夏季河西地区绿洲-沙漠环境相互作用热力过程的初步分析   总被引：10，自引：6，他引：4  

吕世华  陈玉春  陈世强  朱伯承 《高原气象》2004,23(2):127-131

从绿洲和沙漠地面能量平衡方程和水分平衡方程出发,得到了表达绿洲稳定度和绿洲环流的表达式,绿洲地表温度低于沙漠的最主要原因是绿洲地表明显的蒸发。绿洲上大气稳定度的增加对于维持绿洲是一个重要的自我保护机制。从动力学角度来看,绿洲区明显的下沉(上升)运动将使大气稳定(不稳定)。反照率效应将减弱绿洲风环流,相反,蒸发效应会驱动它。绿洲中过多的蒸发使绿洲地表温度低于周围沙漠。这种温度差异使绿洲风环流产生,并且使绿洲区产生下沉运动、沙漠区产生上升运动。  相似文献   

Characteristics of boundary fault systems and its hydrocarbon controlling on hydrocarbon accumulation in Awati Sag,Tarim Basin,China     

《China Geology》2019,2(1):94-107

Based on the interpretation of two-dimensional seismic data, this paper analyzes the characteristics of three boundary fault systems including the Shajingzi fault, the Aqia fault and the Tumuxiuke fault around the Awati sag of the Tarim Basin, and studies its controlling on hydrocarbon accumulation. Neotectonic movement is ubiquitous in oil and gas bearing basins in China, such as Neogene intense activities of large boundary thrusting faults of the Awati sag: Shajingzi fault, Aqia fault and Tumuxiuke fault. Based on a large number of seismic data, it is showed that they have section wise characteristics in the direction of fault strike, and active periods and associated structures formed of different sections are different. Usually, large anticlinal structures are formed in the upper wall, and faulted anticline controlled by companion faults are formed in the bottom wall. Large faults cut the strata from Cambrian up to Neogene. For the anticline in the upper wall, fault activities caused by neotectonic movement played a destructive role in hydrocarbon accumulation, thus the preservation condition is critical for reservoir formation. In this sense, attention should be paid to formations in the upper walls of Aqia fault and Tumuxiuke fault under the Cambrian salt bed, whose plastic deformation could help to heal faults. Companion faults in the bottom wall cut down to the Cambrian and up to the Triassic serving as the pathway for hydrocarbon migration, and associated structures in the bottom wall are noteworthy exploration targets.©2019 China Geology Editorial Office.  相似文献   

Crossing Boundaries in a Collaborative Modeling Workspace     

Jeffrey T. Morisette  Amanda E. Cravens  Brian W. Miller  Marian Talbert  Colin Talbert  Catherine Jarnevich 《社会与自然资源》2017,30(9):1158-1167

There is substantial literature on the importance of bridging across disciplinary and science–management boundaries. One of the ways commonly suggested to cross boundaries is for participants from both sides of the boundary to jointly produce information (i.e., knowledge co-production). But simply providing tools or bringing people together in the same room is not sufficient. Here we present a case study documenting the mechanisms by which managers and scientists collaborated to incorporate climate change projections into Colorado’s State Wildlife Action Plan. A critical component of the project was the use of a collaborative modeling and visualization workspace: the U.S. Geological Survey’s Resource for Advanced Modeling (RAM). Using video analysis and pre/post surveys from this case study, we examine how the RAM facilitated cognitive and social processes that co-produced a more salient and credible end product. This case provides practical suggestions to scientists and practitioners who want to implement actionable science.  相似文献   

WRF模式对青藏高原那曲地区大气边界层模拟适用性研究   总被引：2，自引：0，他引：2  

许鲁君  刘辉志  徐祥德  杜群  王雷 《气象学报》2018,76(6):955-967

采用WRF（Weather Research and Forecasting）模式4种边界层参数化方案对青藏高原那曲地区边界层特征进行了数值模拟,并利用"第三次青藏高原大气科学试验"在青藏高原那曲地区5个站点的观测资料对模拟结果进行验证,分析不同参数化方案在那曲地区的适用性。研究表明,YSU、MYJ、ACM2和BouLac方案对2 m气温和地表温度的模拟偏低。BouLac方案模拟的地表温度偏差较小。通过对能量平衡各分量的对比分析发现,温度模拟偏低可能是向下长波辐射模拟偏低以及感热通量和潜热通量交换过强导致的。对于边界层风、位温和相对湿度垂直结构的模拟,局地方案的模拟效果均优于非局地方案。BouLac方案对那曲地区近地层温度、边界层内位温和相对湿度的垂直分布模拟效果较好。   相似文献   

