Study on multiple attenuation method based on match filterzhenhuarui
常规滤波方法对浅海多次波压制不能取得理想效果. 通过改变模型表面边界条件, 求解波动方程实现多情
景地震数值模拟.利用自由边界条件模拟时获得含海平面强反射多次波地震记录, 而利用吸收边界条件时得到理想
条件下无多次波地震记录.对比分析多次波对有效地震信号的影响得到海平面强反射多次波改变了有效地震信号的
振幅、频率和相位. 利用归一化方法计算得到压制多次波滤波器算子, 并作用于含海平面强反射多次波地震记录. 叠
加地震剖面对比分析表明,归一化滤波器算子较好的压制了地震记录中的多次波, 提高地震资料分辨率. 最后, 根据
多次波产生条件,给出了利用实际区域简化地质模型的地震数值模拟结果计算归一化滤波器算子的方法, 从而利用
该方法压制实际地震数据中多次波.The conventional filtering method can not work well in marineseismic multiple attenuating for shallow water.
Seismic numerical simulationin different conditions was done by solving wave equation and changing the surface
border conditions. Seismic with multiple produced by strong reflectionof seasurfacecan be modeled withfree border
conditions , and seismic without multiplecan be modeled withabsorbing border conditions. That the multiple produce
by strong reflectionof seasurface has changed amplitude, frequency and phase of the effectivereflected wave, canbe
seen after the compare of seismic simulatedindifferent border conditions . Thefiltering operators for attenuating multiple
can be calculated bythe normalized method, and thenthey are worked onthe seismic with multiple . The compares
betweenthe stacked seismic sections showthat the normalized filtering operators work well in attenuating the
seismic multiple, andthe seismic resolutionisi mproved after process . Thereafter, according the conditions affecting
the multiple, the method to calculate normalized filtering operator for real seismic acquired in shallow sea fields is
presented. They can be calculated using seismic si mulated based on the simplified model of real conditions ,in which
the sea water depth, the shots’depthand thereceivers’depth are morei mportant .
Keywords multiple, normalization, wave equation, numerical si mulation, filtering operator
Study on multiple attenuation method based on match filterzhenhuarui
常规滤波方法对浅海多次波压制不能取得理想效果. 通过改变模型表面边界条件, 求解波动方程实现多情
景地震数值模拟.利用自由边界条件模拟时获得含海平面强反射多次波地震记录, 而利用吸收边界条件时得到理想
条件下无多次波地震记录.对比分析多次波对有效地震信号的影响得到海平面强反射多次波改变了有效地震信号的
振幅、频率和相位. 利用归一化方法计算得到压制多次波滤波器算子, 并作用于含海平面强反射多次波地震记录. 叠
加地震剖面对比分析表明,归一化滤波器算子较好的压制了地震记录中的多次波, 提高地震资料分辨率. 最后, 根据
多次波产生条件,给出了利用实际区域简化地质模型的地震数值模拟结果计算归一化滤波器算子的方法, 从而利用
该方法压制实际地震数据中多次波.The conventional filtering method can not work well in marineseismic multiple attenuating for shallow water.
Seismic numerical simulationin different conditions was done by solving wave equation and changing the surface
border conditions. Seismic with multiple produced by strong reflectionof seasurfacecan be modeled withfree border
conditions , and seismic without multiplecan be modeled withabsorbing border conditions. That the multiple produce
by strong reflectionof seasurface has changed amplitude, frequency and phase of the effectivereflected wave, canbe
seen after the compare of seismic simulatedindifferent border conditions . Thefiltering operators for attenuating multiple
can be calculated bythe normalized method, and thenthey are worked onthe seismic with multiple . The compares
betweenthe stacked seismic sections showthat the normalized filtering operators work well in attenuating the
seismic multiple, andthe seismic resolutionisi mproved after process . Thereafter, according the conditions affecting
the multiple, the method to calculate normalized filtering operator for real seismic acquired in shallow sea fields is
presented. They can be calculated using seismic si mulated based on the simplified model of real conditions ,in which
the sea water depth, the shots’depthand thereceivers’depth are morei mportant .
Keywords multiple, normalization, wave equation, numerical si mulation, filtering operator
2024 State of Marketing Report – by HubspotMarius Sescu
https://www.hubspot.com/state-of-marketing
· Scaling relationships and proving ROI
· Social media is the place for search, sales, and service
· Authentic influencer partnerships fuel brand growth
· The strongest connections happen via call, click, chat, and camera.
· Time saved with AI leads to more creative work
· Seeking: A single source of truth
· TLDR; Get on social, try AI, and align your systems.
