Stories tagged The Water Cycle, Weather and Climate

Apr
09
2010

By Our Hands: Cities are perhaps the most impressive mark humankind has left upon the face of planet Earth.
By Our Hands: Cities are perhaps the most impressive mark humankind has left upon the face of planet Earth.Courtesy anaxila

Throughout the ongoing debate about exactly how, to what extent, and the ethical implications, the indisputable fact remains that humankind has altered the planet. Back when the human population was only a few thousand strong and agriculture and cooked food were the latest inventions, it was easy for the Joneses to pick up and move camp when the water ran dry, the soil stopped producing tasty wheat, or the garbage piled too high in the backyard. The same can’t be said for the populations of world cities today.

Advances in public health, industry, and agriculture have blown the human population out of the brush. There will soon be 9 billion people on the face of planet Earth! Coupled with rising affluence, our ballooning population’s resource consumption and waste outputs are wrecking havoc on natural systems. New research (see several links below for more info) suggests that within a fixed amount of space, humankind is in danger of causing our own extinction and the only way out is to discard traditional ideas of industrialization and embrace sustainability.

No, silly...: Not THAT kind of tipping point!
No, silly...: Not THAT kind of tipping point!Courtesy Go Gratitude

The first step to bailing out humankind is to investigate how close to failure the world actually is. This was the point of a recent international collaboration: to calculate safe limits for pivotal environmental processes. The key idea here is that of “tipping points,” which can be thought of as thresholds or breaking points. Think about being pestered by your brother or sister: aren’t you able to put up with the annoyance for even a little while before you get so upset you retaliate? That’s your tipping point – the last straw that put you over the edge.

Led by Stockholm Resilience Center’s Johan Rockstrom, a group of European, Australian, and American scientists – including the University of Minnesota’s Institute on the Environment’s director, Jonathan Foley – identified nine processes reaching their tipping points. Three (climate change, nutrient cycles, and biodiversity loss) have already been pushed past their tipping points, four (ocean acidification, ozone depletion, freshwater use, and land use) are approaching their tipping points, and two (aerosol loading and chemical pollution) do not yet have identified tipping points because they require more research. The Institute on the Environment recently released a YouTube video addressing the conclusion of this new research:

Blissfully, there are things we can do to stop hurting the planet and begin patching its wounds. According to Foley’s article, we can’t let ourselves get any closer to the tipping points and piecemeal solutions won’t cut it because of the interconnectedness of the issues. Instead, we should focus on switching to low- or no-carbon fuel sources, stopping deforestation, and rethinking our approaches to agriculture.

There's No Place Like Home: It's worth keeping healthy.
There's No Place Like Home: It's worth keeping healthy.Courtesy NASA

The conclusions of this research have been well-accepted, but there has been some criticisms for 1) attempting to establish tipping points at all, and 2) for the appropriateness of the establish tipping points. If you would like more information, including commentaries, please check out the following sources:

Article in Nature: A safe operating space for humanity

Commentaries: Planetary Boundaries

Article in Scientific American: Boundaries for a Health Planet

Article in Ecology and Society: Planetary Boundaries: Exploring the Safe Operating Space for Humanity

Two questions to consider as you watch the YouTube video and take a look through the links and articles referenced above are:

1) What are the consequences of being past our tipping points?

2) How do the solutions discussed prevent us from reaching tipping points?

You are encouraged to post your thoughtful answers below!

Mar
26
2010

Recently, I was sitting at my desk asking myself, “With the Mississippi River flood of 2010 past-peak, now what?” I mean, if I can’t obsessively check the latest crest predictions or watch the Science Museum's flood cam, what am I supposed to do with all my free time??

Thankfully, Pat Nunnally and Joanne Richardson of the Institute on the Environment's program River Life agreed to meet with me to discuss how I can keep up on the Mississip’ all year long.

