![Page 1: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/1.jpg)
SOIL WATERSOIL WATER
GES175, GES175, Science of SoilsScience of Soils
![Page 2: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/2.jpg)
Water Movement- Surface water moves due to gravitational force
Does water always flow downward?
3.2
![Page 3: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/3.jpg)
CapillarityCapillarity Water moves into capillary soil poresWater moves into capillary soil pores
- due to adhesive and cohesive forces- due to adhesive and cohesive forces
3.3
![Page 4: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/4.jpg)
OH
H
OH
H
OH
H OH
H
OH
H
OH
H
OH
H
OH
H
K+
Cl-
OH
H
Osmotic Force
Water movement across semi-permeable membrane
3.4
![Page 5: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/5.jpg)
Energy ConceptEnergy Concept
Water moves from Water moves from high to low free energyhigh to low free energy
wet soil wet soil dry soil dry soilHH22O movementO movement
HH22O freeO free H H22O freeO free energy isenergy is energy is energy is
higherhigher lower lower
- difference in free energy causes H- difference in free energy causes H22O to moveO to move
3.5
Large Pores Small Pores
![Page 6: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/6.jpg)
Properties of WaterProperties of WaterHydrogen bondingHydrogen bonding
3.6
![Page 7: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/7.jpg)
Capillary ForcesCapillary Forces
- smaller pores hold water with greater energy - smaller pores hold water with greater energy - nondirectional- nondirectional
h = 0.15/rh = 0.15/r
2T cos r d gh =
T = surface tension = wetting angler = radius of pored = density of waterg = gravity
3.7
![Page 8: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/8.jpg)
Water Movement by Capillary Action3.8
![Page 9: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/9.jpg)
3.9
![Page 10: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/10.jpg)
UnitsUnits
cm Hcm H22OO barsbars kPakPa
300300 -0.3 -0.3 -30-30
1,0001,000 -1 -1 -100-100
10,00010,000 -10-10 -1000-1000
15,00015,000 -15-15 -1500-1500
see Table 5.1 in textsee Table 5.1 in text
3.10
1 atm = 760 mm Hg = 1020 cm H2O = 1 bar = 100 KPa
![Page 11: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/11.jpg)
3.11
Sandy Soil
Clayey Soil
Water Content (%)
Suc
tion
(ba
rs)
0
-20
Water Retention Curves
![Page 12: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/12.jpg)
Aggregated Soil
Water Content (%)
Suc
tion
(ba
rs)
0
-100
Compacted Soil
Water Retention Curves 3.12
![Page 13: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/13.jpg)
Hysteresis
drying
wetting
Suction (bars)
2r
2R
drying
wetting
0 -100
0.5
3.13
![Page 14: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/14.jpg)
Soil Water:Soil Water: Classification and AvailabilityClassification and Availability
physical biological0
-30
-15
-0.3
gravitational
capillary
vapor
values are only semiquantitativevalues are only semiquantitative
unavailable (drainage)
available
unavailable
(bars)
3.14
![Page 15: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/15.jpg)
3.15
clayey
sandy
H2O
Concepts of Movement
sandy
clayey
H2O
clayey
sandy
H2O
![Page 16: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/16.jpg)
3.16
Hpi
Hgi
Hinlet= Hpi + Hgi
Reference level
soil
Hpo
Hgo
Ho = Hpo + Hgo
H
H= Hinlet - Houtlet
= Hpi - Hpo
Saturated Flow- Horizontal Column
L
![Page 17: SOIL WATER GES175, Science of Soils. Water Movement - Surface water moves due to gravitational force Does water always flow downward? 3.2](https://reader034.vdocument.in/reader034/viewer/2022051819/5517af4a5503460e6e8b61a7/html5/thumbnails/17.jpg)
3.17
H1
L
inlet
Reference plainoutlet
Hi = H1 + L
Ho = 0 + 0
Saturated Flow- Vertical Column
H = H1 + L