Mississippi Flooding and the Atchafalaya spillway

News sources are quoting a figure of 1.5 million cubic feet per second for the current flow of the Mississippi River at the Morganza spillway. That is a lot of water!





To get a visceral idea of how much water that is, my brother Mike from Sandy, Utah sent me some calculations describing how the flow at Morganza (above Baton Rouge) compares to the flow of the Colorado River. 1.5 million cfs is equal to 34.43526 acre feet / second. By comparison, the total capacity of Lake Powell is 24,322,000 acre feet; currently 53.99% full, available capacity 11,205,145 acre feet. The Upper Colorado Basin is supposed to provide an average of 7.5 million acre feet each year past Lees Ferry, Arizona. On Wednesday (May 11, 2011) the flow into Lake Powell was 31,862 cfs, and outflow was 14,791 cfs. Little Cottonwood Creek flood stage is around 500 cfs (coming down into Sandy from Alta and Snowbird).


Lake Powell capacity and percent full numbers are taken from http://lakepowell.water-data.com/. Lake Mead capacity and percent full numbers are taken from from http://lakemead.water-data.com/.


So at 1.5 million cfs, the Mississippi would deliver the annual flow past Lees Ferry in 2.52 days, would fill the currently available storage in Lake Powell in 3.77 days, and would then fill the available capacity in Lake Mead in another 4.96 days. That’s a lot of water! If I could somehow capture and store 1 second of the current Mississippi flow, I could easily water my yard for the rest of my life. And they would never miss it!


You can read more about this at “The Control of Nature: Atchafalaya”: (February 23, 1987):


That link is an old article by John McPhee about attempts to control nature, which is probably getting a lot of web traffic these days. If the Old River Control Structure were to fail, most of the flow of the Mississippi would flow down the Atchafalaya River, taking a much shorter route to the sea and leaving New Orleans and Baton Rouge along a backwater channel.


The interesting thing to Mike is that in the long term, the Mississippi Delta is eroding and subsiding while most of the sediment is funneled into deeper waters in the Gulf of Mexico. He further observes that to prevent the loss of the Delta and associated flooding from the ocean (especially during hurricanes), they should allow flooding from the Mississippi River to deposit sediment (mud) on the land, and probably need to let the Mississippi River take new channels to the Gulf every few hundred years.


And he’s right. That long lobe of the Mississippi delta past New Orleans is called a “bird’s-foot delta” because it looks like one. It’s unnatural for a delta to form like that, and it’s a consequence of 100 years of levees upriver and in the delta itself. He’s right – all the sediment is going to exactly the wrong place.


There is a way to fix this.


The Morganza diversion needs to be a sediment trap:


We need clean water to flow down the Mississippi to New Orleans (thereby eroding and deepening the built-up channel), and muddy water to pass down the Atchafalaya (thereby building up that lower-elevation lobe). How can we separate the muddy water from the clean water? Build a sediment trap!


The Army Corps of Engineers needs to create a small lake at the point of the diversion. When muddy water flows into a lake, the mud settles to the bottom as sediment. Clear water flows beyond that inflow delta, and eventually flows out of the lake. This is why Lake Powell is getting filled up with sediment in its upper reaches, and why the Grand Canyon is sediment-starved. The lake should have two major outflow pipes: one positioned at the lake bottom close to the inflow, and the second positioned near the lake surface at the downstream end of the lake. The “bottom near the inflow” pipe feeds sediment-laden water down the Atchafalaya river. The “surface downstream” pipe feeds clear water down the Mississippi. After decades, and some big floods like the current one, the Atchafalaya lobe will build up and the New Orleans bird’s-foot will erode away.


The Morganza spillway already has a stilling basin, but that’s designed to dissipate energy, not separate out the sediment.


Yes, it will cost a lot of money to build the sediment trap, but the alternatives are a lot more expensive. What is the cost of relocating New Orleans and Baton Rouge? We are hoping to accomplish here a controlled stream capture and relocation of the sediment load. By the way, the natural event when a river distributary carves a new channel is called a “crevasse event.” The river catastrophically breaks through the natural levee and forms a crevasse where the new channel pours out. A lot of people in the John McPhee article were terrified of a crevasse event happening on its own.


We need a sediment trap and decades of patience to let it work.


