Numerical simulation of sedimentation processes in reservoirs as a function of outlet location     

Horacio TONIOLO 《国际泥沙研究》2009,24(3):339-351

This paper builds on a recently published one-dimensional moving-boundary model of the coevolution of topset, foreset and bottomset in a reservoir that captures the dynamics of the internal muddy pond typical to reservoirs. This model was modified to account for different outlet locations at the reservoir＇s downstream end. This model considers a river carrying two sustained phases of sediments： coarse （sand） and fine （mud）. The coarse phase deposits in the topset and delta foreset, while the fine phase forms a dilute suspension of wash load in the river. As the river enters the reservoir, the muddy water plunges on the foreset to form a Froude-supercritical （purely depositional） turbidity current. This turbidity current emplaces the bottomset. The modified numerical model was tested against five laboratory experiments previously reported by the author. The model successfully locates the muddy-water/clear-water interface. In addition, modeled and measured bed deposits are in good agreement. Results clearly indicate that the location of the internal hydraulic jump plays a key role in the final bed deposit.  相似文献   

Evaluation of a gravel transport sensor for bed load measurements in natural flows     

Athanasios N. 《国际泥沙研究》2009,24(1):1-15

A recent acoustic instrument （Gravel Transport Sensor, GTS） was tested for predicting sediment transport rate （bed load rate） in gravel bed streams. The GTS operation is based on the particle collision theory of submerged obstacles in fluids. When particles collide with the GTS cylinder their momentum is recorded in the form of ping rates. The GTS is attractive for further consideration here because of its potential to provide continuous unattended local bed load measurements, especially in areas found in streams that access may be difficult under extreme conditions. Laboratory experiments coupled with numerical simulations for the same flow conditions were performed in order to determine the conditions under which particles of different size will hit the GTS cylinder and be able to register a ping rate. The GTS was able to detect the number of particles with diameter in the range of 15.9 to 25.4 mm, with reasonable accuracy, if the applied Shields effective stress τ＊e = τ＊ - τ＊cr was in the range of 0.006 to 0.015. A drawback of the tested prototype GTS, however, was that it exerted increased resistance on the incoming particles. The added drag effects increased the overall resistance that was exerted by the flow on particles and thus increased the likelihood that particles will rest in the ambient region of the cylinder instead of hitting it. Numerical simulation of the flow around the GTS cylinder revealed that changing the prototype geometry from cylindrical to ellipsoid or rhomboid will increase the likelihood of the particles hitting the instrument under the same flow conditions failed by the original tested GTS cylinder.  相似文献   

Using in situ REE analysis to study the origin and diagenesis of dolomite of Lower Paleozoic,Tarim Basin     

WANG XiaoLin  JIN ZhiJun  HU WenXuan  ZHANG JunTao  QIAN YiXiong  ZHU JingQuan & LI Qing State Key Laboratory for Mineral Deposits Research  School of Earth Sciences  Engineering  Nanjing University  Nanjing  China  Petroleum Exploration  Development Institute of SINOPEC  Beijing  SINOPEC Northwest Oil Field Branch  Urumqi 《中国科学D辑(英文版)》2009,(5)

In situ REE concentrations of various dolomites from Tarim Basin were obtained by LA-ICP-MS analysis,and the data were normalized to standard seawater(Seawater Normalized=SWN).Most of the samples have a ΣREE range of less than 20 ppm.All samples show similar REESWN distributions with heavy REE depletion,and positive Ce anomaly,which indicates that they have the same dolomitization fluids(seawater).According to the origin and diagenetic process of dolomite,two types of dolomite are determined and described a...  相似文献   

论华蓥山地区天青石矿石的两种成因   总被引：3，自引：0，他引：3  

王吉平  胡墨田 《地质学报》2000,74(4):325-332

本文分析了四川－重庆华蓥山地区天青石矿床的野外宏观特征和微观特征,对三种主要类型的天青石矿石：层状天青石矿石、巨晶天青石矿石和条带状天青石矿石中的暗色条带天青石和白色条带天青石进行了野外产状、结构构造特征、稀土元素含量特征、天青石包裹体成分和包裹体盐度的比较分析,结果表明,层状矿石和条带状矿石中的暗色条带天青石是沉积形成的,巨晶矿石和条带状矿石中的白色条带天青石属热卤水成因。  相似文献   