· More human marketing, powered by robots
ChatGPT is a revolutionary addition to the world since its introduction in 2022. A big shift in the sector of information gathering and processing happened because of this chatbot. What is the story of ChatGPT? How is the bot responding to prompts and generating contents? Swipe through these slides prepared by Expeed Software, a web development company regarding the development and technical intricacies of ChatGPT!
Product Design Trends in 2024 | Teenage EngineeringsPixeldarts
The realm of product design is a constantly changing environment where technology and style intersect. Every year introduces fresh challenges and exciting trends that mold the future of this captivating art form. In this piece, we delve into the significant trends set to influence the look and functionality of product design in the year 2024.
How Race, Age and Gender Shape Attitudes Towards Mental HealthThinkNow
Mental health has been in the news quite a bit lately. Dozens of U.S. states are currently suing Meta for contributing to the youth mental health crisis by inserting addictive features into their products, while the U.S. Surgeon General is touring the nation to bring awareness to the growing epidemic of loneliness and isolation. The country has endured periods of low national morale, such as in the 1970s when high inflation and the energy crisis worsened public sentiment following the Vietnam War. The current mood, however, feels different. Gallup recently reported that national mental health is at an all-time low, with few bright spots to lift spirits.
To better understand how Americans are feeling and their attitudes towards mental health in general, ThinkNow conducted a nationally representative quantitative survey of 1,500 respondents and found some interesting differences among ethnic, age and gender groups.
Technology
For example, 52% agree that technology and social media have a negative impact on mental health, but when broken out by race, 61% of Whites felt technology had a negative effect, and only 48% of Hispanics thought it did.
While technology has helped us keep in touch with friends and family in faraway places, it appears to have degraded our ability to connect in person. Staying connected online is a double-edged sword since the same news feed that brings us pictures of the grandkids and fluffy kittens also feeds us news about the wars in Israel and Ukraine, the dysfunction in Washington, the latest mass shooting and the climate crisis.
Hispanics may have a built-in defense against the isolation technology breeds, owing to their large, multigenerational households, strong social support systems, and tendency to use social media to stay connected with relatives abroad.
Age and Gender
When asked how individuals rate their mental health, men rate it higher than women by 11 percentage points, and Baby Boomers rank it highest at 83%, saying it’s good or excellent vs. 57% of Gen Z saying the same.
Gen Z spends the most amount of time on social media, so the notion that social media negatively affects mental health appears to be correlated. Unfortunately, Gen Z is also the generation that’s least comfortable discussing mental health concerns with healthcare professionals. Only 40% of them state they’re comfortable discussing their issues with a professional compared to 60% of Millennials and 65% of Boomers.
Race Affects Attitudes
As seen in previous research conducted by ThinkNow, Asian Americans lag other groups when it comes to awareness of mental health issues. Twenty-four percent of Asian Americans believe that having a mental health issue is a sign of weakness compared to the 16% average for all groups. Asians are also considerably less likely to be aware of mental health services in their communities (42% vs. 55%) and most likely to seek out information on social media (51% vs. 35%).
AI Trends in Creative Operations 2024 by Artwork Flow.pdfmarketingartwork
This article is all about what AI trends will emerge in the field of creative operations in 2024. All the marketers and brand builders should be aware of these trends for their further use and save themselves some time!
A report by thenetworkone and Kurio.
The contributing experts and agencies are (in an alphabetical order): Sylwia Rytel, Social Media Supervisor, 180heartbeats + JUNG v MATT (PL), Sharlene Jenner, Vice President - Director of Engagement Strategy, Abelson Taylor (USA), Alex Casanovas, Digital Director, Atrevia (ES), Dora Beilin, Senior Social Strategist, Barrett Hoffher (USA), Min Seo, Campaign Director, Brand New Agency (KR), Deshé M. Gully, Associate Strategist, Day One Agency (USA), Francesca Trevisan, Strategist, Different (IT), Trevor Crossman, CX and Digital Transformation Director; Olivia Hussey, Strategic Planner; Simi Srinarula, Social Media Manager, The Hallway (AUS), James Hebbert, Managing Director, Hylink (CN / UK), Mundy Álvarez, Planning Director; Pedro Rojas, Social Media Manager; Pancho González, CCO, Inbrax (CH), Oana Oprea, Head of Digital Planning, Jam Session Agency (RO), Amy Bottrill, Social Account Director, Launch (UK), Gaby Arriaga, Founder, Leonardo1452 (MX), Shantesh S Row, Creative Director, Liwa (UAE), Rajesh Mehta, Chief Strategy Officer; Dhruv Gaur, Digital Planning Lead; Leonie Mergulhao, Account Supervisor - Social Media & PR, Medulla (IN), Aurelija Plioplytė, Head of Digital & Social, Not Perfect (LI), Daiana Khaidargaliyeva, Account Manager, Osaka Labs (UK / USA), Stefanie Söhnchen, Vice President Digital, PIABO Communications (DE), Elisabeth Winiartati, Managing Consultant, Head of Global Integrated Communications; Lydia Aprina, Account Manager, Integrated Marketing and Communications; Nita Prabowo, Account Manager, Integrated Marketing and Communications; Okhi, Web Developer, PNTR Group (ID), Kei Obusan, Insights Director; Daffi Ranandi, Insights Manager, Radarr (SG), Gautam Reghunath, Co-founder & CEO, Talented (IN), Donagh Humphreys, Head of Social and Digital Innovation, THINKHOUSE (IRE), Sarah Yim, Strategy Director, Zulu Alpha Kilo (CA).