Tags: , , , , ,

Rome Wasn’t Built Without Deadlines

There is no truth that the unofficial Boy Scout Motto is “There is no time like the last minute.” It is, however, the unofficial Motto of my Boy Scout Troop. And that was before I even joined.


What Open Access Does For Me

On August 30, 2010 I published a scientific paper in the peer-reviewed journal PLoS ONE entitled “Dynamics of Wind Setdown at Suez and the Eastern Nile Delta”. This post is a follow-up to my earlier post of August 31, which focused on Open Access. So – what happened?

Plenty! My employer issued a press release on September 21, 2010, which is our standard practice for research that we think will have popular interest. There was extensive media coverage during that week, including segments by ABC News, Fox 31 KDVR in Denver, National Public Radio, CNN.com, and the BBC. After working hard on this research for years as a graduate student, it was gratifying to receive the attention! The number of article views at PLoS ONE is now at 39,009. Our animation of Parting the Waters has been viewed 542,928 times on YouTube, and my verbal explanation there has been viewed 58,618 times.

What role did Open Access play in the publication of my research results?

1. Open Access is ideally suited to inter-disciplinary topics of popular interest.

Many scientific journals focus on a single area of science, and reject manuscripts that are judged to fall outside that discipline. Is my research: oceanography, meteorology, archaeology, history, coastal oceanography, biblical studies, numerical modeling, geology, or what? A limited access journal tends to exclude from its readership those scientists who do not subscribe to the journal, placing a barrier to experts outside the journal’s focus. That same barrier to readership also discourages interested amateurs who are willing to brave the paper’s scientific rigor and try to understand what it’s about. I recognized that the Exodus problem is highly inter-disciplinary, and this publication might spark great popular interest. I didn’t want to exclude anyone from reading the paper, even with a small download fee.

2. Open Access increases the number of article views.

PLoS ONE includes a number of useful metrics, including the number of article views. As noted in my previous post, I want lots of people to read my paper. Although I don’t have extensive metrics on article views between Open Access and limited access, my colleagues tell me that 39,009 views is a lot for a scientific paper! We think it would be hard to get those numbers with limited access. Unfortunately, I cannot re-run this publication experiment with a traditional journal and count up the views again.

But I can plot the article views on a daily basis and try to extract some meaning out of the graphs! Here the cumulative and daily views on a log scale (see figure at right):

Plots of article views on a daily basis.

Cumulative and daily article views.

Obviously the press release and subsequent media coverage had a huge effect on article readership. Over two weeks the number of article views zoomed up from 500 to over 35,000! Since the graph doesn’t shoot up until the press release, people must be reading the news first and then looking up my scientific paper. It is safe to say that the media coverage caused a jump in article views, not the other way around. Media coverage drives people to my research; Open Access lets them in the front door. 35,000 people became interested enough to look at the original paper, and indeed they could (with some repeat visitors). Open Access works together with media publicity to increase drastically the societal impact of scientific research.

3. Open Access assists helpful amateurs to educate the general public.

In comments and blog posts I have noticed about 1 in every 20 posts is from a knowledgeable person who is trying to educate the rest of the folks on the forum. Often they have posted a link to the original paper, with the remark that it’s open access. These knowledgeable people are “amateurs”; and I use that term in the sense that they love science! They take time to educate themselves, they read technical articles, and they provide helpful references for everyone else. They look up facts instead of just typing in something and hitting the Post button. They verify the details and correct mistaken assumptions. Helpful amateurs are very important in communicating science. Professional scientists cannot do it alone. I can make the amateurs’ job easier by providing open access to my scientific publications. I appreciate their valuable efforts.

Open Access increases my impact as a scholar. Scientific research is hard work! The societal impact makes it all worthwhile.

Weatherwise magazine

On a related note, I have just published an article in Weatherwise magazine as a follow-up to the earlier scientific paper. This magazine article “Could Wind Have Parted the Red Sea?” explains the parting of the sea to the general public. So if you don’t want to read about drag coefficients and Mellor-Yamada mixing, that’s where to go!

UCAR Policy

The views expressed here are not necessarily those of my employer. UCAR has adopted an Open Access Policy, and has implemented that policy by the creation of an institutional repository of scholarly works known as OpenSky.

