挟沙水流中沙粒对底壁湍流猝发的影响

本文在常规的边界层方程中保留了法向压力梯度项和增加了固粒对流体的使用项，结合Ｂａｔｃｈｅｏｌｒ对交界面提供的分析方法和小扰动稳定性理论，由理论分析和计算得到了包括沙粒之类的悬浮体的尺寸，比重，流动Ｒｅ数，两相速度差以及扰动波数与水流底壁湍流猝发角的关系，计算结果与Ｒａｓｈｉｄｉ等的实验结果相符。文中所得结果有助于进一步了解江河底部水流的流动特性以及泥沙的沉积和输运机理。     

絮凝法处理油田作业废液技术研究(1)——悬浮物处理

利用絮凝法对胜利油田作业过程中产生的废液进行处理,考察了两种絮凝剂A、B的使用浓度对悬浮物处理效果的影响。正交实验的结果表明:复配絮凝剂A+B能有效脱除作业废液中的悬浮物,絮凝剂A的浓度与污水体系的pH值是影响处理效果的主要因素,通过正交实验筛选出复合絮凝剂对悬浮物处理的最佳实验条件。     

悬索缆道(带铅鱼)在义棠水文站的应用

文中以山西省首家悬索自动化测流缆道在义棠水文站淤泥质河床的应用为例，叙述了该站缆道的设计、安装、试验研究的基本情况、设计指标、缆道总体布设、信号传输线路的设计及工作原理等。“失重”开关与河底开关的双重保险功能是解决我国北方地区淤泥质河床信号的产生与传输的关键。文中对此做了具体叙述，旨在为类似的缆道工程设计采用时参考。     

Quality assessment of SRTM C- and X-band interferometric data: Implications for the retrieval of vegetation canopy height

The Shuttle Radar Topography Mission distinguished itself as the first near-global spaceborne mission to demonstrate direct sensitivity to vertical vegetation structure. Whether this sensitivity is viewed as exploitable signal or unwanted bias, a great deal of interest exists in retrieving vegetation canopy height information from the SRTM data. This study presents a comprehensive application-specific assessment of SRTM data quality, focusing on the characterization and mitigation of two primary sources of relative vertical error: uncompensated Shuttle mast motion and random phase noise. The assessment spans four test sites located in the upper Midwestern United States and examines the dependence of data quality on both frequency, i.e., C-band vs. X-band, and the number of acquired datatakes. The results indicate that the quality of SRTM data may be higher than previously thought. Novel mitigation strategies include a knowledge-based approach to sample averaging, which has the potential to reduce phase noise error by 43 to 80%. The strategies presented here are being implemented as part of an ongoing effort to produce regional- to continental-scale estimates of vegetation canopy height within the conterminous U.S.     

一维河网非恒定流及悬沙数学模型的节点控制方法

本文的一维河网非恒定流及悬沙数学模型，是根据以一维圣维南方程组，悬沙非平衡输运方程及水位、含沙量节点控制法而建立。首先，利用单一河流有限差分方程组转换形式和节点处质量、能量守恒性，写出所有节点的水位控制方程组。求解此不规则稀疏矩阵方程组得到得有节点的水位，再由单一河流非恒定流的求解方法可获得所有单一河流的断面水位和流量。基于水注的节点水位控制法，本文提出了节点悬沙控制法。假设节点处冲刷或淤积较小，所有节点的含沙量控制方程组可通过输沙量守恒方程用矩阵形式写出。求解此不规则稀疏矩阵方程组，得到所有节点处的含沙量。所有单一河流断面处的含沙量通过单一河流悬沙输运的求解方法获得。本文介绍的模型适用于各种河网类型。作为检验，该模型成功地应用于珠江三角洲流域河网水流及悬沙的数值计算。     