Trends In Paid Search: Navigating The Digital Landscape In 2024Search Engine Journal
The search marketing landscape is evolving rapidly with new technologies, and professionals, like you, rely on innovative paid search strategies to meet changing demands.
It’s important that you’re ready to implement new strategies in 2024.
Check this out and learn the top trends in paid search advertising that are expected to gain traction, so you can drive higher ROI more efficiently in 2024.
You’ll learn:
- The latest trends in AI and automation, and what this means for an evolving paid search ecosystem.
- New developments in privacy and data regulation.
- Emerging ad formats that are expected to make an impact next year.
Watch Sreekant Lanka from iQuanti and Irina Klein from OneMain Financial as they dive into the future of paid search and explore the trends, strategies, and technologies that will shape the search marketing landscape.
If you’re looking to assess your paid search strategy and design an industry-aligned plan for 2024, then this webinar is for you.
5 Public speaking tips from TED - Visualized summarySpeakerHub
From their humble beginnings in 1984, TED has grown into the world’s most powerful amplifier for speakers and thought-leaders to share their ideas. They have over 2,400 filmed talks (not including the 30,000+ TEDx videos) freely available online, and have hosted over 17,500 events around the world.
With over one billion views in a year, it’s no wonder that so many speakers are looking to TED for ideas on how to share their message more effectively.
The article “5 Public-Speaking Tips TED Gives Its Speakers”, by Carmine Gallo for Forbes, gives speakers five practical ways to connect with their audience, and effectively share their ideas on stage.
Whether you are gearing up to get on a TED stage yourself, or just want to master the skills that so many of their speakers possess, these tips and quotes from Chris Anderson, the TED Talks Curator, will encourage you to make the most impactful impression on your audience.
See the full article and more summaries like this on SpeakerHub here: https://speakerhub.com/blog/5-presentation-tips-ted-gives-its-speakers
See the original article on Forbes here:
http://www.forbes.com/forbes/welcome/?toURL=http://www.forbes.com/sites/carminegallo/2016/05/06/5-public-speaking-tips-ted-gives-its-speakers/&refURL=&referrer=#5c07a8221d9b
ChatGPT and the Future of Work - Clark Boyd Clark Boyd
Everyone is in agreement that ChatGPT (and other generative AI tools) will shape the future of work. Yet there is little consensus on exactly how, when, and to what extent this technology will change our world.
Businesses that extract maximum value from ChatGPT will use it as a collaborative tool for everything from brainstorming to technical maintenance.
For individuals, now is the time to pinpoint the skills the future professional will need to thrive in the AI age.
Check out this presentation to understand what ChatGPT is, how it will shape the future of work, and how you can prepare to take advantage.
A brief introduction to DataScience with explaining of the concepts, algorithms, machine learning, supervised and unsupervised learning, clustering, statistics, data preprocessing, real-world applications etc.
It's part of a Data Science Corner Campaign where I will be discussing the fundamentals of DataScience, AIML, Statistics etc.
Time Management & Productivity - Best PracticesVit Horky
Here's my presentation on by proven best practices how to manage your work time effectively and how to improve your productivity. It includes practical tips and how to use tools such as Slack, Google Apps, Hubspot, Google Calendar, Gmail and others.
The six step guide to practical project managementMindGenius
The six step guide to practical project management
If you think managing projects is too difficult, think again.
We’ve stripped back project management processes to the
basics – to make it quicker and easier, without sacrificing
the vital ingredients for success.
“If you’re looking for some real-world guidance, then The Six Step Guide to Practical Project Management will help.”
Dr Andrew Makar, Tactical Project Management
2024 State of Marketing Report – by HubspotMarius Sescu
https://www.hubspot.com/state-of-marketing
· Scaling relationships and proving ROI
· Social media is the place for search, sales, and service
· Authentic influencer partnerships fuel brand growth
· The strongest connections happen via call, click, chat, and camera.