Tags: , , , , , , , ,

Three Quotes About The Character of The Irish

“The Irish are a fair people; they never speak well of one another.”
Samuel Johnson

“The Irish are often nervous about having the appropriate face for the occasion. They have to be happy at a wedding, which is a strain, so they get depressed; they have to be sad at funerals, which is easy, so they get happy.”
Peggy Noonan

“When anyone asks me about the Irish character, I say look at the trees. Maimed, stark, and misshapen, but ferociously tenacious.”
Edna O’Brien

Crossing the Red Sea with Moses and Open Access

Yesterday the scientific journal PLoS ONE published my article “Dynamics of Wind Setdown at Suez and the Eastern Nile Delta”. This publication represents a portion of my Master’s thesis, which was announced here last year. We now present this research in a peer-reviewed journal. Here is the paper’s Abstract:

Wind setdown is the drop in water level caused by wind stress acting on the surface of a body of water for an extended period of time. As the wind blows, water recedes from the upwind shore and exposes terrain that was formerly underwater. Previous researchers have suggested wind setdown as a possible hydrodynamic explanation for Moses crossing the Red Sea, as described in Exodus 14.

Since the paper is about dynamics instead of biblical history, the contents focus on fluid mechanics instead of on Moses and the Hebrew refugees. But for those readers who are interested in the Exodus, Point B in Figure 8 is Pi-hahiroth. The famous crossing is from Point B across to Tell Kedua. My Tanis hypothesis suggests where and how Moses crossed the yam suf. When remains a thorny issue. As with any new hypothesis, scholars from many disciplines will have to consider the proposal from all angles (history, linguistics, military science, archaeology, meteorology, refugee movement, sociology, oceanography, etc.).

What Open Access means for me

PLoS ONE is an Open Access journal, meaning in a general sense that access to the publications is not restricted. You don’t have to pay a download fee or a subscription fee to download and read the articles. It’s free Free FREE! For what Open Access means for the world of science at large, Google for the term and do some reading. Go ahead and peruse some of the debates. I’ll describe here what it means for me.

It means that my co-author and I paid a publication fee to cover the cost of reviewing and preparing the document for on-line publication. Some journals (Open Access or not) are free to publish in, and others require certain page charges. PLoS ONE follows the “author pays” model.

The “Dynamics of Wind Setdown” article is of general interest. I want oceanographers to read it, I want journalists to read it, I want high school students to read it. I want teachers, gardeners, Norwegians, mechanics, historians, kids, pastors, marketing directors, software engineers, physicists, Australians, poor people, airline pilots, retired people, shepherds, and checkout clerks to read it. I want you to read about the parting of the Red Sea. Skip right to Figure 8 if you want! I don’t want any barriers to readership. I want the paper’s exposure to be as wide as possible. And I can achieve that goal by opening up access.

Peer-reviewed articles are read by scholars, who cite previous research when they publish a subsequent study. The citation count is a measure of the impact of a paper – the importance that a paper has on its field. Open Access papers are supposed to have higher citation counts, so this publishing model will presumably be better for my career.

What Open Access means for you

Open Access means that you can make use of the material that we published. The content at PLoS ONE is licensed under a Creative Commons Attribution License. This means that you can use the article in ways described by the license, so long as you properly cite the authors and the journal. The idea behind the CCA license is that scholars’ work should be used and extended, with due credit given to the original publication. You don’t have to get our written permission. Please refer to the Creative Commons web site for further information.

Open Access means that you don’t have to pay $30 or even $15 to download the paper and read it. Your institution or library doesn’t have to pay thousands of dollar$ in subscription fees to get the document. You just have to click. That’s right, you simply have to click on this link. What are you waiting for? Click! Download and read it now!

Tags: , , , , ,

You Like Me, You Really Like Me!

Call it beginner’s luck, luck of the Irish, or just plain old dumb luck, but somehow I managed to win the Caption of the Day Contest at Ipse Dixit. It was an honor to just be nominated among such a wonderful group of comedians, and I never expected to win, so I don’t have anything prepared. Oops, wrong prepared speach.

If any of you have come here from there wondering just who this Murphy guy is, please feel free to look around, check out the archives, hit my non-blog web site, put your feet up, and remember, mi casa es mi casa – so pick up after yourself.

