MATHEMATICAL MODEL OF OVERLAND FLOW AND MECHANISM OF SOIL CONSERVATION FOR FORESTED STEEP HILLSLOPE－－（II）Mechanism of Soil Conservation Over Steep Hillslope

ＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＯＦＯＶＥＲＬＡＮＤＦＬＯＷＡＮＤＭＥＣＨＡＮＩＳＭＯＦＳＯＩＬＣＯＮＳＥＲＶＡＴＩＯＮＦＯＲＦＯＲＥＳＴＥＤＳＴＥＥＰＨＩＬＬＳＬＯＰＥ－－（ＩＩ）ＭｅｃｈａｎｉｓｍｏｆＳｏｉｌＣｏｎｓｅｒｖａｔｉｏｎＯｖｅｒＳｔ...     

EFFECTS OF EXISTENCE OF SEDIMENT PARTICLES ON THE ENERGY LOSS OF FLOW

ＥＦＦＥＣＴＯＦＥＸＩＳＴＥＮＣＥＯＦＳＥＤＩＭＥＮＴＰＡＲＴＩＣＬＥＳＯＮＴＨＥＥＮＥＲＧＹＬＯＳＳＯＦＦＬＯＷ￥ＬＩＵＱｉｎｇｑｕａｎ；ＣＨＥＮＬｉａｎｄＬＩＵＤａｙｏｕ（Ａｓｓｏｃ．ＲｅｓｅａｒｃｈＦｅｌｌｏｗ，ＩｎｓｔｉｔｕｔｅｏｆＭｅｃｈａ...     

STUDY ON THE MATHEMATICAL MODEL OF HEAVY－METAL POLLUTANT TRANSPOPT－TRANSFORMATION IN RIVERS

ＳＴＵＤＹＯＮＴＨＥＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＯＦＨＥＡＶＹ－ＭＥＴＡＬＰＯＬＬＵＴＡＮＴＴＲＡＮＳＰＯＰＴ－ＴＲＡＮＳＦＯＲＭＡＴＩＯＮＩＮＲＩＶＥＲＳ￥Ｓｕｉ－ｌｉａｎｇＨｕａｎｇａｎｄＺｈａｏ－ｈｕｉＷａｎ（ＰｏｓｔｄｏｃｔｏｒａｌＦｅ...     

SOME APPROACHES FOR STUDYING THE INTENSITY OF SMALL RIVER AGGRADATION

ＳＯＭＥＡＰＰＲＯＡＣＨＥＳＦＯＲＳＴＵＤＹＩＮＧＴＨＥＩＮＴＥＮＳＩＴＹＯＦＳＭＡＬＬＲＩＶＥＲＡＧＧＲＡＤＡＴＩＯＮＶ．Ｎ．Ｇｏｌｏｓｏｖ（ＬａｂｏｒａｔｏｒｙｏｆＳｏｉｌａｎｄＦｌｕｖｉａｌＰｒｏｃｅｓｓｅｓ，ＦａｃｕｌｔｙｏｆＧｅｏｇｒａｐｈ...     

THE PANTANAL:AN ECOSYSTEM IN NEED OF PROTECTION

ＴＨＥＰＡＮＴＡＮＡＬ：ＡＮＥＣＯＳＹＳＴＥＭＩＮＮＥＥＤＯＦＰＲＯＴＥＣＴＩＯＮ￥ＭａｒｅＰ．Ｂｏｒｄａｓ（Ｐｒｏｆｅｓｓｏｒ，ＤｅｐａｒｔｍｅｎｔｏｆＨｙｄｒａｕｌｉｃｓ，ＩｎｓｔｉｔｕｔｅｏｆＨｙｄｒａｕｌｉｃＲｅｓｅａｒｃｈ（ＩＰＨ），Ｆｅｄ...     

ON SOME ASPECTS OF DISTORTED RIVER MODEL WITH MOVABLE BED

ＯＮＳＯＭＥＡＳＰＥＣＴＳＯＦＤＩＳＴＯＲＴＥＤＲＩＶＥＲＭＯＤＥＬＷＩＴＨＭＯＶＡＢＬＥＢＥＤＺＨＵＰｅｎｇｃｈｅｎｇＩ．ＩＮＴＲＯＤＵＣＴＩＯＮＧｅｏｍｅｔｒｉｃａｌｓｉｍｉｌａｒｉｔｙｉｓｔｈｅｂａｓｉｓｏｆｈｙｄｒａｕｌｉｃｍｏｄｅｌｔｅｓｔ...     

