using gis to predict arsenic over 10 ppb in drinking watermichael gastner, cosma shalizi, and mark...
TRANSCRIPT
![Page 1: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/1.jpg)
Using GIS to Predict Arsenic Over 10 ppb in Drinking Water
OrHow to lie with statistics and maps
Rich SouleMDH
![Page 2: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/2.jpg)
![Page 3: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/3.jpg)
![Page 4: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/4.jpg)
![Page 5: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/5.jpg)
All Blue
All Red
Michael Gastner, Cosma Shalizi, and Mark Newman University of Michigan
![Page 6: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/6.jpg)
Michael Gastner, Cosma Shalizi, and Mark Newman University of Michigan
![Page 7: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/7.jpg)
Make a Statewide Map of Arsenic in Groundwater in Less Than 3 Hours
1) Come up with a single physical process.It must be mapped at state scale.
2) Find the data sets representing this process and arsenic.
Evaluate data set bias.3) Generate a Probability Map for Arsenic
over 10 ppb.
![Page 8: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/8.jpg)
Clay
Sand
Sand withIron
ReducedBlack, green and grey
Rotten eggs odor.
Red, brown and, tanLittle to no odor.
Deep
Shallow Oxygen+
Carbon+
MicrobesHAsO4HAsO4--22
HAsO4HAsO4--22
As+5
HAsO4-2
As+3
H2AsO3 Ars
enic
Confining Thickness
HydrogeologicModel
Ars
enic
Time
BiologicalModel
GeochemicalModel
Oxidized
![Page 9: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/9.jpg)
Conceptual Model• Pr(As) > 10 ppb ≈ Clay Thickness.
• Groundwater is reduced by microbes at a constant rate and is limited by electron acceptors (O2, FeNO3, Fe ).
• The flow of electron acceptors is determined by vertical groundwater recharge. – Q=KiA, Assume average “K” and “i” .
• Assume Steady State.
![Page 10: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/10.jpg)
Why?: Spatial RelationshipsArsenic & DM Lobe Wood & DM Lobe
Arsenic >10 ppbArsenic <10 ppb
![Page 11: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/11.jpg)
Data Sets: Geology (CWI)VerifiedLocations
RawLocations
170,000Wells
200,000Wells
Use it All.
![Page 12: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/12.jpg)
VerifiedLocations
RawLocations
Bias: Well Density
![Page 13: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/13.jpg)
Summarizing Well Logs
37 ft
56 ft
21 ft
15 ft
Clay Thickness
+Total 138 ft
Clay
Clay
Clay
Clay
Do this370,000 Times.Takes 20 min.
![Page 14: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/14.jpg)
5 kmGrid
10 kmGrid
Grid Clay Thickness
> 100 Ft.
None
Clay Thickness
![Page 15: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/15.jpg)
Grid Clay Thickness
1 kmGrid
1 kmGrid with Brakes
> 100 Ft.
None
Clay Thickness
No Data
![Page 16: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/16.jpg)
MARSAreaLooks Really Bad….Population Declining….Co-incidence?
![Page 17: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/17.jpg)
Data Sets: Arsenic
Yes
No
Yes
Location
High As?Deeper?
YesWest Central
MARS
State
State
Area
No
Yes
Geology Bias Data
No LocationShallower?
Construction?
CDC/MDH
Deeper?Construction?
GWMAPS
![Page 18: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/18.jpg)
Use MARS Data?
Over 10 ppbNumber in AreaData Set
49%47CDC48%50GWMAPS52%893MARS
Yes, but cautiously.
![Page 19: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/19.jpg)
Get Clay Grid Values
![Page 20: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/20.jpg)
10
%
%
![Page 21: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/21.jpg)
0 20 40 60 80 100Avg. Feet Clay Above Screen
0
20
40
60
80
Pr (
As>
10)
Probability As >10 ppb All Arsenic Data
All Data
MARS Data
GWMAPS
CDC Data
![Page 22: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/22.jpg)
Low
Medium
High
Medium
0 20 40 60 80 100Avg. Feet Clay Above Screen
0
20
40
60
80
Pr(
As>
10)
Mapping Arsenic Using “Blocks”
All Data
MARS Data
GWMAPS
CDC Data
![Page 23: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/23.jpg)
Results
10 ppb
![Page 24: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/24.jpg)
Results
10 ppb
![Page 25: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/25.jpg)
Low
Medium
High
Medium
Score Card
0 20 40 60 80 100Avg. Feet Clay Above Screen
0
20
40
60
80
Pr(
As>
10)
MARS
All
MARS
MARS
MARS
All
AllAll
GWMAPS
GWMAPS
GWMAPS
GWMAPS
CDC
CDC
CDC CDC
![Page 26: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/26.jpg)
Implications• State Scale: the proposed processes may impact
the arsenic concentration in groundwater.• County Scale: These processes are probably
variable (i.e. K, infiltration…).• Section Scale: The change of the redox state of
groundwater through time may be the most important factor.
![Page 27: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/27.jpg)
![Page 28: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/28.jpg)
![Page 29: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/29.jpg)
MPCA & others
![Page 30: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/30.jpg)
Changing the Redox StateBorehole Chemistry & Microbial Ecosystems
“Reducing Factors” Increase Arsenic:Decreasing Infiltration (Tile Drains)Increasing Carbon Load (Monoculture)
“Oxidizing Factors” Decrease Arsenic:Increased Nitrate Loading
![Page 31: Using GIS to Predict Arsenic Over 10 ppb in Drinking WaterMichael Gastner, Cosma Shalizi, and Mark Newman University of Michigan. Make a Statewide Map of Arsenic in Groundwater in](https://reader036.vdocuments.net/reader036/viewer/2022071402/60f049d7872c4a352a66e709/html5/thumbnails/31.jpg)
Acknowledgements• Arsenic Lunch Group:
Mindy Erickson Randal BarnesRoman Kanivetsky Karla PetersonDavid Rindal Mike Berndt
• MDHBruce Olsen Sheila GrowBrian Johnson Justin BlumAl Epp Mike Baker