Students in GEOL 21062, Spring 2016, at Kent State University have been sharing interesting news stories with me all semester long. Here’s our complilation. Hopefully these are interesting things for other people too!
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Today, Brock Freyer will be defending the results of his M.S. research. The title of his research project is: Fluvial Response to River Management and Sediment Supply: Pool 6 of the Upper Mississippi River System, Southeastern Minnesota.
Brock’s committee is composed of Anne Jefferson (advisor), John Diemer and Ross Meentemeyer.
The defense is on Tuesday April 23, 2013, at 1:30 pm in McEniry 307 of UNC Charlotte. As Brock is currently located in Alaska, this will be a Skype defense. All are welcome to attend.
In this age of environmental restorations and rehabilitations, the scale and extent of projects have been getting larger and more expensive. In the Upper Mississippi River System (UMRS) the U.S. Army Corp of Engineers (USACE) has begun the task of restoring the negative effects that over a century of river management has incurred. Due to the scale and cost of such projects, it is essential to understand the natural and human processes that have affected the river system. In the UMRS, erosion and land loss are considered the dominant geomorphological trend, but Pool 6 of the UMRS is an exception to this norm. In Pool 6, deposition and land growth in recent decades have allowed the river morphology to begin reverting to its condition prior to intense river management. Through the application of varied chronological data sets within ArcGIS, spatial variations were measured to better understand where and why changes have occurred. A nested study area approach was applied to Pool 6 by dividing it into three scales: a general Pool wide observation; a smaller more in-depth observation on an area of island emergence and growth in the lower pool; and a subset of that section describing subaqueous conditions utilizing bathymetric data. The results from this study have indicated that site-specific geographic and hydrologic conditions have contributed to island emergence and growth in Pool 6. In Pool 6 land has been emerging at an average rate of 0.08km2/year since 1975. Within lower Pool 6, land has been emerging on an average rate of 18m2/year since 1940. The bathymetric subset has shown that sediments on average have gained 2.41m in vertical elevation, which translates into just under 828,000 m3 of sediments being deposited in 113 years. By identifying and describing these conditions river managers will be able to apply such knowledge to locate or reproduce similar characteristics within degraded sections of the UMRS. If the observations hold true in other locations, restoration efforts will be cheaper, more self-sustaining, promote natural fluvial dynamics, and ultimately be much more successful.
We are currently preparing a manuscript for publication.
A student and I are working on finishing a project that has lingered for too many years: a careful analysis of the cumulative effects of river management on islands in the lower part of Pool 6 of the Mississippi River, near my hometown of Winona, Minnesota. There will be a MS thesis soon and hopefully a journal manuscript shortly to follow that, but for now, I’m enjoying discovering new and old research and resources on “the father of waters.”
First, check out this 17-minute silent film on the 1927 Mississippi River flood:
For more information on the film made by the Signal Corps in the 1930s, head here: http://archive.org/details/mississippi_flood_1927
Then, check out this 2012 publication from the USGS on “A Brief History and Summary of the Effects of River Engineering and Dams on the Mississippi River System and Delta.”
Finally, there’s a paper just out in Geophysical Research Letters by Frans et al. titled “Are climatic or land cover changes the dominant cause of runoff trends in the Upper Mississippi River Basin?.”
And that’s my afternoon reading sorted.
It all began at the end of February, when I travelled to La Crosse, Wisconsin to the Upper Midwest Stream Restoration Symposium, which was a really stimulating and vital mix of academics, consultants, and government folks all interested in improving the state of the science and practice of stream restoration. I gave a talk on Evaluating the success of urban stream restoration in an ecosystem services context, which was my first time talking about some hot-off-the-presses UNCC graduate student research, and I learned a lot from the other speakers and poster presenters. While the conference was incredibly stimulating, travel delays due to bad weather on both ends of my trip made for a somewhat grumpy Anne (nobody really wants to spend their birthday stuck in a blizzard in O’Hare), so I’ll be thinking carefully about how to plan my travel to the Upper Midwest during future winters. Nonetheless, the view from the conference venue was phenomenal.