RECENT UNDERTHRUSTS OF TIANSHAN AND POSSIBLE MECHANISM OF THEIR ORIGIN

ＲＥＣＥＮＴＵＮＤＥＲＴＨＲＵＳＴＳＯＦＴＩＡＮＳＨＡＮＡＮＤＰＯＳＳＩＢＬＥＭＥＣＨＡＮＩＳＭＯＦＴＨＥＩＲＯＲＩＧＩＮ￥Ｏ．Ｋ．Ｃｈｅｄｉａ（ＩｎｓｔｉｔｕｔｅｏｆＳｅｉｓｍｏｌｏｇｙＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓＲｅｐｕｂｌｉｃｏｆＫｉｒｇ...     

AN EXPERIMENTAL STUDY OF BED DEFORMATION IN UNSTEANY NON-UNIFORM FLOWS

ＡＮＥＸＰＥＲＩＭＥＮＴＡＬＳＴＵＤＹＯＦＢＥＤＤＥＦＯＲＭＡＴＩＯＮＩＮＵＮＳＴＥＡＮＹＮＯＮ－ＵＮＩＦＯＲＭＦＬＯＷＳ￥ＺｈａｏｙｉｎＷａｎｇ；ＷｏｌｆｇａｎｇＫｒｏｎ；ａｎｄＥｒｉｃｈＪ．ＰＩａｔｅ（Ｐｒｏｆ．Ｄｒ．ＳｅｎｉｏｒＥｎｇｉｎｅｅｒ...     

INFLUENCE OF CONSTRUCTIONAL ELEMENTS ON SEDIMENT TRANSPORT

ＩＮＦＬＵＥＮＣＥＯＦＣＯＮＳＴＲＵＣＴＩＯＮＡＬＥＬＥＭＥＮＴＳＯＮＳＥＤＩＭＥＮＴＴＲＡＮＳＰＯＲＴ￥ＳｉｌｋｅＷｉｅｐｒｅｃｈｔａｎｄＷｉｌｈｅｌｍＢｅｃｈｔｅｌｅｒ（ＲｅｓｅａｒｃｈＡｓｓｏｃｉａｔｅ，ＩｎｓｔｉｔｕｔｅｆｏｒＨｙｄｒａｕｌｉ...     

THE ROLE PLAYED BY WASH LOAD DEPOSITION IN THE FORMATION OF DIFFERENT RIVER PATTERNS

ＴＨＥＲＯＬＥＰＬＡＹＥＤＢＹＷＡＳＨＬＯＡＤＤＥＰＯＳＩＴＩＯＮＩＮＴＨＥＦＯＲＭＡＴＩＯＮＯＦＤＩＦＦＥＲＥＮＴＲＩＶＥＲＰＡＴＴＥＲＮＳＴｈｅｌｏｗｅｒｌａｙｅｒｏｆｔｈｅｂｅｄｍａｔｅｒｉａｌｃｏｎｓｉｓｔｓｏｆｔｉｎｅｓａｎｄａｎｄｔｈｅｕｐｐｅｒｌａｙｅｒｃｏｎｓｉｓｔｓｏｆａｍｉｘｔｕｒｅｏｆｃｌａｙ（１０％）ａｎｄｔｉｎｅｓａｎｄ（９０％）．ＮＡＴＵＲＡＬＲＩＶＥＲＳｌ．ＣｈａｎｇｅｏｆｃｈａｎｎｅｌｐａｔｔｅｒｎｓａｌｏｎｇａｒｉｖｅｒｃｏｕｒｓｅＩｔｉｓｃｏｍｍｏｎｔｈａｔｉｎｔｈｅｕｐｐｅｒＰａｒｔｏｆａｎａｌｌｕｖｉａｌｒｉｖｅｒｔｈｅｌｏｎｇｉｔｕｄｉｎａｌｓｌｏｐｅｉｓｓｔｅｅｐａｎｄｔｈｅｒｉｖｅｒｃａｒｒｉｅｓｈｅａｖｙｓｅｄｉｍｅｎｔｌｏａｄ．Ｄｕｅｔｏｔｈｅｓｔｅｅｐｓｌｏｐｅａｎｄａｓｓｏｃｉａｔｅｄｈｉｇｈｖｅｌｏｃｉｔｙｃｌａｙｓｅｔｔｌｅｓｌｉｔｔｌｅｅｖｅｎｏｎｔｌｏｏｄｐｌａｉｎ．Ｆｌｏｏｄｐｌａｉｎｏｒｒｉｖｅｒｈａｎｋｃｏｎｓｉｓｔｓｏｆｓｉｌｔａｎｄｔｉｎｅｓａｎｄ．Ｔｈｅｒｉｖｅｒｂｅｈａｖｅｓａｓａｗａｎｄｅｒｉｎｇｏｎｅ．Ｐａｓｓｉｎｇａｃｅｒｔ     

