内江洪涝特点及成因分析

本文利用1961～2005年内江各市(区)县气象资料,分析了我市洪涝的特点、气候规律,进而探讨了形成洪灾的主要成因,提出了防御洪涝的对策建议.     

南海及周边地区TBB季节内振荡及其与ENSO的联系

文中利用1980～1997年TBB资料,采用小波变换分析方法,对南海及周边地区季节内振荡(ISOs)进行了诊断分析。结果表明:南海及菲律宾以东洋面TBB具有相似的ISOs特征,其年变化表现为单峰型,夏秋季强,冬春季弱,而孟加拉湾地区的ISOs有所不同,呈双峰型,峰值出现5月和11月。南海地区ISOs的周期结构具有复杂性,主要有两个周期段,即以53.8d为峰值的50～70d振荡(ISO1)和以32d为峰值的13～36d振荡(ISO2)。南海地区ISO1的年际变化与周边地区(孟加拉湾、菲律宾以东洋面以及南半球澳大利亚与印度尼西亚之间洋面)ISO1的年变化有显著的正相关,说明这种ISO1的年变化为较大范围的区域现象;而南海地区ISO2的年际变化与周边地区相关性不显著,为局地现象。影响南海地区ISOs的传播具有多向性,ISO1以东传为主,ISO2以西传为主,它们都具有北传的特征。可见,南海地区ISOs既受到来自赤道地区的影响,也受到来自西太平洋和孟加拉湾的影响,同时南海地区局地也可以生成强烈对流活动,从而使得南海地区对流的ISOs变得复杂化。统计结果发现,ENSO与ISO1有密切的联系,但对ISO2的影响不明显。ENSO对ISO1的影响不但表现在南海地区,对孟加拉湾和菲律宾以东洋面上的ISO1有更加明显影响作用,负相关表明ENSO冷事件发生时上述地区ISO1受到压制。可以推测,ENSO通过对热带大气环流(特别是副热带高压)的影响来对南海及周边地区ISO1进行调制。     

青海贵德盆地晚新生代沉积演化与青藏高原北部隆升

青海贵德盆地发育巨厚的新生代地层,并含较丰富的重要哺乳动物化石,对确定盆地及周边相似地层的年代和研究高原隆升过程具有重要的科学意义。本文结合哺乳动物采用典型剖面精确古地磁测年为基础的时间框架,对近11 Ma BP以来盆地沉积相进行了分析,划分出19个沉积岩相和湖泊、三角洲、辫状河流、水下扇三角洲和水上洪积扇5个沉积环境,以及8个沉积演化阶段。通过盆地沉积对构造隆升的响应探讨表明:>11～7.65Ma BP为高原构造稳定期,7.65～3.6Ma BP高原具阶段性逐步隆升构造特征,3.6～>2.6 Ma BP为高原整体快速隆升,2.6Ma BP左右高原大规模挤压断陷,1.8 Ma BP左右高原大规模整体快速隆升并使贵德盆地古湖被切穿排干,黄河在此诞生。     

天津港驴驹河附近海域的浮游植物与赤潮植物

于 2 0 0 3年 7月在天津港驴驹河附近海域设 5个点采样。鉴定表明 ,共有浮游植物 19属 31种 ;优势种类有星脐圆筛藻 (Coscinodiscusasteromphalus)、太阳双尾藻 (Ditylumsol)、菱形海线藻 (Thalassionemanitzschioides)、链状亚历山大藻 (Alexandriumcatenella)等。天津港浮游植物密度较高 ,各站点平均总生物量为 1.2 16× 10 5个 /m3,各站点生物量与叶绿素含量变化规律基本一致。经单项营养指数和营养状态综合指数分析表明 ,除一个站点的COD和两个站点的无机磷略高外 ,所有站位均未达到富营养化水平。调查期间 ,共发现赤潮生物 14种 ,其中主要有星脐圆筛藻、链状亚历山大藻、叉状角藻 (Ceratium furca)、窄隙角刺藻(Chaetocerosaffinis)等。     