The whole purpose of River Life is to help people like me and you collaborate on issues of river sustainability. You say: “Hold up. What's ‘river sustainability’?” Good question! I asked Pat and Joanne myself and they said river sustainability is the study of how to continue urban living without harming the natural processes of rivers. Put another way, river sustainability is the study of maintaining harmony between human, aquatic, and terrestrial ecology. But don’t take my word for it, Pat speaks for himself about River Life in the Institute on the Environment’s, River Reflections:

The Mississippi RIver Watershed: The Mississippi drains almost half of the continental United States (and some of Canada)!
The Mississippi RIver Watershed: The Mississippi drains almost half of the continental United States (and some of Canada)!Courtesy National Park Service

Did you know the Mississippi River is considered among the world’s largest watersheds? Me neither! A watershed is a geographic area within which all water flows into the same stream. The Mississippi River watershed covers about 40% of the continental United States. As part of River Life, this and other fascinating river facts will compose a River Atlas. This River Atlas is a work in progress set to debut fall 2010 and will eventually contain scientific data, videos, photos, art, and people’s stories about rivers.

The River Atlas section about people's river stories is called – no surprise here! – River Stories. Pat says river stories are important because they inspire people into action. While that’s certainly true, river stories are also simply fascinating in themselves. For example, did you know the upper landing area upstream from the Science Museum was known as “Little Italy” until the flood of 1952? After that, the city used the area for a scrap yard and then a parking lot. Today, it has been developed into high-rise apartments.

River Life’s dream for the Mississippi River is that people will learn how to engage the river in a mutually meaningful way. What does that really mean? It’s all about the river sustainability principle we talked about earlier: living with the river instead of against it. Pat’s example of a mutually meaningful river engagement is Harriet Island who’s flood-resistant social space is a great city amenity that also respects the natural process of flooding.
Harriet Island: This place is a beautiful example of how a city can live alongside its river.
Harriet Island: This place is a beautiful example of how a city can live alongside its river.Courtesy St. Paul, Minnesota

Mar
20
2010

NOAA flood prediction: Up and up.
NOAA flood prediction: Up and up.Courtesy NOAA
When I woke up this morning and checked the NOAA flood forecast for the downtown Saint Paul station it was at 19.7 feet above the normal stage. Yikes, the forecast still keeps going up. The river is predicted to crest on March 24th (next Wednesday).

Other flood related resources from my morning browsing:

The StarTribune visits the NOAA, National Weather Service Weather Forecast Office, in Chanhassen, MN. The scientists at NOAA explain what's different about this year's snow melt...complete with some classic Minnesota accents.

Check out what downtown Saint Paul looked like in the 2001 Mississippi River flood. So far, no one's predicting this year's food will be as bad as that historic spring melt, when the river crested at 23.67 feet.

And, for purely nostalgic purposes, here's a pic of Minnesota Governor Karl Rolvaag (he's in front of the guy with a bag on his head), President Lyndon Johnson, and Senator Walter Mondale (looking quite dashing back in the day) standing dangerously close to the river in the really bad 1965 Mississippi river flood. The river crested at 26 feet that year.

Check out our full feature on the 2010 Mississippi River flooding.

Mar
19
2010

The Mississippi River here in Saint Paul is currently forecasted to crest at 19.8 feet next Wednesday and was measured at 12.9 feet at 7:00 this morning (Friday). All these river height numbers got me thinking about a really good question someone asked me last year about just what these numbers mean and how they are measured.

Stream gauge location: Readings of the Mississippi River at downtown St. Paul are taken by instruments here.
Stream gauge location: Readings of the Mississippi River at downtown St. Paul are taken by instruments here.Courtesy USGS

Here is an explanation: The Mississippi here in Saint Paul started being measured way back in 1893. The actual location of the measurement station is right by the High Bridge on the west side of the river. Currently the station is operated by the US Geological Survey and the US Army Corps of Engineers. At the time that the station was established, an arbitrary 0 measuring point was chosen (probably the bottom of the channel at the time). When the river reaches 14 feet at this station it is pretty much flowing above its banks in the vicinity of the gauge. All this is to say that the gauge numbers aren't really measuring anything specific about the river other than its height above a point established over a 100 years ago. This means that gauge readings can only be compared to other readings at the same gauge.