西藏高原斜压对流边界层风、温、湿廓线特征

利用1998年夏季第2次青藏高原大气科学试验当雄观测站的边界层观测资料以及拉萨、改则和武汉等地探空资料,分析讨论西藏高原斜压对流边界层风、温、湿廓线的特征. 研究结果表明,高原地区白天对流边界层发展可高达2200m,显著超过中纬度平原地区和海面上对流边界层高度. 高原对流边界层中温度廓线具有较好的混合特征,湿度廓线有时在某一高度上出现湿度极大值. 高原对流边界层内热量和水汽收支分析表明,水平平流作用对边界层结构具有重要作用. 在对流边界层中平均风速垂直分布存在风切变现象. 水平温度梯度形成较强的斜压性是形成边界层风切变的主要原因.     

云覆盖对流边界层顶部湍流结构参数的研究

应用飞机探测资料分析研究云覆盖对流边界层顶部温度和湿度湍流结构,在考虑对流边界层顶部夹卷过程的基础上得到计算温度和湿度结构参数的公式。应用实际观测资料分析了云覆盖对流边界层顶部的湍流特征．资料分析表明,云外晴空区温度和湿度结构函数值明显高于云内的值．云顶边界清晰,通过界面温度和湿度具有明显的跃变特征．应用观测资料检验了温度和湿度结构参数计算公式,计算结果与观测结果符合较好．     

A Numerical Simulation of the Seasonal Cycle of Temperature, Salinity and Velocity Fields in Tokyo Bay

To understand when oxygen-depleted waters occur, how they develop and when they dissipate in inner Tokyo Bay, realistic simulations were attempted with fine spatial and temporal resolution by applying realistic time dependent external forcing. A 3D hydrodynamic model was driven by time-dependent external forcing factors/parameters such as solar radiation, air temperature, relative humidity, wind velocity, and fluvial discharge, under the open boundary conditions of 1995. A simulated time series of salinity and temperature agreed fairly well with observed data, except in summer. The model failed to reproduce the development of the surface mixed layer in summer. Several sensitivity analyses on the external forcing parameters such as wind velocity and vertical diffusivity were conducted to reproduce the mixed layer. However, changing these parameter values did not improve the model results.     

Effects of shear in the convective boundary layer: analysis of the turbulent kinetic energy budget

Effects of convective and mechanical turbulence at the entrainment zone are studied through the use of systematic Large-Eddy Simulation (LES) experiments. Five LES experiments with different shear characteristics in the quasi-steady barotropic boundary layer were conducted by increasing the value of the constant geostrophic wind by 5 m s^-1 until the geostrophic wind was equal to 20 m s^-1. The main result of this sensitivity analysis is that the convective boundary layer deepens with increasing wind speed due to the enhancement of the entrainment heat flux by the presence of shear. Regarding the evolution of the turbulence kinetic energy (TKE) budget for the studied cases, the following conclusions are drawn: (i) dissipation increases with shear, (ii) the transport and pressure terms decrease with increasing shear and can become a destruction term at the entrainment zone, and (iii) the time tendency of TKE remains small in all analyzed cases. Convective and local scaling arguments are applied to parameterize the TKE budget terms. Depending on the physical properties of each TKE budget contribution, two types of scaling parameters have been identified. For the processes influenced by mixed-layer properties, boundary layer depth and convective velocity have been used as scaling variables. On the contrary, if the physical processes are restricted to the entrainment zone, the inversion layer depth, the modulus of the horizontal velocity jump and the momentum fluxes at the inversion appear to be the natural choices for scaling these processes. A good fit of the TKE budget terms is obtained with the scaling, especially for shear contribution.     

边界层参数化方案对边界层热力和动力结构特征影响的比较

本文利用高分辨率中尺度WRF模式,通过改变边界层参数化方案进行多组试验,评估该模式对美国北部森林地区边界层结构的模拟能力,同时比较了五种不同边界层参数化方案模拟得出的边界层热力和动力结构.结果表明：除个别方案外,配合不同边界层方案的WRF模式都能成功模拟出白天对流边界层强湍流混合特征和夜间稳定边界层内强逆温、逆湿和低空急流等热力和动力结构.非局地YSU、ACM2方案在白天表现出强的湍流混合和卷夹,相比于局地MYJ、UW方案,模拟的对流边界层温度更高、湿度更低、混合层高度更高、感热通量更大,更接近实际观测,这表明在不稳定层结下考虑非局地大涡输送更为合理,但局地方案在风速和风向的预报上存在一定优势.TEMF方案得到的白天局地湍流混合强度为所有方案中最弱,混合层难以发展,无法体现对流边界层内气象要素垂直分布均匀的特点.对于夜间稳定边界层的模拟,不同参数化方案之间的差异较小,但是YSU方案在一定程度上高估了机械湍流,导致局地湍流混合偏强,从而影响了其对稳定边界层的模拟能力.     

