1998长江大水期间对流云团活动特征研究   总被引：17，自引：0，他引：17  

师春香  江吉喜  方宗义 《气候与环境研究》2000,5(3):279-286

运用1998年6～8月逐日逐时GMS辐射亮度温度TBB资料,统计和分析了长江流域4个大暴雨时段中各自中尺度对流云团活动的一些主要特征,指出长江流域的这场罕见大水是在特定的环流形势下,由315个β中尺度和α中尺度对流云团直接造成的.与此同时,对7月21～22日发生在武汉及其以东黄冈地区的特大暴雨作了较详细的分析,发现它是由4次强对流云团形成发展及向西传播造成的,并指出低空强西南风急流与切变线及特定的地形条件是对流云团形成和发展的根本原因.  相似文献   

瞬变电磁法在煤矿水患区预测中的应用   总被引：1，自引：0，他引：1  

姚馨  雷忠林 《中国煤炭地质》2008,20(4):67-68

在青杠林煤矿工作中,利用MSD-1脉冲瞬变电磁仪,选用100m×100m正方形重叠回线装置,观测时窗8～25920μs,采样道数40道进行数据采集。经数据处理,获得该区多测道剖面图及虚拟全区视由阻率剖面图,从中解释其含水岩溶管道3处,含水岩溶空洞2处,节理、裂隙5条。根据依照水患危险程度划分标准该区岩溶管道、空洞的位置及节理、裂隙的贯穿深度,将该区定为中等程度隐患预测区。  相似文献   

AVHRR 资料在大庆地区受灾耕地与春季可播种耕地分析中的应用     

王育光  项忠南  张金喜  韩英 《黑龙江气象》2001,(2):18-20

应用AVHRR资料，在形成土地利用分类图的基础上，判定耕地的受灾范围，同时在春播前通过增处理，进一步判别可播种耕地，提交决策依据。  相似文献   

鄂尔多斯盆地陇东地区三叠纪最大湖泛期沉积物稀土元素地球化学特征及其物源意义     

范萌萌  李文厚  卜军 《地质通报》2016,35(203):390-397

上三叠统延长组长7沉积时期为鄂尔多斯盆地的最大湖泛期,对陇东地区及盆地周缘古陆的岩石样品进行稀土元素地球化学分析,发现研究区泥岩样品特征与大陆上地壳一致,其稀土元素配分模式与盆地北—东北缘阴山大青山、西南缘陇西古陆、西北缘阿拉善古陆和南缘秦岭的古老岩浆岩和变质岩的稀土元素配分模式基本一致,与东缘吕梁山古老花岗岩则极度不同。研究认为,研究区沉积物源岩主要来自于上地壳,以长英质岩石为主,长7时期周缘古陆均为湖盆提供物源,而吕梁山当时并未隆起,不提供物源。  相似文献   

钱塘江下切河谷充填及其层序地层学特征   总被引：20，自引：0，他引：20  

张桂甲  李从先 《海洋地质与第四纪地质》1995,15(4):57-68

钱塘江口是世界著名的强潮型河口湾。平面上呈典型的喇叭状，具明显的三分性：上部的正常河流段、中部的河口湾漏斗、下部的口门带。据沉积作用和沉积相组合，钱塘江河口湾的形成及其发育可以分为四个阶段：（１）末次冰期（２００００－１５０００ａＢ，Ｒ）──下切河谷形成；（２）冰后期早期海侵（１５０００－７５００ａＢ，Ｐ．）─－河口湾充填；（３）最大海侵（７５００－６０００ａＢ．Ｐ．）──海湾形成；（４）海面相对稳定期（６０００ａＢ．Ｐ．至今）──河口湾发育。其间形成了一套完整的海退－海侵进积旋回沉积层序。下切河谷底部的厚度异常的河床相砂砾层，从形成阶段上看，可以分为两个阶段，早期是河流下切的滞留沉积，晚期是基面抬升河流加积作用形成，它们的界限即为初次海泛面。加积作用形成的河床相砂砾层，有别于滞留沉积作用形成的河床相砂砾层，前者具加积副层序组合、向上变细的正粒序，且形成的地质年代较晚。  相似文献   

The June 2013 Alberta Catastrophic Flooding Event: Part 1—Climatological aspects and hydrometeorological features          下载免费PDF全文

A. Q. Liu  C. Mooney  K. Szeto  J. M. Thériault  B. Kochtubajda  R. E. Stewart  S. Boodoo  R. Goodson  Y. Li  J. Pomeroy 《水文研究》2016,30(26):4899-4916

In June 2013, excessive rainfall associated with an intense weather system triggered severe flooding in southern Alberta, which became the costliest natural disaster in Canadian history. This article provides an overview of the climatological aspects and large‐scale hydrometeorological features associated with the flooding event based upon information from a variety of sources, including satellite data, upper air soundings, surface observations and operational model analyses. The results show that multiple factors combined to create this unusually severe event. The event was characterized by a slow‐moving upper level low pressure system west of Alberta, blocked by an upper level ridge, while an associated well‐organized surface low pressure system kept southern Alberta, especially the eastern slopes of the Rocky Mountains, in continuous precipitation for up to two days. Results from air parcel trajectory analysis show that a significant amount of the moisture originated from the central Great Plains, transported into Alberta by a southeasterly low level jet. The event was first dominated by significant thunderstorm activity, and then evolved into continuous precipitation supported by the synoptic‐scale low pressure system. Both the thunderstorm activity and upslope winds associated with the low pressure system produced large rainfall amounts. A comparison with previous similar events occurring in the same region suggests that the synoptic‐scale features associated with the 2013 rainfall event were not particularly intense; however, its storm environment was the most convectively unstable. The system also exhibited a relatively high freezing level, which resulted in rain, rather than snow, mainly falling over the still snow‐covered mountainous areas. Melting associated with this rain‐on‐snow scenario likely contributed to downstream flooding. Furthermore, above‐normal snowfall in the preceding spring helped to maintain snow in the high‐elevation areas, which facilitated the rain‐on‐snow event. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Vertical surface water–groundwater exchange processes within a headwater floodplain induced by experimental floods          下载免费PDF全文

