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1.
浮游植物是水体生态系统中的重要初级生产者,其中硅藻贡献海洋初级生产力约40%,因此估算硅藻浓度对了解海洋生物地球化学过程和生态系统演变至关重要。本文基于2016年6月黄渤海和2018年7月黄渤海航次实测色素浓度数据集,利用CHEMTAX软件,获取硅藻浓度信息;之后,结合实测遥感反射率数据,利用奇异值分解方法,构建硅藻浓度反演模型。检验结果表明：模型的决定系数为0.80(p<0.001),平均绝对百分比误差和中值误差分别为58.62%和39.12%,模型适用度较高;经过卫星验证,该模型适用于GOCI(Geostationary Ocean Color Imager)传感器。将模型应用于2020年6月份GOCI月平均数据,其硅藻浓度空间分布趋势与前人研究一致。本研究成果可为近海水体硅藻生物量的遥感估算研究提供技术方法支撑。 相似文献
2.
水深可见光遥感方法研究进展 总被引：2，自引：0，他引：2
水深测量对于水利、航运、近海工程等具有重要作用。在总结国内外水体遥感测深主要方法和研究进展的基础上,对水深遥感反演中各类模型存在的问题进行了讨论。结果表明:理论解译模型模拟了光在水体内的辐射传输过程,水深反演精度较高,但模型计算需要大量的水体光学参数且计算过程烦琐;半理论半经验模型对理论解译模型进行了简化,所需水体光学参数少且具有较好的精度而被广为应用;统计相关模型通过直接建立遥感图像光谱值和实测水深之间的相关关系而获得水深数据,且计算相对简单,但由于实测水深值与遥感图像光谱值的事实相关性无法保证,使采用该类模型反演的水深结果有时并不理想。提高水深遥感反演精度,必须进一步加强遥感器研究,充分考虑水体中的溶解、悬浮物质等信息干扰,科学构建水深模型和大气校正模型。 相似文献
3.
在总结国内外悬浮泥沙遥感监测的基础上,以长江南京段水域为研究区,对实测的水体光谱值与悬浮泥沙浓度回归分析,建立了悬浮泥沙浓度遥感反演模式。 相似文献
4.
浮游植物的粒级结构是一个重要的生物参数。基于南海北部海区不同水体环境下测量的生物光学数据, 作者深入研究了粒级结构对浮游植物吸收光谱的影响。结果表明, 选择443和510nm波段计算得到的浮游植物光谱斜率S对粒级结构的变化具有较高的敏感性, 其随着小型浮游植物比例的增大呈不断增加的趋势。S与水体叶绿素a浓度、浮游植物吸收系数(aph(443))之间表现出明显的正相关特征。以40%为界对不同粒级浮游植物的优势进行定义, 发现在S与叶绿素a浓度、aph(443)的关系分布中小型(Micro)和微微型(Pico)浮游植物占据优势的水体表现出较为明显的分界, 叶绿素a浓度和aph(443)分别在0.70mg•m-3和0.05m-1附近, 相应的S在0.0004(m•nm)-1左右。基于实测数据建立的遥感反射率蓝绿波段比值与S之间的统计关系, 决定系数高达0.91, 为从水色遥感数据反演浮游植物粒级结构提供了重要手段。 相似文献
5.
利用高光谱监测数据反演浮游植物种群组成是当前海洋光学和水色遥感的研究热点。文章采用大西洋经向断面航次中走航式观测系统测量的海水总颗粒物吸收光谱数据, 尝试建立了两种模型对浮游植物粒级结构(Phytoplankton size class, 简称PSC)进行反演和比较讨论。一类模型是基于总颗粒物吸收光谱高斯分解获得的典型波段高斯带强度与色素浓度之间的关系, 建立了偏最小二乘回归模型(Partial Least Squares regression model, 简称PLS回归模型); 另一类模型是采用长波波段吸收基线高度推算海水总叶绿素a浓度, 进而根据Brewin等(2010) 生物量算法推算PSC的三组分模型(简称三组分模型)。模型比较验证结果显示, 两类模型对海水总叶绿素浓度的反演都有较高的精度, 相对偏差ME在15%左右; 对于三个粒级浮游植物对应的叶绿素浓度(Pico级Cp, Nano级Cn, Micro级Cm)的反演效果也相当, PLS回归模型反演的ME分别为28.4%、31.9%和41%, 三组分模型反演的ME分别为31%、35.9%、37.7%。研究结果初步表明了采用高光谱吸收系数反演浮游植物种群结构的潜在优势, 可为不同海域走航式高光谱观测系统的推广应用提供思路。 相似文献
6.