· Time saved with AI leads to more creative work
· Seeking: A single source of truth
· TLDR; Get on social, try AI, and align your systems.
· More human marketing, powered by robots
ChatGPT is a revolutionary addition to the world since its introduction in 2022. A big shift in the sector of information gathering and processing happened because of this chatbot. What is the story of ChatGPT? How is the bot responding to prompts and generating contents? Swipe through these slides prepared by Expeed Software, a web development company regarding the development and technical intricacies of ChatGPT!
Product Design Trends in 2024 | Teenage EngineeringsPixeldarts
The realm of product design is a constantly changing environment where technology and style intersect. Every year introduces fresh challenges and exciting trends that mold the future of this captivating art form. In this piece, we delve into the significant trends set to influence the look and functionality of product design in the year 2024.
How Race, Age and Gender Shape Attitudes Towards Mental HealthThinkNow
Mental health has been in the news quite a bit lately. Dozens of U.S. states are currently suing Meta for contributing to the youth mental health crisis by inserting addictive features into their products, while the U.S. Surgeon General is touring the nation to bring awareness to the growing epidemic of loneliness and isolation. The country has endured periods of low national morale, such as in the 1970s when high inflation and the energy crisis worsened public sentiment following the Vietnam War. The current mood, however, feels different. Gallup recently reported that national mental health is at an all-time low, with few bright spots to lift spirits.
To better understand how Americans are feeling and their attitudes towards mental health in general, ThinkNow conducted a nationally representative quantitative survey of 1,500 respondents and found some interesting differences among ethnic, age and gender groups.
Technology
For example, 52% agree that technology and social media have a negative impact on mental health, but when broken out by race, 61% of Whites felt technology had a negative effect, and only 48% of Hispanics thought it did.
While technology has helped us keep in touch with friends and family in faraway places, it appears to have degraded our ability to connect in person. Staying connected online is a double-edged sword since the same news feed that brings us pictures of the grandkids and fluffy kittens also feeds us news about the wars in Israel and Ukraine, the dysfunction in Washington, the latest mass shooting and the climate crisis.
Hispanics may have a built-in defense against the isolation technology breeds, owing to their large, multigenerational households, strong social support systems, and tendency to use social media to stay connected with relatives abroad.
Age and Gender
When asked how individuals rate their mental health, men rate it higher than women by 11 percentage points, and Baby Boomers rank it highest at 83%, saying it’s good or excellent vs. 57% of Gen Z saying the same.
Gen Z spends the most amount of time on social media, so the notion that social media negatively affects mental health appears to be correlated. Unfortunately, Gen Z is also the generation that’s least comfortable discussing mental health concerns with healthcare professionals. Only 40% of them state they’re comfortable discussing their issues with a professional compared to 60% of Millennials and 65% of Boomers.
Race Affects Attitudes
As seen in previous research conducted by ThinkNow, Asian Americans lag other groups when it comes to awareness of mental health issues. Twenty-four percent of Asian Americans believe that having a mental health issue is a sign of weakness compared to the 16% average for all groups. Asians are also considerably less likely to be aware of mental health services in their communities (42% vs. 55%) and most likely to seek out information on social media (51% vs. 35%).
AI Trends in Creative Operations 2024 by Artwork Flow.pdfmarketingartwork
This article is all about what AI trends will emerge in the field of creative operations in 2024. All the marketers and brand builders should be aware of these trends for their further use and save themselves some time!
A report by thenetworkone and Kurio.
