winter hydrology: modeling ground frost and river ice to improve flood and flash flood warning...
TRANSCRIPT
Winter Hydrology: Modeling Ground Frost and River Ice to
Improve Flood and Flash Flood Warning Accuracy
Steve DiRienzoSenior Service Hydrologist National Weather Service
Albany NY
OverView
1. Ice Jams
2. Ground Frost
Ice Jams in Albany HSA
• Ice Jams Occur in Preferred Locations
• Bob Kilpatrick Catalogued Ice Jam Locations for WFO Albany
• Question: Not Where, But WHEN
River Ice
1. Goal: Predict When River Ice Freeze Up and Break Up Jams Possible to Enhance Watch/Warning Lead Times and Accuracy
River Ice
1. When Are Freeze Up Jams Possible
2. Ice Thickness Equation
3. How Thick Does The Ice Need To Be For Break Up Jams?
4. When Does The Ice Break Up?
5. Case Studies
When Are Freeze Up Jams Possible
Freeze Up: Three Consecutive Days with daily average temperatures <= 0°F Tavg = (Tmax+Tmin)/2
The Average Discharge During the Freeze Up Period Had Little Effect on the Formation of Frazil Ice Jams
Freeze Up Jams More Likely If Some Ice In Place Before Cold Snap
Can Use Representative MEX or MAV MOS Data To Issue Watch 24-36hrs Before Event
http://aprfc.arh.noaa.gov/pubs/newsltr/pub4/frazil.html
Ice Thickness Calculation Ice thickness in inches is estimated using the modified Stefan
equation presented in USACE Manual(2002):ti = C (AFDD)0.5
Constant C can range from 0.1 to 0.8NWS Albany studies show C ~ 0.4 for KALY HSA(Bob K.)
Freezing Degree Day (FDD) = 32°F – Daily Average Temp (°F)
Thawing Degree Day (TDD) = Daily Average Temp (°F) – 32 °F
USACE (2002) Engineering and Design: Ice Engineering. U.S. Army Corps of Engineers Engineer Manual 1110-2-1612.
How Thick Does The Ice Need To Be?
Around a Foot Thick or More – Ice Rigid Enough to Cause Jams
Estimations showed 11 Inches or More Were Enough to Jam
~ 850-900 AFDD
When Does The Ice Break Up?
• BUF Chart• Thanks Steve M.
When Does The Ice Break Up? Accumulated Thawing Degree Hours (ATDH) has linear
relationship to ice breakup
From previous chart: 240 ATDH/24 Hours
240/24 >= 10 TDD/Day to cause breakup = Tavg >=42°F
Can use MEX, MEN or NDFD data to estimate date of breakup
Conversion to Thawing Degree Days (TDD) allows for coarse studies using daily data from previous years
Case Studies
Following case studies use data from nearest METAR station to jam location
Graph title shows nearest METAR (3-letter ID)
Case 1 – Predicted Breakup March 2nd, 2004
Upper Mohawk Basin (UCA)
0
2
4
6
8
10
12
14
10
/1/2
00
3
11
/1/2
00
3
12
/1/2
00
3
1/1
/20
04
2/1
/20
04
3/1
/20
04
4/1
/20
04
Date
Ice
Th
ick
ne
ss
(in
)
Est_Ice
ti = 0.4 (AFDD)0.5 - Ice thickness set to zero when average daily temp >= 42°F
March 2nd, 2004 – Fulmer Creek
Case 3 – Predicted Breakup February 27th, 2000
Lamoille River (MPV)
0
2
4
6
8
10
12
14
10/1
/199
9
10/1
5/19
99
10/2
9/19
99
11/1
2/19
99
11/2
6/19
99
12/1
0/19
99
12/2
4/19
99
1/7/
2000
1/21
/200
0
2/4/
2000
2/18
/200
0
3/3/
2000
3/17
/200
0
3/31
/200
0
4/14
/200
0
4/28
/200
0
Date
Ice
Th
ickn
ess
(in)
Est_Ic
ti = 0.4 (AFDD)0.5 - Ice thickness set to zero when average daily temp >= 42°F
Lamoille River Nr Hardwick, VT– February 28th, 2000
Case 4 – Predicted March 16th, 2003
Cazenovia Creek (BUF)
0
2
4
6
8
10
12
14
1-O
ct-0
2
14
-Oct
-02
27
-Oct
-02
10
-No
v-0
2
23
-No
v-0
2
6-D
ec-
02
19
-De
c-0
2
2-J
an
-03
15
-Ja
n-0
3
28
-Ja
n-0
3
10
-Fe
b-0
3
23
-Fe
b-0
3
8-M
ar-
03
21
-Ma
r-0
3
3-A
pr-
03
16
-Ap
r-0
3
29
-Ap
r-0
3
Date
Ice
Th
ick
ne
ss
(in
)
Est_Ic
ti = 0.4 (AFDD)0.5 - Ice thickness set to zero when average daily temp >= 42°F
Cazenovia Creek – March 18th, 2003
Ice Jam Watch/Warning Guidelines
Freeze Up: Three Consecutive Days with daily average temperatures <= 0°F (Observed or Forecast)?Freeze Up Jams Possible - Consider Flood Watch
Break Up:1) Ice around 1 foot thick or more?And2) Daily Average Temperature forecast to be >= 42°F or more?Break Up Jams Possible - Consider Flood Watch
Daily Average Temperature = (Tmax+Tmin)/2
Forecasting ice jam potential for individual river basins is possible using the nearest MAV, NDFD or MEX MOS data.
