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Distribution and dynamics of niche and interspecific association of dominant phytoplankton species in the Feiyun River basin,Zhejiang,China

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Journal of Oceanology and Limnology 2024年第4期42卷 1157-1172页

作者： Shengnan ZHU Zengchuan DONG Guobin FU Shujun WU Jinyu MENG Weilin LIU Yupeng LIU Xun CUI Yuejiao ZHOU College of hydrology and water resources Hohai UniversityNanjing 210098China CSIRO Environment Private Bag 5Wembley WA 6913Australia Department of Agricultural and Biological Engineering Indian River Research and Education CenterUniversity of FloridaFort Pierce 34945USA Jiangxi Provincial Key Laboratory of hydrology-water resources and water Environment Nanchang Institute of TechnologyNanchang 330099China

To investigate the dominant species and interspecific association in the phytoplankton community of the Feiyun River basin in Zhejiang province,East China,the main stream and the Shanxi Zhaoshandu Reservoir in the downstream were chosen as the study area,for which 22 sampling sites were *** was conducted in September 2021,January,May,and July *** species were identified from both quantitative samples and in-vivo *** was quantified by direct *** show that there were 98 species belonging to 6 phyla and 78 *** addition,to clarify the niches of the dominant phytoplankton species and their interspecific association,the dominance index was calculated,and a comprehensive analysis was conducted including niche width,niche overlap value,ecological response rate,overall association,chi-square test,and the *** phytoplankton community exhibited characteristics of a Cyanobacteria-Chlorophyta-Diatom type community,showing higher diversity in spring and lower diversity in *** 11 dominants phytoplankton species from 3 phyla,both frequency and dominance degree varied seasonally,of which Microcystis *** the dominant species in Spring,Autumn,and *** niche widths of the dominant species ranged from 0.234 to 0.933,and were categorized into three *** niche overlap values of the 11 dominant species ranged from 0.359 to 0.959,exhibiting significant seasonal differences-highest in winter followed by autumn,spring,and summer in *** overall correlation among dominant species in all four seasons revealed a non-significant negative association,resulting in an unstable community structure.A significant portion(84.2%)of species pairs displayed positive associations,suggesting a successional pattern where Diatoms dominated while other dominant species shared resources and *** this pattern,stability measurements indicated that the dominant species community remained unstable.T

关键词： phytoplankton dominant species niche interspecific association Feiyun River basin

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What control the spatial patterns and predictions of runoff response over the contiguous USA?

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Journal of Geographical Sciences 2024年第7期34卷 1297-1322页

作者： JIANG Shanhu DU Shuping REN Liliang GONG Xinglong YAN Denghua YUAN Shanshui LIU Yi YANG Xiaoli XU Chongyu The National Key Laboratory of water Disaster Prevention Hohai UniversityNanjing210098China College of hydrology and water resources Hohai UniversityNanjing210098China School of water Conservancy&Civil Engineering Northeast Agricultural UniversityHarbin150030China Department of water resources China Institute of Water Resources and Hydropower ResearchBeijing100038China Department of Geosciences University of OsloOsloNorway

Understanding the nonlinear relationship between hydrological response and key factors and the cause behind this relationship is vital for water resource management and earth system *** this study,we undertook several steps to explore the ***,we partitioned runoff response change(RRC)into multiple components associated with climate and catchment properties,and examined the spatial patterns and smoothness indicated by the Moran's Index of RRC across the contiguous United States(CONUS).Subsequently,we employed a machine learning model to predict RRC using catchment attribute predictors encompassing climate,topography,hydrology,soil,land use/cover,and ***,we identified the primary factors influencing RRC and quantified how these key factors control RRC by employing the accumulated local effect,which allows for the representation of not only dominant but also secondary ***,we explored the relationship between ecoregion patterns,climate gradients,and the distribution of RRC across *** findings indicate that:(1)RRC demonstrating significant connections between catchments tends to be well predicted by catchment attributes in space;(2)climate,hydrology,and topography emerge as the top three key attributes nonlinearly influencing the RRC patterns,with their second-order effects determining the heterogeneous patterns of RRC;and(3)local Moran's I signifies a collaborative relationship between the patterns of RRC and their spatial smoothness,climate space,and ecoregions.