The contributing experts and agencies are (in an alphabetical order): Sylwia Rytel, Social Media Supervisor, 180heartbeats + JUNG v MATT (PL), Sharlene Jenner, Vice President - Director of Engagement Strategy, Abelson Taylor (USA), Alex Casanovas, Digital Director, Atrevia (ES), Dora Beilin, Senior Social Strategist, Barrett Hoffher (USA), Min Seo, Campaign Director, Brand New Agency (KR), Deshé M. Gully, Associate Strategist, Day One Agency (USA), Francesca Trevisan, Strategist, Different (IT), Trevor Crossman, CX and Digital Transformation Director; Olivia Hussey, Strategic Planner; Simi Srinarula, Social Media Manager, The Hallway (AUS), James Hebbert, Managing Director, Hylink (CN / UK), Mundy Álvarez, Planning Director; Pedro Rojas, Social Media Manager; Pancho González, CCO, Inbrax (CH), Oana Oprea, Head of Digital Planning, Jam Session Agency (RO), Amy Bottrill, Social Account Director, Launch (UK), Gaby Arriaga, Founder, Leonardo1452 (MX), Shantesh S Row, Creative Director, Liwa (UAE), Rajesh Mehta, Chief Strategy Officer; Dhruv Gaur, Digital Planning Lead; Leonie Mergulhao, Account Supervisor - Social Media & PR, Medulla (IN), Aurelija Plioplytė, Head of Digital & Social, Not Perfect (LI), Daiana Khaidargaliyeva, Account Manager, Osaka Labs (UK / USA), Stefanie Söhnchen, Vice President Digital, PIABO Communications (DE), Elisabeth Winiartati, Managing Consultant, Head of Global Integrated Communications; Lydia Aprina, Account Manager, Integrated Marketing and Communications; Nita Prabowo, Account Manager, Integrated Marketing and Communications; Okhi, Web Developer, PNTR Group (ID), Kei Obusan, Insights Director; Daffi Ranandi, Insights Manager, Radarr (SG), Gautam Reghunath, Co-founder & CEO, Talented (IN), Donagh Humphreys, Head of Social and Digital Innovation, THINKHOUSE (IRE), Sarah Yim, Strategy Director, Zulu Alpha Kilo (CA).
Trends In Paid Search: Navigating The Digital Landscape In 2024Search Engine Journal
The search marketing landscape is evolving rapidly with new technologies, and professionals, like you, rely on innovative paid search strategies to meet changing demands.
It’s important that you’re ready to implement new strategies in 2024.
Check this out and learn the top trends in paid search advertising that are expected to gain traction, so you can drive higher ROI more efficiently in 2024.
You’ll learn:
- The latest trends in AI and automation, and what this means for an evolving paid search ecosystem.
- New developments in privacy and data regulation.
- Emerging ad formats that are expected to make an impact next year.
Watch Sreekant Lanka from iQuanti and Irina Klein from OneMain Financial as they dive into the future of paid search and explore the trends, strategies, and technologies that will shape the search marketing landscape.
If you’re looking to assess your paid search strategy and design an industry-aligned plan for 2024, then this webinar is for you.
5 Public speaking tips from TED - Visualized summarySpeakerHub
From their humble beginnings in 1984, TED has grown into the world’s most powerful amplifier for speakers and thought-leaders to share their ideas. They have over 2,400 filmed talks (not including the 30,000+ TEDx videos) freely available online, and have hosted over 17,500 events around the world.
With over one billion views in a year, it’s no wonder that so many speakers are looking to TED for ideas on how to share their message more effectively.
The article “5 Public-Speaking Tips TED Gives Its Speakers”, by Carmine Gallo for Forbes, gives speakers five practical ways to connect with their audience, and effectively share their ideas on stage.
Whether you are gearing up to get on a TED stage yourself, or just want to master the skills that so many of their speakers possess, these tips and quotes from Chris Anderson, the TED Talks Curator, will encourage you to make the most impactful impression on your audience.
See the full article and more summaries like this on SpeakerHub here: https://speakerhub.com/blog/5-presentation-tips-ted-gives-its-speakers
See the original article on Forbes here:
http://www.forbes.com/forbes/welcome/?toURL=http://www.forbes.com/sites/carminegallo/2016/05/06/5-public-speaking-tips-ted-gives-its-speakers/&refURL=&referrer=#5c07a8221d9b
ChatGPT and the Future of Work - Clark Boyd Clark Boyd
Everyone is in agreement that ChatGPT (and other generative AI tools) will shape the future of work. Yet there is little consensus on exactly how, when, and to what extent this technology will change our world.
Businesses that extract maximum value from ChatGPT will use it as a collaborative tool for everything from brainstorming to technical maintenance.
For individuals, now is the time to pinpoint the skills the future professional will need to thrive in the AI age.
Check out this presentation to understand what ChatGPT is, how it will shape the future of work, and how you can prepare to take advantage.
A brief introduction to DataScience with explaining of the concepts, algorithms, machine learning, supervised and unsupervised learning, clustering, statistics, data preprocessing, real-world applications etc.
It's part of a Data Science Corner Campaign where I will be discussing the fundamentals of DataScience, AIML, Statistics etc.
Time Management & Productivity - Best PracticesVit Horky
Here's my presentation on by proven best practices how to manage your work time effectively and how to improve your productivity. It includes practical tips and how to use tools such as Slack, Google Apps, Hubspot, Google Calendar, Gmail and others.
The six step guide to practical project managementMindGenius
The six step guide to practical project management
If you think managing projects is too difficult, think again.
We’ve stripped back project management processes to the
basics – to make it quicker and easier, without sacrificing
the vital ingredients for success.
