利用T106数值预报产品作江西暴雨动态落区预报   总被引：1，自引：0，他引：1  

曹晓岗 《气象与减灾研究》1998,(1)

首先将江西测站的降水插值到1°×1°的经纬度网格点上,然后利用1°×1°的T106数值预报产品,对江西网格点上的暴雨送行诊断分析与相关普查,最后建立了江西暴雨动态落区预报模式和动态落区预报流程。  相似文献   

我国西部地区一些强震及中强震前后波速异常的初步研究（二）——波速异常区及其特性          下载免费PDF全文

冯德益  王周元  顾瑾平  盛国英  高世磊 《地球物理学报》1977,20(2):115-124

本文介绍了根据近地震直达波到时资料确定震前波速异常区（简称孕震区）的方法,并给出了我国西部地区某些较大地震前波速异常区（孕震区）的初步测定结果。探索并讨论了孕震区的一些基本特性,即孕震区的形状、大小,孕震区的定向,主震在孕震区内所处的部位,孕震区内部波速异常状态的分布与发展等。最后还导出了孕震区线度与震源区尺度间的关系式,并作了简单的讨论。  相似文献   

2007年红河州一次典型两高辐合区强降水过程分析     

周秀美  兰兰  侬耀辉 《云南地理环境研究》2007,(Z1)

2007年7月,红河州多受两高间辐合区影响,产生强降水,选取7月18～20日强降水过程进行分析,得出:单纯的两高辐合区并不一定能产生强降水。虽然此次过程中有深厚的西南涡从四川东南移,但强降水的触发机制并不是西南涡,而是高空冷平流,且高空冷平流具有高层强、低层弱的特点。水汽、能量条件表现出在高层随着环流背景场南移、中低层少变的特点,较强的上升运动也集中在对流层中上层。MM5对于此次过程较强降水发生的时间、区域有较好的预报能力,但降水量级偏小。  相似文献   

城市边缘区土地利用／覆盖变化过程研究——以广州市番禺区为例     

彭笃明 《湖南地质》2008,(6):58-62

以广州市1992年、2000年、2005年TM、ETM遥感影像资料为数据源，在GIs技术支持下，对处于广州市南部边缘的番禺区近13年来的土地利用／覆盖变化过程进行了定量研究。结果显示番禺区在1992～2005年间建设用地、园地、水域大幅增加，耕地大量减少，林地、未利用地有增有减；各类型之间的转化主要表现为耕地向建设用地、园地、水域大量转移；研究区土地利用程度逐年增加，范围不断扩大。表明番禺区对广州大都市的生产功能、缓冲功能、生态功能的影响力不断加大。  相似文献   

强震孕育与断层形变异常形态及时空分布特征   总被引：4，自引：4，他引：0  

刘善华  张鹤  李民 《大地测量与地球动力学》2004,24(4):48-56

分析了华北北部20世纪70年代初以来的断层形变资料。结果表明：震前断层活动存在明显的阶段性特征；短临阶段断层形变异常主要形态有两种：一种是在α、β相后的γ相短临异常，这种异常一般在近源区出现；另一种是较大幅度的突跳型短临异常，这种异常一般在远源区出现，这些都是断层形变前兆由中期过渡到短期的明显标志；断层形变短临异常有从外围向震中迁移的特征；唐山地震前出现γ相短临异常的比例高于大同和张北地震，主要表现为在中期趋势积累背景上的反向；3次强震前α、β、γ相异常场地的分布具构造控制特征；强震前场地断层异常活动存在象限性分布特征，且与震源机制解的结果基本一致。  相似文献   

全球洋底增生构造及其演化   总被引：3，自引：0，他引：3  

马宗晋  李存梯  高祥林 《中国科学D辑》1998,(2)

根据Cande等人 1 989年发表的第 3代全球洋底磁条带图 ,以增生区和增生期的概念对全球三大洋洋底增生构造进行了系统的单元划分 ,揭示了洋底构造的演化过程 .共划分出 49个增生区和 6个增生期 .发现后期增生过程对前期增生区具有裂解和楔入等改造作用 ,从整体上看 ,洋底增生过程具有全球尺度的同步性幕式特性 ,在空间分布上则有很强的非均匀性和局部的不连续性 .  相似文献   

黑龙江省海林市新兴林场一带金、多金属矿成矿规律与找矿靶区选择     

蒋世军 《黑龙江国土资源》2007,(5):47-47

黑龙江省海林市新兴林场一带地处小兴安岭-张广才岭贵金属、有色金属成矿带的南段，大地构造位置属兴凯湖-布列亚山地块区张广才岭-太平岭边缘隆起带。张广才岭边缘隆起中部，本区先后经历了张广才岭期、加里东期、印支期、燕山期的演化，地质构造背景较复杂，出露有新元古界张广才岭群、古生界、中生界及张广才岭期、印支期、燕山期侵入岩，并伴有中—低温成矿作用，变形构造以南北向线型紧密褶皱为主。  相似文献   

