the pursuit of science at the ground- water surface-water...
TRANSCRIPT
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The pursuit of science at the ground-water surface-water interfaceWhy do we study this topic?And why should the public care?
What we do really matters to the public but they usually do not realize that. The following are a few examples of times when the public did take notice. As scientists, we need to do a better job of showing how what we do is important to society as well as to science.
GW/SW is important for many reasons•Issues pertaining to the public—relevant to society
•Drought-deluge cycles
•Water supply
•Water quality
•Ecosystem health
•Recreation
•Infrastructure impacts
•Public safety
•Issues pertaining to the science
•Hyporheic processes
•Ecological impacts
•Scaling issues
•Quantification methods33,000 copies
There are many reasons we study the interaction between groundwater and surface water, relevant to both societal issues and scientific pursuits. In this talk we will talk about relevance related to drought, floods, water supply, ecosystems, recreation, public safety, and water quality.
Onsen
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How is this relevant to the typical taxpayer?. . . and why did you take this course?
Drought
Remember this dry lakebed? Imaging your horror if you were to show up at your lake cottage and find a dry lakebed instead of a sparkling lake.
Rosenberry, Luukkonen, unpublished data
Area of rapid downward seepage
Pumping well
Drought
Sometimes being proactive and doing something doesn’t work. In this case, a hydrogeologist should have been consulted as part of the process.
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Drought
It is during times of drought or floods that the public really cares about what we do and really appreciates the science that provides understanding about how to minimize the impacts on water resources.
Zhengzhou, Henan province, eastern ChinaDrought
And this public concern exists world-wide.
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Rosenberry MGWA 2003
Floods When private-property values are affected, our research becomes even more important in the eyes of the property owners.
3.5
Site 10
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2
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70 5 10 15 20 25
Distance from shore, in meters
De
pth
bel
ow
lake
su
rfac
e, in
met
ers
water table at well
-240
assumed water table
lake bottom
nearly all air with
~ 5% water
unsaturated sand
saturated sand
Site 30
0.5
1
1.5
2
2.5
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0 1 2 3 4 5 6 7Distance from shore, in meters
assumed water table
lake bottom
-51
-43
De
pth
bel
ow
lake
su
rfac
e, in
met
ers
> -100
~ -100 -65
> -100 -59
-63
Lake Belle Taine
well
Rosenberry, 2000, Water Resources Research
It was the realization that the lake lost water to groundwater, and that the lakebed was the limiting factor, that made the public and the water-resource managers very interested in this research.
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Positive feedback related to hydrology and GW-SW exchange enhances wetland sensitivity and response to changes in climate.
Floods
This flooding was of interest to farmers and duck hunters and scientists, but not many other people noticed because they weren’t affected.
Positive feedback from groundwater here too
FloodsBut when the flooding started affecting houses and villages and roads then anything related to flooding, including groundwater feedback, was of great interest to almost everyone.
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Floods
This is a fishing pier that was specially modified to allow wheelchair access. It would take a special wheelchair indeed to access the fishing pier now. Groundwater was greatly important in determining the magnitude of this flooding because this lake is situated in a huge sand-dune complex. The lake is basically a flat spot in a regional, sloping groundwater flow system. As the groundwater rises and falls, so does the lake level.
Sonoma County Water Agency, Russian River, CA
• Produce 300,000 m3/day
• Inflatable dam raises river stage 3 m
• Still can’t get enough water because the riverbed is becoming clogged
Water supply
Without exchange between surface water and groundwater, this water-supply agency simply cannot meet the demand for water in this part of California.
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More water is always better, right?
Yes if you want to water your grass but no if you want to have water in the river
As scientists, it is our job to help them provide more water to supply a thirsty public, right?
Water supply versus recreation
Well, maybe not. It depends on who we are working for. For Masaki and me, because we are employed by publicly funded agencies (university and U. S. government), It is our job to understand processes that control exchange between groundwater and surface water. We should provide unbiased information and then let the resulting improved understanding be used in the decision-making process.
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Submarine GW DischargeMethods Comparison•Seepage meters•Automated seepage meters•Radium isotopes•Chemical tracers•Hydraulic head•MODFLOW
Ecosystems
Here is an example of why research at the fresh-water-ocean interface is important to the public.
Damaged and/or stressed coral may be the result of discharge of contaminated ground water
Rosenberry MGWA 2003
Dead or distressed coral is a global issue that is caused by many factors, among them discharge of contaminated groundwater to the ocean.
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GW-SW provides recreation opportunities
Recreation
Exploitation of groundwater resources can reduce flow in springs, hot or cold.
If suddenly the recreation area dries up the public suddenly cares of GW-SW exchange
It can also reduce or eliminate flow in streams as well. If the stream dries up, all sorts of environmental changes occur, not to mention the huge impact on fish.