为提高我国海洋水色遥感技术和海水环境监测水平,文章根据北海区海水遥感现场监测数据,基于经验算法和荧光基线高度法的回归分析,开展海水表层叶绿素a浓度的遥感定量反演,并选取北黄海近岸海域样本数据进行算法检验。研究结果表明:辽东湾等9个北海区典型海域具有相同或相似海水表层光学特性,适宜建立海水表层叶绿素a浓度遥感定量反演模型;典型海域海水表层叶绿素a浓度与遥感反射率之间的相关关系较强,模型均为简单波段比值模型;二类海水研究区域海水表层叶绿素a浓度与荧光基线高度之间的相关关系不明显;北黄海近岸海域海水表层叶绿素a浓度的最优模型遥感定量反演值的相对误差的平均值为0.669μg/L。 相似文献
7.
在南海北部、大亚湾及珠江口3个不同水体生物-光学数据的基础上, 研究了浮游植物粒径结构的变化特征, 建立了基于浮游植物吸收光谱提取的浮游植物粒径参数(S<f>)的混合光谱模型。南海海区不同的水体环境下浮游植物的粒级结构有着很大的差异: 在河口和沿岸水体小型浮游植物占优势, 在外海水体微微型浮游植物占优势。浮游植物粒径参数随小型浮游植物增多而减少, 随微微型浮游植物增多而增大。叶绿素a浓度从外海到沿岸逐渐增大, 浮游植物粒径参数随叶绿素a浓度的增大而减小, 它们之间呈幂函数关系。结果表明, 利用混合光谱模型得到的浮游植物粒径参数与南海海区不同水体的生物-光学特征(粒级结构Rpico和Rmicro、粒级指数SI、叶绿素a浓度)有一定的相关性。具体的相关性表示为: S<f>与粒级结构(Rpico和Rmicro)存在一定的关系, 与小型浮游植物和微微型浮游植物之间的线性相关系数分别是0.55和0.65; S<f>与浮游植物粒级指数(SI)有较好的线性关系, 相关系数是0.57; S<f>与叶绿素a浓度呈幂函数关系, 相关系数是0.64。这个混合光谱模型为从光学参数反演浮游植物种群的生态学信息提供了有效的手段, 同时又可用于分析浮游植物优势粒径结构对光学特性的影响。 相似文献
8.
水体吸收系数是影响水体光场分布的重要参数,在水色遥感探测中受到广泛关注。本文利用2012年9月辽东湾区域航次调查数据分析该区域水体各组分吸收系数的分布情况,结果表明,辽东湾水体中浮游植物含量相对较高。并利用该航次数据,建立了区域性半分析算法,该算法基于相邻波段间固有光学量的线性关系,首先通过遥感反射率反演得到550 nm波段的水体总吸收系数,再通过后向散射波段相关关系外推得到其他波段的总吸收系数。经独立测试数据检验,3个波段(412、443、550 nm)总吸收系数反演的平均相对误差分别为19.71%,17.99%,9.35%,说明区域性半分析算法能较好地估算研究区域的水体总吸收系数。本文还通过引入随机误差对算法稳定性进行了检验,结果表明算法具有较好的稳定性。 相似文献
9.