关键词： hydrological response prediction machine learning accumulated local effect Moran’s Index large-sample study

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Hydrodynamic characteristics and particle tracking of 90° lateral intakes at an inclined river slope

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water Science and Engineering 2024年第2期17卷 197-208页

作者： Wei He Si-yuan Feng Jian Zhang Hong-wu Tang Yang Xiao Sheng Chen Chun-sheng Liu College of water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China State Key Laboratory of hydrology water resources and Hydraulic Engineering Hohai UniversityNanjing 210098China Collaborative Innovation Center on water Safety and water Science Hohai UniversityNanjing 210098China

Lateral intakes are common in *** pump effciency and sediment deposition are determined by the local hydrodynamic characteristics and mainstream division *** hydraulic characteristics of lateral withdrawal from inclined river slopes at different intake elevations should be ***,the division width exhibits significant vertical non-uniformity at an inclined river slope,which should be ***,a three-dimensional(3-D)hydrodynamic and particle-tracking model was developed with the Open Source Field Operation and Manipulation(Open FOAM),and the model was validated with physical model tests for 90°lateral withdrawal from an inclined side *** flow fields,withdrawal sources,and division widths were investigated with different intake bottom elevations,withdrawal discharges,and main channel *** study showed that under inclined side bank conditions,water entered the intake at an oblique angle,causing significant 3-D spiral flows in the intake rather than two-dimensional closed recirculation.A lower withdrawal discharge,a lower bottom elevation of the intake,or a higher main channel velocity could further strengthen this *** average division width and turbulent kinetic energy were smaller under inclined side bank conditions than under vertical bank *** a low intake bottom elevation,a low withdrawal discharge,or a high main channel velocity,the sources of lateral withdrawal were in similar ranges near the local inclined bank in the vertical *** inclined slope conditions,sediment deposition near the intake entrance could be reduced,compared to that under vertical slope *** results provide hydrodynamic and sediment references for engineering designs for natural rivers with inclined terrains.

关键词： Lateral withdrawal Hydrodynamic characteristics Particle tracking Inclined river slope Bottom elevation of intake OpenFOAM

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Multiscale causes of the 2022 Yangtze mega-flash drought under climate change

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Science China Earth Sciences 2024年第8期67卷 2649-2660页

作者： Xing YUAN Yumiao WANG Shiyu ZHOU Hua LI Chenyuan LI School of hydrology and water resources Nanjing University of Information Science and TechnologyNanjing 210044China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China Key Laboratory of Hydrometeorological Disaster Mechanism and Warning of Ministry of water resources Nanjing University of Information Science and TechnologyNanjing 210044China

The 2022 Yangtze mega-flash drought is characterized by strong intensity and rapid development both in time and space,accompanied by a persistent anticyclonic circulation ***,the causes of the extreme event remain elusive given the multiscale nature of *** we presented a brief overview for the oceanic and terrestrial causes of the megaflash drought during the summer of 2022,and estimated the risk in a changing *** the soil moisture percentile as the drought index,it was found that the drought expanded to the entire Yangtze River basin within two months,with 80%of basin under severe drought conditions at the end of *** the intensity and onset speed of the 2022 mega-flash drought were ranked as the first during the past 62 years,with return periods of 86 and 259 years,*** results of composite analysis showed that the spring La Ni?a can facilitate the abrupt change from a wet/normal condition in May–June to drought in July–August over the Yangtze River basin,which was beneficial for the increase of flash drought intensity and onset speed *** analysis through the linear regression also indicated that the unprecedented intensity was associated with the negative phase of the Pacific Decadal *** by a coupling strength index for soil moisture and vapor pressure deficit,it was found that there was a strong land-atmosphere coupling over the Yangtze River basin during July–August *** attribution by using CMIP6 climate models suggested that land-atmosphere coupling increased the risks of flash drought intensity and onset speed like 2022 by 61%±6%and 64%±7%under natural climate forcings,and the synergy of coupling and anthropogenic climate change would increase the risks by 75%±22%and 85%±12%.Our findings emphasized the role of landatmosphere coupling combined with anthropogenic climate change in intensifying flash droughts.