Frost Depth/Frozen Ground
Anybody in the Northeast Measuring this?
Any thought to installing Frost Tubes or soil temperature probes?
Some Utility Companies and State Road Departments estimate/measure. Mainly to prevent frozen water pipes or estimate Frost Heave and winter/spring weight restrictions on roads.
Equation Used by Canadian Utility Company
A Practical measure to prevent frozen water service lines - the Region of Ottawa Carleton's Experience, National Research Council Canada, 1999.
Brown, W.G. Difficulties associated with predicting depth of freeze or thaw. Canadian Geotechnical Journal, 1(4):215-226, 1964.
Soil Temperature Curves – MN DOT
Frost With Snow (Snow depth manipulation and its influence on soil frost
and water dynamics in a northern hardwood forest (CRREL – 2001))
Measured vs Estimated
Plover WI 0405
-40
-30
-20
-10
0
10
20
1 O
ct
18
Oct
4 N
ov
21
No
v
8 D
ec
25
De
c
11
Ja
n
28
Ja
n
14
Fe
b
3 M
ar
20
Ma
r
6 A
pr
23
Ap
rDate
De
pth
(in
) Est_Frost_Depth
Est_Thaw
Meas FD
Snow
Measured vs Estimated
MKX Frost 0405
-30-25-20-15-10
-505
101520
1 O
ct
18 O
ct
4 N
ov
21 N
ov
8 D
ec
25 D
ec
11 J
an
28 J
an
14 F
eb
3 M
ar
20 M
ar
6 A
pr
23 A
pr
Date
Dep
th(in
) Est Frost DepthEst Thaw DepthMeasured Frost DepthSnow
KALY Frost SimulationsKALY Frost w/Snow 0304
-25
-20
-15
-10
-5
0
1 O
ct
14
Oct
27
Oct
9 N
ov
22
No
v
5 D
ec
18
De
c
31
De
c
13
Ja
n
26
Ja
n
8 F
eb
21
Fe
b
5 M
ar
18
Ma
r
31
Ma
r
Date
De
pth
(in
)
Frost_depth
Thaw_depth
Sec_frost_depth
KALY Frost w/Snow 0405
-25
-20
-15
-10
-5
0
1 O
ct
17 O
ct
2 N
ov
18 N
ov
4 D
ec
20 D
ec
5 Ja
n
21 J
an
6 Fe
b
22 F
eb
10 M
ar
26 M
ar
Date
Dep
th (i
n) Frost_Depth
Thaw_Depth
Sec_Frost_Depth
0405: Flash Flooding January 14th 2005.A few inches of frost left on April 2 prior to record floods.
Depth of Frost (m) = .0174(AFDD(°C))**.67***AFDD = AFDD + FDD/Snow Depth
Can Estimate When Soil Thaw Complete
To calculate the total number of thawing degree days until the thaw is complete, multiply the Winter Freezing Index (AFDD) by 0.3.
For example, for a Winter Freezing Index of
1375 °F AFDD, the Thawing Index would be 412 ATDD: 0.3 x 1375 = 412
Ref: Wisconsin Transportation Bulletin No 8 November 2003
The End
Questions/Comments?
2004 Cold Regions Hydrology Workshop – Section on Frozen Ground Modeling contains info/plans for Frost Gauges:
• http://aprfc.arh.noaa.gov/resources/crw04/Agenda.htm