March proper saw me give variations of the restoration talk two other times. On the 15th, I gave it as the seminar for Kent State’s Biological Sciences department, and on the 26th, I gave it at the North Dakota State University Department of Geosciences (more about that trip below). In between, I gave a seminar on the co-evolution of hydrology and topography to the Geology Department at Denison University in Granville, Ohio. Students in that department had just returned from a trip to Hawaii, and a very memorable dialogue occured in the midst of me talking about the High Cascades:
“You’ve seen a young lava flow. What would happen if you poured a bottle of water on it?” “It would steam!” “Not that young!”
Closer to home I also hosted a couple of prospective graduate students, helped interview candidates for a faculty position in our department, and went with a colleague to visit an acid mine drainage site about an hour to the south of Kent. In one fairly small watershed, we were able to tour a number of different remediated and unremediated sites, and it certainly lent a whole different perspective to the ideas of stream restoration and constructed wetlands to look at a landscape irrevocably scarred by mining activities.
At the end of the month, we finally got our turn for spring break. I ended up with a somewhat epic combination of mounds of work and a big trip to take, possibly the worst combination of the untenured and tenured professor spring break stereotypes (see this PhD comics strip). The first half of the week, I spent in Fargo, North Dakota, home to the famously flood-prone Red River of the North. (I’ve blogged before about why the river so often produces expansive floods.) It was truly fascinating to put my feet on the ground in a place that I’ve read about and watched from afar for years. And my visit was made all the more interesting by my host and guide, Dr. Stephanie Day, a geomorphologist newly at NDSU and who may well unravel some of the Red’s geomorphological peculiarities.
There’s a pretty good chance we’ll see a major flood on the Red River later this spring, as the >24″ of snow melts out of the watershed, runs off over frozen ground, and enters the northward flowing river. The Fargo Flood page is the place to go to follow the action, and you can count on updates (and more pictures) here as events unfold.
The latter half of my spring break saw me diagonal across the state of Minnesota to my beloved Driftless Area, back across the Mississippi River, and into the state of Wisconsin. I saw my family, finished paper revisions, and wrote part of a grant proposal. Then I flew home, with nary a weather delay in sight.
If March was a tight, recursive meander of talks and trips to the Upper Midwest, then April promises to be a bit anastomosing with lots of different threads woven together to make another month of scientific delight.
The 100th anniversary of Ohio’s greatest disaster is just days away. This epic hydro-meteorological event utterly ravaged river towns from Illinois to Ohio and beyond, but it seems like the event has largely been forgotten in history’s annals. Even flood-obsessed me had lived in Ohio for a few months before I even began to piece together the full extent of the disaster. For a crash course in the events of March 23rd-27th, 1913, navigate through this Prezi:
If you want to know more, there’s lots of details at the Silver Jackets’ 1913 Flood website and you can follow along as historian Trudy Bell researches a book on the flood.
It’s been quite a week. My home in northeastern Ohio got off lightly from “Superstorm” Sandy, compared to places closer to the Atlantic seaboard and in the Caribbean. But still, over 250,000 people lost power due to high wind, especially in Cuyahoga and Lorain counties along the shores of Lake Erie, where huge waves also caused closure of an interstate and damage. Power crews are still working to restore power to tens of out thousands, and most schools and universities were closed for at least one day, if not longer.
There was also some rain. At my house, I got 4.25 inches (108 mm), which is almost exactly what the forecasts predicted. It came as both a drizzle and as heavy rains, but since last Friday afternoon we haven’t seen the sun. Now, northeastern Ohio is supposed to be quite cloudy, but given the local grumbling, this might be a bit of an extraordinary gray and damp cold run. It wasn’t warm rain either, with temperatures neither climbing out of the 40s F (8 C) or dipping below freezing. Isotopic results are pending, but my money is on our moisture source being almost entirely that northern airmass that got itself entangled with the tropical cyclone. Again, any whining about the damp is pretty well offset by everyone acknowledging that we are extremely lucky compared to states to our east.