Starting My Weight Loss Regimen (Again)

I have gone back on a low carb diet which I have found to be an effective way for me to lose weight (although I have to be careful, sometimes I think I have lost some weight and I turn around quickly to find it following along behind me).

I read Gary Taubes “What It It’s all Been a Big Fat Lie” in the New York Times in 2002 and it completely changed my perspective on dieting.  He came out with “Good Calories, Bad Calories” in 2008, and I recently re-read it to help me recommit to a low carb regimen. On page 454 he offers what he calls his “inescapable conclusions” based on fifteen years of research:

  1. Dietary fat, whether saturated or not, is not a cause of obesity, heart disease or any other chronic disease of civilization.
  2. The problem is the carbohydrates in the diet, their effect on insulin secretion, and thus the hormonal regulation of homeostasis—the entire harmonic ensemble of the human body. The more easily digestible and refined the carbohydrates, the greater the effect on your health, weight and well-being.
  3. Sugars—sucrose and high-fructose corn syrup specifically—are particularly harmful, probably because the combination of fructose and glucose simultaneously elevates insulin levels while overloading the liver with carbohydrates.
  4. Through their direct effect on insulin and blood sugar, refined carbohydrates, starches and sugars are the dietary cause of coronary heart disease and diabetes. They are most likely dietary causes of cancer, Alzheimer’s disease, and the other chronic diseases of civilization.
  5. Obesity is a disorder of excess fat accumulation, not overeating, and not sedentary behavior.
  6. Consuming excess calories does not cause us to grow fatter, any more than it causes a child to grow taller. Expending more energy than we consume does not lead to long-term weight loss; it leads to hunger.
  7. Fattening and obesity are caused by an imbalance—a disequilibrium—in the hormonal regulation of adipose tissue and fat metabolism. Fat synthesis and storage exceed the mobilization of fat from the adipose tissue and its subsequent oxidation. We become leaner when the hormonal regulation of fat tissue reverses this balance.
  8. Insulin is the primary regulator of fat storage. When insulin levels are elevated—either chronically or after a meal—we accumulate fat in our fat tissue. When insulin levels fall, we release fat from our fat tissue and use it for fuel.
  9. By stimulating insulin secretion, carbohydrates make us fat and ultimately cause obesity. The fewer carbohydrates we consume, the leaner we will be.
  10. By driving fat accumulation, carbohydrates also increase hunger and decrease the amount of energy we expend in metabolism and physical activity.

Practical Advice From Keith Hennessy

Keith Hennessy had a great blog post on “Oil Spill Crisis as Opportunity” where he makes the following suggestion for new legislation:

Imagine that the President proposes new legislation targeted at the problem of engineering safety in deepwater drilling.  Imagine his legislation contains five provisions:

  1. Require that all deepwater wells have a relief well in place before production begins.
  2. Mandate requirements for double piping and a list of other industry engineering best practices.  The prior best practice for engineering safety becomes the legally mandated minimum.
  3. Mandate that each deepwater drilling operation be insured for at least $20 B of environmental damage before production can begin.  Insurers will therefore require further engineering stringency to protect themselves.
  4. Raise the legal liability cap for any drilling platform to $50 B, just to be safe.
  5. All new wells must meet all of the above requirements, and all existing wells must cease production until they meet them.  (The details here might need some work.)

He makes this suggestion after offering the following analysis of current energy consumption usage patterns and the limits of battery technology:

If you are focused on carbon emissions, then oil, coal, and natural gas naturally group together as “fossil fuels” and are the combined source of the problem.  If you are focused on energy, then oil is one issue (transportation), and coal and natural gas are another (electric power).

We use almost no oil to produce power in the U.S., and electricity powers only a tiny fraction of our transportation, despite recent increases in hybrid and natural gas vehicles.  Yes, they’re growing at a rapid rate.  But the overlap between oil as one type of energy source vs. coal and natural gas as another is vanishingly small.

Someday when battery technologies improve, the fuel and power worlds will blend in the U.S., and there will be strong and direct economic relationships between the production of electric power and the use of oil.  Until that day, from an energy perspective, “fossil fuels” conflates oil with coal and natural gas in a way that is at best confusing and at worst misleading.  Substituting biofuels for oil or making vehicles more fuel efficient has almost no effect on the amount of coal or natural gas we use.  “Produc[ing] wind turbines,” “installing energy-efficient windows, and small businesses making solar panels” are quantitatively irrelevant to our use and production of oil.  All the windmills and solar panels you could imagine will not reduce our dependence on oil as a transportation fuel.

