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基于高光谱的射阳河口悬浮泥沙浓度定量反演研究 总被引：1，自引：0，他引：1
通过提取高光谱遥感信息,对射阳河口悬浮泥沙浓度与实测光谱及Hyperion影像光谱反射率进行了相关性分析,结果表明：射阳河口含沙水体对实测光谱反射率的敏感波段为898～904nm,对光谱分辨率为10nm的Hyperion影像敏感波段正好位于896nm处,以此构建的指数模型,其相关指数达到0．89。模型的检验显示,相对根均方差值为38．78％,表明单波段896nm对预测射阳河口的悬沙质量浓度具有良好的精度。由于试验取样时间与Hyperion影像的成像时间相匹配,此时水流场较稳定,河口水体中的泥沙运移与扩散规律与影像解译结果相似,即：近岸悬沙质量浓度高,远海浓度低;河口南侧由于属于淤长性海岸,悬沙质量浓度比北侧高。研究结果为利用高光谱分析技术构建海洋悬沙含量的定量反演模型提供了可靠依据,也为海洋水体其他物质成分的定量反演奠定了基础。 相似文献
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机载高光谱遥感是悬沙浓度反演的重要方法。针对高光谱悬沙浓度反演中敏感波段和反演方法的确定,以机载高光谱影像为数据源,采用相关性分析法确定单波段模型和双波段组合模型的敏感波段,并基于敏感波段构建单变量回归模型,确定最佳反演模型并获取长江口北港区域的悬沙浓度空间分布特征。结果发现,基于归一化差值指数(NDWI)构建的二次多项式模型为最佳反演模型,精度上优于其他5种常用的反演模型;且长江口北港区域的悬沙浓度与水下地形基本上呈倒数关系。相较于基于多光谱卫星影像进行遥感反演,本文的结果表明高光谱影像的精细化光谱能够更为准确地表达含沙水体的光谱信息变化,在复杂的水环境反演研究中具有重要的应用价值。 相似文献
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以粤港澳大湾区中山市及其邻近水域河网水体为试验区, 同步采集现场光谱及水质数据, 研究受测水体的高光谱反射率特征, 并分析非光学活性参数中化学需氧量(CODCr)、总磷(TP)浓度与高光谱反射率的相关性。结果显示, 各河流水体光谱反射率主要受悬浮颗粒物和叶绿素a的影响; 在500~680nm波段范围内, 水体光谱反射率大小与CODCr、TP浓度呈负相关关系; 与单波段相比, 特定波段的反射率比值与CODCr、TP浓度值的相关性较高, 与CODCr、TP浓度值相关性最高的反射率比值波段组合分别为R675/R794、R690/R815。选择上述波段组合建立的水质反演模型具有良好的估算精度, 模型估算平均相对误差分别为27.2%、32.1%, 表明高光谱技术在珠江口河网水体非光学活性参数CODCr、TP浓度反演上具有较大的应用潜景。 相似文献
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长江口枯季悬沙粒度与浓度之间的关系 总被引：4，自引：0，他引：4
2003和2004年枯季在长江口采集水样并作水文观测，对所获水样进行过滤和粒度分析，以计算悬沙浓度和悬沙粒度分布。结果表明，2003年11月小潮期间，悬沙中值粒径与悬沙浓度存在着显著的指数关系，在大潮期间没有显著关系；在2004年2月小湖期间，两者之间没有显著关系，但在大潮期间存在着显著的指数关系。枯季水体悬沙以粉砂组份为主，并且随着向口外的推移，细颗粒组份逐渐增加，但在拦门沙最大浑浊带附近，由于絮凝作用，沉积物粒度变幅较大，可产生粒径粗化的现象。小潮期间，砂含量较低，但与悬沙浓度之间有显著相关关系；大潮期间，悬沙粒径粗化，但砂含量与悬沙浓度之间的关系不显著。上述分布趋势与沉积物来源、当地的水动力条件和絮凝作用等因素有密切关系。 相似文献
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为了解獐岛和大鹿岛近岸海域悬沙浓度的分布特征及其与潮流动力的关系,促进海岛生态环境保护和资源开发利用,文章通过样品采集和分析计算,研究相关海域悬沙浓度的平面和垂直分布特征、潮流场分布特征、悬沙浓度与潮流的动力关系以及全潮单宽输沙量。研究结果表明:大、小潮期的悬沙浓度均存在较明显的水平梯度,同一层水体大潮期的悬沙浓度大于小潮期;悬沙浓度呈近岸较高、向海逐渐降低的分布状态;悬沙浓度与海水涨落变化的关系非常密切,具有明显的周期性,垂直分布从表层到底层逐渐变大,垂直梯度近岸海域较大、远岸海域较小;涨潮流的流速明显大于落潮流,潮流运动形式按逆时针方向旋转,主流向大致呈NNE-SSW走向;远岸站位各层潮流流速的平均值略大于近岸站位,同一站位的潮流流速随水深的增加而有所降低;潮流变化使悬沙浓度出现周期性变化,悬沙浓度峰值出现在流速峰值后,且在落潮期更大;全潮单宽输沙量在大潮期和小潮期分别为151.7～1 017.9kg/d和146.3～931.9kg/d,净输沙方向均为西南向,即落潮方向。 相似文献
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长江口最大浑浊带是陆海交汇的核心区域,其航槽是扼海-河联运的咽喉,悬沙峰的涨落潮周期变化深刻影响航槽的稳定性。本文利用长江口南槽上、中、下段3个站点枯季小潮和大潮的流速、盐度、悬沙平均粒径和悬沙浓度的实测资料,分析最大浑浊带悬沙峰特征及其动力机制。发现:流速和滩槽交换增强导致大潮平均悬沙浓度比小潮增加了0.78—1.97倍,絮凝也导致憩流底层悬沙浓度增加8%左右,但流速和絮凝与悬沙浓度的关系均非线性。大小潮盐度梯度与底层悬沙浓度关系呈现高线性相关关系,表明盐度梯度强化或突变是泥沙再悬浮形成悬沙峰的主要动力。 相似文献
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辽河口海区悬浮体运移扩散动力特征 总被引：1，自引：0，他引：1
控制着辽河口海区悬浮体运移的主要动力是河流迳流、潮流和余流．它们对最大浑浊带中河水与海水的混合，密度流循环以及悬浮物的沉降和运移共同起作用．悬浮物向海运移与河口区最大浑浊带有关，即与河流迳流、潮流和余流作用所控制的悬浮物数量有关。悬浮物向海运移似乎遵循两个周期：１．小潮—大湖周期；２．河流迳流丰枯周期．最大运移发生在大潮期和河流迳流丰水期。 相似文献
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A Comparison of Near-Bed Acoustic Backscatter and Laser Diffraction Measurements of Suspended Sediments 总被引：2，自引：0，他引：2