All that cold rain brought the local river levels way up. There was major flooding on the Cuyahoga River at the downstream end by Wednesday, and the river at its upstream-most gage in Hiram crested on Thursday night. Flow at Hiram peaked around 1900 cubic feet per second (53.8 cubic m/s), which as I eyeball it on the USGS annual peakflow graph appears to be about a 2-year flood. This is actually consistent with my eyeballed estimate of the flow frequency produced by Sandy on Passage Creek, near Callan Bentley’s house in Virginia. I wonder whether that will be consistent for other rivers affected by Sandy.
For me, this was the first chance to the Cuyahoga River in action as it flows through Kent. The river sits in a gorge than separates the two halves of town, and that seems to keep the river from endangering much property in the town. But it did make for a pretty impressive roaring site and sound as I crossed the bridges today. Here are two pictures of Heritage Park in Kent on Friday afternoon about 4 pm. Contrast that with the low water pictures from early June.
There’s nothing particularly deterministic about starting a new year on January 1st. Our wall calendars happen to do so because of the circumstances of history. For hydrologists in the northern hemisphere, January 1st is not a great time to declare one year dead and a new one born. So instead, we transition between years on the 1st day of October. October 1st, 2012 marks day 1 of the 2013 water year. But, why?
Many hydrologic analyses involve calculating statistics on an annual basis. We might want to calculate annual streamflow to determine how much drier 2012 was than 2011. Or we might want to look for trends in the size of floods. For the example of flood statistics, the most common way to get a time series of floods is to identify the largest flood occurring in each year. This “annual peak flow” record is then used within the framework of a probability distribution function to assign a probability of given size flood occurring in any one year. (Problematically, this has been called a “flood frequency distribution”, leading to unnecessary confusion on the part of the public, but I digress…)
We use only the largest flow each year to calculate statistics because it avoids statistical complication. Principally, we want to ensure all of our events are independent of each other. Let’s say there are two days with really high flows in a year. The highest flow is 27.8 m3/s and the second flow is 24.1 m3/s. If the first measurement was made on January 29th and the second one was from March 18th, then these two data are independent (i.e., not the same flood). But if one is from January 29th and the other is January 30th, they are clearly not independent and should not both be used to calculate statistics as if they were. So, we try to avoid this dependence issue by using only the largest flow each year.
Here’s where we come back to the idea of the water year. Let’s use an example from my local stream gage – the Cuyahoga River at Hiram Rapids. There was a big flood on December 31st, 1990 – the biggest flood of the whole year – reaching a peak flow of 71.4 m3/s. On January 1st, 1991 the water was still high – 66.8 m3/s. After that excitement, the rest of 1991 was pretty dry and flow never again gets anywhere near as high, peaking at 25.0 m3/s in early March. How do we calculate the statistics? If we used the calendar year as our basis, we’d end up double counting that late December flood and we’d throw our flood statistics off.
Instead, hydrologists use October 1st as our cut-off date. In many parts of the Northern Hemisphere, summer is a period of low streamflow, driven by strong evapotranspiration and atmospheric circulation patterns. (A prominent exception to the lack of summer flooding is when tropical cyclones make landfall.) In winter, rain-on-snow can produce large floods in some regions, while decreased evapotranspiration and more frontal storms increase the chances of flooding in some southern regions. In the spring, seasonal snowmelt produces flooding in northern and alpine regions. That leaves the autumn as the period least likely to have frequent flooding. Also, because evapotranspiration is subsiding with cooler temperatures, soil moisture and stream flow don’t tend to be recovering from their low points in the summer. So autumn is a time of transition and a time when extremes are unlikely. The graphs below illustrate this for my local stream gage, but similarly shaped distributions would likely exist for many other gages in the US and beyond.
Thus, it’s a perfect time of year to the clear the books and declare a new year for hydrologic statistics. And it’s got as much or more physical rationale than when we change the calendar on the wall. Happy New Water Year Everyone!