“If you’re looking for some real-world guidance, then The Six Step Guide to Practical Project Management will help.”
Dr Andrew Makar, Tactical Project Management
5. 1.2 背景概述
Mosely (1976)开展试验研究找出了控制
水流结构和河床形态的两个关键变量:
交汇角和流量比
汇流区的水流输沙特性
Shabayek et al. (2002) 提出的理论模型中
建立了交界面上切应力系数与交汇角的
正相关关系,以及分离区切应力系数与
交汇角的负相关关系。
Zhang et al. (2015) 通过试验将高含沙支
流入汇节点附近的河床形态特征区域分
为四部分,并提出壅水区的淤积量随支
流来沙量增长而线性增长
Zhang et al.
(2015)
Shabayek et al. (2002)
Hsu et al. (1998) 提出了交汇节点上下游水深比的理论表达式
6. 1.2 背景概述
河网模型内边界处理方法
Sanders et al.
(2001)
1 2 3
1 2 3
Q Q Q
z z z
有限差分法
(1) 追赶法:按照上下游关系逐
河段计算
(2) 预测矫正法
(1) 无河段连接单元法
1 2 3
*=( ) / 3
z z z z
(2) 河段连接单元法
(3) 一维二维模型耦合
有限体积法
CUDA, OpenMP等并行架构已被广泛应用于二维浅水模型,还未应用
于河网模型中
Ghostine et al. (2015)
7. 溯源冲刷基本概念
1.2 背景概述
产生条件
侵蚀基准面快速下降
突然变陡的底坡
初始河床形态
顶坡段
坡折点
前坡段
基本类型
跌坎式
旋转式
(Morris and Fan, 1998)
溯源冲刷是河道中具有大底坡、高侵蚀速率的区域自下游向上游发
展的冲刷过程 (Morris and Fan, 1998).
顶坡段
坡折点
水面线
0
10
20
30
40
50
0 1 2 3 4 5
高程
(cm)
x (m)
初始床面
0
min
5
min
10
min
15
min
20
min
D50=0.03 mm
干容重1250kg/m3
(a)
10.06
10.10
10.14
10.18
10.22
0 2 4 6 8 10
高程(m)
x(m)
1800s
1500s
960s
(b)
D50=0.13 mm
干容重1310 kg/m3
8. 溯源冲刷基本方程的理论研究
① 提出溯源冲刷的输沙率公式,推导纵剖面演化方程
2
s
q J
g K
D
(曹叔尤, 1983)
2
2
2
Z Z
a
t x
② 从床沙起动悬浮的机理出发提出适合溯源冲刷过程的侵蚀速率
或床沙上扬通量公式
0.5 0.3
*
tan( )
1 0.012 1.3
tan( )
D
(Winterwerp et al., 1983)
0
*
sin( )
(1 )
sin( ) sin
1 ( ) ,
sin( ) /
m n
e
cr wal
wal l
n
V
A D V
V n k
(Mastbergen and Van den
Berg, 2003)
③ 直接对溯源冲刷段的床面形态作出假设,通过理论分析得到关
键形态参数的表达式(范家骅,2011;韩其为,2003)
溯源冲刷过程模拟(Castillo et al., 2015; 刘茜, 2015; 齐梅兰等, 2016)
齐梅兰等(2016)使用MPM公式构建了溯源冲刷模型,在跌坎处模型
计算的输沙率比实测结果小很多
9. 2 高含沙河网模型
• 共3+N个控制方程
2.1 数学模型
t x
U F
S
1
2
1
( ) / (1 )
/
, ,
0
( ) / (1 )
N
k k l
k
w
k k k lk l
k
N
b
k k
k
B E D p q
Q
A
M
Q Q A
AC B E D C q
QC
A
B D E p
U F S
1 1
( ) ( )
(1 )
N N
b m s w
w k k k lk l f
k k
m m
m
c
m
M BU E D C C qU gAS
p
z A
gA gh
x x
Ck— 体积比含沙量
w, m—— 清水与浑水密度
s, b—— 泥沙颗粒与床沙湿
密度
p ——孔隙率
z ——水位
河网模型中的计算单元划分
10. 2.2 数值方法
水面梯度使用上风梯度与下风梯度加权平均法(Ying et al., 2004),
权重根据柯朗数计算
1
1/ 2 1/ 2
( )
m m m m m
i i i i i
t
t
x
U U F F S
数值通量计算
I. 单元格交界面两侧的水深使用WSDGM方法(Aureli et al., 2008)
进行数值重构
II. 干湿交界面处的波速修正。HLLC近似黎曼算子计算数值通量。
, , , ,
1 1 1 1 1 1 1 1
2 2 2 2 2 2
(1 ) (1 )
L L DGM L SGM R R DGM R SGM
i i i i
i i i i i i
h h h h h h
lim
lim
lim
1
1 cos( ) 0
2
1
i
i
i
i
Fr