关键词： Flash drought Yangtze River basin Land-atmosphere coupling Climate change Attribution

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ANALYTICAL SOLUTION OF GROUNDwater FLUCTUATIONS IN ESTUARINE AQUIFER

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Journal of Hydrodynamics 2005年第5期17卷 641-646页

作者： CHEN Jing ZHOU Zhi-fang JIA Suo-bao College of Civil Engineering Hohai University Nanjing 210098 China hydrology and water resources investigation bureau of jiangsu province Nanjing 210029 China

As a basic factor in the environment of estuary, tidal effects in the coastal aquifer have recently attracted much attention because tidal dynamic also greatly influences the solute transport in the coastal aquifer. Previous studies on tidal dynamic of coastal aquifers have focused on the inland propagation of oceanic tides in the cross-shore direction, a configuration that is essentially one-dimensional. Two-dimensional analytical solutions for groundwater level fluctuation in recent papers are localized in presenting the effect of both oceanic tides and estuarine tides in quadrantal aquifer. A two-dimensional model of groundwater fluctuations in estuarine zone in proposed in this paper. Using complex transform, the two-dimensional flow equation subject to periodic boundary condition is changed into time-independent elliptic problem. Based on Green function method, an analytical solution for groundwater fluctuations in fan-shaped aquifer is derived. The response to of groundwater tidal loading in an estuary and ocean is discussed. The result show that its more extensive application than recent studies.

关键词： coastal aquifer analytical solution fanshaped area groundwater fluctuations Green function method estuary environment

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Modeling of turbidity dynamics caused by wind-induced waves and current in the Taihu Lake

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International Journal of Sediment Research 2013年第2期28卷 139-148页

作者： Ting-feng WU Bo-qiang QIN Guang-wei ZHU Meng-yuan ZHU Wei LI Cheng-mei LUAN State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences jiangsu province hydrology and water Resource investigation bureau

A simple turbidity model was developed with a sound physical basis based on in situ high-frequency observations of short-term,strong wind-induced sediment suspension in Taihu Lake,*** validation results show that the model could successfully simulate turbidity caused by strong wind events,despite the relatively poor simulation accuracy for high values of turbidity caused by the entrainment of cyanobacteria by turbulence. The in situ observations and model simulation results indicate that the wind waves were within a narrow spectral band,with spectral energy mainly distributed within the 0.28-0.75 Hz band on opposite sides of the peak *** high-frequency and low-energy wind waves are sensitive to depth ***,the average depth of the lake is only 1.9 m,and wind waves still represent the main force of sediment suspension at the sediment-water ***,lake currents were of significance to the maintenance of background turbidity in calm waves or ripples and in the determination of critical shear *** considering the spatial distribution of hydrodynamics and sediment,the model can be used to simulate the turbidity of the entire lake as well as boundary conditions for three-dimensional numerical models.

关键词： Taihu Lake Wind-driven current Wind wave frequency spectrum Turbidity Critical shear stress Model

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Analysis of black water aggregation in Taihu Lake

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water Science and Engineering 2011年第4期4卷 374-385页

作者： Gui-hua LU Qian MA Jian-hua ZHANG National Engineering Research Center of water resources Efficient Utilization and Engineering Safety Hohai University Nanjing 210098 P. R. China hydrology and water resources investigation bureau of jiangsu province Nanjing 210029 P. R. China water resources Department of jiangsu province Nanjing 210029 P R. China

Black water aggregation （BWA） in Taihu Lake is a disaster for the lake environment. It is a phenomenon resulting from water environmental deterioration and eutrophication caused by accumulation of pollutants in the lake, according to research on the water quality, pollutants of BWA, and occurrence mechanisms of BWA. Dead algae are the material base of BWA, the polluted sediment is an important factor for the formation of BWA, and hydrological and meteorological conditions such as sun light, air temperature, wind speed, and water flow are the other factors that may lead to the formation of BWA. Thioether substances such as dimethyl trisulfide are the representative pollutants of BWA. Parameters such as chlorophyll-a, DO, pH, and water temperature are sensitive indicators of BWA. Measures such as algae collection, ecological dredging, pollution control, and water diversion from the Yangtze River to the lake, are effective, and strengthening aeration is an emergency measure to control BWA.