莱州湾南岸中全新世聚落遗址时空分布特征及其环境背景

基于ArcGIS10.3平台对莱州湾南岸中全新世聚落遗址的高程、坡度、坡向、濒河度等指标进行分析,得出该时期聚落遗址的时空分布及演变特征,并结合全新世莱州湾南岸的环境背景,探讨全新世环境演变对聚落遗址分布及演变的影响。研究表明：① 全新世莱州湾南岸的聚落遗址数量、出现频率及在总数中的比重基本呈现明显的先增后降的倒V型（非对称）变化趋势。② 遗址高程分布具有一定的规律性,几乎所有时期的遗址点均分布于高程范围在0~29 m的地区,而大汶口文化时期遗址高程分布范围为10~29 m。从坡度来看,聚落遗址主要分布于坡度范围在0~4°的平缓地区;从坡向来看,古人大多集中在南向、东南向和西南向的位置。后李文化至龙山文化时期,河流对聚落选址的影响程度逐渐降低。③ 8.5~6.9 ka B.P.气候总体进入温暖期,且冷暖波动,干湿交替,后李文化由此得到发展;6.9~4.5 ka B.P.出现了短暂的降温,但整体较温和,优越的自然条件促进了大汶口文化的发展;4.5~4.0 ka B.P.左右气候条件较大汶口文化时期略干,但在此基础上新石器文化仍得到进一步发展,并于龙山文化时期进入鼎盛阶段;4.0 ka B.P.左右气候突变,出现剧烈降温事件,变化幅度超出了人类的适应能力,岳石文化随之衰落。④ 海水入侵限制了人类活动,而古湖泊和古河道的形成为古人生活质量的提高创造了天然条件。     

基于变化检测的DOM与DEM数据同步更新

针对现有DOM与DEM生产模式不能满足数字城市、智慧城市信息化建设的需要和信息化测绘体系的网络化、自动化更新需求,该文提出了基于变化检测的DOM与DEM网络化同步编辑更新方法,形成一套针对变化区域的快速更新技术流程。完成了DOM与DEM网络化快速编辑更新平台的研发,基于网络并行环境实现网络化任务分发、多人员同步编辑的生产更新模式。通过丽水和平湖两个测区的生产实践,结果表明总体效率比传统生产方式提高27%左右。     

The Influences of Destruction Effects of Earthquake Faults on the Dynamic Stability of Highway Slopes

In highway projects, the common destruction effects of earthquake faults include the sand seismic liquefaction, the instability and failure of slopes. Thereinto, the dynamic instability of slopes induced by earthquake faults is most commonly seen. In order to research the influences of the destruction effects of earthquake faults on the dynamic stability of highway slopes, the distribution of previous earthquakes happening in the research area is qualitatively analyzed to establish the earthquake fault model and explore the kinematic characteristics. On this basis, representative slopes–cutting slopes in seismic damage areas are selected to calculate their earthquake response using the ABAQUS finite element program. The displacement field and acceleration output from the program are used to analyze the variation in the displacement of slope top and calculate the distribution coefficient of acceleration. Then, the stress fields output by the dynamic finite element analysis (FEA) are substituted in the genetic algorithm programmed by MATLAB to obtain the time history curves of safety factor of slopes and intelligently search the critical slip surfaces. By doing so, the changing rule of safety factor with seismic acceleration is obtained, together with the range of the safety factor of the envelope diagram of critical slip surfaces.     

Analysis of interdecadal variation of tropical Pacific thermocline based on assimilated data

1IntroductionAfterNittaandYamada(1989)andTren-berth(1990)haveinitiallydescribedthe1977climaticvariationovertheNorthPacificwithstep-likeshiftofwintermeansealevelpressurefield,thePacificinterdecadaloscillation(PDO)hasextensivelybeenstudied.TheworkaboutthecauseofPDOfromtheviewoftheNorthPacificincludesthermodynamicexplanationoflow-frequencysea-surfacetemperature(SST)affectedbyatmosphericrandomforcing(FrankignoulandHasselmann,1977),themeridionalchangeofthermaltransportbysubtropicalgyreandhen…     

Deployment and Exploration of a Gas Storage Well PatternBased on the Threshold Radius

To tackle the problem that wells that are deployed in a specific pattern based on the requirements of gas reservoir development are not suitable for gas storage,we have conducted concentrically circular injection and production simulation experiments for gas storage,discovered the existence of a threshold radius,denoted by Rt, and derived the expression for Rt.Based on the analysis and discussion results,we propose a strategy for deploying gas storage wells in specific patterns.The expression for Rt shows that it is affected by factors such as the gas storage gas production/injection time,the upper pressure limit,the lower pressure limit,the bottomhole flow pressure at the ends of injection and production,the and permeability. The analysis and discussion results show that the Rt of a gas storage facility is much smaller than the Rt for gas reservoir development.In the gas storage facilities in China,the Rt for gas production is less than the Rt for the gas injection, and Rt increases with the difference in the operating pressure and with permeability K.Based on the characteristics of Rt,we propose three suggestions for gas storage well pattern deployment:(1)calculate Rt according to the designed functions of the gas storage facility and deploy the well pattern according to Rt;(2) deploy sparser,large-wellbore patterns in high-permeability areas and denser,small-wellbore patterns in high-permeability areas;and (3)achieve the gas injection well pattern by new drilling,and the gas production well pattern through a combination of the gas injection well pattern and old wells.By assessing a gas storage facility with a perfect well pattern after a number of adjustments,we found that the Rt of the 12 wells calculated in this paper is basically close to the corresponding actual radius,which validates our method.The results of this study provide a methodological basis for well pattern deployment in new gas storage construction.