He has a great chart and more details, go read the whole post.

Colorado Joins the Pac-10

In sports news, we learn that the University of Colorado at Boulder has joined the Pacific-10 Conference. I have a Bachelor of Science degree in Electrical Engineering from Stanford University, and a Master of Science degree in Atmospheric and Oceanic Sciences from the University of Colorado. This means that my two alma maters will now be playing each other on a regular basis. Yay! This is cool!

This is a good move for Colorado. The Pac-10 is a great conference! In college football, the Pac-10 has a lot of great west coast teams, with exciting offenses and tough defensive squads. UC-Berkeley was always a great game, UCLA is tough to get by, Washington usually has lots of talent, and the Arizona fans in Sun Devil Stadium made for a deafening contest whenever Stanford played there. USC was always tough (sometime too tough), but Stanford football has earned some wins and ties against Southern California. The other athletic programs provide worthy competition, too – baseball, basketball, water polo, tennis, and so on. It will also be good for CU to join the stellar academics of the Pac-10 schools (Stanford, Berkeley, University of Washington, UCLA, etc.).

For Colorado sports fans, the Pac-10 schools are wonderful places to visit. Oregon is the most beautiful state in the country when the sun’s out. Seattle is a kick! Southern California is a fun place to spend a few extra days visiting Disneyland or going surfing. When in the Bay Area during fall, head to San Francisco and on to the wine country! San Francisco is the first big city I ever enjoyed.

During my senior year at Stanford, before I had ever visited Boulder, I remember a guy from the Stanford radio station telling me what an amazing place Boulder is when he traveled here for a rare Stanford-CU football game. So I came. I’m still here.

I don’t even know who I should root for! Undergraduate ties to the school’s athletic program are usually stronger, but I have been steeped in local football enthusiasm for decades now. I’ll go to the first Boulder game and just let the competitive juices flow where they will.

To all those Pac-10 students, fans, and alumni I have this to say: Come out and see us! Boulder is a great place to visit in the fall. Spend a few extra days in the mountains, hang out on the Pearl Street Mall, drive over the Trail Ridge Road before the snow flies, go skiing after the snow flies, have a meal at the Dushanbe Tea House and ask some local to tell you the real history of the place, or bag a Fourteener!

We’ll give you a good football game and send you on home, tired but happy.

Tags: , , , , , ,

Leaf Boats and Sediment Traps

Last week we had a big thunderstorm pass over the house during the evening, and my two boys (ages 10 and 6) put on their raincoats and went out into the front yard to see what was going on. They love to send leaf boats down the edge of the street when it rains. When I came out to check on them, they had piled up some landscaping gravel in the gutter to make a dam, causing a large puddle of murky rainwater to collect in the street near our driveway. The two of them were really excited about their civil engineering: “Look, Dad! We made a dam! But our lake keeps rising and flowing around the dam, so we need more gravel!” I grinned. This arms race continued until their dam started to leak through the gravel, kind of like the turbines at the bottom of Glen Canyon Dam. “What? You guys aren’t generating electricity?”

They noticed that the water coming into their little lake was murky with silt, while the water seeping out through the gravel was clear and clean. “Yep, you guys have built a sediment trap“, I explained. “The fast-flowing river water carries dirt with it, but in the calm lake water the dirt drops out to the bottom. That’s why it’s called a sediment trap, because the river sediment can’t get past the lake.” “Wow! We built a sediment trap!” they exulted. “Sediment trapping is a big problem for silty rivers like the Colorado and the Nile“, I elaborated. “The Glen Canyon Dam and the Aswan High Dam trap the river silt and prevent it from flowing downstream. That’s why the Grand Canyon and the Nile Delta are losing their sand.” [Yes, sometimes I talk in html.] The boys were thrilled to hear the world-wide implications of their little experiment.

After the rain we put the gravel back around the mailbox and washed our hands. And I thought to myself, What a great neighborhood / country / life I have! My kids can play safely in the yard, forget their video games, get dirty, have fun, and learn about fluid mechanics all at the same time!

Tags: , , , , , ,