海洋中光后向散射系数的变化包含了浮游植物生物量的信息, 可应用于卫星遥感和光学剖面观测平台获取海洋中大时空尺度-高分辨率剖面的浮游植物生物量变化特征。本文选取了琼东上升流影响下生物—光学变异性较为显著的海域, 基于2013年航次实测数据, 建立了颗粒物后向散射系数(bbp)与叶绿素a浓度(Chl a)间的区域性关系模型。模型假定颗粒物后向散射系数由不随叶绿素浓度变化的固定背景值, 以及较大粒级(>2μm)和pico级(微微型, <2μm)两类浮游植物的后向散射贡献累加所得。采集的数据集进行了模型检验, 结果表明, 模型能很好地模拟琼东海域水体的bbp与Chl a间的变化趋势, 性能优于常用的幂函数关系模型, 尤其在低叶绿素浓度范围, 很好地解决幂函数显著低估的现象; 琼东海域的bbp和Chl a关系存在显著的水层变化, 底层后向散射固定背景值显著高于上层水体背景值, 表明底层受上升流的影响, 水体中不随Chl a共变的颗粒物浓度增大, 其后向散射相应增强; 叶绿素最大层的后向散射固定背景值显著低于上层其他水体的固定背景值, 后向散射固定背景值的贡献百分比约为21%~35%; 随着叶绿素浓度增大, 较大粒级的浮游植物对颗粒物后向散射系数的贡献也显著增大, 可达到50%以上, pico级浮游植物贡献稳定在40%附近。本研究的结果将为琼东海域浮游植物生物量的光学遥感、生物地球化学过程研究提供更为精确的区域性模型和基础支撑数据。 相似文献
10.
总悬浮物浓度是海洋的重要水质参数之一,其对水体透明度、水下光场及初级生产力有显著影响,同时对河流入海口与海岸带冲淤变化过程有重要作用。本文基于我国自主研制的SDGSAT-1卫星遥感影像,使用准分析算法（Quasi-Analytical Algorithm,QAA）获取水体固有光学量,并结合2022年4月黄河口区域总悬浮物浓度实测数据,建立水体固有光学量与总悬浮物浓度实测数据的单波段、波段加减、波段比值,以及多波段组合等模型并开展遥感反演,最后将反演结果同实测数据及基于Sentinel-2B影像的总悬浮物浓度反演结果进行对比。研究结果表明：基于SDGSAT-1影像的总悬浮物浓度反演结果在黄河口高浓度区域的决定系数为0.622,均方根误差为7.94 mg/L;基于Sentinel-2B影像的总悬浮物浓度反演结果在黄河口高浓度区域的决定系数为0.589,均方根误差为8.27 mg/L。故在我国近岸海域总悬浮物浓度反演方面,SDGSAT-1影像反演精度与Sentinel-2B影像反演精度相媲美。 相似文献
11.
The response of chlorophyll a (Chl a) concentration to wind stress is analyzed in the South China Sea (SCS), using in-situ data of Chl a and remote sensing data (QuikScat-sea surface wind (SSW), AVHRR-sea surface temperature (SST), AVISO merged-sea level anomalies (SLA), SeaWiFSderived Chl a and MODIS Terra-derived Chl a) in August/September/October 2004, 2006 and 2009. The variability of SSW, SST and SLA 7 d before in-situ Chl a sampling (including the work day of in-situ Chl a sampling) with the same latitude and longitude of the study area are investigated, and the correlation coefficients are calculated between these hydrographic factors and in-situ Chl a concentration. The results show that the Chl a-SSW correlation coefficients at upper layers (such as 0 m and 25 m) are more significant than those at deeper layers (such as 50, 75 and 100 m) 1-3 d before, which indicates that there is a time lag of strong surface winds stimulating phytoplankton bloom. By analyzing the relationship among the daily remote sensing derived (RSderived) SSW, SST, SLA and 3 d averaged SeaWiFS/MODIS-derived Chl a concentration in the northern SCS in September 2004 and 2009 respectively, it shows that the intensity and speed of surface winds could have great influence on extend of Chl a increase. If surface winds reach 4-5 m/s over, Chl a concentration would increase 1-3 d after the process of strong surface winds in open sea area of the northern SCS mainly during September. 相似文献
12.
HY-1 CCD宽波段水色要素反演算法 总被引：7，自引：4，他引：3
利用2003年春季黄海、东海区现场实测数据,建立了HY1卫星4波段CCD成像仪水色要素反演算法.由于HY1CCD的宽波段特性阻碍了黄色物质的反演,因此反演的水色要素仅包括水体表层的总悬浮物、悬浮泥沙(SS)以及叶绿素a的浓度.现场遥感反射率光谱由ASD地物波谱仪测量,对于叶绿素a的浓度利用现场萃取荧光法测量,总悬浮物、悬浮泥沙由实验室滤膜称重法获得.反演算法的拟合相关系数均大于0.88,平均相对误差在40%以下.对反演算法进行了误差灵敏度分析,结果表明对于总悬浮物、悬浮泥沙和低浊度水体中的叶绿素a的浓度反演算法能够满足日常的业务运行要求,但是对于高浊度水体中叶绿素a的浓度反演算法对某个波段组合比较敏感,仍需要进一步探讨. 相似文献
13.