西准噶尔前陆盆地二叠纪火山—沉积序列与盆地演化耦合   总被引：15，自引：1，他引：14  

赵玉光  肖林萍 《地质论评》2000,46(5):530-535

本文探讨了西准噶尔前陆盆地二叠系序界面属性及层序的内部构成,识别并标定了６类层序界面：消截角度不整合、削截不整合、削蚀不整合、削蚀上超不整合、侵蚀上超不整合和上超界面,在此研究的基础上,二叠系被划分为６个三级层序。建立了区内二叠纪火山－沉积盆地演化的序列模型。下二叠统的４个三级层序是火山沉积盆地演化的结果,与前陆盆地早期残余海的演化耦合;中、上二叠统发育的两个三级层序的时空堆叠与前陆盆地晚期地演化  相似文献   

初夏敦煌荒漠戈壁大气边界结构特征的一次观测研究   总被引：34，自引：9，他引：25  

张强  卫国安  侯平 《高原气象》2004,23(5):587-597

利用"西北干旱区陆气相互作用野外观测实验"加强期在甘肃省敦煌市气象站进行的风、温、湿探空观测资料,分析了西北典型干旱区大气边界层的结构特征和变化规律。结果表明,大气边界层厚度总体而言明显偏高,对流边界最高层厚度可超过4000m,稳定边界层也在1000m左右的高度;2750m附近为风向转变高度,其下全为偏东风,其上全为偏西风,这个风向转变高度有一定日变化,在观测的9天内每天的日变化规律保持了很好的一致性;边界层风速切变较大,大多数时候有低空东风急流出现,急流最强可达到近20m·s-1,急流高度在500m左右;边界层内比湿廓线有时在大约500m高处出现逆湿,一般以夜间更为显著。  相似文献   

Experimental study on dispersive soil in western Jilin     

ZHANG Jing  WANG Qing  WANG Wenhua    CHEN Hui'e  WANG Ying.College of Construction Engineering  Jilin University  Changchun  China.College of Civil Engineering  Changchun Institute of Technology  Changchun  China 《东北亚地学研究》2010,(1)

In order to research engineering geological properties of the soil in Zhenlai of western Jilin,especially the dispersivity of soil,the authors carried out the basic physicochemical test and dispersivity identification test.The results show that the dispersivity of the soil increases with the increase of depth within 0-30 cm (surface soil);it decreases as the depth increases within in 30-100 cm.Furthermore,the statistical analysis of the dispersivity indexes and physicochemical propertity indexes show that t...  相似文献   

Application of multi-channel two-dimensional transient Rayleigh wave exploration in goaf detection     

DU Lizhi  ZHANG Xiaopei  WANG Yong College of Construction Engineering  Jilin University  Changchun  China 《东北亚地学研究》2010,(1)

The transient Rayleigh wave exploration has high detection accuracy in shallow exploration.The effect of detection array is comprehensive reflection of the velocity of rock and soil mass.Therefore,the rolling multi-channel transient acquisition system has been adopted in this study,which turns one dimensional transient Rayleigh wave exploration into two dimensions,consequently,the two-dimensional velocity distribution of rock and soil mass under the survey line has been achieved.Through comparing with the s...  相似文献   

Desorption-diffusion model and lost gas quantity estimation of coalbed methane from coal core under drilling fluid medium   总被引：1，自引：0，他引：1  

Geoff WANG 《中国科学:地球科学(英文版)》2010,(4)

The differences of coalbed methane(CBM) desorption-diffusion from coal drilling-core under various drilling fluid medium are not considered in the present calculating methods of lost CBM quantity,which leads possibly to the inaccuracy of CBM quantity in coal seam.Here we took the desorption of CBM from coal core under drilling fluid medium as a pressure-swing process,and based on the Langmuir equation and Fick-first law,established the desorption-diffusion model and numerical modeling method of lost gas(inc...  相似文献   

Glacier runoff variation and its influence on river runoff during 1961–2006 in the Tarim River Basin, China     

GAO Xin    YE BaiSheng  ZHANG ShiQiang  QIAO ChengJun  & ZHANG XiaoWen State Key Laboratory of Cryospheric Sciences CAREERI  Chinese Academy of Sciences  Lanzhou  China  Cold  Arid Regions Environmental  Engineering Research Institute  The Resource Environment  Urban  Rural Planning Department  Lanzhou Commercial College  Lanzhou 《中国科学:地球科学(英文版)》2010,(6)

Using monthly precipitation and temperature data from national meteorological stations, 90 m resolution DEM and a digital vector map of modern glaciers from the Chinese Glacier Inventory, the glacier mass balance and glacier runoff in the Tarim River Basin (TRB), China, were estimated based on a monthly degree-day model for 1961–2006. The results suggest that the modified monthly degree-day model can simulate the long-term changes in glacier mass balance and glacier runoff, which have been confirmed by shor...  相似文献