Contamination of agricultural soils by heavy metals has become a major concern due to their toxic effects on plant growth,symbiosis and consequently the yields of crops. In the present study, to enhance plant growth i...Contamination of agricultural soils by heavy metals has become a major concern due to their toxic effects on plant growth,symbiosis and consequently the yields of crops. In the present study, to enhance plant growth in Cr（VI）-amended soils, novel metalresistant plant growth-promoting bacteria（PGPB） were isolated from a soil contaminated with industrial waste effluent. One of the bacterial isolates, identified as Enterobacter sp. C1 D by 16 S r RNA gene sequencing, was found to be multi-metal resistant in nature with excellent plant growth-promoting（PGP） traits. Mung bean（Vigna radiata var. GM4） inoculation with Enterobacter sp.C1 D significantly（P ＆lt; 0.01） increased root and shoot length, shoot and root weight, and chlorophyll content in a range of Cr（VI）treatments. Plant tolerance towards Cr（VI） measured as effective concentration showed higher values with Enterobacter sp. C1 Dtreated plants compared to un-inoculated plants. Root colonization study was also carried out using green fluorescence protein-labeled Enterobacter sp. C1 D under a hydroponic system. Confocal laser scanning microscopy of the plant roots showed heavy bacterial loads on the surface of the plant root specifically at the root tip and the point of root hair/lateral root formation. The results of PGP traits showed that elevated indole acetic acid levels and 1-aminocyclopropane-1-carboxylate deaminase activity enabled Enterobacter sp. C1 D to enhance V. radiata growth in Cr（VI）-amended soils, whereby it significantly increased plant tolerance towards elevated Cr（VI） concentrations.展开更多
Icebergs are big chunks of ice floating on the ocean surface,and melting of icebergs contributes for the major part of freshwater flux into ocean.Dynamic monitoring of the icebergs in Antarctica and accurate estimatio...Icebergs are big chunks of ice floating on the ocean surface,and melting of icebergs contributes for the major part of freshwater flux into ocean.Dynamic monitoring of the icebergs in Antarctica and accurate estimation of their volume are important for predicting the trend of freshwater budget of the Southern Ocean.The iceberg freeboard is a key parameter for measuring the thickness and volume of an iceberg and is defined as the difference between the elevation of iceberg surface and sea level.So far,freeboards of icebergs have been successfully extracted using InSAR DEM,and the laser and radar altimeter.However,uncertainties exist in these results mainly caused by missed detection of small icebergs due to the spatially sparse and temporally incomplete data coverage.In addition to the above techniques,optical images can also be used to extract the iceberg freeboard based on its geometric relationship with shadow length,which can effectively compensate for the above shortcomings.Although the feasibility has been preliminarily presented,the precision and extensive application of shadow-height method deserves further research,such as estimating the basal melting of icebergs.In this work,we tested an optical image-based freeboard extraction method over icebergs in Prydz Bay,Antarctica.A normalized shadow pixel index(NSPI)is designed to identify iceberg shadows with different shapes in HY-1C/D CZI and Sentinel-2 MSI optical images.The iceberg freeboard can be determined with an acceptable precision(2 m)in optical images compared with laser altimeter(i.e.ICESat-2)measurements.Moreover,basal melting of icebergs has been assessed according to the variation of freeboard using repeated optical observations.The results indicate that icebergs in the study area were with a mean freeboard of about 56 m in early December 2022,and experienced a decrease in freeboard of 1.9 m within two months,in correspondence with the Antarctic seasonal trend.The methodological framework,therefore,turns out to be a reliable complementary approach to studying the iceberg freeboard in polar regions.展开更多
海洋一号C星(HY-1C)和海洋一号D星(HY-1D)是中国首次对地观测组网的海洋水色业务化应用卫星,其上搭载了海洋水色水温扫描仪COCTS (Chinese Ocean Color and Temperature Scanner)、海岸带成像仪CZI(Coastal Zone Imager)、紫外成像仪UVI...海洋一号C星(HY-1C)和海洋一号D星(HY-1D)是中国首次对地观测组网的海洋水色业务化应用卫星,其上搭载了海洋水色水温扫描仪COCTS (Chinese Ocean Color and Temperature Scanner)、海岸带成像仪CZI(Coastal Zone Imager)、紫外成像仪UVI (Ultra-Violet Imager)、星上定标光谱仪SCS (Satellite-based Calibration Spectrometer)和船舶自动识别系统AIS (Automatic Identification System),实现了全球海洋水色要素每天2次、海表温度每天4次的全球覆盖观测,中国近海及海岸带区域每3天2次的50 m高分辨率观测。本文介绍了HY-1C/D卫星及其载荷性能、产品处理流程、产品分级与分发等相关信息,HY-1C/D卫星产品体系完整且数据产品处理与分发高效。同时阐述了HY-1C/D卫星的叶绿素a浓度估算和海表温度反演产品,以及HY-1C/D卫星数据在浒苔绿潮、海冰/极冰、近海养殖、内陆水体和台风云图等方面的典型监测应用且具有较好的产品质量、在海洋与海岸带环境监测中具有较高的应用价值。展开更多
近海及海湾总悬浮物是重要的水质参数之一,而杭州湾及其邻近海域是典型的海湾与近岸海域,与人类关系密切。卫星遥感广泛应用于海水总悬浮物浓度的探测与分析。利用现场实测数据,建立了中国HY-1C/D卫星水色水温扫描仪(Chinese Ocean Colo...近海及海湾总悬浮物是重要的水质参数之一,而杭州湾及其邻近海域是典型的海湾与近岸海域,与人类关系密切。卫星遥感广泛应用于海水总悬浮物浓度的探测与分析。利用现场实测数据,建立了中国HY-1C/D卫星水色水温扫描仪(Chinese Ocean Color and Temperature Scanner, COCTS)及其他当前在轨的典型水色遥感器在杭州湾及邻近海域的总悬浮物卫星遥感反演方法模型,模型平均相对误差不高于19%。反演并融合获得了HY-1C/D等多源卫星2015-2022年杭州湾及邻近海域的总悬浮物浓度卫星遥感及其融合数据。融合数据经实测数据对比验证,两者之间线性相关系数为0.72,平均相对偏差为26%。卫星遥感结果表明,2015-2022年间杭州湾及其邻近海域总悬浮物浓度年际变化不大,其线性变化不超过其年平均浓度值的0.5%。研究结果表明利用包括HY-1C/D卫星COCTS等的海洋水色遥感载荷,可有效遥感反演得到杭州湾及其邻近海域的总悬浮物浓度并分析其时空变化特征。展开更多
溢油是海洋环境监测的重要目标之一。近年来,光学遥感对海面溢油不同污染类型的识别、分类与估算原理得到阐明,其技术优势获得认可;能为海面溢油监测提供颠覆性的技术支持,提高了溢油的识别精度,实现精细化定量探测。随着中国海洋水色...溢油是海洋环境监测的重要目标之一。近年来,光学遥感对海面溢油不同污染类型的识别、分类与估算原理得到阐明,其技术优势获得认可;能为海面溢油监测提供颠覆性的技术支持,提高了溢油的识别精度,实现精细化定量探测。随着中国海洋水色业务卫星—HY-1C/D(Haiyang-1C/D)的投入应用,其搭载的海岸带成像仪CZI(Coastal Zone Imager)在中国近海溢油监测中体现了较好的效能;但HY-1C/D星CZI载荷开展中国近海溢油业务化监测应用,还需要不断丰富并发展溢油识别提取算法。在HY-1C/D星CZI载荷的高空间分辨率影像中,不同的海面溢油污染类型具有明确的光谱响应特征和形态特征;太阳耀光反射差异,有助于海面溢油的遥感检测,同时也给溢油污染的识别分类与定量估算带来不确定性影响。本研究在CZI载荷数据对海面溢油波段响应基础上,通过溢油海面与背景干扰的耀光反射特征分析,厘清CZI图像中海面耀光干扰的空间分布特点;进一步在优选波段的移动窗口分割及其参数统计基础上,通过对不同分割窗间的耀光形态特征及其相关性判断,实现了CZI图像上海面溢油较高精度的识别与提取。其中,弱耀光条件下油膜提取的平均精度为90.24%、乳化油的平均精度为80.55%;强耀光条件下溢油提取总体效果也较好。面向国产自主海洋水色业务卫星数据,发展溢油光学遥感识别、分类、提取与估算,不仅能促进国产海洋光学卫星的业务化应用,更能为全面掌握中国近海溢油污染状况提供数据参考。展开更多
红夜光藻是我国主要的赤潮优势种,在渤海、黄海、东海和南海均有发生。近年来,红夜光藻赤潮发生频率明显上升,监测需求迫切。但红夜光藻赤潮发生具有分布范围广、变化速度快、多呈条带状分布的特点,其探测对卫星影像空间分辨率、覆盖范...红夜光藻是我国主要的赤潮优势种,在渤海、黄海、东海和南海均有发生。近年来,红夜光藻赤潮发生频率明显上升,监测需求迫切。但红夜光藻赤潮发生具有分布范围广、变化速度快、多呈条带状分布的特点,其探测对卫星影像空间分辨率、覆盖范围和重访周期要求高。虽然水色卫星在赤潮监测中发挥了重要作用,但其空间分辨率低,无法准确探测条带状分布的红夜光藻赤潮。海洋一号C、D(HY-1C/D)卫星搭载的海岸带成像仪(Coastal Zone Imager,CZI)以其高空间分辨率、大幅宽和短重访周期的优势,被越来越多地用于赤潮监测。现有的红夜光藻赤潮HY-1C/D CZI探测模型大多基于深度学习方法,需要大量赤潮样本,但赤潮样本获取困难,影响模型的精度。因此,本文以2022年3月发生在广东省汕尾市红海湾的红夜光藻赤潮为例,分析了红夜光藻赤潮光谱特征,基于红夜光藻赤潮在红光和近红外波段的高反射特性和浑浊水体在绿光波段的高反射特性,构建了一个面向HY-1C/D CZI的红夜光藻赤潮探测方法。实验结果表明,该方法可以有效地探测赤潮,并避免浑浊水体的干扰,精确率和F1-Score达到89.72%和0.90。而且,该方法具有较好的适用性,可适用于不同海洋环境、不同宽波段卫星传感器的红夜光藻赤潮探测。展开更多
基金supported by the Department of Science and Technology (DST), Government of India (No. SR/S4/ES-21/Baroda Window/P3)
文摘Contamination of agricultural soils by heavy metals has become a major concern due to their toxic effects on plant growth,symbiosis and consequently the yields of crops. In the present study, to enhance plant growth in Cr（VI）-amended soils, novel metalresistant plant growth-promoting bacteria（PGPB） were isolated from a soil contaminated with industrial waste effluent. One of the bacterial isolates, identified as Enterobacter sp. C1 D by 16 S r RNA gene sequencing, was found to be multi-metal resistant in nature with excellent plant growth-promoting（PGP） traits. Mung bean（Vigna radiata var. GM4） inoculation with Enterobacter sp.C1 D significantly（P ＆lt; 0.01） increased root and shoot length, shoot and root weight, and chlorophyll content in a range of Cr（VI）treatments. Plant tolerance towards Cr（VI） measured as effective concentration showed higher values with Enterobacter sp. C1 Dtreated plants compared to un-inoculated plants. Root colonization study was also carried out using green fluorescence protein-labeled Enterobacter sp. C1 D under a hydroponic system. Confocal laser scanning microscopy of the plant roots showed heavy bacterial loads on the surface of the plant root specifically at the root tip and the point of root hair/lateral root formation. The results of PGP traits showed that elevated indole acetic acid levels and 1-aminocyclopropane-1-carboxylate deaminase activity enabled Enterobacter sp. C1 D to enhance V. radiata growth in Cr（VI）-amended soils, whereby it significantly increased plant tolerance towards elevated Cr（VI） concentrations.
基金supported by National Key Research and Development Program of China[Grant number 2021YFC2803301]China Europe Dragon 5 Cooperation Program[Grant number 59310]National Natural Science Foundation of China[Grant number 42071387].
文摘Icebergs are big chunks of ice floating on the ocean surface,and melting of icebergs contributes for the major part of freshwater flux into ocean.Dynamic monitoring of the icebergs in Antarctica and accurate estimation of their volume are important for predicting the trend of freshwater budget of the Southern Ocean.The iceberg freeboard is a key parameter for measuring the thickness and volume of an iceberg and is defined as the difference between the elevation of iceberg surface and sea level.So far,freeboards of icebergs have been successfully extracted using InSAR DEM,and the laser and radar altimeter.However,uncertainties exist in these results mainly caused by missed detection of small icebergs due to the spatially sparse and temporally incomplete data coverage.In addition to the above techniques,optical images can also be used to extract the iceberg freeboard based on its geometric relationship with shadow length,which can effectively compensate for the above shortcomings.Although the feasibility has been preliminarily presented,the precision and extensive application of shadow-height method deserves further research,such as estimating the basal melting of icebergs.In this work,we tested an optical image-based freeboard extraction method over icebergs in Prydz Bay,Antarctica.A normalized shadow pixel index(NSPI)is designed to identify iceberg shadows with different shapes in HY-1C/D CZI and Sentinel-2 MSI optical images.The iceberg freeboard can be determined with an acceptable precision(2 m)in optical images compared with laser altimeter(i.e.ICESat-2)measurements.Moreover,basal melting of icebergs has been assessed according to the variation of freeboard using repeated optical observations.The results indicate that icebergs in the study area were with a mean freeboard of about 56 m in early December 2022,and experienced a decrease in freeboard of 1.9 m within two months,in correspondence with the Antarctic seasonal trend.The methodological framework,therefore,turns out to be a reliable complementary approach to studying the iceberg freeboard in polar regions.
文摘海洋一号C星(HY-1C)和海洋一号D星(HY-1D)是中国首次对地观测组网的海洋水色业务化应用卫星,其上搭载了海洋水色水温扫描仪COCTS (Chinese Ocean Color and Temperature Scanner)、海岸带成像仪CZI(Coastal Zone Imager)、紫外成像仪UVI (Ultra-Violet Imager)、星上定标光谱仪SCS (Satellite-based Calibration Spectrometer)和船舶自动识别系统AIS (Automatic Identification System),实现了全球海洋水色要素每天2次、海表温度每天4次的全球覆盖观测,中国近海及海岸带区域每3天2次的50 m高分辨率观测。本文介绍了HY-1C/D卫星及其载荷性能、产品处理流程、产品分级与分发等相关信息,HY-1C/D卫星产品体系完整且数据产品处理与分发高效。同时阐述了HY-1C/D卫星的叶绿素a浓度估算和海表温度反演产品,以及HY-1C/D卫星数据在浒苔绿潮、海冰/极冰、近海养殖、内陆水体和台风云图等方面的典型监测应用且具有较好的产品质量、在海洋与海岸带环境监测中具有较高的应用价值。
文摘近海及海湾总悬浮物是重要的水质参数之一,而杭州湾及其邻近海域是典型的海湾与近岸海域,与人类关系密切。卫星遥感广泛应用于海水总悬浮物浓度的探测与分析。利用现场实测数据,建立了中国HY-1C/D卫星水色水温扫描仪(Chinese Ocean Color and Temperature Scanner, COCTS)及其他当前在轨的典型水色遥感器在杭州湾及邻近海域的总悬浮物卫星遥感反演方法模型,模型平均相对误差不高于19%。反演并融合获得了HY-1C/D等多源卫星2015-2022年杭州湾及邻近海域的总悬浮物浓度卫星遥感及其融合数据。融合数据经实测数据对比验证,两者之间线性相关系数为0.72,平均相对偏差为26%。卫星遥感结果表明,2015-2022年间杭州湾及其邻近海域总悬浮物浓度年际变化不大,其线性变化不超过其年平均浓度值的0.5%。研究结果表明利用包括HY-1C/D卫星COCTS等的海洋水色遥感载荷,可有效遥感反演得到杭州湾及其邻近海域的总悬浮物浓度并分析其时空变化特征。
文摘溢油是海洋环境监测的重要目标之一。近年来,光学遥感对海面溢油不同污染类型的识别、分类与估算原理得到阐明,其技术优势获得认可;能为海面溢油监测提供颠覆性的技术支持,提高了溢油的识别精度,实现精细化定量探测。随着中国海洋水色业务卫星—HY-1C/D(Haiyang-1C/D)的投入应用,其搭载的海岸带成像仪CZI(Coastal Zone Imager)在中国近海溢油监测中体现了较好的效能;但HY-1C/D星CZI载荷开展中国近海溢油业务化监测应用,还需要不断丰富并发展溢油识别提取算法。在HY-1C/D星CZI载荷的高空间分辨率影像中,不同的海面溢油污染类型具有明确的光谱响应特征和形态特征;太阳耀光反射差异,有助于海面溢油的遥感检测,同时也给溢油污染的识别分类与定量估算带来不确定性影响。本研究在CZI载荷数据对海面溢油波段响应基础上,通过溢油海面与背景干扰的耀光反射特征分析,厘清CZI图像中海面耀光干扰的空间分布特点;进一步在优选波段的移动窗口分割及其参数统计基础上,通过对不同分割窗间的耀光形态特征及其相关性判断,实现了CZI图像上海面溢油较高精度的识别与提取。其中,弱耀光条件下油膜提取的平均精度为90.24%、乳化油的平均精度为80.55%;强耀光条件下溢油提取总体效果也较好。面向国产自主海洋水色业务卫星数据,发展溢油光学遥感识别、分类、提取与估算,不仅能促进国产海洋光学卫星的业务化应用,更能为全面掌握中国近海溢油污染状况提供数据参考。
文摘红夜光藻是我国主要的赤潮优势种,在渤海、黄海、东海和南海均有发生。近年来,红夜光藻赤潮发生频率明显上升,监测需求迫切。但红夜光藻赤潮发生具有分布范围广、变化速度快、多呈条带状分布的特点,其探测对卫星影像空间分辨率、覆盖范围和重访周期要求高。虽然水色卫星在赤潮监测中发挥了重要作用,但其空间分辨率低,无法准确探测条带状分布的红夜光藻赤潮。海洋一号C、D(HY-1C/D)卫星搭载的海岸带成像仪(Coastal Zone Imager,CZI)以其高空间分辨率、大幅宽和短重访周期的优势,被越来越多地用于赤潮监测。现有的红夜光藻赤潮HY-1C/D CZI探测模型大多基于深度学习方法,需要大量赤潮样本,但赤潮样本获取困难,影响模型的精度。因此,本文以2022年3月发生在广东省汕尾市红海湾的红夜光藻赤潮为例,分析了红夜光藻赤潮光谱特征,基于红夜光藻赤潮在红光和近红外波段的高反射特性和浑浊水体在绿光波段的高反射特性,构建了一个面向HY-1C/D CZI的红夜光藻赤潮探测方法。实验结果表明,该方法可以有效地探测赤潮,并避免浑浊水体的干扰,精确率和F1-Score达到89.72%和0.90。而且,该方法具有较好的适用性,可适用于不同海洋环境、不同宽波段卫星传感器的红夜光藻赤潮探测。
