检索结果-南通市图书馆

Flash flood type identification and simulation based on flash flood behavior indices in China

Science China Earth Sciences 2021年第7期64卷 1140-1154页

作者： xiaoyan zhai Liang GUO Yongyong ZHANG State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin Research Center on Flood and Drought Disaster ReductionChina Institute of Water Resources and Hydropower ResearchBeijing 100038China Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Flash floods present significant heterogeneity over both space and time due to diverse topographic,geomorphologic,and hydro-meteorological conditions of *** identification and simulation of typical flash flood types are of great significance for the mitigation of flash flood disasters at the national *** flood peak indices and dynamic indices were adopted to characterize the behavioral variability of flash *** typical flash flood types and corresponding behavior indices were identified and simulated using statistical analysis(i.e.,principal component analysis,dynamic K-means clustering,and analysis of similarity)and hydrological modelling(i.e.,HEC and XAJ models).There were 177 flash flood events at the hourly scale being selected for case study from eight catchments with various climatic and geographic *** showed that all the flash flood events were clustered into three types(named Types 1,2,and 3).Type 1 was characterized by low peak flow intensity,early flood peak occurrence time,and thin flood process with short *** 2 was characterized by low peak flow intensity,late flood peak occurrence time,and flat flood process with long *** 3 was characterized by high peak flow intensity and late flood peak occurrence *** flood types showed high consistency with their influencing factors(e.g.,catchment forest ratio and drainage area,occurrence time and magnitude of maximum storm intensity,and concentration of a storm event).The simulation performances were basically the same for HEC and XAJ *** for flash flood event simulations,the average relative error varied from 23.25%to 27.98%,from 11.95%to 18.19%,and from 8.30%to18.25%for Types 1,2 and 3,*** average Nash-Sutcliffe efficiency coefficient varied from 0.39 to 0.54,from 0.76 to 0.85,and from 0.86 to 0.91,*** for the six flash flood behavior indices simulations,the average relative rootmean-square error(RMSEr)varie

关键词： Flood similarity Flood behavior Statistical analysis HEC and XAJ models Humid and semi-humid catchments

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Uncertainty analysis for integrated water system simulations using GLUE with different acceptability thresholds

引用

Science China(Technological Sciences) 2021年第8期64卷 1791-1804页

作者： ZHANG YongYong XIA Jun SHAO QuanXi LI Lu YEN Haw zhai xiaoyan ZHAO TongTieGang LIN KaiRong Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing100101China CSIRO Data 61 WembleyWestern Australia6913Australia Bjerknes Centre for Climate Research NORCE Norwegian Research CentreBergen5007Norway Blackland Research and Extension Center Texas A&M UniversityTempleTexas76502USA China Institute of Water Resources and Hydropower Research Beijing100038China Department of Water Resources and Environment Sun Yat-sen UniversityGuangzhou510275China

Integrated water quantity and quality simulations have become a popular tool in investigations on global water *** integrated and complex models,conventional uncertainty estimations focus on the uncertainties of individual modules,e.g.,module parameters and structures,and do not consider the uncertainties propagated from interconnected ***,this study investigated all the uncertainties of integrated water system simulations using the GLUE(i.e.,generalized likelihood uncertainty estimation)method,including uncertainties associated with individual modules,propagated uncertainties associated with interconnected modules,and their *** changes in both acceptability thresholds of GLUE and the uncertainty estimation results were also investigated for different fixed percentages of total number of iterations(100000).Water quantity and quality variables(i.e.,runoff and ammonium nitrogen)were selected for the case *** results showed that module uncertainty did not affect the runoff simulation performance,but remarkably weakened the water quality responses as the fixed percentage increased during calibration and validation *** propagated uncertainty from hydrological modules could not be ignored for water quality simulations,particularly during *** combination of module and propagated uncertainties further weakened the water quality simulation *** uncertainty intervals became wider owing to an increase in the fixed percentages and introduction of more uncertainty ***,the acceptability threshold had a negative nonlinear relationship with the fixed *** fixed percentages(20.0%-30.0%)were proposed as the acceptability thresholds owing to the satisfactory simulation performance and noticeably reduced uncertainty intervals they *** study provided methodological foundations for estimating multiple uncertainty sources of integrated water system models.

