• 全国中文核心期刊
  • 中国科技核心期刊
  • 美国工程索引(EI)收录期刊

1991 Vol. 2, No. 3

Display Method:
The Eddy Transport of Atmospheric Moisture over China
Liu Guowei, Cui Yifeng
1991, 2(3): 145-153.
Abstract:
Based on the computation of eddy transport of atmospheric moisture by using the balloon sounding data collected from 149 meteorologic stations in 1983, some new findings for the feature of eddy transport over the territory of China have been obtained: (1) The routs of eddy transport flux present meridionality, the general direction of eddy transport is similar to that of the moisture gradient tranports atmospheric moisture to arid region in the northwest of the country from its southeast. The phenomena are of significant importance to provide and maintain the atmospheric moisture over the inland region in northwest China. (2) The eddy transport is active especialy in middle latitude zone (30°~40°N) of China, some divergence and convergence centers of eddy transport flux are available and the location of the center varies with different month and is closely related to the places of high precipitation. (3) The mainland of China shows a region with eddy vapour source in winter month and eddy vapour sink in summer month. 88% of eddy transport of atmospheric moisture enters China in the south and 55% and 40% leave China from the north and the east boundries. The exchange of atmospheric moisture by means of eddy transport between regions is considerable. (4) The contribution of eddy transport to total transport of atmospheric moisture is important, for example, the amount of atmospheric moisture by means of eddy transport from Yangtze River basin to north China is more than 90% of the total atmospheric moisture transport.
A Universal High-Performance Algorithm for Two-Dimensional Unsteady Shallow Water Flow Computation——The Finite-Volume Osher Scheme
Tan Weiyan, Hu Siyi
1991, 2(3): 154-161.
Abstract:
The unstructured mesh is adopted, which can be refined locally and adaptively according to the planar geometry of computational domain, bathymetry, and the requirements of specific engineering applications. The two-dimensional open flow computation problem is formulated with the finite volume method. Numerical flux in the normal direction to and across each side of elements is obtained by solving a Riemann problem by using Osher's scheme. Related formulas of normal numerical flux are derived. The merits of the new algorithm are pointed out, including: universality, conservativity, upwindness, high efficiency, monotonicy-preserving, high resolution in discontinuities, consistency between boundary procedure and internal scheme, nonexistence of numerical boundary conditions, etc. Lastly, the good performance is demonstrated through a case study of tidal flow computation for the southern branch of the Yangtze estuary.
Bubble Oscillations in Solid-Liquid Two-Phase Fluid
Lu Li
1991, 2(3): 162-170.
Abstract:
An equation of motion for spherical bubbly oscillations in solid-liquid two-phase fluid, with the incorporation of the resistance coupling effects between the liquid and solid particles, is derived. The effects of particles on bubble motion and bubble wall pressure are analysed by using numerical methods. It is shown that bubble oscillation amplitude and bubble wall pressure are decreased when liquid contains solid particles. The large the solid particle concentration, the larger the effects of particles on bubble oscillation. When the solid particle concentration are the same, the smaller the sine of the particles, the larger the effects of the particles on bubble oscillation.
Formative Causes of the Anabranched Rivers
Zhang Ren, Ni Jinren
1991, 2(3): 171-178.
Abstract:
In the present paper,both the similarities and the differences between the anabranched rivers and meandering rivers are discussed with the observations in laboratories and fields. As a result,the formative causes of anabranched rivers are revealed and contradiction which can not be clearly explained in the previous investigations are solved.
Discussion on Output Coordination about Period-Stationary Markov Policies
Wen Depu
1991, 2(3): 179-187.
Abstract:
The concept of output coordination about period-stationary Markov policies and their measurement method were provided in this paper and it was described that the use of the unlinear return-function will improve the output coordination of policies. There are a lot of examples, tables and figures as evidence and some suggestions for use in practice.
Numerical Simulation of Flood Routing in the Xiaoqinghe Flood Plain
Liu Shukun, Li Xiaopei, Li Shigong, Yu Tianyi
1991, 2(3): 188-193.
Abstract:
The flood flow resulting from the mitigation of the Xiaoqinghe flood-zone of the middle Yongdin river is numerically simulated by using finite difference method. Based on the obtained results,the flooding-risk maps for this area are worked out and some measures for reducing losses of life and property in the potentially inundated region are investigated. The practical experience shows that this type of results can be provided as a basis for in flood-control decision-making.
Some Reviews on Geomorphologic Instantaneous Unit Hydrograph
Rui Xiaofang
1991, 2(3): 194-200.
Abstract:
The basic hypotheses of the Geomorphologic Instantaneous Unit Hydrograph (GIUH), the waiting time probability density function(WPDF), and the relationship between the GIUH and conceptual models of concentrated flow in a watershed (CFW) are reviewed. It is indicated that handling of CFW by means of statistical mechanics is theoretically not reasonable because of non-weak interaction between the water particles. Although determination of the waiting time probability density fu nction is a key to the GIUH, the existing methods involve some unproved hypotheses about it. If the area-time curve and exponential type function are used as the waiting time probability density function, then the GIUH is equivalent tojthe conceptual models of CFW. Because the GIUH depends only on the parameters of geomorphology and flow velocity of channel network, it may provide a new parameter esti mation method for conceptual models of CFW.
Progress and Protects of China’s Estuarine Hydrographic Studies
Shen Huanting
1991, 2(3): 201-205.
Abstract:
The following are the major aspects of hydrographic studies of China's estuaries emptied into the sea: accumulated a large number data, develop widely the experiments of the physical models and mathematic simulations, and obtained much achievements of the estuarine tides, tidal current. salt-and fresh-water mixing, non-tidal circulation, wave, storm surge and sediment etc. aspects. The auth or suggests that we must improve the estuarine hydrographic observation station net, pay attention to the application of new techniques, such as the remote sensing and multi-discipline, strengthen the series observation for a long term, at the same time, pay attention to the basic theoretic study.
1991, 2(3): 206-215.
Abstract:
1991, 2(3): 216-216.
Abstract: