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Differentiation of Algal Blooms and Aquatic Vegetation in Chinese Lakes Using Modified Vegetation Presence Frequency Index Method

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Chinese Geographical Science 2022年第5期32卷 792-807页

作者： PU Jing SONG Kaishan LIU Ge wen zhidan FANG Chong HOU Junbing LV Yunfeng College of Geographical Sciences Changchun Normal UniversityChangchun 130032China Northeast Institute of Geography and Agro ecology Chinese Academy of ScienceChangchun 130102China

Algal blooms in lakes have become a common global environmental problem. Nowadays, remote sensing is widely used to monitor algal blooms in lakes due to the macroscopic, fast, real-time characteristics. However, it is often difficult to distinguish between algal blooms and aquatic vegetation due to their similar spectral characteristics. In this paper, we used modified vegetation presence frequency index(VPF) based on Moderate-resolution Imaging Spectroradiometer(MODIS) imagery to distinguish algal blooms from aquatic vegetation, and analyzed the spatial and temporal variations of algal blooms and aquatic vegetation from a phenological perspective for five large natural lakes with frequent algal bloom outbreaks in China from 2019 to 2020. We simplified the VPF method to make it with a higher spatial transferability so that it could be applied to other lakes in different climatic zones. Through accuracy validation, we found that the modified VPF method can effectively distinguish between algal blooms and aquatic vegetation, and the results vary from lake to lake. The highest accuracy of 97% was achieved in Hulun Lake, where the frequency of algal outbreaks is low and the extent of aquatic vegetation is stable, while the lowest accuracy of 76% was achieved in Dianchi Lake, which is rainy in summer and the lake is small. Analyses suggests that the time period when algal blooms occur most frequently might not coincide with that when they have the largest area. However, in most cases these two are close in terms of time period. The modified VPF method has a broad scope of application, is easy to implement, and has a high practical value. Furthermore, the method could be established using only a small amount of measured data, which is useful for water quality monitoring on large spatial scales.

关键词： algal blooms aquatic vegetation modified vegetation presence frequency index(VPF) phenology lake

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Re-estimating China's lake CO_(2)flux considering spatiotemporal variability

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Environmental Science and Ecotechnology 2024年第3期19卷 152-160页

作者： zhidan wen Yingxin Shang Lili Lyu Hui Tao Ge Liu Chong Fang Sijia Li Kaishan Song Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun130102China School of Environment and Planning Liaocheng UniversityLiaocheng252000China

The spatiotemporal variability of lake partial carbon dioxide pressure(pCO_(2))introduces uncertainty into CO_(2)fluxestimates at the lakewater-air *** the variationpattern of pCO_(2)isimportant for obtaining accurate global *** we examine seasonal and trophic variations in lake pCO_(2)based on 13 field campaigns conducted in Chinese lakes from 2017 to *** found significant seasonal fluctuations in pCO_(2),with decreasing values as trophic states intensify within the same *** lakes exhibit lower pCO_(2)levels thanfreshwater *** pCO_(2)dynamics result invariable areal CO_(2)emissions,withlakes exhibiting different trophic states(oligotrophication>mesotrophication>eutrophication)and saline lakes differing from freshwater lakes(-23.1±17.4 vs.19.3±18.3 mmol m^(-2)d^(-1)).These spatiotemporal pCO_(2)variations complicate total CO_(2)emission *** area proportions of lakes with varying trophic states and salinity in China,we estimate China's lake CO_(2)flux at 8.07 Tg C yr^(-1).In future studies,the importance of accounting for lake salinity,seasonal dynamics,and trophic statesmust be noticed to enhance the accuracy of large-scale carbon emission estimates from lake ecosystems in the context of climate change.

关键词： Carbon dioxide Eutrophication Saline lakes Overestimation Carbon budget

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Remote estimates of suspended particulate matter in global lakes using machine learning models

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International Soil and Water Conservation Research 2024年第1期12卷 200-216页

作者： zhidan wen Qiang Wang Yue Ma Pierre Andre Jacinthe Ge Liu Sijia Li Yingxin Shang Hui Tao Chong Fang Lili Lyu Baohua Zhang Kaishan Song Northeast Institute of Geography and Agroecology CASChangchunJilin130102China Department of Geology Indiana University∼Purdue UniversityIndianapolisIN44602USA University of Chinese Academy of Sciences Beijing100100China College of Geography and Urban Planning Liaocheng UniversityLiaochengChina

Suspended particulate matter(SPM)in lakes exerts strong impact on light propagation,aquatic ecosystem productivity,which co-varies with nutrients,heavy metal and micro-pollutant in *** lakes,SPM exerts strong absorption and backscattering,ultimately affects water leaving signals that can be detected by satellite *** regression models based on specific band or hand ratios have been widely used for SPM estimate in the past with moderate *** are still rooms for model accuracy improvements,and machine learning models may solve the non-linear relationships between spectral variable and SPM in *** assembled more than 16,400 in situ measured SPM in lakes from six continents(excluding the Antarctica continent),of which 9640 samples were matched with Landsat overpasses within±7 *** machine learning algorithms and two simple regression methods(linear and partial least squares models)were used to estimate SPM in lakes and the performance were *** overcome the problem of imbalance datasets in regression,a Synthetic Minority Over-Sampling technique for regression with Gaussian Noise(SMOGN)was adopted in this *** comparison,we found that gradient boosting decision tree(GBDT),random forest(RF),and extreme gradient boosting(XGBoost)models demonstrated good spatiotemporal transferability with SMOGN processed dataset,and has potential to map SPM at different year with good quality of Landsat land surface reflectance *** all the tested modeling approaches,the GBDT model has accurate calibration(n=6428,R^(2)=0.95,MAPE=29.8%)from SPM collected in 2235 lakes across the world,and the validation(n=3214,R^(2)=0.84,MAPE=38.8%)also exhibited stable ***,the good performances were also exhibited by RF model with calibration(R^(2)=0.93)and validation(R^(2)=0.86,MAPE=24.2%)*** applied GBDT and RF models to map SPM of typical lakes,and satisfactory result was *** addition,the GBDT model was evaluated b

关键词： Landsat imagery Remote estimation SPM Transferability

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Agricultural Development and Implication for Wetlands Sustainability: A Case from Baoqing County, Northeast China

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Chinese Geographical Science 2019年第2期29卷 231-244页

作者： FANG Chong wen zhidan LI Lin DU Jia LIU Ge WANG Xiaodi SONG Kaishan Northeast Institute of Geography and Agroecology Chinese Academy of Sciences University of Chinese Academy of Sciences Department of Earth Science Indiana University-Purdue University Indianapolis School of Geography and Tourism Harbin University

Historical thematic maps and remote sensing data were applied to address spatiotemporal dynamics of land use/land cover(LULC)changes and its impact on wetlands sustainability based on eight LULC datasets from 1954 to 2015 in Baoqing County,Northeast *** study demonstrated that LULC drastically changed in the past six decades due to conversion of wetlands,woodland,and grassland into *** cropland was 578.8 km^2 in 1954,accounting for 5.8% of the area in Baoqing County,and it increased to 54.3% in 2015,which was nearly equivalent to 9.4 times of that in *** increased 4843.6 km^2 from 1954 to 2015 with average increased area of 79.4 km^2/*** conversion of wetlands was the main reason for cropland increase(49.7%),and woodland(18%)and grassland(16.3%)conversion were other *** also revealed that 78% of wetlands were lost during the past six decades,of which 91.2% were converted *** increasing(population across Baoqing in 2015 was 7.8 times of that in 1949),agricultural technology development was the main reason for cropland increase,institutional and economic policies also played important roles for cropland dynamics,particularly paddy field influenced by market *** development has caused severe wetlands degradation both in area and functionality,and still being the major threads for wetlands sustainable *** suggestions concerning the future land use policy formulation and wetlands sustainability were *** are adjusting the‘food first’agricultural policy,reinforce management for wetlands nature reserves,creating infrastructure for the rational use of surface and groundwater,harnessing the degraded cultivated land.

关键词： Baoqing County cropland Geographic Information System(GIS) Remote Sensing(RS) wetlands

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预处理对阈通量的影响

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哈尔滨工业大学学报 2013年第12期45卷 38-42页

作者：王兆之梁恒李圭白哈尔滨工业大学城市水资源与水环境国家重点实验室哈尔滨150090

选择合适的阈通量是超滤膜在城市水处理工艺应用成功与否的关键问题之一,为此,使用聚偏氟乙烯(PVDF)过滤原水、混凝水、沉后水和滤后水,通过通量循环法求解不同水质的阈通量,分析不同预处理对阈通量的影响.结果表明:原水的有机物和浊度... 详细信息

选择合适的阈通量是超滤膜在城市水处理工艺应用成功与否的关键问题之一,为此,使用聚偏氟乙烯(PVDF)过滤原水、混凝水、沉后水和滤后水,通过通量循环法求解不同水质的阈通量,分析不同预处理对阈通量的影响.结果表明:原水的有机物和浊度高,不可逆阈通量为11 L/(m2.h);通过混凝沉淀沙滤后,不可逆阈通量大于55 L/(m2.h).过滤沉后水和滤后水的阈通量相似,建议在沉后直接安装超滤设备.

关键词：超滤预处理阈通量通量循环法膜污染

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基于HJ-CCD和MODIS的吉林省中西部湖泊透明度反演对比

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湖泊科学 2016年第3期28卷 661-668页

作者：马建行宋开山邵田田赵莹温志丹中国科学院东北地理与农业生态研究所中国科学院湿地生态与环境重点实验室长春130102 中国科学院大学北京100049

水体透明度能够反映光在水体中的穿透程度,影响水生植被及以光为依赖条件的水生生物的分布,获取透明度的传统方法是采用透明度盘进行测量,但也可以通过遥感方法获得.环境减灾卫星是专门用于环境与灾害监测预报的小卫星星座,影像覆盖范围... 详细信息

水体透明度能够反映光在水体中的穿透程度,影响水生植被及以光为依赖条件的水生生物的分布,获取透明度的传统方法是采用透明度盘进行测量,但也可以通过遥感方法获得.环境减灾卫星是专门用于环境与灾害监测预报的小卫星星座,影像覆盖范围广,空间、时相分辨率较高,可以为水环境遥感提供较好的数据源.MODIS数据在近岸水体和内陆大型湖泊水环境监测中也有广泛应用,它的时相分辨率也很高,但空间分辨率低.利用HJ-1A卫星CCD数据和MODIS日反射率产品(MOD09GA),以2012年9月吉林省石头口门水库、二龙湖、查干湖、月亮泡等地的实测透明度为基础(实测点数74个,最小值为0.134 m,最大值为1.410 m,平均值为0.488 m),根据灰色关联度选取构建模型的波段组合,建立水体透明度反演模型.HJ1A-CCD数据与MOD09GA数据建立的模型R2分别为0.639和0.894,均方根误差(RMSE)分别为0.248和0.135,模型验证的平均相对误差(MRE)分别为17.1%和9.5%,RMSE分别为0.207和***数据以其较高的辐射分辨率使模型精度较高,但是HJ数据在应用于透明度小于1 m的水体时精度也较高(MRE=13.5%,RMSE=0.066).HJ-CCD数据在空间分辨率上的优势使其能够获得透明度空间分布的细节信息.比较两者反演得到的湖泊平均透明度,结果较为一致.

关键词：水体透明度遥感 HJ-CCD MODIS 湖泊

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基于MODIS数据的太湖蓝藻水华时空变化规律研究

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湿地科学 2018年第3期16卷 432-437页

作者：沙林伟刘阁温志丹宋开山中国科学院湿地生态与环境重点实验室中国科学院东北地理与农业生态研究所吉林长春130102 中国科学院大学北京100049

地处长江中下游经济和农业发达地区的太湖的水体富营养化问题严重,蓝藻水华频发。对太湖蓝藻进行实时监测和掌握其时空变化规律是治理蓝藻水华的前提。利用2000-2011年期间的1 341景MODIS影像,采用浮游藻类指数（floating algae index,... 详细信息

地处长江中下游经济和农业发达地区的太湖的水体富营养化问题严重,蓝藻水华频发。对太湖蓝藻进行实时监测和掌握其时空变化规律是治理蓝藻水华的前提。利用2000-2011年期间的1 341景MODIS影像,采用浮游藻类指数（floating algae index,FAI）,提取太湖蓝藻水华信息,研究其时空变化规律。研究结果表明,2000-2003年,太湖水体零星蓝藻水华所占比例最大,太湖蓝藻水华发生面积较小;在蓝藻大量生长期和上浮积聚期,竺山湾、梅梁湾、贡湖湾和大太湖西北部水域的蓝藻水华发生频率较高。2004年,太湖水体中第一次出现了区域蓝藻水华,从2004年开始,局部蓝藻水华所占比例超过零星水华,且开始发生区域和全湖蓝藻水华。蓝藻水华月平均面积呈单峰变化,蓝藻水华频发区域向太湖湖心扩展,蓝藻水华频率由太湖东南向西北逐渐增大,离湖岸越近,蓝藻水华发生频率越高。2004-2011年期间,除2009年外,其它年份太湖都有区域蓝藻水华发生。其中,2006年和2007年都有2次全湖蓝藻水华发生;2004-2007年整个太湖水体中的蓝藻水华发生频率都较高,2008-2011年蓝藻水华发生频率相对较低。

关键词：蓝藻水华 MODIS数据浮游藻类指数太湖

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内陆水体藻蓝蛋白遥感反演研究进展

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遥感学报 2022年第1期26卷 32-48页

作者：吕丽丽宋开山刘阁温志丹尚盈辛李思佳中国科学院东北地理与农业生态研究所遥感中心长春130102 中国科学院大学北京100049 聊城大学环境与规划学院聊城252000

藻蓝蛋白(PC),作为蓝藻的标志性色素,通常被用作进行蓝藻水华遥感监测的标志物。近年来,内陆水体水质恶化,富营养化加剧,藻华频发,PC遥感反演研究越来越受到关注。本文从PC光学特性、反演算法开发、卫星传感器应用等方面难点及干扰因素... 详细信息

藻蓝蛋白(PC),作为蓝藻的标志性色素,通常被用作进行蓝藻水华遥感监测的标志物。近年来,内陆水体水质恶化,富营养化加剧,藻华频发,PC遥感反演研究越来越受到关注。本文从PC光学特性、反演算法开发、卫星传感器应用等方面难点及干扰因素,综合梳理了过去30 a PC遥感反演研究的发展历程和趋势,以期理解国内外相关研究的新思路和新方法,掌握未来PC遥感反演发展研究的新动态,为水质和水资源的监管提供数据和理论基础。过去的30 a里,PC遥感反演研究发文量持续走高,并在算法上取得突破性进展,先后出现了很多经典算法,如波段比法、基线法、嵌套波段比法、生物光学模型、衍生算法和机器学习算法等,成功地分离出PC特征吸收波段(620 nm)的光谱信息,弱化了其他光学活性物质的影响,获得了较可靠的精度。另外,除高光谱航空/卫星影像数据(Hyperion、HICO)外,多光谱卫星遥感平台的PC遥感反演研究也日趋成熟,可选择的数据源种类较多,如Landsat系列、MODIS、MERIS、Sentinel-2 MSI、Sentinel-3 OLCI,其中MERIS和Sentinel-3 OLCI由于其辐射分辨率、空间分辨率和波段设置更适合用于PC遥感反演,在PC遥感反演中被广泛使用。由于PC光谱信号较弱,且易受叶绿素a、悬浮颗粒物等的干扰,想获得高精度的PC遥感估算,仍然是个挑战,未来PC遥感反演研究将向着PC测试方法的标椎化、算法精细化、时空格局大尺度化及PC遥感反演应用深入化等方面发展。

关键词：湖泊遥感内陆水体藻蓝蛋白光学特性反演算法卫星传感器

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内陆水体悬浮物波段比值优化模型及藻类丰度对模型精度影响研究

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遥感技术与应用 2022年第4期37卷 993-1002,1011页

