Transcript HYDROLOGIC CYCLE - Purdue Agriculture

Meteorology – Storm Events
Knowledge of Precipitation
Amounts and Patterns
• Plan drainage
structures
– Size temporary
culverts to handle
storm events
during period of
operations
– Size permanent
drainage structure
to handle 100
year storms
Know Precipitation Amounts
and Patterns
• Time operations
– Expose soil during dry periods
if possible
– Establish vegetative cover as
soon as possible
– Use native vegetation
whenever possible
What’s Wrong?
Become familiar
with precipitation
patterns
• Sources of data
– NOAA
– NWS
– State climatologist
• Usually at Land Grant
University
• Vast amount of data
available on line
Ochocos Mountains of Central Oregon
National Climatic Data Center
http://www.ncdc.noaa.gov/oa/ncdc.html
National Weather Service
http://www.weather.gov/view/national.php?thumbs=on
National Oceanic and Atmospheric
Administration's
National Weather Service
Indiana State Climatologist
http://www.agry.purdue.edu/climate/
Variation in Precipitation
• Random
• Seasonal
• Proximity to water
body (lake affect)
• Prevailing winds
with moisture
• Topographic
Seasonal Variation
Indiana Total Precipitation
5
NC
SC
State
3
2
1
Month
No
v.
Se
p.
Ju
ly
M
ay
M
ar
.
0
Ja
n.
Inches
4
Proximity to Water Body
Prevailing Winds
Topographic Affect
• Rising air cools
• Dew point reached
• Water vapor
condenses to form
clouds
• Precipitation may
occur
• Cloud patterns
induced by passage
of air current over
mountains
• Precipitation
concentrated on
windward side of
mountain, and
mountain top
• Tends to be rain
shadow on leeward
side
• Fidalgo Island in rain shadow of the Olympic Mountains.
• Rainforests with up to 200 inches of precipitation on the west
side.
• Rain shadow area northeast of the Peninsula with only onehalf (20 inches) of the normal rainfall for the rest of the
region.
Puget Sound Area, Washington
20
18
16
14
12
10
8
6
4
2
0
Clearwater 118.5”
Coupeville 21.14”
Ja
n.
Fe
b.
M
ar
.
Ap
r.
M
ay
Ju
ne
Ju
ly
Au
g.
Se
p.
O
ct
.
No
v.
D
ec
.
Inches
Avg. Monthly Rainfall 1931-1998
Month
3/26/99
3/19/99
3/12/99
3/5/99
2/26/99
2/19/99
2/12/99
2/5/99
1/29/99
1/22/99
1/15/99
1/8/99
1/1/99
Inches
Storm Events, 1st Qtr.
Daily Precipitation, Bedford, IN, 1998
1
0.8
0.6
0.4
0.2
0
6/24/99
6/17/99
6/10/99
6/3/99
5/27/99
5/20/99
5/13/99
5/6/99
4/29/99
4/22/99
4/15/99
4/8/99
4/1/99
Inches
Storm Events, 2nd Qtr.
Daily Precipitation, 1998, Bedford, IN
5
4
3
2
1
0
9/30/99
9/23/99
9/16/99
9/9/99
9/2/99
8/26/99
8/19/99
8/12/99
8/5/99
7/29/99
7/22/99
7/15/99
7/8/99
7/1/99
Inches
Storm Events, 3rd Qtr.
Daily Precipitation, 1998, Bedford, IN
1.2
1
0.8
0.6
0.4
0.2
0
12/31/99
12/24/99
12/17/99
12/10/99
12/3/99
11/26/99
11/19/99
11/12/99
11/5/99
10/29/99
10/22/99
10/15/99
10/8/99
10/1/99
Inches
Storm Events, 4th Qtr.
Daily Precipitation, 1998, Bedford, IN
2.5
2
1.5
1
0.5
0
Monroe County Airport, April 15-16, 1998
.03
1053
.26
1158
.00
1253
.01
1353
.0
1453
.04
1553
.0
0.3
1953
.14
0.2
2053
.12
0.1
2153
.10
2253
.36
2353
.17
0053
.32
0153
.22
0253
.25
0353
.08
Hourly Precipitation
0.4
Series1
16 53
-00
5
16
-02 3
53
2
-22
53
15
-20
53
15
-15
53
15
-13
58
15
15
-11
53
0
-09
16th
0953
15
15th
Some Basic Hydrologic Concepts
Weirs are used to measure volume
of water flowing past a point.
What Happens to Precipitation?
• Hydrologic cycle
P = RO + ET + S,
Where,
•
•
•
•
P ≡ precipitation
RO ≡ runoff
ET ≡ evapotranspiration
S ≡ storage
Evapotranspiration
• Loss of water from a given
area during a specified time by
evaporation from the soil
surface and by transpiration
from the plants.
• Supports plant life
• Reduces water yield
Runoff Provides Major Benefits
RO = P – ET
Moose Creek, Clearfield County, PA (WLH)
Where does runoff go to?
• RO = CI + SRO + SSF + BF,
– where,
• CI ≡ channel interception
• SRO ≡ surface run off
• SSF ≡ subsurface flow
• BF ≡ base flow
Where does runoff go to?
– CI ≡ channel interception
• Precipitation falling directly into
channel
Susquehanna River, Clearfield, PA, (WLH)
Where does runoff go to?
– SRO ≡ surface runoff or overland flow
• Precipitation not infiltrating soil
Source: http://www.agric.gov.ab.ca/agdex/500/72000003.html
Sheet erosion of cropland
resulting from surface runoff
Where does runoff go to?
– SSF ≡ subsurface flow, or interflow
• Infiltrating precipitation intercepted by hardpan or
bedrock before entering groundwater pool
Where does runoff go to?
– BF ≡ base flow or ground water flow
• Precipitation entering water table
Research results come from
experimental watersheds such as:
What We’ll Look At
• Erosion
– Impacts of
• Roads
• Harvests
• Water flows
– Storm events
– Storage
• Water yield
– Amount
– Timing
Montgemory Reservoir, Clearfield, PA, WLH