关键词： module uncertainty propagated uncertainty uncertainty combination integrated water system simulations GLUE

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Ecological health analysis of wetlands in the middle reaches of Yangtze River under changing environment

引用

International Journal of Digital Earth 2023年第1期16卷 3125-3144页

作者： Shengqing Zhang xiaoyan zhai Peng Yang Jun Xia Sheng Hu Libo Zhou Cai Fu Hubei Key Laboratory of Regional Ecology and Environmental Change School of Geography and Information EngineeringChina University of GeosciencesWuhanPeople’s Republic of China State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin Research Center on Flood and Drought Disaster ReductionChina Institute of Water Resources and Hydropower ResearchBeijingPeople’s Republic of China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhanPeople’s Republic of China Yangtze Valley Water Environment Monitoring Center WuhanPeople’s Republic of China Wuhan CGeo Clouds Science&Tech Co.Ltd WuhanPeople’s Republic of China

Changes in wetland ecosystems have a critical impact on the local ecology and species *** development scenarios and policies are key factors influencing their ***,we studied changes of wetlands in the middle Yangtze River basin(MYRB)in 2001-2020,and a patch-generated land use simulation(PLUS)model and random forest(RF)method were applied to predict and analyze the changes under different scenarios in the MYRB in the future(i.e.2035-2095).The results indicated that:(1)The regions with high wetland proportions were concentrated in the central and eastern MYRB in 2001-2020,with a 1.5%decrease in overall wetland area;(2)The RF could simulate the future ecological quality with training and testing accuracies of 0.98 and 0.92,respectively;(3)Remote Sensing Ecological Index(RSEI)less than 0.5 in the central and eastern regions and 13.3%reduction in the northwest in the SSP245 *** general,the study provides a basis for future regional studies of ecosystem quality and provides data to support wetland conservation and management.

关键词： Remote sensing machine learning ecological prediction ecological change Yangtze River basin

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Runoff variation and its response to climate change in the Three Rivers Source Region

引用

Journal of Geographical Sciences 2012年第5期22卷 781-794页

作者： ZHANG Yongyong ZHANG Shifeng zhai xiaoyan XlA Jun Key Laboratory of Water Cycle and Related Land Surface Processes CAS Beijing 100101 China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan430072 China

Runoff at the three time scales （non-flooding season, flooding season and annual period） was simulated and tested from 1958 to 2005 at Tangnaihai （Yellow River Source Region： YeSR）, Zhimenda （Yangtze River Source Region： YaSR） and Changdu （Lancang River Source Region： LcSR） by hydrological modeling, trend detection and comparative analysis. Also, future runoff variations from 2010 to 2039 at the three outlets were analyzed in A1B and B1 scenarios of CSIRO and NCAR climate model and the impact of climate change was tested. The results showed that the annual and non-flooding season runoff decreased significantly in YeSR, which decreased the water discharge to the midstream and down- stream of the Yellow River, and intensified the water shortage in the Yellow River Basin, but the other two regions were not statistically significant in the last 48 years. Compared with the runoff in baseline （1990s）, the runoff in YeSR would decrease in the following 30 years （2010-2039）, especially in the non-flooding season. Thus the water shortage in the mid- stream and downstream of the Yellow River Basin would be serious continuously. The runoff in YaSR would increase, especially in the flooding season, thus the flood control situation would be severe. The runoff in LcSR would also be greater than the current runoff, and the annual and flooding season runoff would not change significantly, while the runoff variation in the non-flooding season is uncertain. It would increase significantly in the B1 scenario of CSIRO model but decrease significantly in B1 scenario of NCAR model. Furlhermore, the most sensitive region to climate change is YaSR, followed by YeSR and LcSR.

关键词： climate change runoff variation SWAT (Soil and Water Assessment Tool) Mann-Ke:~dall test ThreeRivers Source Region

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

淮河流域水质时空分布及土地利用区域影响

引用

水资源保护 2022年第5期38卷 181-189页

作者：翟晓燕张永勇中国水利水电科学研究院水利部防洪抗旱减灾工程技术研究中心北京100038 中国科学院地理科学与资源研究所陆地水循环及地表过程重点实验室北京100101

采用淮河流域22个水质断面2008—2018年周监测数据,将趋势检测、空间自相关性识别、聚类、回归分析等统计分析技术相结合,检测了pH值和DO、COD_(Mn)、NH_(3)-N质量浓度等4个水质指标的时空变化特征,辨识了典型水质类型及其与不同时空尺... 详细信息

采用淮河流域22个水质断面2008—2018年周监测数据,将趋势检测、空间自相关性识别、聚类、回归分析等统计分析技术相结合,检测了pH值和DO、COD_(Mn)、NH_(3)-N质量浓度等4个水质指标的时空变化特征,辨识了典型水质类型及其与不同时空尺度土地利用类型的关系。结果表明:淮河流域水环境整体状况有所改善,各断面水质指标周尺度显著性变化趋势主要集中在非汛期(10月至次年5月),分别有23%、9%、41%和55%的断面pH值显著减小、DO质量浓度显著增加、COD_(Mn)和NH_(3)-N质量浓度显著减小,淮河水系水质指标变化坡度大于沂沭泗水系;3个低pH值聚集中心主要分布在淮河干流上游和洪汝河下游,3个低DO质量浓度聚集中心和2个高COD_(Mn)和NH_(3)-N质量浓度聚集中心主要分布在沙颍河和涡河。22个断面可划分为3种典型水质类型:类型1为弱碱性、低COD_(Mn)和NH_(3)-N质量浓度断面,分布在淮河上游和淮河干流;类型2为偏碱性、低DO质量浓度、高COD_(Mn)和NH_(3)-N质量浓度断面,分布在沙颍河;类型3为偏碱性、高DO质量浓度、低COD_(Mn)和NH_(3)-N质量浓度断面,分布在淮河中游和沂沭泗水系。类型1水质指标主要与2013—2018年水田和旱地等显著相关,其中水田对pH值影响较大,旱地对其余指标影响较大;类型3的DO和NH_(3)-N质量浓度与各时期不同缓冲区内城镇用地均显著相关,COD_(Mn)质量浓度与2013—2018年其他林地显著相关。