Fr Fr
Fr
Fr Fr
源项计算
1 1
1 1
= ,
n n n n
i k i k i k i k
down up
i k i k i k i k
z z z z
z z
x x x x x x
11. 2.2 数值方法
内边界处理
交汇区地形插值
① AB、CD和EF为已知断面,连接构成
六边形,以缩放比例β做内部相似多
变形,其内部点高程为定值z*
② 连接OP得S1、S2,OP高程由S1、S2
高程插值得到。S1高程在AB上插值。
S2高程等于z*
③ 连接OQ得S3、S4,OP高程由S3、S4
高程插值得到。S4高程在ED上插值。
S2高程等于E、D高程的最小值
从重构地形中提取河段连接单元的
水位—容积—水面面积关系
交汇区地形插值结果
汇流区地形插值法示意图
12. 2.2 数值方法
河段连接单元内的计算
① 河段连接单元与一维控
制单元间的数值通量
1
1
1
M JC
M M
M JC
z z
U U
C C
② 计算蓄水量
3
1
1
1
( , ( ))
n n
i
VW VW F i G i t
𝐹1(𝑖, 𝐺(𝑖))表示数值通量的第一个分量,以和河段连接单元相连的第i个一维单
元为左单元,以相应的虚拟单元G(i)为右单元。该定义保证了进入河段连接单
元的流量为正值,流出为负值,与每个河段的局部坐标系中的正向定义无关
③ 计算冲淤,更新水位—容积—水面面积关系
1
/ (1 )
N
k k JC
JC
k
VB D E A t p
④ 计算含沙量
3
, 2
1 1
, 1
( , ( ))
n n
k JC k k k JC
JC
n i
k JC n
C VW F i G i t D E A t
C
VW
13. 2.2 数值方法
考虑交汇角度影响后的改进
交界面右侧的流速设置
( )
i i x xi y yi
U u n u n
当第i个河段的局部坐标系中坐标
轴正向指向河段连接单元时δi取1,背
离河段连接单元时δi取-1
交界面右侧的水位设置
2 2 2
( ) / 2
i JC x y i
z z u u U g
河段连接单元内水量、冲淤量、含沙量的计算方法同基本算法,动量计
算如下
3
2 0
1
3
2 0
1
( , ( )) ( )
( , ( )) ( )
n
x xi x fx
i
n
y yi y fy
i
M t F i G i n g VW S S
M t F i G i n g VW S S
3
1
0 3
1
( )( )
xi JC i
i
x
JC i
i
sign n z z
S
x x
29. 控制方程
4 高速冲刷条件下悬浮通量理论与溯源冲刷模型
在x轴水平的坐标系下建立,底坡较大时cosα 不可忽略
Sa 是表达泥沙运动对水流运动影响的附加项
水动力方程具有well-balanced 特性(Xia and Liang, 2018)
分组上扬通量Ek 的计算使用Van Rhee (2010)提出的高速冲刷条
件下悬浮通量公式
𝜕𝐔
𝜕𝑡
+
𝜕𝐅
𝜕𝑥
= 𝐒0 + 𝐒𝑎
0
4
1
2 2
2
0
1
0
0
1
0
( ) / (1 )
1 (cos )
cos
1 1
2
( )
,
(1 ) 2
/ cos
0
( ) / (1 )
0
N
k k b
k
b x
N
b
k k
a
k
b
k k bk e
N
k k b
k
E D n c
z
gh gh
x x
u E D gh
n c x
E D c v
D E n c
S S
2 4 2
1
(cos )
, 2
0
k
k
b
hu
h
hu u h g h
hC
huC
z
U F
(1) (2)
(3)
30. Van Rhee的悬浮通量理论
4.1 数学模型
修正Van Rijn(1984)的泥沙上扬通量公式, 修正后
E 和ve相互影响
sin ( cos )tan
s i
F G G F
坡面上泥沙的平衡条件
倾斜床面上泥沙的稳定性(Van
Rhee, 2010)
修正后的临界Shields参数 0
sin( )
sin 1
e l
cr cr
l l
v n n A
k n
表层泥沙在剪切作用下重新排列,孔隙增大
0.3
*
v
cr
cr
E k gd D
泥沙悬浮/上扬通量
31. 4.1 数学模型
床沙质量守恒
0
( ) (1 )
b s e e
c v E v n
淤积时的床沙质量守恒(Van Rhee, 2010)
0
cos
1
e
b
E D
v
n c
相对于运动床面的
沉降速度
应用扩展—非均匀沙输移
0.6
,
1 1
0.03 /
N N
j k
hk bj ek bj cr k ek hk
j j
k j k j
d d
p p p p p p
d d d d
泥沙起动时的隐暴效应(Wu et al., 2000)
0.3
*
cr
k v k k
cr
E k gd D
1
cos
k bk
k N
j bj
j
E p
E E
E p
不考虑底坡和渗流的估计
分组悬浮通量
32. 3 数值方法
Fi+1/2 使用HLLC黎曼算子计算
4 4
1
1/2
(cos ) (cos )
2
i i
i
g g
数值通量
1
1/2 1/2 0
( ) ( )
n n n n n n
i i i i i ai
t
t
x
U U F F S S