Cross-posted at Highly Allochthonous When Hurricane Isaac passed over New Orleans as a Category 1 storm on the seventh anniversary of the disastrous Hurricane Katrina, everyone in the US let out a big sigh of relief. A category 1 storm, the lowest level of hurricane intensity on the Saffir-Simpson scale, meant sustained winds in the 74-95 mile per hour (119-153 km/hr) range, which are described as “very dangerous winds [that] will produce some damage.” There were few, if any, mandatory evacuation orders in Louisiana, and the media interviewed people saying that they heard Isaac would be a Category 1 storm so they “didn’t think it would be that bad.” Those people opted to stay in their homes Louisiana’s Plaquemines Parish, along the Mississippi River near New Orleans. Indeed, as the early reports from Louisiana came out, it sounded as if the storm had been relatively low in drama.
Only later did reports start to trickle out of levees overtopped, and people stranded on rooftops and in attics, being rescued by neighbors with boats. The flooding this time wasn’t in New Orleans itself, but in nearby Plaquemines Parish, where levee upgrades weren’t scheduled to be completed for a few more years. At least one levee overtopped, flooding the town of Braithwaite and surrounding areas where about 1700 people live, with up to 4.3 m (14 ft) of water. That water ended up trapped between the federal, main Mississippi River levee and more locally managed back levees. State officials have now breached those back levees to more quickly drain the water out of the town, rather than slowly pump the area dry. But several people died inside their flooded homes.
It’s not clear to me from the news reports whether the levee overtopped from a wind- and pressure-driven storm surge or whether it overtopped from the sheer amount of rain that fell on the area, but in either case the slow-moving nature of Hurricane Isaac turned out to make the meager Category 1 hurricane into something much more horrific for some Lousiana communities. A reporter on the scene in Braithwaite described the eyewall, with the most intense winds and rain, stalling out in the area, but throughout its life Isaac was a fairly slow moving tropical cyclone. As it moved across Louisiana, its center was moving north about 9 miles per hour (14.5 km/hr). Typical hurricanes move about 15-20 mph (24-32 km/hr), and some can move up to 60 mph (96.5 km/hr).
The problem with a slow-moving hurricane is that vast amount of precipitation can occur in the affected areas. In some parts of Louisiana, Alabama, Mississippi, and Florida more than 15 inches (380 mm) of rain have fallen in the last week. In New Orleans, the Hydrometeorological Prediction Center reports that 20.08 inches (510 mm). In the image below, you can also see the northward progression of the storm since making landfall.
All that water can lead to levee over-topping, like in Plaquemines Parish, and the risk of dam failures. Evacuations were ordered along the Tangipahoa River, which drains into Lake Pontchartrain, because of fears that Percy Quin Dam would fail. More than 50,000 people have been evacuated as the risk of dam failure or the need to intentionally breach the dam is still being evaluated. And, of course, while media attention (and this blog post, guilty as charged) focuses on the dramatic stories, there are many other areas in the Gulf Coast where flooding is on-going. Even as far north as Kansas City and southern Illinois, flood warnings are in effect.
Isaac is a good reminder why the primary cause of death in the US from tropical cyclones is from freshwater flooding. And it suggests that the single-minded focus on hurricane windspeeds may distract us from taking the flooding threat as seriously as we should. Those people who decided to stay in Plaquemines Parish because the Category 1 hurricane wouldn’t be that bad? When the interview was conducted, they were expressing their regret. The president-elect of the American Meteorological Society, J. Marshall Shepherd, wrote a blog post about the Lessons from Isaac, in which he suggested: “Is it time to consider an augmentation of the Saffir Simpson scale to capture the rainfall-flood threat? It is a difficult science problem, but probably one worth investigating. I also argue that our media colleagues must consider their coverage strategy and category “anticipation” or hype carefully.”
