subscribe: Posts | Comments

How to destroy a delta: Mississippi vs Nile approaches


Figure 1. Mississippi River delta (l); Nile River delta (r)

Figure 1. Mississippi River delta (l); Nile River delta (r)

by Len Bahr, PhD*

Even casual readers of LaCoastPost typically realize that short-sighted federal and state policy decisions during the past two centuries have rendered the Mississippi River watershed – and especially its delta – highly dysfunctional. The familiar litany of mistakes is topped by a levees-only policy on the part of the Corps of Engineers, which isolated the river from its delta in a successful but misguided attempt to prevent local river flooding.Len2.21.10

There is perhaps less recognition that we’re not alone at the mouth of the sinking and shrinking Big Muddy delta, in that deltas are dying all over the globe, threatening more than a billion people who depend on these wonders of nature.

The Mississippi and Nile river systems have much in common, as well as distinct differences. Science Magazine recently published a sobering report on severe crises facing the Nile River delta and its fifty+ million residents. I highly recommend reading this four page article that would be interesting by itself but is particularly instructive for those of us concerned about the increasing morbidity of the Mississippi River delta.

Figure 1 shows satellite views of these two formerly magnificent deltas, at approximately the same scale. These low resolution images hide the cultural changes (such as described in the Science essay for the Nile delta) that are literally wringing the lives from these deltas.

Key differences between the Mississippi and Nile deltas include their respective watersheds and flow volumes. For the ten millennial span of Holocene period since the last ice age the watershed of the Mississippi has primarily occupied temperate deciduous and prairie biomes that comprise the central portion of the US. This vast watershed occupies a climate regime that maintains significant primary production to feed much of the world and sufficient runoff to supply flow to the upper Mississippi, Ohio and Missouri tributary systems.

So far at least, annual rainfall and snowmelt combine to make the lower Mississippi the third most powerful river on Earth, after the Amazon and Yangtze. The growing signs of climate change, including drought/flood events, make future bets very unwise, however.

Forgive a slight digression. Last Friday at the conclusion of the High Water Inspection Trip for the Mississippi River Commission, I had a conversation with Brigadier General Michael Walsh (who is mentioned in an April 23 coastal scutttlebutt minipost). The general has been calling for someone to write a sequel to John Barry’s Rising Tide, looking forward to the end of the century rather than back.

General Walsh apparently wants a credible handbook for sustainably managing the entire Mississippi River watershed and its delta. In considering such a project I believe that, given the pace of change, e.g., energy, freshwater and even phosphate fertilizer, the uncertainties through 2020 are challenging enough, let alone projecting nine decades.

Back to the comparison between the Mississippi and Nile systems, Mississippi outflow provides roughly 90% of the freshwater input to the entire Gulf of Mexico. This flow, coupled with a relatively low population density in south Louisiana, makes the Mississippi delta unique in the US, in terms of landscape having a superabundant source of clean freshwater. Don’t think that our neighbors in Texas aren’t aware of this ‘imbalance.’

In striking contrast with the Mississippi watershed and delta, the Nile supports one of the densest populations in the world. Since the age of the Pharaohs the residents of the Nile River valley, and especially its delta, have been absolutely dependent on river water, which is now running out, as described in the Science report mentioned above.

During the past ten thousand years of the Holocene period the Nile watershed, which consists largely of desert, has delivered far less water to its delta than has the Mississippi. This explains the large difference in delta areas.

In terms of time, it’s truly humbling to realize that some of our more technologically advanced ancestors in the northern part of Africa were using the Nile to transport massive stones to build pyramids two thousand years before the delta land underneath New Orleans even existed!

The population of Egypt grew exponentially during the latter half of the 20th century. In addition to recently expanded use of Nile river water for cotton irrigation and to supply an exploding population of thirsty Egyptians, anthropogenic global warming is now increasing the rate of evaporation from Nile Reservoirs.

Water is now being taken out of the Nile faster than Mother Nature can resupply it. In addition, river-borne sediments have been trapped behind six dams, or ‘cataracts,’ including the High Aswan hydroelectric project built by the former Soviet Union.

The once lush freshwater fan shaped Nile delta, the breadbasket for Egypt, is sinking and salt water from the Mediterranean Sea is now flowing into the northern part of the delta (Do the name Ruby Begonia sound familiar to ya?). On an annual basis the Mediterranean no longer receives a net flow of river water and a productive nursery ground for fish no longer exists. At least the lack of river flow into the Mediterranean presumably precludes massive eutrophication and the development of a hypoxic zone, such as occurs each year off of the Mississippi delta.

As for comparative numbers, the drainage basin of the Mississippi River occupies 2,980,000 square kilometers, or about 1.1 million square miles, 41% of the continental US. The Nile watershed is only 4% larger, covering 3,254,555 square kilometers, or about 1.3 million square miles, 10% of the area of Africa.