Kate's photos, 3/18 (2): Look across the river to the floodwall: thats the high-water mark for the 1965 flood, the highest in recorded history. That year, the river crested here in downtown St. Paul at 26.01' and spelled the end for the communities down on the river flats.
Kate's photos, 3/18 (2): Look across the river to the floodwall: thats the high-water mark for the 1965 flood, the highest in recorded history. That year, the river crested here in downtown St. Paul at 26.01' and spelled the end for the communities down on the river flats.Courtesy Kate Hintz

So if you call up your friends and family in Fargo/Moorhead today to compare notes about who is experiencing the worst flooding, you'll find that your Mississippi River measurement of 12.9 feet doesn’t look impressive by the measurement of over 35 feet at Fargo. And, your 12.9 feet will seem straight up puny compared to the 677 feet the Mississippi is flowing today at Prairie Island, Minnesota, where the river is measured against elevation.

For details on just how river gauges work, check out this explanation the US Geological Society offers.

Noteworthy flood heights in Saint Paul:
14.0 Portions of the Lilydale park area begin to experience flooding.
17.5 Harriet Island begins to become submerged.
18.0 Warner Road may become impassable due to high water.
19.8 Forecasted crest
26.4 Record 1965 crest!

Want to learn more about floods and the Mississippi River? Stop by the Mississippi River Visitor Center in the lobby of the Science Museum and talk to a National Park Ranger!

Check out our full feature on the 2010 Mississippi River flooding.

Mar
18
2010

If you're visiting the Science Museum of Minnesota, look out the windows from the Mississippi River Gallery on level 5. If you're in downtown St. Paul, stop by the museum and look at the river from the overlook on Kellogg Plaza. (City officials are asking folks not to flock to areas where barriers are going up - especially Harriet Island - but the view from in or around the museum is spectacular and safe.)

Kate's photos, 3/18 (3): Looks peaceful, doesn't it? Still, the city is warning people to stay off of the river, out of the low-lying parks, and away from Harriet Island and Water Street.
Kate's photos, 3/18 (3): Looks peaceful, doesn't it? Still, the city is warning people to stay off of the river, out of the low-lying parks, and away from Harriet Island and Water Street.Courtesy Kate Hintz

The Mississippi is going up FAST today, and forecasters expect that the river will officially reach "flood stage" by early this afternoon. (It's 10:45am, and the river's at 11.67'. It's risen a foot and a half in the last 24 hours, should reach 12' ("action stage") pretty soon, and 14' ("flood stage") by late today.

Kate's photos, 3/18 (2): Look across the river to the floodwall: that's the high-water mark for the 1965 flood, the highest in recorded history. That year, the river crested here in downtown St. Paul at 26.01' and marked the end for the communities then down on the river flats.
Kate's photos, 3/18 (2): Look across the river to the floodwall: that's the high-water mark for the 1965 flood, the highest in recorded history. That year, the river crested here in downtown St. Paul at 26.01' and marked the end for the communities then down on the river flats.Courtesy Kate Hintz

Kate's photos, 3/18 (1): Shepard/Warner roads will close from Chestnut Street to US 61 starting Saturday morning, and could remain closed for weeks. Take your river sightseeing drive/bike ride/walk before then!
Kate's photos, 3/18 (1): Shepard/Warner roads will close from Chestnut Street to US 61 starting Saturday morning, and could remain closed for weeks. Take your river sightseeing drive/bike ride/walk before then!Courtesy Kate Hintz

So what's going on around the river?

  • The city has closed all city boat launches and temporarily banned all recreational boating within the city limits.
  • Water Street will be entirely closed, starting this afternoon.
  • Hidden Falls and Lilydale regional parks are closed.
  • Flood barriers are going up at the St. Paul downtown airport and at Harriet Island.
  • Harriet Island will close once the river reaches 17'.
  • Warner/Shepard Roads will be closed from Chestnut Street to US 61 starting Saturday morning in preparation for the construction of a temporary levee that could withstand river levels to 26'. These roads could be closed for weeks, depending on the extent of the flooding.

Here's the latest hydrology graph:
3/18 hydrology graph, 10:15am
3/18 hydrology graph, 10:15amCourtesy USGS

Check out our full feature on the 2010 Mississippi River flooding.

