共查询到20条相似文献，搜索用时 15 毫秒
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近几十年来,我国的砂质、淤泥质海岸正呈现侵蚀加剧的演变趋向。随着卫星遥感数据在光谱、时间和空间分辨率方面的不断提高,海岸侵蚀和淤积监测具备了精度越来越高的数据源。在前人研究的基础上,以废黄河三角洲海岸为研究对象,利用遥感技术和野外实地调查对海岸岸线变迁及冲淤动态进行了研究。研究表明:遥感技术在岸线变迁、侵蚀淤积监测和预测方面具有其他技术无可比拟的优势,在海岸带地质环境监测中的应用已成为具有实用价值的技术。 相似文献
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1993年汛期黄河下游河势遥感调查 总被引：2，自引：0，他引：2
利用ＭＥＲＩＤＩＡＮ遥感图象处理系统，通过ＴＭ图象最佳波段组合、线性拉伸放大、密度分割等处理手段，首次在黄河上进行了卫星遥感河势调查，其优势在于：（１）可以弥补目估河势的不足；（２）能够对河势流路、主流线位置、洪漫滩范围及水边线、生产堤、主要滩区洪水进出口门位置、进水和水围村庄等准确定位；（３）可以详细计算各类滩区面积与分布密度。 相似文献
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利用卫星影像开展河道水域非法占用监测,存在后期数据处理周期长、实时性弱等不足。为此,基于无人机正射影像图提出一种集Mask RCNN网络与图像差值计算的河道水域动态监测模型,通过机器识别改善现存问题。首先对正射影像进行拼接、矫正与分割,获取原始数据集后利用有监督学习方式训练Mask RCNN模型。最后获取河道轮廓图并计算两期同一位置正射影像的差值与阈值对比,来判定河道水域是否发生变化。试验结果表明,在机器识别与人工处理对比中本方法具有平均90%左右的准确率。本模型准确性较高,可辅助作为小型河道水域非法占用的实时动态监测工具。 相似文献
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A GIS‐based approach to mapping probabilities of river bank erosion: regulated River Tummel,Scotland
This study explores the use of Geographic Information Systems (GIS) techniques for mapping river channel planform change and bank erosion probability. The method used is primarily based on an approach developed by Graf (Graf, W.L. 1984. ‘A probabilistic approach to the spatial assessment of river channel instability’, Water Resour. Res., 20 (7), 953–962), which proposed that bank erosion probability could be determined for any given cell on a floodplain by taking into account (i) its distance laterally and in the upstream direction to the active river channel, and (ii) a value representing flood magnitudes for the given period. In this study, Graf's method is refined by using a GIS approach and by incorporating the influence of geomorphic variables, such as river bank morphology, sediment type and floodplain vegetation, on bank erosion rates. In addition, the technique is applied to a wandering gravel‐bed river of roughly 80 m width, representing a different type and size of river to that used in Graf's study. Thus, the wider applicability of the technique is tested. In addition, the analysis here covers only a short time scale (1988–1994) compared with that used by Graf. The high temporal resolution of this study is enabled by the use of aerial photography and also by the substantial channel changes that occurred within this time period as a result of several high magnitude flood events. The results of the study indicate the usefulness and validity of the approach, particularly with regard to floodplain erosion hazard mapping and the assessment of the effects of altered flood regimes and land use. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
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基于国产卫星多光谱影像的河流水体浊度遥感联合反演研究 总被引：1，自引：0，他引：1
基于集合建模思想,在水体光谱特征分析与敏感波段选择基础上,集成多种遥感反演模型优势,构建了河流水体浊度多光谱遥感联合反演模型(Combined Model-BP,CM-BP)。选择汉江中下游典型河段为研究区,利用2012—2013年原位观测数据,以具有较高时间分辨率和空间分辨率的国产卫星数据作为多光谱遥感数据源,测试评估了CM-BP浊度遥感反演模型适用性,并与传统波段组合模型进行精度比较,基于反演结果分析了研究区浊度时空分布特征。结果表明:基于集合建模思想构建的CM-BP模型的反演精度、适应性及稳定性均高于波段组合模型;从光谱分辨率、时空分辨率等角度考虑,环境与灾害监测预报小卫星星座系统、高分一号卫星、资源三号等国产卫星多光谱遥感数据是河流水体水质反演优选数据源;国产卫星遥感数据可以满足河流水体水质高精度、实时性与大尺度等遥感反演需要,为河流水环境监测研究提供数据基础。 相似文献
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以位于内蒙古的第一大湖-呼伦湖为研究对象,综合应用RS、GIS等现代分析技术手段,通过解译该区1973、1975、1986～2009年近36a的MSS、TM、ETM遥感影像,实现了呼伦湖湖泊水位、面积的遥感动态监测,并建立了关系模型：研究发现呼伦湖面积在1999年达到了1959年以来的最大水面面积2106．95km2后开始骤然下降到2009年的最低水面面积1813．69km2。以24．44km2／a的速度减少了293．26km2,水面面积比1999年最大面积时减少了近14％。水位高程自1999年的最高水位下降了3．94m,是呼伦湖平均水深（9m）的39．4％。收集、整理了呼伦湖及上游流域4个气象站点、3个水文站点近52a的气象、水文资料。分析了呼伦湖区域尺度内的水热状况变化,发现研究区域温度升高。降水呈波动性减少．并且在1999年后温度和降水的变率增大,是呼伦湖面积减小、水位下降的主要原因。最后．分析了气候变化对呼伦湖生态环境的影响效应。并建立了湖泊水位和降水、气温等气象因子以及径流量之间的关系模型．研究可为寒旱区湖泊水环境管理提供参考。 相似文献
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长江源区地处我国三江源自然保护区内,作为长江的源头是整个长江开发利用和环境保护的关键一环。从源区土地利用/覆盖角度分析源区自然环境状态变化,利用ENVI和Arc GIS软件对1980-2010年4期长江源区遥感数据进行解译,以土地利用动态度、综合程度指数及转移矩阵作为评价指标。结果表明:长江源区地貌类型以草地和裸地为主,建筑用地和耕地最少;全时段1980-2010年间,水域面积减少最多,裸地面积增加最多,相对于初期而言源区自然环境有所下降; 1990-2000年间是土地利用开发强度最强的时段,随着2000年三江源保护区的建立,2000-2010年长江源区土地利用朝着恢复方向发展,自然环境有所改善。 相似文献
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简述了无人机航测和卫星遥感的基本特点,对新技术与传统监测方法进行了比较,阐述了无人机航测在长江河道监测中的作业流程和卫星遥感在河道管理中的应用,并结合具体实例,论证了新技术在长江河道测绘、河势分析和抢险救灾中的重要作用和价值,该技术方法为推进数字孪生流域建设、全面实现“十四五”水利信息化提供了新的思路和方法。 相似文献
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C. J. Legleiter 《河流研究与利用》2013,29(6):760-780
