检索结果-南通市图书馆

Comparison of three regionalization techniques for predicting streamflow in ungaged watersheds in Nebraska,USA using SWAT model

引用

International Journal of Agricultural and Biological Engineering 2018年第3期11卷 110-119页

作者： Michael W.Van Liew Aaron R.Mittelstet Department of Biological Systems Engineering University of NebraskaLincolnNE 68583USA

This study compared three approaches,regional averaging,nearest neighbor,and donor techniques,to regionalize parameters in the Soil and Water Assessment Tool(SWAT)on eleven watersheds located in the Dissected Plains,Plains,and Rolling Hills Landforms in the eastern portion of the State of Nebraska,*** the Rolling Hills Landform,three watersheds were randomly selected as calibration watersheds while two were randomly selected as validation *** watersheds were randomly selected as calibration watersheds while one was randomly selected as a validation watershed within each of the Dissected Plains and Plains *** seven calibration watersheds were used to provide the necessary calibrated parameter sets to execute each of the regional approaches,while the four validation watersheds were used to assess the impact of applying each of these approaches to an uncalibrated *** Bias(PBIAS)and the Nash Sutcliffe Coefficient of Efficiency(NSE)were used to assess model *** results of this study show that all three methods performed poorly,since the majority of watersheds among each method tested exhibited PBIAS values greater than ±25% and/or NSE values less than 0.50,which were considered to be unsatisfactory in terms of model *** average regionalization,nearest neighbor and donor methods resulted in only four(two calibration and two validation),zero and one satisfactory set of simulated watershed results,*** findings from this study indicate that although each watershed was successfully calibrated with NSE values ranging from 0.51 to 0.84,none of the three regionalization methods provided suitable calibration data sets to define parameter values for performing satisfactory simulations on ungaged watersheds across the eastern Nebraska landscape.

关键词： SWAT model watersheds hydrology model calibration parameter regionalization Nebraska ungaged watersheds

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

Assessment of Flash-Flood Hazard in Arid watersheds of Jordan

引用

Journal of Geographic Information System 2017年第6期9卷 717-751页

作者： Yahya Farhan Atef Ayed Retired Professor Amman Jordan Geography Department University of Jordan Amman Jordan

Flash flood hazard initiated by heavy rainstorms is common in arid Jordan, and often has induced immense damage to life and infrastructures. The current study presents a flash flood assessment for Wadi Rajil (northern Jordan) and Wadi Wuheida (southern Jordan) watersheds using ASTER DEM, GIS, and geomorphic field observation. A total of 23 morphometric parameters of paramount relation to flash flood risk estimation were extracted and calculated using ASTER DEM, GIS, and mathematical formulae developed for this purpose. Two methods were employed to assess flash floods and to generate flooding risk susceptibility maps. The first method is El-Shamy’s approach, and the second is the morphometric hazard degree assessment method. Consequently, sub-basins with high and extreme flooding susceptibility were demarcated and displayed spatially using GIS. The maps so produced are meant to help planners and decision makers to devise appropriate plans to mitigate harmful flooding impacts, and to deal with flooding hazards.

关键词： Flash Flood ASTER DEM Morphometry Arid watersheds El-Shamy’s Approach Jordan

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

The Effect of Trihalomethanes in Contaminating the Major watersheds of Middle Tennessee

引用

Natural Science 2019年第7期11卷 233-245页

作者： Sujata Guha Paige Harlin Ryan Beni Department of Chemistry Tennessee State University Nashville TN USA

We have analyzed the contamination of the three major watersheds in Middle Tennessee (Middle Cumberland River Watershed, Stones River Watershed, and Harpeth River Watershed) by trihalomethanes, such as chloroform, bromodichloromethane, dibromochloromethane, and bromoform. These chemicals play an important role in the develop-ment of cancer and adverse reproductive outcomes, and were found to be present above the threshold established by the Environmental Protection Agency. Certain portions of each watershed were found to be contaminated by the trihalomethanes, and deemed un-healthy. The household incomes in the major areas in the three watershed regions were also examined to determine a possible relationship with the level of water contamination. We concluded that income did not necessarily relate to water quality. Specific areas within each watershed that had lower average household incomes were found to have a higher concentration of the trihalomethanes in their drinking water, while other high-income areas were also affected by unhealthy water. However, these effects were random, and the level of contamination remained below the guidelines regulated by the State of Tennessee.