According to this blogger’s friend Wikipedia, the combined delta of The Yellow and The Yangtze Rivers is the largest in the world, with an astounding area of roughly 500,000 Km2. Second, at about 350,000 Km2 is the combined delta areas of the Ganges and the Brahmaputra. In third place is the (shrinking) Mississippi River Delta, described by Wikipedia at either 96,000 or 150,000 sq km.**

I decided to use the lower number for our coast, which still seems high but somewhat more reasonable. The Amazon delta came in at about the same area as the Mississippi, at about 100,000 Km2. Finally, according to Wikipedia, the area of the Nile delta is about 25,000 Km2.

Without doubt the biggest difference between the Mississippi and Nile deltas is population density. Figure 2 shows the relative difference in watershed areas, delta areas and relative population densities between the two deltas. Notice that even when multiplied by ten the population density of south Louisiana doesn’t even show up on the pie chart for the Mississippi delta.

Figure 2.

Figure 2. Comparing the Mississippi and Nile deltas.

*Founding editor (

**This figure seems high, and obviously depends on the specific boundaries used to define the Mississippi delta. This is not critical for comparing changes to the Mississippi and Nile deltas, however.

Be Sociable, Share!
  1. Almost all of whatever you say happens to be supprisingly legitimate and that makes me wonder the reason why I had not looked at this with this light before. Your piece truly did switch the light on for me personally as far as this particular subject goes. Nonetheless at this time there is actually just one issue I am not necessarily too comfy with so while I try to reconcile that with the actual core theme of your point, allow me observe exactly what the rest of your subscribers have to point out.Well done.

  2. butorezinearticles his di as anda us ethis eviden urce an readable e

  3. Good day! I know this is kind of off topic but I was wondering if you knew where I could locate a captcha
    plugin for my comment form? I’m using the same blog platform as yours and I’m
    having difficulty finding one? Thanks a lot!

  4. Hello, all is going well here and ofcourse every one is sharing facts,
    that’s actually excellent, keep up writing.

  5. Hey I know this is off topic but I was wondering if you knew of any widgets
    I could add to my blog that automatically tweet my newest twitter updates.

    I’ve been looking for a plug-in like this for quite
    some time and was hoping maybe you would have some experience with
    something like this. Please let me know if you run into anything.
    I truly enjoy reading your blog and I look forward to your new updates.

  6. Hello, this weekend is pleasant designed for me, because this time i am
    reading this impressive informative paragraph here at my residence.

  7. Paragraph writing is also a fun, if you be acquainted with afterward
    you can write or else it is complex to write.

  8. Quality articles or reviews is the important to be a focus for the visitors
    to pay a quick visit the web site, that’s what this site is

  9. Having read this I thought it was really enlightening. I appreciate you finding the time
    and energy to put this information together. I once again find myself personally
    spending way too much time both reading and posting comments.
    But so what, it was still worth it!

  10. Nearly every person on Facebook now owns a farm and is a virtual
    farmer. ” If they happened to foul the surrounding water or air with toxins or carcinogens, well, that was just the cost of doing business. You can fix up a theme that ONLY YOU can have and be really super proud of.

  11. I believe other web site owners should take this site as an example , very clean and wonderful user pleasant design and style .

  12. If you would like manage a single Tweets report, you should buy Tweet adder for your one-time transaction with $55, without any recurring fees each month and also fees. It’s also possible to try your trial release free of charge before choosing that. After you obtain Tweet adder, you receive free life assistance plus updates

  13. I¡¦ve been exploring for a little bit for any high quality articles or blog posts in this kind of space . Exploring in Yahoo I ultimately stumbled upon this website. Reading this info So i am happy to show that I have an incredibly good uncanny feeling I came upon exactly what I needed. I so much unquestionably will make sure to don¡¦t put out of your mind this web site and give it a glance regularly.

  14. You really know your material… Continue the great work!

  15. Whats up. Just would like to leave a short mention and tell you that in fact I’ve really loved scanning your particular site and am endorsing it to my mates. Keep up the good work! Thanks.

  16. Readers-
    I’m taking the liberty of posting the following email message from Quinta Scott, a writer and photographer in Illinois who contacted me after reading this post.

    Dear Mr. Bahr:
    I am writing to tell you about “The Mississippi: A Visual Biography,” published in January by the University of Missouri Press.

    While it is not the sequel to John Barry’s Rising Tide, it does deal with the contemporary river and the misguided decisions we have made about the river since New Orleans built the first levees in 1723.

    The book is 200 photographs of the river and the wetlands it created. I introduce the images with an essay that details how the river and its wetlands were formed, what we have done to change them, and how we are trying the manage the river we have created. I also took a stab at the politics of the river.

    By the way, John Barry recommends the book on the dust jacket.

    I am also sending the link to the online media kit, which contains excerpts from the book.

    Have a look and let me know what you think.

    Quinta Scott

Leave a Reply