies considered. The differences are small in the P -waves, but partly large in later arrivals.  相似文献   

末次冰期以来中国季风区西北边缘沙漠演化研究   总被引：26，自引：0，他引：26       下载免费PDF全文

高尚玉  王贵勇  哈斯  苏志珠 《第四纪研究》2001,21(1):66-71

我国季风区西北边缘的沙漠是全球中纬度敏感带的重要组成部分.本文选取区内的毛乌素沙地、共和沙地和腾格里沙漠,通过对末次冰期以来地层年代学、沉积相和地层空间分布的研究,重点探讨了末次冰期和全新世时期两个特征时段的沙漠演化.其中末次冰期是沙漠的持续发展、扩张期,奠定了沙漠的空间格局;全新世早期沙漠总体趋于固定、缩小,中期沙漠大部处于固定、缩小状态,晚期沙漠有所扩大,但未达到末次冰期的最大规模.  相似文献   

新疆齐求Ⅰ金矿床毒砂找矿矿物学研究   总被引：2，自引：0，他引：2  

胡大干 《矿物学报》1991,11(1):70-77

所研究的毒砂有两个成矿阶段。早期成矿阶段结晶的毒砂不含金，晶体形态为菱形短柱状以及由此组成的双晶；晚期成矿 毒砂富含, 长柱状，毒砂成分中Fe/(S As)>0.5,As/Sb>1000，显微硬度值低于1000kg/mm^2是其含金的标型特征之一。毒砂皆属电子心型半导体，其热电系数与金矿化之间的关系目前尚不十分清楚，但是在同一粒级中，存在着热电系数愈大，含矿性愈好的趋势。  相似文献   

Isotopic abundances of water of crystallization of gypsum from the Miocene evaporite formation,Carpathian Foredeep,Poland     

S. Hałas  H.R. Krouse 《Geochimica et cosmochimica acta》1982,46(2):293-296

For sulfates of Miocene evaporites in the Carpathian Foredeep, the waters of crystallization of gypsum (w.c.g.) have $\text{δD = ?38 to ?113\%.}$ and $\text{δ}{}^{18}\text{O = 0 to ?11\%.}$ (SMOW). The $\text{δ}{}^{34}\text{S}$ and $\text{δ}{}^{18}\text{O}$ values of the sulfates are uniform and consistent with a marine origin. It is proposed that the original w.c.g. was equilibrated with marine water. Subsequently, it re-equilibrated towards very isotopically light water (δD ～ ?100%., δ¹⁸O ～ ?14%) during a glacial or postglacial period and is now trending towards current waters circulating through the deposits (δD ～ ?50%., δ¹⁸ ～ ?7%). The extent of reequilibration increased with decreasing crystal size.  相似文献   

临汾盆地的现代构造活动          下载免费PDF全文

胡惠民  黄立人  王纪尧 《地震工程学报》1987,9(4):88-90,83

临汾盆地位于山西省中南部,属山西断陷盆地之一,也是强震集中带,历史上曾发生过两次八级强震。本文着重讨论临汾盆地地壳形变特征和近期断裂活动强度及其活动方式,为进一步研究临汾盆地近期地震危险性提供一些依据。1.构造基本特征临汾盆地的范围北以近东西向什林断裂为界,南与北东东向展布的紫金山断裂相接,东  相似文献   

The diffusion of smoke gases from factory chimneys and its meteorological conditions     

Milan Hašek 《Studia Geophysica et Geodaetica》1964,8(1):82-96

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黄河宁蒙段河道过流能力     

白涛  哈燕萍  马盼盼  麻蓉  畅建霞 《中国沙漠》2018,38(5):1093-1098

宁蒙段河道过流能力过低是威胁黄河上游洪凌安全的关键因素,也是宁蒙河段水沙调控的重要影响因素。通过水位-流量关系曲线法确定了过流能力,对现状过流能力与历史过流能力进行对比分析,探讨了造成宁蒙河段河道过流能力过低的原因。结果显示：宁蒙河段自建站以来有剧烈的河床抬高和过流能力下降现象;宁蒙河段各断面的现状过流能力由5 200~6 200m³·s^-1降至1 500~2 200m³·s^-1,部分断面超过1 500m³·s^-1就会导致漫滩,过流能力大大降低。提出建设标准化堤防,提高宁蒙河段河道的过流能力;以标准化堤防为前提获得了宁蒙河段各断面的最大过流能力。  相似文献   

Landslide Hazard Assessment Using Random SubSpace Fuzzy Rules Based Classifier Ensemble and Probability Analysis of Rainfall Data: A Case Study at Mu Cang Chai District,Yen Bai Province (Viet Nam)     

Binh Thai Pham  Dieu Tien Bui  Ha Viet Pham  Hung Quoc Le  Indra Prakash  M. B. Dholakia 《Journal of the Indian Society of Remote Sensing》2017,45(4):673-683

Landslide hazard assessment at the Mu Cang Chai district; Yen Bai province (Viet Nam) has been done using Random SubSpace fuzzy rules based Classifier Ensemble (RSSCE) method and probability analysis of rainfall data. RSSCE which is a novel classifier ensemble method has been applied to predict spatially landslide occurrences in the area. Prediction of temporally landslide occurrences in the present study has been done using rainfall data for the period 2008–2013. A total of fifteen landslide influencing factors namely slope, aspect, curvature, plan curvature, profile curvature, elevation, land use, lithology, rainfall, distance to faults, fault density, distance to roads, road density, distance to rivers, and river density have been utilized. The result of the analysis shows that RSSCE and probability analysis of rainfall data are promising methods for landslide hazard assessment. Finally, landslide hazard map has been generated by integrating spatial prediction and temporal probability analysis of landslides for the land use planning and landslide hazard management.  相似文献   

Mechanism of two rapid and long-runout landslides in the 16 April 2016 Kumamoto earthquake using a ring-shear apparatus and computer simulation (LS-RAPID)   总被引：3，自引：3，他引：0  

Khang Dang  Kyoji Sassa  Hiroshi Fukuoka  Naoki Sakai  Yuji Sato  Kaoru Takara  Lam Huu Quang  Doan Huy Loi  Pham Van Tien  Nguyen Duc Ha 《Landslides》2016,13(6):1525-1534

Around hundred landslides were triggered by the Kumamoto earthquakes in April 2016, causing fatalities and serious damage to properties in Minamiaso village, Kumamoto Prefecture, Japan. The landslides included many rapid and long-runout landslides which were responsible for much of the damage. To understand the mechanism of these earthquake-triggered landslides, we carried out field investigations with an unmanned aerial vehicle to obtain DSM and took samples from two major landslides (Takanodai landslide and Aso-ohashi landslide) to measure parameters of the initiation and the motion of landslides. A series of ring-shear tests and computer simulations were conducted using a measured Kumamoto earthquake acceleration record from KNet station KMM005, 10 km west of Aso-ohashi landslide. The research results supported our assumed mechanism of sliding-surface liquefaction for the rapid and long-runout motion of these landslides.  相似文献