As part of the U.S. Office of Naval Research (ONR, Arlington, VA) mine burial program, an experiment was conducted off the pier at Santa Cruz, CA, to measure the near-bed suspended sediment reference concentration under waves and currents. Two tripods were deployed to carry out the measurements; one consisting mainly of acoustical instrumentation and the other solely of optical instruments. The tripods were located within 15 m of one another on a sandy bed and measurements of the suspended sediment were made using acoustics and optics. Although the experiment was not primarily designed to conduct an intercomparison of acoustical and optical measurements, it was considered interesting to take advantage of the situation and to examine if these two techniques gave comparable results. In particular, measurements of particle size and concentration, obtained using a triple frequency acoustic backscatter system (ABS) have been compared with the commercially available laser miniature scattering and transmissometry instrument (MSCAT). It was found that the mean grain size estimated by the two methods was consistent; however, in contrast, the concentration time series showed differences, both in magnitude and form. 相似文献
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长江、黄河悬移载荷粒度组成的比较研究 总被引：4，自引：0，他引：4
针对沉积物粒度参数对入海泥沙通量、物源和沉积动力模型研究的重要性,利用激光粒度分析仪对2000～2001年期间长江、黄河下游不同季节悬移载荷的粒度组成进行了比较研究。结果显示,长江下游悬移载荷的粒度组成以粉砂、粘土为主,几乎不含砂,分选较差,泥沙来源比较复杂。黄河下游悬移载荷的粒度组成以粉砂为主,粘土次之,并含少量砂,分选较差,泥沙绝大部分来自黄土高原。长江下游不同季节悬移载荷粒度组成差别较小,而黄河下游悬移载荷组成有明显的季节性变化。黄河与长江悬浮沉积物的粒度组成有显著的差异．沉积物物源、河道形态和纵比降以及水量变化可能是造成这一区别的主要原因。 相似文献
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应用遥感技术分析钦州湾悬沙的动态特征 总被引：5，自引：0，他引：5
依据美国陆地卫星（Landsat）所接收的MSS、TM资料，得到钦州湾海区表层悬沙分布的解译图，分析钦州湾及湾外海区水流流场特征，悬沙的分布及输移扩散特征，并就潮流、径流等水动力对湾内悬沙运动、滩槽冲淤的作用和影响进行了讨论。 相似文献
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Novigatsky A. N. Lisitzin A. P. Shevchenko V. P. Klyuvitkin A. A. Kravchishina M. D. Politova N. V. 《Oceanology》2020,60(3):372-383
Oceanology - A new approach has been applied to studying marine sedimentation using dispersed sedimentary material in sediment traps compared to the surface layer of bottom sediments. Based on... 相似文献
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M. Alber 《Estuarine, Coastal and Shelf Science》2000,50(6):805
Suspended particle dynamics were investigated in the Ogeechee River Estuary during neap tide in July 1996. Samples were operationally separated into ‘ truly suspended ’ (settling velocity <0·006 cm s−1) and ‘ settleable ’ (settling velocity >0·006 cm s−1) fractions over the course of a tidal cycle to determine whether these two fractions were comprised of particles with differing biological and chemical characteristics. Total suspended sediment, organic carbon and nitrogen, chlorophyll a and phaeopigment concentrations were measured in each fraction, as well as rates of bacterial hydrolytic enzyme activity [β-1,4-glucosidase (βGase) and β-xylosidase (βXase)]. The majority of the suspended sediment (by weight) was in the truly suspended fraction; all measured parameters were largely associated with this fraction as well. When compared to the settleable material, the truly suspended material was significantly higher in % POC (5·7±0·6 vs. 3·9±1·8), % chlorophyll (0·07±0·02 vs. 0·03±0·01), % phaeopigment (0·030±0·006 vs. 0·018±0·012), and weight-specific maximal uptake rates (Vmaxper mg suspended sediment) of both enzymes (1·8±0·4 vs. 0·7± 0·2 nmol mg−1 h−1βGase and 1·1±0·3vs . 