3. The complexity of what wwee aarree ttrryyiinngg ttoo
aaccccoommpplliisshh……..
Infiltration
Evaporation &
Condensation
The Water
Budget
Photosynthesis &
Respiration
Antecedent
Moisture
Conditions
Transpiration &
Interception
Variable Source
Area
Time of
Concentration The “sphere” concept was borrowed
from Dr. Peter Black:
Watershed Hydrology – 2nd Edition,
Peter Black, 1996, Ann Arbor Press
(ISBN# 1-5704 027-1)
4. MMooddeellss ttrryy ttoo mmiimmiicc tthhiiss!!
Basin Process
Representation
Infiltration
Excess Precip.
Interception
Storage
Time
Series Time
Series
5. FFrroomm AA BBaassiinn VViieeww
Excess Precip.
Excess Precip.
Model
Basin “Routing”
Runoff
Stream Hydrograph
“Routing”
14. How much wwaatteerr iiss tthheerree??
DDiissttrriibbuuttiioonn ooff EEaarrtthh''ss WWaatteerrss aanndd RReessiiddeennccee
TTiimmeess........
Location of
Storage
Total Water
(acre-feet)
Percent of
Total
Percent of
Fresh
Residence
Time
(years)
Total water on
earth
1.033 x 1015 100.0
Oceans 1.0 x 1015 96.8
Total Fresh
Water
3.314 x 1013 3.2 100.0 6977
Ice and
Glaciers
2.475 x 1013 75.4 5210
Groundwater
Deep
4.62 x 1012 14.0 973
Groundwater
Shallow
3.63 x 1012 11.0 764
Lakes 9.9 x 1010 0.3 21
Biosphere 8.1 x 1010 0.24 17.1
Soil Moisture 1.98 x 1010 0.06 4.17
Atmosphere 1.155 x 1010 0.035 2.43
Rivers 9.9 x 1010 0.003 2.1
15. Units && PPrrooppeerrttiieess ooff
WWaatteerr
Property Symbol Value Comments
Density
r ~1.94 slugs/ft3
(mass/volume)
~ 1.0 g/cm3
Slug = lb*s2/ft
Specific Weight
(weight/volume)
g 62.4 Lbs/ft3
9.81 kN/m3
g = rg
Specific Volume n n = 1/r
Specific Gravity s.g. 1.0 for water
@ 32.9o F
s.g.fluid =
gfluid/gwater
Vapor Pressure ~0.4 psi Vapor pressure of
the fluid - not the
atmosphere
18. RRuunnooffff VVoolluummee
• 11--iinncchh ooff rruunnooffff oovveerr 11 ssqquuaarree mmiillee ::
• 11//1122 ffeeeett xx 11 mmii22 xx 664400 aaccrreess//mmii22 xx 4433,,556600
fftt22//mmii22 == 22,,332233,,220000 fftt33
19. DDiisscchhaarrggee
• 11 ccffss == 11 ccuubbiicc ffoooott ppeerr sseeccoonndd
• 11 ccffss xx 77..4488 ggaall//fftt33 xx 33660000 sseecc//hhrr xx 2244 hhrrss//ddaayy ==
664466,,227722 ggppdd == 00..664466 MMGGDD
• 11 ccffss xx 33660000 sseecc//hhrr xx 2244 hhrrss//ddaayy == 8866,,440000 ccffss//ddaayy
• 8866,,440000 ccffss//ddaayy xx 11 aacc--fftt//4433,,556600 fftt33 == 11..998833 aacc--fftt//ddaayy
((~~ 22 aacc--fftt//ddaayy))
• 11..998833 aacc--fftt//ddaayy xx 1122 iinncchheess//fftt xx 11 ddaayy//2244 hhrrss ==
00..999922 aacc--iinn//hhrr
• 11 aacc--iinn//hhrr xx 4433,,556600 fftt33//aacc--fftt xx 11 hhrr//33660000 sseecc xx 11 fftt//1122
iinncchheess == 11..000088 ccffss
20. PPoowweerr
• HHpp == gHHQQ//555500
• 11 hhpp == 555500 fftt**llbb//sseecc == 00..77554477 kkiilloowwaattttss
g = weight of water
H = head or elevation difference
Q = flow
Hydropower wants a lot of flow and
a full reservoir…..