GIS-based landslide susceptibility zonation for roadside slope repair and maintenance in the Himalayan region     

Bhoj Raj Pantha Ryuichi Yatabe Netra Prakash Bhandary 《《幕》》2008,31(4):384-391

Roadside slope failure is a common problem in the Himalayan region as road construction activities disturb natural slopes. Therefore, landslide susceptibility zonation is necessary for roadside slope disaster management and planning development activities. In this study, we consider a 53-kin section of a major highway in Nepal where road services are suspended for several days in the monsoon season every year. A number of methods have been used for landslide susceptibility zonation. We employed a bivariate statistical approach for this study. Relevant thematic layer maps represent- ing various factors （e.g., slope, aspect, land use, lithology, drainage density, proximity to stream and proximity to road） that are related to landslide activity, have been prepared using Geographic Information System （GIS） techniques. A total of 277 landslides （covering a total of 29.90 km2） of various dimensions have been identified in the area. A landslide susceptibility map was prepared by overlaying a landslide inventory map with various parameter maps segmented into various relevant classes. The landslide susceptibility index was seg- mented into five zones, viz. very low, low, moderate, high and very high susceptibility. Landslide susceptibility zonation maps are useful tools for the efficient planning and management of roadside slope repair and maintenance tasks in the Himalayan region.  相似文献   

Impacts of Climatic Factors on Runoff Coefficients in Source Regions of the Huanghe River   总被引：4，自引：0，他引：4  

CHEN Liqun LIU Changming LI Yanping WANG Guoqiang 《中国地理科学(英文版)》2007,17(1):047-055

Runoff coefficients of the source regions of the Huanghe River in 1956–2000 were analyzed in this paper. In the 1990s runoff of Tangnaihai Hydrologic Station of the Huanghe River experienced a serious decrease, which had at- tracted considerable attention. Climate changes have important impact on the water resources availability. From the view of water cycling, runoff coefficients are important indexes of water resources in a particular catchment. Kalinin baseflow separation technique was improved based on the characteristics of precipitation and streamflow. After the separation of runoff coefficient (R/P), baseflow coefficient (Br/P) and direct runoff coefficient (Dr/P) were estimated. Statistic analyses were applied to assessing the impact of precipitation and temperature on runoff coefficients (including Dr/P, Br/P and R/P). The results show that in the source regions of the Huanghe River, mean annual baseflow coefficient was higher than mean annual direct runoff coefficient. Annual runoff coefficients were in direct proportion to annual pre- cipitation and in inverse proportion to annual mean temperature. The decrease of runoff coefficients in the 1990s was closely related to the decrease in precipitation and increase in temperature in the same period. Over different sub-basins of the source regions of the Huanghe River, runoff coefficients responded differently to precipitation and temperature. In the area above Jimai Hydrologic Station where annual mean temperature is –3.9oC, temperature is the main factor in- fluencing the runoff coefficients. Runoff coefficients were in inverse relation to temperature, and precipitation had nearly no impact on runoff coefficients. In subbasin between Jimai and Maqu Hydrologic Station Dr/P was mainly affected by precipitation while R/P and Br/P were both significantly influenced by precipitation and temperature. In the area be-tween Maqu and Tangnaihai hydrologic stations all the three runoff coefficients increased with the rising of annual precipitation, while direct runoff coefficient was inversely proportional to temperature. In the source regions of the Huanghe River with the increase of average annual temperature, the impacts of temperature on runoff coefficients be-come insignificant.  相似文献   

淮河源区中更新世黄土堆积的元素地球化学特征及其古气候意义   总被引：1，自引：1，他引：0  

刘奇  宋传中  崔王  王化可  张妍  王荻  曹宗平 《地球科学与环境学报》2007,29(4):356-361

利用地球化学元素分析方法,对淮河源区中更新世黄土、古土壤剖面含有的化学元素及多种化学元素指标进行了分析。研究表明:区内中更新世以来的气候变化,主要以湿热气候为主,淋溶及氧化作用较强;表现在气温上HT-1~HT-3的气温较低,HT-4~HT-7的气温高,HT-8的气温又相对较低,其变化趋势表现为中更新世经历了从早期寒冷转湿热转温干,中期凉干转暖湿到晚期温湿转暖湿。  相似文献