Mapping and initial dilution estimation of an ocean outfall plume using an autonomous underwater vehicle     

P.A. Ramos  M.V. Neves  F.L. Pereira 《Continental Shelf Research》2007

A monitoring mission to study the shape and estimate initial dilution of the S. Jacinto outfall plume using an autonomous underwater vehicle (AUV) was performed on July 30, 2002. In order to reduce the uncertainty about plume location and to concentrate the vehicle mission only in the hydrodynamic mixing zone, outputs of a near-field prediction model, based on effective real-time in situ measurements of current speed and direction and density stratification, were opportunistically used to specify in real time the mission transects. The surface characteristics of the outfall plume were found to be influenced strongly by the relatively weak stratification and low current velocities. Dilution was estimated using a temperature–salinity (TS-) diagram with initial mixing lines between wastewater and ambient waters. Effluent dilutions were at least 30:1 in this study. In order to efficiently map the plume dispersion we applied the least-squares collocation method technique. Our results demonstrate that AUVs can provide high-quality measurements of physical properties of effluent plumes in a quite effective manner and valuable considerations about the initial mixing processes under real oceanic conditions can be further investigated.  相似文献   

用变分法修正黑河试验数据的初步研究          下载免费PDF全文

马刚  王强  邱崇践 《大气科学》2002,26(2):271-278

为了对黑河试验观测资料进行订正,利用一个一维边界层垂直扩散模式和以拟牛顿极小化算法为基础的最优化方法建立了一个变分同化系统,其中,目标函数相对于控制变量的梯度用扰动法求取.并利用模式资料和黑河试验若干时刻的观测资料进行了一些数值试验.试验证明,将初始场变量与模式误差系数同时作为控制变量加以调整,能够有效调整初始场观测资料.并且,用变分同化方法能够较线性插值(时间、空间)方法更有效、合理的修正黑河试验观测资料场的种种缺陷.  相似文献   

基于GPS技术的农田信息采集系统的现状及展望   总被引：3，自引：0，他引：3  

刘卉 《全球定位系统》2002,27(5):33-36

基于GPS技术实现对农田信息的定位采集，是目前精细农业领域中重要应用之一，本文在分析了当前国外、国内相关农田信息采集系统现状的基础上，提出了国内研制开发基于GPS技术的农田信息采集发展思路。  相似文献   

测井曲线在地层基准面旋回划分中的应用   总被引：5，自引：0，他引：5       下载免费PDF全文

段秋梁  陈永进  陈国强  冯庆忠  赵翠霞  梁秀光 《沉积与特提斯地质》2002,22(1):35-39

利用视电阻率测井曲线的周期性对渤南海油田沙三段中上部地层进行地层基准面旋回的划分对比后发现：该旋回界面与地层基准面由上升到下降期间可容纳空间单向增加的极限位置基本一致；地层基准面旋回的划分与测井分析结合可以进行储层。特别是高渗透储层预测。  相似文献   

樊家川油田储层渗流单元分析及其剩余油分布   总被引：2，自引：0，他引：2       下载免费PDF全文

石京平  李永军  付国民 《沉积与特提斯地质》2002,22(4):50-54

樊家川油田已进入开发后期，为了精确预测层内剩余油潜力，解剖更小级别的储层非均质单元分布，在储层沉积微相研究的基础上，应用储层FZI值进行单-河流沉积单元的渗流单元划分，并讨论了成因砂体与渗流单元的关系以及渗流单元中剩余油分布规律，从而提高了剩余油预测的精度。  相似文献   

缅北中部脉金矿带控矿因素及成矿作用浅析     

何文举 《云南地质》2001,20(3):279-288

缅北中部，印缅岛弧及弧后盆地东侧、新生代造山带的前缘推覆构造带中，分布有许多脉金矿床及矿点，构成金矿带。矿带、矿田、矿床及矿体的形成、分布及其规模，受不同级别的近南北向逆冲断裂，及其间派生的北东向张性扩容断裂组成的剪切断裂带控制。可渗透的下麦尔组下部中一粗粒砂岩，起着很好的容矿作用。下麦尔组上部泥岩、细砂岩、粉砂岩和页岩互层单元，在携金热液的迁移、氧化硅的沉淀和矿质沉积定位等方面，可能起到圈闭作用。  相似文献   

Palynostratigraphy and palynofacies indications of depositional environments and source potential for hydrocarbons: the mid Cretaceous Nahr Umr and lower Mauddud formations, Iraq   总被引：1，自引：0，他引：1  

T. K. Al-Ameri  T. K. Al-Najar  D. J. Batten 《Cretaceous Research》2001,22(6):735

Palynomorphs recovered from core and cuttings samples from five boreholes in the East Baghdad Oilfield indicate a mid Albian–early Cenomanian age-range for the Nahr Umr Formation and the lower part of the overlying Mauddud Formation. Two palynomorph zones and four types of palynofacies have been identified. The latter are interpreted to indicate delta-top swamp and marsh, silty–muddy deltaic, inner silty and carbonate-rich platform, and limestone-platform environments. The palynofacies of the two types of platform accumulations suggest that these are potential sources of biogenic methane and condensates, and may yield more liquid hydrocarbons in areas where the formations are at greater depths than within the region studied.  相似文献   

GPS工程控制网的若干特殊问题   总被引：9，自引：1，他引：9  

卓健成 《测绘工程》1996,5(1):1-7

根据ＧＰＳ定位技术的优点，讨论了建立ＧＰＳ工程控制网在踏勘、设计、观测及数据处理方面的若干特殊问题，并提出高精度工程控制网ＧＰＳ数据处理方案。  相似文献   

SPECTRUM期间目标台风移动的数值试验   总被引：2，自引：1，他引：2  

罗哲贤  马镜娴  王咏青 《气象学报》1996,54(2):166-174

在目标台风Ｙａｎｃｙ的移动过程中，选择４个时段进行预报数值试验。模式初始场系根据ＳＰＥＣＴＲＵＭ和ＴＣＭ－９０加强观测资料确定。结果表明：实际大气中目标台风移动的若干特征在模式大气中能够显示出来，如Ｙａｎｃｙ在１９９０年８月２０日００时移向的转折现象等；台风非对称结构的低频振荡是产生移向转折现象的一个重要原因。  相似文献   

Field compaction control studies on road bases in a new settlement area in Ghana     

E. M. Frempong 《Geotechnical and Geological Engineering》1995,13(4):227-241

Summary Among the major causes for failure of roads in the tropics is inadequate compaction during construction. There is, therefore, the need to strictly control the compaction of the pavement layers if the design life of the road is to be attained; thereby eliminating large maintenance costs.This note reports on pavement compaction control studies undertaken on the road bases of service roads in a new settlement area in Ghana. These roads were to be provided with bituminous surfacing immediately after compaction. Studies concerning particle breakdown during field compaction by two contractors executing the works under the same conditions have been made, together with an assessment of contractor efficiency.It was found that the placement moisture contents varied greatly from the optimum. One contractor was compacting the gravels on the dry side of optimum, consequently achieving relatively high densities. The other contractor was compacting on the wet side and achieving lower density levels. This was still the case even after initial test sections were found to have been undercompacted.Compaction levels achieved in the crowns were generally found to be higher than those at the shoulders of the road test sections. The breakdown of coarse particles due to compaction was quite significant. There is therefore the need for highway material engineers to ensure that in addition to meeting the grading requirements, road base materials must adequately meet the requirements on weathering and mechanical strength properties.  相似文献