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The Brainerd Lakes Area.... Mysterious Black HOLE!!!
on North Long Lake
Rosenberry MGWA 2003
Public safety
OK, so I took some artistic license here. Minnesotans are not quite as hardy as this. But holes in what normally is a solidly frozen lake surface is definitely a public-safety concern and one that many thought was caused by groundwater.
BLACK HOLE MYSTERY DEEPENS Why did it freeze over just when weather was getting warmer?
By VINCE MEYEROutdoors Editor
Brainerd Dispatch
District won't pour more money in 'black hole' By VINCE MEYEROutdoors Editor Saying it's no longer a good use of taxpayer money, the Thirty Lakes Watershed District will cease paying for studies of the black hole on North Long Lake.
“. . .the hole on North Long and similar holes on other Minnesota lakes are being caused by strong groundwater upsurges resulting from heavy rains in recent summers.” -- Joe Soucheray, St. Paul Pioneer Press, quoting Steve McComas
Black HolesPublic safety
The article in yellow to the right said they thought this was caused by groundwater. They even sent a diver down under the ice to “look” for groundwater.
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Public safety
Many people enjoy riding a snowmobile on the frozen lake surface. If there is a hole in the ice, and the person riding the snowmobile drives the snowmobile into the hole, they and the snowmobile will fall through the ice and into the lake water. This could be deadly.
Fun!Not so fun. What happened to the snowmobile driver?Not so fun. What happened to the snowmobile driver?
Expensive! The snowmobile rider has to pay these people to remove the snowmobile from the lake.Expensive! The snowmobile rider has to pay these people to remove the snowmobile from the lake.
GW discharge only affect ice in shallow water
Rosenberry MGWA 2003
It is highly unlikely that groundwater is related to these areas where the ice did not form because groundwater discharge almost always is focused at or near the shoreline.
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Water and chemical budgets of Mirror Lake, New Hampshire
Water quality
Here again is the lake where we have shown large amounts of heterogeneity based on seepage-meter data.
We get to work in some very nice places.
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300 kg per lane per km = 1200 kg/km
Mirror Lake freeway
Water quality
They apply salt to the road to keep ice from forming during winter. They apply a lot of salt and some of the salt dissolves in surface water and groundwater and moves from the freeway to the lake
Mirror Lake NE Inlet
Water quality
This salt loading has doubled concentration of sodium and increased the concentration of chloride by 4 times in the lake. Concentrations have increased by two orders of magnitude in the NE Inlet stream. Groundwater delivered quite a bit of this salt to the lake, and at the outlet side of the lake, groundwater carried away some of the salt as well. Exchange between groundwater and surface water was an important process that influenced the resulting concentrations of sodium and chloride in the lake.
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What person on the street will ever read this?
Rosenberry, D.O., Bukaveckas, P.A.,
Buso, D.C., Likens, G.E., Shapiro,
A.M., and Winter, T.C., 1999,
Migration of road salt to a small New
Hampshire lake: Water Air and Soil
Pollution, v. 109, p. 179-206.
Water quality
This was of great interest to the scientific community that was concerned with road salt and the resulting contamination of water resources. But we worried that few other than our fellow scientists would read these results.
NH DOT read our paper
Water quality
Fortunately, the people who maintain the roads read our paper and they contacted us to see what could be done to reduce this problem.
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Problem solved . . .
. . . we hope
Continued monitoring will tellWater
quality
The freeway was scheduled for some major upgrades. They simply designed a better flow diversion system to divert surface water and some of the groundwater out of the watershed. We are monitoring the response in the lake following this engineered solution.
NEWS Groundwater study underway in Upper DelawareBy Sandy Long
“The concern is that as we use more groundwater to supply our homes and infrastructure, there may be less groundwater discharging to the river. So at times when the river temperature is very warm, the fish and the animals that live in the substrate may become stressed.”
Endangered speciesWater rights
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Nobody asked any questions about endangered species while we were out collecting data. Everyone who asked about what we were doing was concerned about what it had to do with hydraulic fracturing, a relatively new process for improving the ability to extract oil or natural gas.
New tools – new understanding
SERVICE Engineering Group
Others also have developed new tools to quantify exchange between groundwater and surface water, some based on previous designs but then modified for specific applications. This meter used one seepage bag to measure water flow and another to collect samples of gas released from contaminated sediments.
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The amount of seepage through contaminated sediments will affect how the site is cleaned up. Measurements with modified seepage meters will play a big role in the decision for how to clean up this contaminated site. Cleanup costs are expected to be in the billions of dollars!
Money!
Advances come from working together
Is there a hydrobiogeochemopaleoecologist in the house?