Presentation by Brian Smith of FHWA on Careers in Transportation - Chicago HS for Agricultural Sciences Shadow Day 02-08-12.

1. Hydrology
The science of
water, its
properties,
distribution and
circulation, both on
the surface and
underground.

2. Hydrology
Water flows
through our
site by a
variety of
pathways

3. Water Budgets
Inputs = Outputs + Storage
Precipitation Evapotranspiration
Groundwater discharge Groundwater recharge
Surface Flow Surface flow
- Runoff
- Streams
- Tides

4. Seasonal Variability
Average Monthly Precipitation
6
5
4
Inches
3
2
1
0
1 2 3 4 5 6 7 8 9 10 11 12
MONTH
http://www.sercc.com/climateinfo/historical/historical.html

5. A = R * K * LS * C * P
Where
A = estimated average soil loss in tons per
acre per year
R = rainfall-runoff erosivity factor
K = soil erodibility factor
L = slope length factor
S = slope steepness factor
C = cover-management factor
P = support practice factor

6. Erosivity Index zone map and calculator
http://ei.tamu.edu/index.html

7. When all factors other than rainfall were
held constant, the soil loss is directly
proportional to the total kinetic energy of
the storm event times its maximum 30-
minute intensity.
This factor, Rainfall/Runoff Factor (R), has
been called the Erosion Index (EI)
factor.

8. Erosivity Distribution
Jan-Mar Apr-Jun July- Sept Oct-Dec cumulative
5.79 38.64 76.16 21 141.59
8.77 41.09 71.98 21 142.84
10 46.89 82.04 26.08 165.01
23.67 60.73 73.85 36.67 194.92
July-Sept - High Risk
Apr-Jun – moderate risk