Monitoring water quality in reservoirs with IRS-1A-LISS-I

An attempt has been made to quantify the relationship between the variation in IRS-IA-LISS-I (Indian Remote Sensing Satellite-1A Linear Imaging Self-Scanning System) radiance data and field measured change in secchi disc depth. Secchi disc depth was measured for 47 predetermined sampling locations on reservoir surface water. At extinction depth (secchi depth), water samples were collected from all the sampling locations. Suspended sediments of eight locations representing various reaches of the reservoir were selected for mineralogical, particle size and optical properties analysis. The LISS-I radiance value in band 1 (0.45–0.52µm) band 2 (0-52–0.59 µm) and band 3 (0.62–0.68 µm) were used in a regression analysis. The absorption infrared band 4 (0.77–0.86 µm) was not included in the analysis. In these, the dependable variable was secchi depth (SD) and the LISS-I-radiance data was the estimator variable. Forty-seven data sets of 20 October 1988 from Tawa reservoir surface water were used to obtain an estimator equation for SD. The verification of the estimator equation was tested by applying it to a data set of 21 measurements of 28 September 1988 for this reservoir. The coefficient of correlation between observed and estimated values for the 28 September 1988 data set wasr=0.92 for SD, indicating that the equation could accurately predict the water clarity (SD) for this reservoir on new occasions from IRS-IA-LISS-I spectral data. It is shown that mineral composition and optical properties of suspended sediments influence the reflected radiance of water quality. It is concluded that IRS-IA-LISS-I data provide a useful means of mapping water quality in reservoir.     

An empirical InSAR-optical fusion approach to mapping vegetation canopy height

Exploiting synergies afforded by a host of recently available national-scale data sets derived from interferometric synthetic aperture radar (InSAR) and passive optical remote sensing, this paper describes the development of a novel empirical approach for the provision of regional- to continental-scale estimates of vegetation canopy height. Supported by data from the 2000 Shuttle Radar Topography Mission (SRTM), the National Elevation Dataset (NED), the LANDFIRE project, and the National Land Cover Database (NLCD) 2001, this paper describes a data fusion and modeling strategy for developing the first-ever high-resolution map of canopy height for the conterminous U.S. The approach was tested as part of a prototype study spanning some 62,000 km² in central Utah (NLCD mapping zone 16). A mapping strategy based on object-oriented image analysis and tree-based regression techniques is employed. Empirical model development is driven by a database of height metrics obtained from an extensive field plot network administered by the USDA Forest Service-Forest Inventory and Analysis (FIA) program. Based on data from 508 FIA field plots, an average absolute height error of 2.1 m (r = 0.88) was achieved for the prototype mapping zone.     

河道生产堤对洪水影响的二维数值模拟研究

河道主槽两侧修建的生产堤影响滩槽泥沙横向交换,对河床演变带来很大影响。本文针对黄河下游游荡型河段的现实状况,采用平面二维水沙数学模型按现状生产堤、废除生产堤、限制生产堤三种条件进行了典型洪水的模拟,模拟计算给出了夹河滩-高村河段不同边界洪水演进、漫滩的过程及滩区淹没程度。作者分析了三种不同边界条件对洪水水位、河段流速、滩槽冲淤的影响,表明废除生产堤使洪水提前进滩,与现状生产堤状态相比大大降低了河道洪水位;限制生产堤方案可以适当控制漫滩流量,扩大滩槽泥沙横向交换,改善滩区生产条件。为了维持黄河河槽活力,协调人河关系,抑制二级悬河发展,限制下游河道生产堤治理方案是比较适宜的。     

柘溪水库泥沙淤积情况调查简介

通过对 1995年柘溪水库泥沙冲淤调查资料的分析 ,对比 196 3年建库时及 1974年库区泥沙冲淤情况 ,获得建库以来库区泥沙沉积率及其泥沙分布的关系曲线 ,可为已建或拟建的同类泥沙淤积分析提供参考。     

悬浮泥沙反射光谱特性和泥沙量估算试验研究

通过实验室含沙水体的配比试验，对不同浓度含沙水体进行了光学特性测量，建立了不同悬沙含量遥感反演模型，结果表明：1）确立的水体光谱反射率和悬沙浓度之间的数值关系，为用卫星遥感技术探测表层悬沙浓度做了基础性的研究，取得了令人满意的效果；2）悬沙水样的敏感波段位于700nm～720nm，730～750nm和800～850nm；3）利用主成分分析方法结合多元线性回归可较为精确地估算悬沙含量，其模型反演能力明显优于敏感波段线性模型。对于浓度范围为0．1905g／L～3．6991g/L的悬沙水体，主成分回归模型反演精度更高，反演值和实测值的平均相对误差仅为5％左右；4）用实验室含沙水体配比方法进行的悬沙浓度与光谱关系的研究，其数据采集的同步性好，精度可靠。