Cross-posted at Highly Allochthonous
Here is a brief update on the floods I covered in the last edition of flooding around the world. Note that there has also been flooding in Xiengkoung, Viengtian, Boolikhamxay, and Xayaboury provinces of Laos, as a result of heavy rainfall from a tropical storm; in Russia’s Khabarovsk region (Kiya and Khor rivers), from heavy rainfall; and in the Philippines’ Davao city, from heavy rainfall.
China and the Yangtze River
- Flood after drought, and they both hit the poor the hardest
- Heavy rains have caused a cave in and flooding in two Chinese coal mines, trapping at least 40 miners
- Striking image of floods along the Yangtze River
- Why this spring’s water in the Missouri River basin was so tricky for the Corps of Engineers to master
- Sand shortage causes concern for flood fighters along Missouri River (06/21/11)
- Continued Flooding near Hamburg, Iowa in this @NASA_EO image. [The result of 2 levee breaches]
- Flooding Won’t Overcome Nuclear Plants, Officials Say, but Ft Calhoun has a history of problems:
- Flooding along the Missouri River from @NASA_EO
- A good overview of why flooding in Minot was so much greater than the community anticipated
- Heart-wrenching before and after flooding aerial imagery of Minot
- Manitoba towns frantically prepping as the Souris River rises
- Historic Floodwaters Begin To Recede In Minot, N.D., now levee vigilance [I particularly liked how this story described discharge measurements on the flooded river.]
- Two Towns, Same Flooded River, Different Fates – one managed to sandbag high enough; the other did not
- Historic Flooding along the Souris River from@NASA_EO
- Only 10% of Minot residents had flood insurance, but as Souris River Crests, Minot North Dakota Exhales
Cross-posted at Highly Allochthonous
Since the last edition of flooding around the world, flooding along the Mississippi River has mostly subsided, but flooding continues along the Missouri River and in China. Several new flood wetspots have also popped up, as the image below from The Flood Observatory (at the University of Colorado) depicts.
The big stories are flooding in China, along the Missouri River, and on the Souris River in Saskatchewan and North Dakota. The best summary I’ve seen is by Jeff Masters of Weather Underground, who gets straight to the story in his headline: “Floods overwhelm North Dakota levees; floods kill 175 in China”. The Flood Observatory also has a handy table that includes flood cause, duration, and a snippet of recent news for each of the flood events pictured on the image above.
Flooding continues in central and southern China’s Zhejiang, Jiangsu, Anhui, Jiangxi, Hubei, Hunan and Guangdong provinces, and in parts of the northwest Gansu Province (though drought is still the more dominant threat there).
- What’s happened?: As of June 20 (the last time there were major overview news articles on the situation): More than 170 people dead, 5 million affected, $4.9 billion in damages, dikes barely holding, and more rain on the way (Al Jazeera, CNN)
- What’s happening right now? China prepares for more flooding: rainy season has already brought misery, but new problems are expected, including typhoons and further inundation (22 June) from Al Jazeera English; Tropical Storm Meari drenches east China (including Shangai), while drought plagues northwest (People’s Daily, 26 June) and a similar story from Bloomberg (26 June)
- Dramatic photos:In Focus at The Atlantic, the Sacramento Bee’s “The Frame”, and the International Business Times’ “Picture This.”
- The view from space: NASA’s Earth Observatory has a couple of images from flood-stricken areas in China. They’ve been plagued by cloudy weather for much of the last couple of weeks (very much related to the cause of the flooding!), but they have created an event page where you can look for updates.
The Souris River and Minot, North Dakota
More than 11,000 people have been evacuated and more than 4000 homes inundated in record-breaking flooding in Minot, North Dakota and surrounding communities. Levees in Minot were over-topped, even after emergency preparations by the Corps of Engineers. The river crested yesterday about 2 m above major flood stage, but will remain extremely high for a few more days.
- Where is the Souris River? It is not part of the Missouri basin. No, as the map below shows, the Souris is part of the Assiniboine River River watershed. The Red River, which flooded earlier this year also drains to the Assiniboine, but the currently flooding Souris doesn’t have the same lake bottom geologic history as the Red.