关键词： Middle Tennessee watersheds Trihalomethanes Contaminants Carcinogens

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

A model for simulating the response of runoff from the mountainous watersheds of inland river basins in the arid area of northwest China to climatic changes

引用

Science China Earth Sciences 1999年第S1期42卷 52-63页

作者：康尔泗程国栋蓝永超金会军 State Key Laboratory of Frozen Soil Engineering Lanzhou Institute of Glaciology and Geocryology Chinese Academy of Sciences

A model for simulating the response of monthly runoff from the mountainous watersheds to climatic changes is *** model is based on the modifications to the HBV runoff model, and therefore represents the characteristics and runoff generation processes of inland river basins in the arid area of northwest China. Taking the mountainous watershed of an inland river, the Heihe River originating from the Qilian Mountains and running through the Hexi Corridor as an example, the monthly runoff changes under different climate scenarios are simulated. The simulation indicates that, during the years from 1994 to 2030, if the annual mean air temperature increases by 0.5℃, and precipitation keeps unchanged, then the runoff of May and October will increase because of the increase of the snow melt runoff, but the runoff of July and August will decrease to some extent because of the increase of evaporation, and as a result, the annual runoff will decrease by 4％. If the precipitation still keeps unchanged,

关键词： inland river basins runoff from mountainous watersheds climatic changes response.

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

Flood Change Detection and Attribution Using Simulation Approach in Data-Scarce watersheds: A Case of Wabi Shebele River Basin, Ethiopia

引用

Journal of Water Resource and Protection 2021年第5期13卷 362-393页

作者： Fraol Abebe Wudineh Semu Ayalew Moges Belete Berhanu Kidanewold School of Civil and Environmental Engineering Addis Ababa University Addis Ababa Ethiopia Department of Civil and Environmental Engineering University of Connecticut Connecticut USA

Flood events vary with sub-regions, sites and time and show complex characteristics. This study investigated temporal variabilities in flood discharges and relationships with principal driving factors in data scarce Wabi Shebele River Basin. The preliminary analysis using exploratory data analysis (EDA) on annual and seasonal maximum discharge reveals that there are cycles of extreme flows at five- and ten-year intervals respectively throughout the basin. The statistical verification using the Mann-Kendall test and Quantile perturbation method indicates a significant trend in flood magnitude and frequency entire the basin in the early 21st century. For longest period (1980-2010) annual maximum stream flow shows significant positive trend (p-value < 0.05) in middle catchments and negative trend (p-value < 0.05) in eastern catchments. The years: 1986-1995, 2006-2010 are the years in which positive significant anomalies occurred in all seasons, while the years: 1980-1985, 1996-2005 are the occurrence years of significant negative anomalies. Rainfall from climate drivers;DA, BE, VS and fraction of sand from environmental background drivers;fraction of forest and population density from external factors were identified as the powerful driving factors of flood variabilities in the Wabi Shebele River Basin.

关键词： Flood Events watersheds Wabi Shebele River Hydrological Model Driving Factors of Flood

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

Development of Web Mapping Application for Spatial Ecotourism Information Using QGIS Plugin and Freely Available Web Platforms in North West Highlands of Ethiopia a Case Study: Chokie Mountain watersheds

引用

Advances in Internet of Things 2019年第3期9卷 50-61页

作者： Mengesha Endalew Wobetu Shiferaw Abinet Kindie Geodesy and Geomatics Engineering School of Civil and Water Resource EngineeringInstitute of TechnologyDebre Markos UniversityDebre MarkosEthiopia Software Engineering School of ComputingInstitute of TechnologyDebre Markos UniversityDebre MarkosEthiopia Information Technology School of Computing Bahirdar UniversityBahirdarEthiopia

Ecotourism is a sustainable, green and smokeless industry of the society by providing alternative source to the livelihood and local community, in order to re-naturalize the environment to bring the man closer to the natural environment. The use of web application has changed the way tourists gather information about tourist attraction spots of the research area. The aim of the study is to assess and identify ecotourism attraction sites of Chokie Mountain watersheds for touristic activities to develop a web-based GIS mapping portal for the improvement of nature-based ecotourism activities. The web-based GIS portal for Web Mapping Application is available for the user with the skills necessary to create standard web mapping services. We have implemented web mapping services based on formal cartographic visualization rules in the open source QGIS software and threejs JavaScript plugin. Threejs plugin is used for 3D visualization, interaction and export terrain data, map canvas image and vector data to HTML page and JS. The result of web-based GIS portal supports spatial and non-spatial database of tourist attraction and tourist service data with attractive user interface.