关键词： black water aggregation water quality indicator control measure Taihu Lake

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A rapid assessment of MWRI-RM/FY3G brightness temperature

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Atmospheric and Oceanic Science Letters 2024年第3期17卷 42-46页

作者： Wenying He Xinran Xia Shengli Wu Peng Zhang Hongbin Chen Xiang'ao Xia Yuquan Zhou Miao Cai LAGEO Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina School of hydrology and water resources Nanjing University of Information Science&TechnologyNanjingChina National Satellite Meteorological Centure Chinese Meteorological AdministrationBeijingChina College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijingChina Key Laboratory of Cloud-Precipitation Physics and Weather Modification CMABeijingChina

2023年4月发射的FY-3G上搭载17个频率的测雨微波成像仪(MWRI-RM),其业务定标的微波亮温(Tb)数据于2023年10月23日公开发布.本文比对了发布10天的MWRI-RM与全球降水测量(GPM)卫星上的微波成像仪(GMI)相匹配的Tb数据,并借助辐射传输模式... 详细信息

2023年4月发射的FY-3G上搭载17个频率的测雨微波成像仪(MWRI-RM),其业务定标的微波亮温(Tb)数据于2023年10月23日公开发布.本文比对了发布10天的MWRI-RM与全球降水测量(GPM)卫星上的微波成像仪(GMI)相匹配的Tb数据,并借助辐射传输模式进行双差分(DD)交叉定标分析,旨在快速评估新一代MWRI-RM观测数据质量.观测比较表明,MWR1-RM与GMI测量的Tb一致性很好,大多通道的平均偏差(MBE)和均方根误差(RMSE)均小于1K.两种传感器由于观测角度略有不同在水面产生约0.5 K差异.DD分析也展示出MWRI-RM的大多数通道性能与GMI相当接近,尤其是首次启用的高频166 GHz和183 GHz.

关键词： FY3G MWRI-RM GMI 亮度温度双差分方法

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引江济太不是太湖磷负荷上升的原因

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Engineering 2024年第4期35卷 10-14页

作者： Zhiyuan Wang Qiuwen Chen Jianyun Zhang Hanlu Yan State Key Laboratory of hydrology–water resources and Hydraulic Engineering Nanjing Hydraulic Research InstituteNanjing 210098China Center for Eco-Environment Research Nanjing Hydraulic Research InstituteNanjing 210098China Yangtze Institute for Conservation and Green Development Hohai UniversityNanjing 210098China

Despite frequent cyanobacterial blooms increasing in magnitude and duration,Taihu Lake remains one of the most important water sources in the Yangtze River Delta of *** meet the rising water demand from social–economic development and secure water source during cyanobacterial blooms,the water Diversion Project from the Yangtze River to Taihu Lake(WDYT)through the Wangyuhe(WYH)River channel was initiated in 2002 and has been in operation since 2007.

关键词： Yangtze China initiated

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Understanding groundwater table using a statistical model

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water Science and Engineering 2018年第1期11卷 1-7页

作者： Shao-feng Yan Shuang-en Yu Yu-bai Wu De-feng Pan Jia-gen Dong Key Laboratory of Efficient Irrigation-Drainage and Agricultural Soil-water Environment in Southern China Ministry of EducationHohai UniversityNanjing 210098China Hubei Provincial water resources and Hydropower Planning Survey and Design Institute Wuhan 430064China jiangsu water Conservancy Research Institute Nanjing 210017China jiangsu Coastal water Conservancy Research Institute Dongtui 224200China jiangsu province hydrology and water resources investigation bureau Nanjing 210008China

In this study, a statistical model was established to estimate the groundwater table using precipitation, evaporation, the river stage of the Liangduo River, and the tide level of the Yellow Sea, as well as to predict the groundwater table with easily measurable climate data in a coastal plain in eastern China. To achieve these objectives, groundwater table data from twelve wells in a farmland covering an area of 50 m ~ 150 m were measured over a 12-month period in 2013 in Dongtai City, jiangsu province. Trend analysis and correlation analysis were conducted to study the patterns of changes in the groundwater table. In addition, a linear regression model was established and regression analysis was conducted to understand the relationships between precipitation, evaporation, river stage, tide level, and groundwater table. The results are as follows：（1） The groundwater table was strongly affected by climate factors （e.g., precipitation and evaporation）, and river stage was also a significant factor affecting the groundwater table in the study area （p 〈 0.01, where p is the probability value）. （2） The groundwater table was especially sensitive to precipitation. The significance of the factors of the groundwater table were ranked in the following descending order： precipitation, evaporation, and river stage. （3） A triple linear regression model of the groundwater table, precipitation, evaporation, and river stage was established. The linear relationship between the groundwater table and the main factors was satisfied by the actual values versus the simulated values of the groundwater table （R^2 = 0.841, where R^2 is the coefficient of determination）.

关键词： Groundwater table Precipitation Evaporation Climate factors Regression statistics Coastal plain

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