Mar
17
2010

Look out the window or walk down the street to nearly any river or stream in Minnesota right now and you are likely to observe two things about the river:

  1. it is getting deeper (or “rising” in relation to the banks); and
  2. it appears to be moving faster.

You can, of course, confirm these observations by investigating reports from gauging stations along these rivers, maintained by the U.S. Geological Survey. (See data for the gauging station serving downtown St. Paul.) But what is really happening?

It may be high and fast...: ...but (as of today) the Mississippi at St. Paul is still in a bankfull state.
It may be high and fast...: ...but (as of today) the Mississippi at St. Paul is still in a bankfull state.Courtesy Liza Pryor

Until a river flows over its banks, it is considered to be in a “bankfull” state. In this state, the water flowing through the river is confined to a relatively fixed channel area. Simply put, floods occur because more water is being introduced into this channel from upstream, due to snowmelt, heavy rains, or a dam breach. As this added volume of water moves through a fixed area, it both increases in velocity and in depth until it overflows the banks, at which point some, but not necessarily a lot, of the volume and velocity moving through the channel are reduced.

Scientists call the rate of flow through a channel “discharge." Discharge is defined as the volume of water passing through a given cross-section of the river channel within a specified period of time.A simple equation for determining discharge is

Q = D x W x V

where Q = discharge, D = channel depth, W = channel width and V = velocity.

Looking at this equation, it is easy to see that if discharge becomes greater and channel width is fixed, then an increase in both volume and depth (or height relative to the banks) is likely to be the cause. Discharge can be measured in cubic feet per second or cubic meters per second, for example.

But is the river flowing at the same rate at the surface as it does along its banks and beds? Understanding this requires investigating some more detailed equations, as the banks and bed introduce friction, which affects the rate of flow.

To learn more about rivers and how they flow, you may want to check out the works of Luna Leopold, and M. Gordon Wolman. In particular:

  • Leopold, Luna B. (2006, reprint). A View of the River. Harvard University Press; and
  • Leopold, Luna B.; Wolman, M. Gordon; and Miller, John P. (1995). Fluvial Processes in Geomorphology. Dover Publications, both classics for understanding how rivers work.

Also, check out our full feature on the 2010 Mississippi River flooding.

Mar
17
2010

As of 11:19am, the US Geological Survey is forecasting that the Mississippi River will crest here in downtown St. Paul at 18 feet.

New flood crest prediction, 3/17
New flood crest prediction, 3/17Courtesy USGS

That would put Water Street and the lower section of Lilydale Regional Park underwater (at 14'), require secondary flood walls at the St. Paul Downtown Airport (17'), submerge much of Harriet Island (17.5'), and make Warner Road impassable due to high water.

An 18-foot crest would also make this year's flood #9, historically speaking, bumping the flood of 1986 (16.10') off the top-10 list.

Also, check out our full feature on the 2010 Mississippi River flooding.

Mar
16
2010

All day, up in the Mississippi River Gallery, people have been stopping to look out the window and watch the river.

Here's how the US Geological Survey sees it:
Mississippi River, actual vs. forecast, 3/16/10, 1pm
Mississippi River, actual vs. forecast, 3/16/10, 1pmCourtesy USGS

The river's rising, but not as fast as yesterday. And yesterday's rise outpaced predictions by almost a foot, but today the rise matches the predicted curve almost exactly.

So what are folks seeing out the window? Take a look.

Also check out our full feature on the 2010 Mississippi River flooding.

Watch the steps: They're a good benchmark.
Watch the steps: They're a good benchmark.Courtesy Liza Pryor

Raspberry Island: Still high and dry
Raspberry Island: Still high and dryCourtesy Liza Pryor

Looking upstream: You're still looking at Harriet Island. But low-lying areas of Lilydale (upstream, south side of the river) get inundated when the river reaches 14 feet or so. Right now, that's predicted to happen sometime after 7pm on Sunday, 3/21.
Looking upstream: You're still looking at Harriet Island. But low-lying areas of Lilydale (upstream, south side of the river) get inundated when the river reaches 14 feet or so. Right now, that's predicted to happen sometime after 7pm on Sunday, 3/21.Courtesy Liza Pryor