- Why is there flooding?The seeds of the record floods along the Souris and Missouri Rivers were sown beginning last summer, with persistent heavy rains (that lead to flooding), a wet fall, a snowy winter, and then another very wet spring.
- What’s it like in Minot right now?The city is effectually split in half by the flooding, with 1 in 3 residents is evacuated. It is unclear whether the municipal water supply of Minot and a nearby Air Force base has been contaminated, so the city is under a boil water order. (CNN wire report, 26 June). Residents in unflooded portions of town and surrounding areas are doing what they can to shelter the evacuees and take care of the belongings they got out before the flood arrived. (AP, 26 June)
- Are there problems anywhere else on the river?Yes, the flood has displaced hundreds in southeastern Saskatchewan, upstream of North Dakota (CBC, 20 June). Floodwaters in that area are now receding (Montreal Gazette, 25 June). Downstream of North Dakota, residents along the Souris River in Manitoba are working to build up their defenses, because the flood will be there in less than two weeks. (Toronto Sun, 25 June). This new flooding arrives on top of already a record-breaking year for floods for the province, with $1 billion in damages already and 3 million acres of farmland still soaked and unplantable (UPI, 22 June).
- Are there any good pictures of the flooding?The Sacramento Bee had a striking collection of photos on Friday, 24 June. A lot of the news stories linked to above have photos, NASA’s Earth Observatory has an event page with four sets of images so far, and I’d be really surprised if the other big photo news blogs didn’t have a set of images at some point in the next few days.
Record flooding continues to move downstream in the Missouri River system. Heavy snowpacks and a lot of rain in the Upper Missouri have forced unprecedented releases of water from the dams along the river in the Dakotas. Right now, the biggest flood problems seem to be in Missouri and Iowa, but high water and evacuated areas are stretched all along the river, and the flood won’t fully recede for months. The National Weather Service has a flooding information page set up, with regular updates.
- How has the flood been affected by the dams along the Missouri River? There’s a lot of public debate over whether the Corps of Engineers management plan for the river favors upper basin states’ desires to keep their reservoirs full over the flood-control needs of downstream states. (KC Monitor, 25 June) People are asking why the Corps didn’t release more water earlier this year, in order to prevent such massive releases now. But, flood prediction models couldn’t have forecast the week after week of heavy rain that fell this spring. Still, I expect people and politicians (especially in the lower basin) to keep talking about this as long as the flood and its cleanup lasts. Here’s an editorial from the Des Moines Register (25 June) that tries to put things in perspective.
- How are the levees? “A total of four levees in Missouri have been breached along the Missouri River, according to officials with the U.S. Army Corps of Engineers in Kansas City. The epicenter of the flooding in Missouri is located in Holt County, where two levees have been overtopped and two levees have been breached by raging water flowing down from a reservoir in South Dakota. ” (KC Monitor, 25 June) There have also been levee breaches in multiple places on the Iowa side of the river (Reuters, 25 June).
- What about the nuclear plants? Two Nebraska nuclear plants are in the path of Missouri flood waters, but emergency levees are 0.6 m higher than the expected crest at the Fort Calhoun plant (Omaha World-Herald, 17 June) and 2 m higher than the expected crest at the Cooper station (Chicago Tribune, 25 June). [Update: 6:30 pm 26 June: While I was writing this post, news wires reported than a temporary berm around the Fort Calhoun plant breached last night. Two feet of water now surround reactor buildings, but the reactor systems were unaffected and inside water-tight buildings. (Reuters)] Charmingly, residents near the plants are unconcerned, according to the Chicago Tribune story.
- What does the flood look like from above? NASA’s Earth Observatory has 9 satellite images of the flood, so far. There’s also a nice video taken on 9 June from a low-altitude airplane, by KETV news.
Please use the comment thread below to add links to updated news stories, videos, or imagery about any floods that are occurring in the next few weeks. I’ll write another flood update in mid-July. If there are particular floods you are interested in, or if you’d like me to delve more into the hydrological details, please let me know.