Distributions of chlorophyll a and carbon fixed strength of phyto-plankton in autumn of the southern Huanghai Sea waters 总被引：1，自引：1，他引：1
1IntroductionRecently,the increasing carbon dioxide(CO2)in the atmosphere is viewed by many as perhaps themost serious global environment problemfacing man-kind.Numerous studies and surveys aiming at theglobal CO2flux therefore,have been made to esti-mate… 相似文献
14.
Water samples were collected in order to study the spatial variation of photosynthetic pigments and phytoplankton community composition in the Lembeh Strait(Indonesia) and the Kelantan River Estuary(Malaysia)during July and August 2016, respectively. Phytoplankton photosynthetic pigments were detected using high performance liquid chromatography combining with the CHEMTAX software to confirm the Chl a biomass and community composition. The Chl a concentration was low at surface in the Lembeh Strait, which it was 0.580–0.682 μg/L, with the average(0.620±0.039) μg/L. Nevertheless, the Chl a concentration fluctuated violently at surface in the Kelantan River Estuary, in which the biomass was 0.299–3.988 μg/L, with the average(0.922±0.992) μg/L. The biomass at bottom water was higher than at surface in the Kelantan River Estuary, in which the Chl a concentration was 0.704–2.352 μg/L, with the average(1.493±0.571) μg/L. Chl b, zeaxanthin and fucoxanthin were three most abundant pigments in the Lembeh Strait. As a consequence, phytoplankton community composition was different in the two study areas. In the Lembeh Strait, prasinophytes(26.48%±0.83%) and Synechococcus(25.73%±4.13%) occupied ～50% of the Chl a biomass, followed by diatoms(20.49%±2.34%) and haptophytes T8(15.13%±2.42%). At surface water in the Kelantan River Estuary, diatoms(58.53%±18.44%)dominated more than half of the phytoplankton biomass, followed by Synechococcus(27.27%±14.84%) and prasinophytes(7.00%±4.39%). It showed the similar status at the bottom water in the Kelantan River Estuary,where diatoms, Synechococcus and prasinophytes contributed 64.89%±15.29%, 16.23%±9.98% and 8.91%±2.62%,respectively. The different phytoplankton community composition between the two regions implied that the bottom up control affected the phytoplankton biomass in the Lembeh Strait where the oligotrophic water derived from the West Pacific Ocean. The terrigenous nutrients supplied the diatoms growing, and pico-phytoplankton was grazed through top down control in the Kelantan River Estuary. 相似文献
15.
在多光谱遥感浅海水深反演过程中,考虑到水体和底质影响,水深值和海水表面辐射亮度之间的线性关系不成立。本文以甘泉岛南部0～25m范围的沙质区域为研究区域,利用GeoEye-1多光谱遥感影像和多波束实测水深数据构建XGBoost非线性水深反演模型,研究了XGBoost算法用于水深反演的性能。以决定系数(R~2),均方误差(MSE)和平均绝对误差(MAE)作为评价指标,并与3种传统线性回归模型进行了对比分析。结果表明, XGBoost非线性水深反演模型的R~2、MSE和MAE分别为0.991、0.33m和0.44m,拟合程度最好,精度优于线性回归模型。为进一步探究各模型在不同水深的反演精度,将水深范围分成3段(0～8 m, 8～15 m, 15～25 m)分别进行精度验证和误差分析。结果表明, XGBoost模型在各分段的精度均优于线性回归模型, MSE依次为0.56 m, 0.14 m和0.43 m。可见,在单一底质区域下XGBoost模型的水深反演精度更高,且反演效果更稳定。 相似文献
16.