作者：赵方睿王强温志丹刘晓静尚盈辛陶慧杜云霞宋开山吉林师范大学旅游与地理科学学院吉林四平136000 中国科学院东北地理与农业生态研究所吉林长春130102

内陆水体中浮游植物的存在对悬浮物(TSM)遥感反演模型精度具有一定的影响,藻类丰度会导致水体遥感反射率降低。实验基于中国、澳大利亚和美国内陆水体的372个采样点(4个数据集)水质分析和光谱实测数据,构建内陆水体遥感反射率与TSM的相... 详细信息

内陆水体中浮游植物的存在对悬浮物(TSM)遥感反演模型精度具有一定的影响,藻类丰度会导致水体遥感反射率降低。实验基于中国、澳大利亚和美国内陆水体的372个采样点(4个数据集)水质分析和光谱实测数据,构建内陆水体遥感反射率与TSM的相关关系,建立最优波段比模型(OBR),并分析了藻类颗粒物存在对该模型精度的影响。由于水质的不均一性,不同区域的水质参数敏感波段存在差异,因此各数据集用于建模的最优波段比值不同。结果表明,OBR模型精度较高,误差较小,中国水体模型验证均具有较好效果(石头口门水库:R^(2)=0.87,RMSE=14.1 mg/L;查干湖:R^(2)=0.82,RMSE=23.6 mg/L),澳大利亚水体模型验证效果最佳,R^(2)值高达0.95(RMSE=4.2 mg/L),美国水体模型精度较低(R^(2)=0.78,RMSE=3.7 mg/L)。研究发现,模型精度受水体叶绿素(Chla)浓度和Chla/TSM比率影响,当水体以TSM浓度较高的非藻类颗粒物为主时(如中国石头口门水库和南澳洲地区水体数据集),最优波段比值模型表现更好;而当水体以浮游植物为主时,水体中的浮游植物的丰度会使光谱信号复杂化,从而限制或降低TSM浓度遥感算法的精度(如美国印第安纳州中部水库数据集)。

关键词：遥感反演模型构建悬浮物叶绿素最优波段比值模型

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A data-based review on norfloxacin degradation by persulfate-based advanced oxidation processes:Systematic evaluation and mechanisms

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Chinese Chemical Letters 2023年第12期34卷 65-75页

作者： Pan Wang Huixuan Zhang Zhuohan Wu Xiao Zhao Ying Sun Na Duan zhidan Liu wen Liu College of Water Resources and Civil Engineering China Agricultural UniversityBeijing 100083China College of Environmental Sciences and Engineering Peking UniversityBeijing 100871China Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation College of Resources and Environmental SciencesChina Agricultural UniversityBeijing100193China

Persulfate-based advanced oxidation processes(AOPs)have obtained increasing attention due to the generation of sulfate radical(SO_(4)-)with high reactivity for organic contaminants degradation,Numerous activation methods have been used to activate two common persulfates:peroxymonosulfate(PMS)and peroxydisulfate(PDS).However,the comparisons of activation methods and two oxidants in the comprehensive degradation performance of the target contaminant are still ***,taking norfloxacin(NOR)as the target contaminant,we proposed five key parameters(the observed pseudo-first-order rate constant,kobs;average mineralization rate,rm;utilization efficiency of catalyst,Ucat;utilization efficiency of oxidant,Uox;and net utilization efficiency of oxidant,Uox')to quantify the comprehensive degradation performance of *** irradiation affected target pollutants,catalysts,and oxidants,leading to an improved degradation performance of *** heterogeneous catalysts were compared in terms of the key elements ***,Co,and Mn-based materials performed better,while carbon-based catalysts performed poorly on NOR *** overall degradation performance of NOR was different for PMS and PDS,which can be ascribed to their varied reaction pathways towards NOR,but stemmed from different properties of PMS and ***,the effect of pH on the degradation efficiency of NOR was investigated.A neutral solution was optimal for PMS system,while an acidic solution worked better for PDS ***,we analyzed the molecule structure of NOR by density functional theory(DFT)calculation to study the sites easy to ***,we summarized four typical degradation pathways of NOR in SO_(4)^(-)-based AOP systems,including defluorination,piperazine ring cleavage,piperazine ring oxidation,and quinoline group transformation.

关键词： Persulfate-based AOPs Sulfate radical Norfloxacin Heterogeneous catalysts Antibiotic degradation

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