Effects of wind shear on the atmospheric convective boundary layer structure and evolution

The article reviews past accomplishments and recent advances in conceptual understanding, numerical simulation, and physical interpretation of the wind shear phenomena in the atmospheric convective boundary layer.     

Gradient-based similarity in the atmospheric boundary layer

The “flux-based” and “gradient-based” similarity in the stable boundary layer and also in the interfacial part of the convective boundary layer is discussed. The stable case is examined on the basis of data collected during the CASES-99 experiment. Its interfacial counterpart is considered in both the quasi-steady (mid-day) and non-steady states, utilizing the results of large-eddy simulations. In the stable regime, the “gradient-based” approach is not unique and can be based on various master length scales. Three local master length scales are considered: the local Monin-Obukhov scale, the buoyancy scale, and the Ellison scale. In the convective “quasi-steady” (mid-day) case, the “mixed layer” scaling is shown to be valid in the mixed layer and invalid in the interfacial layer. The temperature variance profile in non-steady conditions can be expressed in terms of the convective temperature scale in the mixed layer. The analogous prediction for velocity variances is not valid under non-steady conditions.     

A comprehensive physical pattern of land-air dynamic and thermal structure on the Qinghai-Xizang Plateau

According to the boundary layer observations of three stations (Garze, Damxung and Qamdu) and relevant earth satellite, radiosonde and surface observations during the intensive observational period (IOP) of the second Tibetan (Qinghai-Xizang) Plateau Experiment of atmospheric science (TIPEX), the land-air physical process and dynamic model on the Tibetan Plateau were comprehensively analyzed in this study. The dynamic characteristics of boundary layer and the rules of turbulent motion on the plateau were illustrated. The characteristics of distributions of wind speed and direction with mutiple-layer structure and deep convective mixed layer on the plateau, the strong buoyancy effect in turbulent motion on the plateau on which the air density is obviously smaller than on the plain, and the Ekman spiral and its dynamic pump effect of the plateau deep boundary layer have been found. The local static distribution of water vapor and the horizontal advection of water vapor in the plateau boundary layer were studied. The abnomal thermodynamic structure on the plateau surface and boundary layer, including the plateau strong radiation phenomenon and strong heating source characteristics of the middle plateau, was also analyzed. The authors synthesized the above dynamic and thermodynamic structures of both surface and boundary layers on the plateau and posed the comprehensive physical model of the turbulence and convective mixture mechanism on the plateau boundary layer. The characteristics of formation, development and movement for convective cloud cluster over the plateau influencing floods in the Yangtze River area of China were studied. The conceptual model of dynamic and thermodynamic structures of turbulent motion and convective plume related to the frequent occurrence of "pop-corn-like" cloud system is given as well.     

星载SAR遥感图像反演海洋大气边界层高度

本研究将边界层相似理论与对流理论应用到具有海洋大气边界层(Marine Atmospheric Boundary Layer, MABL)对流特征的星载合成孔径雷达(Synthetic Aperture Radar, SAR)遥感图像,探讨了星载SAR遥感图像描述海气应力作用下水平扰动尺度变化的潜在可能性.针对具有三维对流涡旋Cell和二维水平滚轴涡旋Roll特征的星载SAR遥感图像,反演了中国海海域MABL高度,并与同步实验获取的MABL高度结果进行对比.结果表明,利用具有对流特征的星载SAR遥感图像反演MABL高度是可行的,展示了以高分辨率、大面积观测为特点的星载SAR遥感图像探测MABL的广阔前景.     

Simulation of Atmospheric Boundary Layer Characteristics during Indian Summer Monsoon using Observations from Monsoon Trough Boundary Layer Experiment at Jodhpur, India

The diurnal structure of the boundary layer during Indian summer monsoon period is studied using a one-dimensional meteorological boundary layer model and the observations collected from the Monsoon Trough Boundary Layer Experiment conducted in 1990 at Jodhpur, India. The model was initialized with the observed temperature profiles at 0530 LST on 17 July, 1990 at Jodhpur and was run for 26 hours. The study is carried out with a geostrophic wind speed of 9.5 m s⁻¹ corresponding to the strong wind simulation. The mean thermodynamic and wind structure simulated by the model are in good agreement with those observed from 30 m tower. The computed surface layer characteristics such as the surface fluxes, TKE and standard deviations of velocity components are found to be reasonably in good agreement with those based on turbulence measurements. The shear and buoyancy budget computed from the model are also compared with the turbulence measurements. The integrated cooling budget in the nocturnal boundary layer is examined.