Remote sensing could facilitate efficient characterization of river systems for research and management purposes, provided that suitable image data are available and that the information derived therefrom is reliable. This study evaluated the utility of public domain multispectral images for estimating flow depths in a small stream and a larger gravel‐bed river, using data acquired through a task‐oriented consortium and the National Agricultural Imagery Program (NAIP). Field measurements were used to calibrate image‐derived quantities to observed depths and to assess depth retrieval accuracy. A band ratio‐based algorithm yielded coherent, hydraulically reasonable bathymetric maps for both field sites and three different types of image data. Applying a spatial filter reduced image noise and improved depth retrieval performance, with a strong calibration relationship (R2 = 0.68) and an observed (field‐surveyed) versus predicted (image‐derived) R2 of 0.6 for tasked images of the smaller stream. The NAIP data were less useful in this environment because of geo‐referencing errors and a coarser spatial resolution. On the larger river, NAIP‐derived bathymetry was more accurate, with an observed versus predicted R2 value of 0.64 for a compressed county mosaic easily accessible via the Internet. Comparison of remotely sensed bathymetric maps with field surveys indicated that although the locations of pools were determined accurately, their full depth could not be detected because of limited sensor radiometric resolution. Although a number of other constraints also must be considered, such as the need for local calibration data, depth retrieval from publicly available image data is feasible under appropriate conditions. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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介绍了遥感技术在洪涝灾害监测评估中的作用以及目前的应用状况 ,指出针对流域洪水汛情的遥感监测分析是遥感技术在防洪减灾应用中的一个重要方面 .提出了基于基础背景数据库、实时水文信息及多时相遥感影像对比等进行洪水汛情遥感监测分析的方法 ,在 2 0 0 3年淮河大洪水中的实例分析表明 ,利用遥感技术综合其它水文等相关信息 ,可以比较准确、及时、全面地把握整个流域洪水的汛情状况及其发展变化趋势 ,能够起到防洪减灾的作用 . 相似文献
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We employed an integrated system of airborne remote sensing and ground surveys for regional mapping of instream habitats under variable flows over a 70 km section of the Lower Yakima River in southern Washington, USA. Airborne multispectral digital imagery was obtained in conjunction with field survey measurements and used to quantify the spatial extent, condition and temporal changes of selected river habitat characteristics under two different flows (14 and 28 m3 s?1). Under each flow, geomorphic measures were quantified (e.g. channel complexity, number and size of habitats). Water depth and velocity were also classified for instream habitats, and temperature and turbidity were recorded. Remote sensing classification accuracies for islands, exposed rocks and water surfaces were greater than 99%, while more detailed depth/flow classifications were less accurate (68% and 72%, for the high and low flows, respectively). While high turbidity (>4 Nephelometric Turbidity Units (NTU)), shadows and bidirectional reflectance factor reduced classification accuracies, the overall effect of these factors was minimal. Under the low‐flow situation, off‐channel habitats were less abundant, more isolated and had shallower depths and warmer temperatures. Our analysis suggests that airborne multispectral imagery, coupled with appropriate ground truth data, can be a viable method for regional mapping of diverse riverine habitats under variable flows. We concluded from this analysis that the higher flow situation provided substantially better habitat than currently exists in the Lower Yakima River. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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针对日益频发的极端暴雨事件使得城市道路积水的问题,为获得及时准确的积水数据,从道路积水监测技术层面,梳理了人工监测、传感器监测、遥感和视频影像监测的技术原理及相关改进,对比分析了不同传感器监测的优缺点。在此基础上,总结了道路积水监测技术的应用情况,并就未来发展趋势进行了展望。分析认为,道路积水监测需充分利用现有的视频设备、改进遥感水体识别技术、构建多源立体监测网以及基于海量监测数据的雨洪物理-数字耦合模型等方面开展研发和应用,全方位提高城市的雨洪预警水平和能力。 相似文献