关键词：水质类型水环境土地利用时空变异淮河流域

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

The mechanism and effect of baicalin on the proliferative ability and apoptosis of human bone marrow mesenchymal stem cells in the elderly

引用

解剖学杂志 2021年第S1期44卷 225-226页

作者： zhai xiaoyan Yang Rong Zhao Huanxin Yang Liwang Ji Xinyan Chu Kaibo Zhang Yumin Zhou Rukui Department of Basic Medicine Shanxi University of Chinese MedicineYuci 030619 Department of Biom edicine Shanxi University of Chinese Medicine

Human bone marrow mesenchymal stem cells(hBM-MSCs)in the elderly were isolated and cultured by whole bone marrow adherent *** hBM-MSCs were treated with different concentrations of baicalin(0,0.5,1,10,50,100,500,1000μmol/L)for 3 days,then cytotoxicity assay of baicalin on the elderly hBM-MSCs was detected with CCK-8 method,and the appropriate baicalin concentration was *** the appropriate concentration range(0.5,1,10μmol/L),the effect of baicalin on the proliferative ability of hBM-MSCs in the elderly was detected by cell counting method,and the optimal drug concentration was *** elderly hBM-MSCs were divided into control group and baicalin ***(1μmol/L)was added to the baicalin group.

关键词： proliferative marrow bone

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

有向网络中具有一个枢纽点的最小支撑树的计算方法

引用

系统科学与数学 2005年第6期25卷 649-657页

作者：翟晓燕张新政广东外语外贸大学广州510420 广东工业大学广州510090

对有向网络中具有一个枢纽点的支撑树的问题和性质进行了研究,给出了在有向网络图中寻找以某一定点为枢纽点的最小支撑树的计算方法,并对算法的复杂性进行了讨论,最后将该算法应用于实际算例的计算．

关键词：有向网络枢纽树最小枢纽树

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Discussion on Drought Tolerance Through Hydraulic Architecture of Woody Plants

引用

Chinese Forestry Science and Technology 2002年第4期1卷 37-46页

作者： LI Jiyue LIU xiaoyan zhai HongboCollege of Resources and Environment. Beiiins Forestry University, Beiiins 100083, P. R. China.

In this paper, ten woody plants grew on the campus of the Beijing Forestry University were selected for measuring hydraulic architecture parameters and water potential of one-year-old twigs. The results show that day and night change of water potential and hydraulic architecture parameters appear to be obviously convex trend. The relationship models between water potential and hydraulic conductivity, special conductivity and leaf special conductivity were respectively established, which were simulated b...

关键词： hydraulic architecture drought resistance water potential model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The mechanism and effect of baicalin on the proliferative ability and apoptosis of human bone marrow mesenchymal stem cells in the elderly

The mechanism and effect of baicalin on the proliferative ab...

引用

中国解剖学会2021年年会

作者： zhai xiaoyan Yang Rong Zhao Huanxin Yang Liwang Ji Xinyan Chu Kaibo Zhang Yumin Zhou Rukui Department of Basic Medicine Shanxi University of Chinese Medicine Department of Biomedicine Shanxi University of Chinese Medicine

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

基于Flexsim的多服务台集装箱码头系统仿真与优化

引用

物流技术 2013年第9期32卷 413-415页

作者：林娜青翟晓燕广东外语外贸大学国际工商管理学院广东广州510006

以珠三角某集装箱码头为例,应用排队论和Flexsim仿真技术构建了集装箱码头装卸系统的仿真模型,通过模型的运算对码头实时运作过程进行了模拟,并对码头吞吐量、船舶在港停泊时间、堆场周转率、设备利用率等指标进行了计算。在此基础上对... 详细信息

以珠三角某集装箱码头为例,应用排队论和Flexsim仿真技术构建了集装箱码头装卸系统的仿真模型,通过模型的运算对码头实时运作过程进行了模拟,并对码头吞吐量、船舶在港停泊时间、堆场周转率、设备利用率等指标进行了计算。在此基础上对系统运作的瓶颈和产生问题的原因进行了分析,提出解决问题的优化方案,从生产效率的角度对码头生产运营优化问题进行了探讨。

关键词： Flexsim 集装箱码头仿真优化

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：