试从土壤物质迁移与积累论亚热带北界的划分--以河南省伏牛山为例   总被引：3，自引：0，他引：3  

马建华 《地理科学》1999,19(6)

对伏牛山中段南坡不同海拔高度7 个土壤剖面进行了野外调查和室内土壤理化分析,选择土壤氧化物迁移系数、硅铝铁率、活性铁与全铁之比、活性锰与全锰之比、Ba值、β值等指标,运用聚类分析等方法,从土壤物质迁移和积累角度深入探讨了河南省伏牛山南坡亚热带北界的划分。研究结果表明,该界线大约在海拔950 m左右。  相似文献   

艾肯达坂风雪流形成机制及其治理   总被引：6，自引：1，他引：5  

王中隆  李长治 《中国沙漠》1995,15(2):105-108

根据天山艾肯达坂地区的野外观测和风洞模拟实验,导出山区风雪流输送量与风速随高度分布方程,指出贴地气层分离是形成道路雪阻的主要原因。首次提出利用透风式下导风清除道路积雪的理论与方法,在风雪流灾害防治工程的实施中取得了巨大的经济和社会效益。  相似文献   

Constraint inversion Algorithm of Lidar Equationfor Deriving Aerosol Optical Property     

邱金桓 《大气科学进展》1999,(2)

1.IntroductionLidarisincreasinglyusedinmeasuringtheopticalpropertiesofaerosolsandcloudssincethe1960's.Ithasbeenshownthatthedeterminationoftheextinctioncoefficientasafunctionofheightisfeasible(Klett,1980;Fernald,1984;LuDarenetal.,1977;Spinhirneetal.,...  相似文献   

Computation of solitary waves during propagation and runup on a slope   总被引：1，自引：0，他引：1  

Sangita Maiti  Debabrata Sen 《Ocean Engineering》1999,26(11):945

A numerical time-simulation algorithm for analysing highly nonlinear solitary waves interacting with plane gentle and steep slopes is described by employing a mixed Eulerian–Lagrangian method. The full nonlinear free surface conditions are considered here in a Lagrangian frame of reference without any analytical approximations, and thus the method is valid for very steep waves including overturning. It is found that the runup height is crucially dependent on the wave steepness and the slope of the plane. Pressures and forces exerted on impermeable walls of different inclinations (slopes) by progressive shallow water solitary waves are studied. Strong nonlinear features in the form of pronounced double peaks are visible in the time history of pressure and force signals with increasing heights of the oncoming solitary waves. The effect of nonlinearity is less pronounced as the inclination of the wall decreases with respect to the bottom surface.  相似文献   

Modelling of pile wave barriers by effective trenches and their screening effectiveness   总被引：2，自引：0，他引：2  

S. E. Kattis  D. Polyzos  D. E. Beskos 《Soil Dynamics and Earthquake Engineering》1999,18(1):78

The three-dimensional problem of isolation of vibration by a row of piles is studied numerically on the basis of a model replacing the row of piles by an effective trench in order to reduce the modelling complexity. The analysis is accomplished with the aid of an advanced frequency domain boundary element method, which is used for both the infilled trench and the soil medium in conjunction with a coupling procedure based on enforcement of equilibrium and compatibility at the trench–soil interface. Linear elastic or viscoelastic material behaviour is assumed for both the piles and the soil. The piles can be tubular or solid and have circular or square cross-section. The vibration source is a vertical force, harmonically varying with time, and the row of piles acts as a passive wave barrier. The effective trench model is constructed by invoking well known homogenization techniques used in the mechanics of fibre-reinforced composite materials, and its accuracy is compared against a rigorous boundary element analysis modelling each pile separately in full contact with the soil medium. On the basis of the effective trench model, the screening effectiveness of a row of piles is studied through parametric studies.  相似文献   

海岸线熏烟扩散模式   总被引：6，自引：0，他引：6  

俎铁林  魏生生 《应用气象学报》1999,10(3):307-313

该文导出一个无需作常涡扩散系数或“面源”假设的海岸线熏烟扩散模式。根据二维理论和观测资料对热力内边界层（TIBL）高度公式进行了简化。分析和预测结果表明:在海岸线附近,应尽可能将高污染源设置在远离海岸或靠近海岸线处,避免设置在有效源高度与当地TIBL高度相等的地点附近。  相似文献