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River corridors play a crucial environmental, economic, and societal role yet also represent one of the world's most dangerous natural hazards, making monitoring imperative to improve our understanding and to protect people. Remote sensing offers a rapidly growing suite of methods by which river corridor monitoring can be performed efficiently, at a range of scales and in difficult environmental conditions. This paper aims to evaluate the current state and assess the potential future of river corridor monitoring, whilst highlighting areas that require further investigation. We initially review established methods that are used to undertake river corridor monitoring, framed by the context and scales upon which they are applied. Subsequently, we review cutting edge technologies that are being developed and focussed around unmanned aerial vehicle and multisensor system advances. We also “horizon scan” for future methods that may become increasingly prominent in research and management, citing examples from within and outside of the fluvial domain. Through review of the literature, it has become apparent that the main gap in fluvial remote sensing lies in the trade‐off between resolution and scales. However, prioritising process measurements and simultaneous multisensor data collection is likely to offer a bigger advance in understanding than purely from better surveying methods alone. Challenges regarding the legal deployment of more complex systems, as well as effectively disseminating data into the science community, are amongst those that we propose need addressing. However, the plethora of methods currently available means that researchers and monitoring agencies will be able to identify suitable techniques for their needs. 相似文献
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G. W. Geerling M. J. Vreeken‐Buijs P. Jesse A. M. J. Ragas A. J. M. Smits 《河流研究与利用》2009,25(7):795-813
Floodplain land cover maps are important tools for river management and ecological assessment. These maps have to be revised regularly due to the dynamic nature of floodplains. Automation of the mapping process cuts the map processing time and can increase overall accuracy. Manual delineation and classification of vegetation is based on colour, contrasts (texture) and often‐stereoscopic view of aerial images. In this study, this is mimicked by the simultaneous use of both structural light detection and ranging (LiDAR) and compact airborne spectral imager (CASI) remote sensing data in an image segmentation routine fractal net evolution approach (FNEA). The segmentation results are tested against manually delineated ecotopes. Ecotope delineation improves when LiDAR and CASI are used simultaneously; the combination significantly lowers the number of segmented objects needed to accurately map ecotopes. Overall map accuracy of the LiDAR and CASI combination is 8–19% higher than single CASI and LiDAR, respectively. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Methods for spectrally based mapping of river bathymetry have been developed and tested in clear‐flowing, gravel‐bed channels, with limited application to turbid, sand‐bed rivers. This study used hyperspectral images and field surveys from the dynamic, sandy Niobrara River to evaluate three depth retrieval methods. The first regression‐based approach, optimal band ratio analysis (OBRA), paired in situ depth measurements with image pixel values to estimate depth. The second approach used ground‐based field spectra to calibrate an OBRA relationship. The third technique, image‐to‐depth quantile transformation (IDQT), estimated depth by linking the cumulative distribution function (CDF) of depth to the CDF of an image‐derived variable. OBRA yielded the lowest depth retrieval mean error (0.005 m) and highest observed versus predicted R2 (0.817). Although misalignment between field and image data did not compromise the performance of OBRA in this study, poor georeferencing could limit regression‐based approaches such as OBRA in dynamic, sand‐bedded rivers. Field spectroscopy‐based depth maps exhibited a mean error with a slight shallow bias (0.068 m) but provided reliable estimates for most of the study reach. IDQT had a strong deep bias but provided informative relative depth maps. Overprediction of depth by IDQT highlights the need for an unbiased sampling strategy to define the depth CDF. Although each of the techniques we tested demonstrated potential to provide accurate depth estimates in sand‐bed rivers, each method also was subject to certain constraints and limitations. 相似文献
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长江源广泛发育辫状河道,共同组成一个庞大的辫状河群,在水流泥沙与河床地形数据缺乏的条件下,长江源辫状河道形态的时空变化尚缺少研究。基于Landsat遥感影像解译,研究长江源通天河局部辫状河段的平面形态特征与分汊强度的时空变化规律。结果表明:1987—2016年辫状河段的水域面积与河床面积之比在年内呈现单峰变化过程,即汛期4—9月份逐渐变大,非汛期10月—次年3月趋于变小至基本不变,而且近30 a有所增加,间接反映了长江源径流量增加的趋势。辫状河段的36个横断面的汊道数指数和汊道长度指数分别为4~10和5~12,在1994,2005,2015年其均值几乎维持不变,表明此辫状河段的整体形态具有自相似性且河型不变。 相似文献