Erich T. Hester  Christopher R. Guth  Durelle T. Scott  Charles N. Jones 《水文研究》2016,30(21):3770-3787

Restoring hydrologic connectivity between channels and floodplains is common practice in stream and river restoration. Floodplain hydrology and hydrogeology impact stream hydraulics, ecology, biogeochemical processing, and pollutant removal, yet rigorous field evaluations of surface water–groundwater exchange within floodplains during overbank floods are rare. We conducted five sets of experimental floods to mimic floodplain reconnection by pumping stream water onto an existing floodplain swale. Floods were conducted throughout the year to capture seasonal variation and each involved two replicate floods on successive days to test the effect of varying antecedent moisture. Water levels and specific conductance were measured in surface water, soil, and groundwater within the floodplain, along with surface flow into and out of the floodplain. Vegetation density varied seasonally and controlled the volume of surface water storage on the floodplain. By contrast, antecedent moisture conditions controlled storage of water in floodplain soils, with drier antecedent moisture conditions leading to increased subsurface storage and slower flood wave propagation across the floodplain surface. The site experienced spatial heterogeneity in vertical connectivity between surface water and groundwater across the floodplain surface, where propagation of hydrostatic pressure, preferential flow, and bulk Darcy flow were all mechanisms that may have occurred during the five floods. Vertical connectivity also increased with time, suggesting higher frequency of floodplain inundation may increase surface water–groundwater exchange across the floodplain surface. Understanding the variability of floodplain impacts on water quality noted in the literature likely requires better accounting for seasonal variations in floodplain vegetation and antecedent moisture as well as heterogeneous exchange flow mechanisms. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

埕北油田聚合物的筛选与性能评价     

刘义刚  ;山金城  ;卢祥国  ;赵兰兰 《海洋地质译丛》2009,(2):38-41

埕北油田具有原油黏度高、油层渗透能力强和非均质性严重等特点,水驱开发效果差,剩余油储量大。目前,埕北油田综合含水90%,采出程度30%左右,而生产平台工作时间已达到设计使用寿命,急需高效、快速的开发技术。针对埕北油藏地质、流体性质和开发现状,利用室内仪器检测和理论分析方法,开展了聚合物筛选和聚合物性能评价,利用模糊综合评判方法对聚合物进行了优选,推荐使用中国石油大庆炼化公司生产＂抗盐＂和＂超高＂部分水解聚丙烯酰胺。  相似文献   

城市建设对暴雨内涝空间分布的影响研究——以武汉市主城区为例     

赵丽元  韦佳伶 《地理科学进展》2020,39(11):1898-1908

城市内涝灾害频繁,用地开发与空间扩张被普遍认为是其致因之一。对比武汉市遥感数据,1984—2017年,超过30%的自然水体被填占开发,城市建设开发活跃、填湖造陆强度大。论文以武汉市为例,采用二项Logistic模型,定量分析不同降雨强度情景下的内涝影响因素。研究表明,填湖造陆将极大地增加极端降雨情景下城市滨水区域的内涝风险。城市地形地势、排水管网条件、用地类型以及邻域用地结构等因素,也直接影响内涝风险。基于2种不同的用地开发策略,预测城市内涝风险结果显示,城市用地的不当开发将引致严重内涝风险。依据内涝风险的空间分布预测结果,论文提出了相应的改善策略,以为科学地制定防涝减灾规划提供参考。  相似文献   

Assessment of annual high‐water events for the Mackenzie River basin,Canada     

Laurent P. de Rham  Terry D. Prowse  Spyros Beltaos  Martin P. Lacroix 《水文研究》2008,22(18):3864-3880

River ice break‐up is known to have important morphological, ecological and socio‐economic effects on cold‐regions river environments. One of the most persistent effects of the spring break‐up period is the occurrence of high‐water events. A return‐period assessment of maximum annual nominal water depths occurring during the spring break‐up and open‐water season at 28 Water Survey of Canada hydrometric sites over the 1913–2002 time period in the Mackenzie River basin is presented. For the return periods assessed, 13 (14) stations are dominated by peak events occurring during the spring break‐up (open‐water) season. One location is determined to have a mixed signal. A regime classification is proposed to separate ice‐ and open‐water dominated systems. As part of the regime classification procedure, specific characteristics of return‐period patterns including alignment, and difference between the 2 and 10‐year events are used to identify regime types. A dimensionless stage‐discharge plot allows for a contrast of the relative magnitudes of flows required to generate maximum nominal water‐depth events in the different regimes. At sites where discharge during the spring break‐up is approximately one‐quarter or greater than the magnitude of the peak annual discharge, nominal water depths can be expected to exceed those occurring during the peak annual discharge event. Several physical factors (location, basin area, stream order, gradient, river orientation, and climate) are considered to explain the differing regimes and discussed relative to the major sub‐regions of the MRB. Copyright © 2008 John Wiley & Sons, Ltd and Her Majesty the Queen in right of Canada.  相似文献