cos4α 可视为对重力加速g的修正,由于修正后g不是常量,在单元
格交界面上重新定义:
交界面两侧黎曼状态重构:
, 1/2 , , 1
, , 1/2 , 1 , 1/2
1
max( , )
max(0, ), max(0, )
, [ ]
b i b i b i
L s i b i R s i b i
L L i R R i
z z z
h z z h z z
hu h u hu h u
源项
4
2 2 2 2
1/2 1/2, 1/2 1/2,
1 (cos ) 1
cos
2 2
b
i i L i i R
i
z
gh gh g h g h
x x
使用黎曼状态重构结果进行源项离散,保持well-balanced特性
(Xia and Liang, 2018)
33. 4.2 数值方法
0
0
cos ( )
sin( )
sin (1 )(1 )
l
cr l l b
D n n A
k n n c
f(ve)的单调递减区间
0
sin( )
sin 1
e l
cr cr
l l
v n n A
k n
0.3
*
cr
v
cr
E k gd D
0
cos
1
e
b
E D
v
n c
悬浮通量的数值计算方法
1 2
( ) ( ) ( )
e e e
f v f v f v
0.3 0
1 *
0
(1 )
( )
( ) 1
(1 )
sin( )
sin ( )
l l
cr l
e v
l l
e
l
k n
n n A
f v k D g d
k n
v
n n A
2 0
( ) cos (1 )
e b e
f v D n c v
0 0
(1 ) (1 )
sin( ) sin( )
sin ( ) ( ) sin
l l l l
ea e eb
l l cr
k n k n
v v v
n n A n n A
为保证f(ve) = 0有根,希尔兹参数应满足
检查θ 是否满足 ② ,若满足,用迭代方法在 区间① 寻找ve
①
②
近底含沙量应满足 0
min(2 ,1 )
b
c C n
47. 论文
Wang, Z., Xia, J., Zhou, M., & Li, T. (2019). Numerical Modeling of Hyperconcentrated Confluent
Floods From the Middle Yellow and Lower Weihe Rivers. Water Resources Research, 55(3), 1972-
1987.
Wang, Z., Xia, J., Zhou, M., Deng, S., Li, T. (2019). Modelling hyperconcentrated floods in the Middle
Yellow River using an improved river network model. CATENA (under review).
Wang, Z., Xia, J., Zhou, M., Deng, S. (2020). One-dimensional morphodynamic model for retrogressive
erosion based on a sediment entrainment theory at high flow velocity. Applied Mathematical
Modelling (under review).
Xia, J., Zhang, X., Wang, Z., Li, J., & Zhou, M. (2018). Modelling of hyperconcentrated flood and
channel evolution in a braided reach using a dynamically coupled one-dimensional approach. Journal
of hydrology, 561, 622-635.
王增辉, 夏军强, 张俊华, 李涛. (2018). 考虑干支流倒回灌的小浪底水库异重流模拟. 工程科学与技
术, 50(01), 85-93.
夏军强, 王增辉, 王英珍, 张晓雷. (2019). 黄河中下游水库-河道-滩区水沙模拟系统的构建与应用.
应用基础与工程科学学报 (在审).
Wang, Z., Xia, J., Zhou, M., Deng, S. (2019). One-dimensional morphodynamic model for retrogressive
erosion based on a sediment entrainment theory at high flow velocity. 14th International Symposium
on River Sedimentation, Chengdu.
专著
夏军强, 王增辉, 多沙河流水库水沙运动特性及其数值模拟, 科学出版社, 2019.
主持科研项目
多沙河流水库溯源冲刷与异重流排沙耦合过程的数值模拟研究, 国家自然科学基金青年基金
(51809196), 2019-2021.
高含沙河网模型及其在黄河干支流洪水演进模拟中的应用,中国博士后科学基金一等资助
(2018M640731), 2018-2019.