0·3±0·2 nmol mg−1 h−1βXase), providing clear evidence for a qualitative distinction between the two fractions. These results are interpreted to mean that the more organic-rich, biologically active material associated with the suspended fraction is likely to have a different fate in this Estuary, as ‘ truly suspended ’ sediments will be readily transported whereas ‘ settleable ’ sediments will settle and be resuspended with each tide. These types of qualitative differences should be incorporated into models of particle dynamics in estuaries. 相似文献
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根据2003年1月份珠江口实测资料获得了适合该海域的相关参数，建立了适用于该海域的二类水体水色三要素优化反演模型，同步优化反演得到了与2003年1月25～26日实测站点相对应的2003年1月29日的SeaWiFs图像像元点的水色三要素，反演与实测水色三要素的平均相对误差分别为：叶绿素14．9％，悬浮泥沙12．1％，黄色物质13．6％。研究结果说明本研究建立的优化反演模型比较适用于珠江口二类水体水色三要素的反演，且具有较高的反演精度。 相似文献
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高生泉 《海洋学报(英文版)》1987,6(2):313-313
A simple and rapid method has been proposed for direct determination of Cd, Pb, Cu in marine sediments and suspended matters by graphite furnace atomic absorption spectrometry, using the HNO_3-HClO_4-HF decomposition. The L'vov platform and matrix modiffer technique were used with peak-area measurement to effectively eliminate the matrix 相似文献
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K. L. Priya 《Ocean Science Journal》2018,53(3):449-459
Settling velocity is one of the important parameters in sediment transport modeling of estuaries. The methods adopted for its determination vary from theoretical equations to experimental methods. The theoretical equation generally adopted in the 1DV model include assumptions in order to simplify the solution. It is generally assumed that either the condition is steady or the vertical diffusion is negligible. This study evaluated the relative importance of the two assumptions made for the estimation of settling velocity. Two approaches were adopted: unsteady and negligible vertical diffusion (NS-NVD) and steady with vertical diffusion (S-VD) to estimate the settling velocity. The Muthupet Estuary in the Coromandal coast of India was selected for the study. The S-VD approach estimated settling velocity fairly well at the two locations with appreciable vertical diffusion. The NS-NVD approach was observed to be superior for estimating settling velocity at shallow reaches of the estuary having low flow velocity. The calculated settling velocity was further applied in 1DV model to predict the suspended sediment concentration. The S-VD approach predicted suspended sediment concentration at those locations with appreciable vertical diffusion with an R2 value of 0.82 against 0.67 for the NS-NVD approach. At the other shallow reach of the estuary with low flow velocity, the NS-NVD approach gave an R2 value of 0.822 against 0.71 for the S-VD approach. The vertical diffusion was observed to play a secondary role at those locations which are shallow with a water depth of 0.6 m and with a low flow velocity of the order of 0.01 m/s. The study demonstrated that localized hydrodynamic conditions influence the method adopted for the estimation of settling velocity. 相似文献