Ai Hattori-Saito Jun Nishioka Tsuneo Ono R. Michael L. McKay Koji Suzuki 《Journal of Oceanography》2010,66(1):105-115
In order to detect iron (Fe) stress in micro-sized (20–200 μm) diatoms in the Oyashio region, western subarctic Pacific during
spring, immunological ferredoxin/flavodoxin assays were applied to samples collected from the surface layer in May 2005. Concomitantly,
the community composition of the micro-sized phytoplankton and hydrographic conditions, including dissolved Fe and macronutrient
concentrations, were also examined. Chlorophyll (Chl) a concentrations were <2 mg m−3 at all sampling stations, except at a station where the Chl a level was 9.0 mg m−3 and a micro-sized diatom bloom occurred. A high abundance of ferredoxin in micro-sized diatoms was detected only at a rather
near-shore station where dissolved Fe and macronutrient concentrations were higher, indicating that the micro-sized diatoms
did not suffer from iron deficiency. On the other hand, flavodoxin in micro-sized diatoms was often observed at the other
stations, including the bloom station, where macronutrients were replete but dissolved Fe concentration was low (0.31 nM).
A significant amount of chlorophyllide a, a degradation product of Chl a, was also observed at the bloom station, suggesting a decline of the diatom bloom. The micro-sized phytoplankton species
at all the stations were mainly composed of the diatoms Thalassiosira, Chaetoceros, and Fragilariopsis spp. Our study indicates that micro-sized diatoms were stressed by Fe bioavailability during the spring season in the Oyashio
region 相似文献
17.
基于进化建模方法的HJ-1 CCD黄海悬浮物和叶绿素a浓度遥感反演模型研究 总被引：2，自引：1，他引：1
本文利用实测数据集,发展了基于进化建模方法的HJ-1CCD黄海悬浮物(TSM)和叶绿素a浓度(Chl a)遥感反演模型,建模过程中有针对性地设计了适合水色反演的端点集和函数集,并利用转基因方法引入水色先验知识。经实测数据检验,TSM反演的平均相对误差约为31%(相关系数R2为0.96),Chl a反演误差约为33%(R2为0.88)。分析了模型对输入误差的敏感性,当输入端引入±5%的误差时,模型误差的波动在大多数情形下都可控制在±10%以内。与神经网络模型相比,本文发展的进化模型具有检验精度高、结构简单等优势。利用不同季节的黄、东海实测数据进行了模型精度的独立检验。本文的研究工作表明,进化建模方法适用于水色遥感反演建模问题,可由程序自动生成多个满足精度要求、结构形式多样的显式模型,为水色反演应用提供了多种选择,对于拥有数百个波段的高光谱数据水色反演具有更大的应用潜力。本文最后探讨了进化建模方法的改进方向。 相似文献
18.
Community Structure and Dynamics of Phytoplankton in the Western Subarctic Pacific Ocean: A Synthesis 总被引：1，自引：1，他引：1
The phytoplankton community in the western subarctic Pacific (WSP) is composed mostly of pico- and nanophytoplankton. Chlorophyll
a (Chl a) in the <2 μm size fraction accounted for more than half of the total Chl a in all seasons, with higher contributions of up to 75% of the total Chl a in summer and fall. The exception is the western boundary along the Kamchatka Peninsula and Kuril Islands and the Oyashio
region where diatoms make up the majority of total Chl a during the spring bloom. Among the picophytoplankton, picoeukaryotes and Synechococcus are approximately equally abundant, but the former is more important in term of carbon biomass. Despite the lack of a clear
seasonal variation in Chl a concentration, primary productivity showed a large seasonal variation, and was lowest in winter and highest in spring. Seasonal
succession in the phytoplankton community is also evident with the abundance of diatoms peaking in May, followed by picoeukaryotes
and Synechococcus in summer. The growth of phytoplankton (especially >10 μm cell size) in the western subarctic Pacific is often limited by
iron bioavailability, and microzooplankton grazing keeps the standing stock of pico- and nano-phytoplankton low. Compared
to the other HNLC regions (the eastern equatorial Pacific, the Southern Ocean, and the eastern subarctic Pacific), iron limitation
in the Western Subarctic Gyre (WSG) may be less severe probably due to higher iron concentrations. The Oyashio region has
similar physical condition, macronutrient supply and phytoplankton species compositions to the WSG, but much higher phytoplankton
biomass and primary productivity. The difference between the Oyashio region and the WSG is also believed to be the results
of difference in iron bioavailability in both regions.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献