关键词： Ecotourism Chokie Mountain watersheds Spatial Mapping Qgis Open Source Software Qgis2threejs Plugins

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

Modeling Reforestation’s Role in Climate-Proofing watersheds from Flooding and Soil Erosion

引用

American Journal of Climate Change 2019年第3期8卷 387-403页

作者： Robert L. France Andrew S. M. Patton Peter W. Aitchison Department of Plant Food and Environmental Science Faculty of Agriculture Dalhousie University Halifax Canada Department of Applied Mathematics University of Manitoba Winnipeg Canada

The mitigation potential of reforestation for offsetting the deleterious effects of increased flooding and soil erosion projected to occur in Atlantic Canada through future climate change was investigated. Modelling determined a strong but non-linear relationship between extent of vegetative cover and runoff volume and discharge rate for a Nova Scotian watershed, suggesting that reforestation will reduce, but not completely prevent, flooding. Predicted erosion rates were found to be progressively reduced in relation to the extent of upland reforestation. Of three scenarios examined in which 60%, 65%, and 85% of the entire watershed are randomly reforested, only the latter would reduce the elevated erosion expected to occur through climate change back to present-day existing levels. Additional modelling revealed that comparable mitigation of soil erosion can ensue through implementation of 70 m streamside buffer strips, which would only take up 19% of the total surface area. Prioritizing riparian zones for reforestation will therefore subsume less of the overall productive land area and therefore enact a less severe socio-economic impact on agriculture and forestry.

关键词： Climate Change watersheds Modeling Flooding Soil Erosion Reforestation

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

Quantification of Metal Contaminants and Risk Assessment in Some Urban watersheds

引用

Journal of Water Resource and Protection 2020年第11期12卷 951-963页

作者： Adeleke Adeniyi Olumuyiwa Okedeyi Mutiu Sowemimo Kafeelah Yusuf Ojo Oluwole Bernadine Ejiogu Iyabode Ajibade Bamitale Fabiyi Olubunmi Adeniji Department of Chemistry Lagos State University Ojo Lagos Nigeria Department of Biochemistry Lagos State University Ojo Lagos Nigeria Centre for Environmental Studies and Sustainable Development (CESSED) Lagos State University Ojo Lagos Nigeria

Contamination by heavy metals is a serious threat to aquatic systems due to their level of toxicity at elevated levels. The pollution of urban watersheds is of particular concern because of its potential impact on the watershed ecosystem and the receiving larger water bodies. This study assessed the occurrence and distribution of cadmium, copper, nickel, lead and zinc in water and sediment samples collected from three urban watersheds in Lagos, Nigeria. The concentrations of metals were determined using atomic absorption spectrometry. The health risk index (HRI) of water usage was evaluated for both adults and children. HRI for cadmium and lead in some of the watersheds recorded HRI > 1 values, a cause for health concern. The pH of water ranged from 6.48 ± 0.28 - 6.54 ± 0.47 (2016) and 6.18 ± 0.56 - 6.53 ± 0.17 (2018) respectively while, for sediments, the pH values ranged from 6.14 ± 0.48 - 6.9 ± 0.15 and 5.38 ± 0.22 - 6.4 ± 0.38 for 2016 and 2018 respectively. The levels of metals in the water samples during the 2016 sampling cycle were found to be within the World Health Organization (WHO) guideline limits for drinking water. However, the 2018 cadmium, lead and zinc concentrations for Ira-Ipaye and Akesan watersheds exceed the WHO guideline limits. Cadmium was not detected in Ira-Ipaye and Akesan 2016 sediment samples. Statistical t-test and analysis of variance (ANOVA) were used to ascertain significant differences of metals concentration in the three watersheds. The pH and metal concentration values obtained for water and sediment for the year 2016 and 2018 were non-significantly different.

关键词： Metals Cadmium Lead watersheds Health Risk

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

Total Trihalomethane Levels in Major watersheds across the United States

引用

Journal of Geoscience and Environment Protection 2020年第6期8卷 1-14页

作者： Kaleh Karim Sujata Guha Ryan Beni Department of Chemistry Tennessee State University Nashville TN USA Department of Biological Sciences Tennessee State University Nashville TN USA

Trihalomethanes, such as chloroform, bromoform, dibromo(chloro)methane, and bromo(dichloro)methane, are present in the major watersheds across the United States. These chemicals play an important role in the development of cancer, have adverse reproductive outcomes, and were found to be present above the threshold established by the Environmental Protection Agency. To understand the impact of socioeconomic background on the quality of water and possible disparities, we have analyzed the levels of total trihalomethanes in the metropolitan areas in the major watersheds across the United States, in 2018, as they correlated to average household incomes. Our study found that Arkansas, Nevada, and Rhode Island demonstrated higher than federally mandated levels of total trihalomethanes in their watersheds. The median annual household and per capita incomes of the three states (Arkansas, Nevada, and Rhode Island) were lower than the national average. In addition, Delaware, New Hampshire, and Wisconsin, which had higher median income levels, demonstrated the lowest total trihalomethane levels across the United States.

关键词： Total Trihalomethanes Contaminants watersheds Household Income Income per Capita Environmental Justice Chlorination

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

watersheds of the world CD

引用

2003年

作者： [research datacompilationandmapproduction CarmenRevenga...etal.].

来源：畅想之星图书光盘版（南... 评论

在线全文

畅想之星图书光盘版（南通市图书馆镜像）

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：