Hillslope Hydrology and Headwater Control (by Maki TSUJIMURA, Ph.D )
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Transcript of Hillslope Hydrology and Headwater Control (by Maki TSUJIMURA, Ph.D )
Maki TSUJIMURA, Maki TSUJIMURA, Ph.D.Ph.D.••Associate Professor in Hydrology and Hydrogeology, Doctoral ProgAssociate Professor in Hydrology and Hydrogeology, Doctoral Program in Sustainable ram in Sustainable Environmental Studies, Graduate School of Life and EnvironmentalEnvironmental Studies, Graduate School of Life and Environmental Sciences; Sciences; ••Executive Leader, EDL Education Program, University of Tsukuba Executive Leader, EDL Education Program, University of Tsukuba ••CoCo--ChairholderChairholder, UNESCO, UNESCO--Chair on Sustainable Management of Groundwater in MongoliaChair on Sustainable Management of Groundwater in Mongolia
Environmental Diplomatic Leader (EDL)Environmental Diplomatic Leader (EDL)Education Program, University of TsukubaEducation Program, University of Tsukuba
Contents� Introduction - rainfall runoff process in watershed
� Transformation from rainfall into runoff
� Infiltration
� Runoff characteristics
� Runoff components: End Members Mixing Analysis
� Subsurface flow process in hillslope and runoff
� Role of bedrock groundwater in runoff
� Residence time of groundwater and spring water in headwaters
2
Headwater: Transform from rainfall to
runoff / Recharge-discharge area
3
Runoff
Rainfall
Time
Runoff
Time
Rainfall
Hydrograph
Hyetograph
Evapotranspiration
Groundwater flow
PrecipitationEvapotranspiration
Runoff
Groundwater
Divide
Water balance of watershed(Precipitation)=(Evapotranspiration)+(Runoff)+(Change of storage)
Hewlett and Nutter (1990)
Topographical watershed and
hydrological watershed
Hewlett and Nutter (1990)
Pg: Precipitation, Tf: Throughfall, Cd: Canopy dropped fall, Sf: Stemflow, Ev:
Interception, Tr: Transpiration, Ab: Absorption, Eg Evaporation from soil surface, If:
Infiltration, Of: Overland flow, Pc: Percolation, Gr: Groundwater recharge, Bi:
Bedrock infiltration, Gd: Groundwater discharge
Pg Pg
Sf
Cd Sf
Tf
Cd
Cd
Of
If
PcGr
Gr
GdBi
Bi
Ab
Ab
Tr
Tr
Ev
Ev
Pg Pg
Soil surface
Groundwater table
Bedrock surface
Soil water zone
Groundwater zone
Soil layer
Bedrock
Eg
Storage type
Tipping bucket type
Time
Infiltra
tion c
apacity / R
ain
fall
RI
FIC
IIC
Occurrence of
overland flow
Hortonian overland flow
Infiltration � subsurface flow
Infiltration capacity curve
IIC: Initial Infiltration capacity
RI: Rainfall Intensity
FIC: Final Infiltration Capacity
Infiltration
9
A) Infiltration capacity >
Rainfall intensityB) Rainfall intensity >
Infiltration capacity
Rainfall
Rainfall
Infiltration capacity Infiltration capacity
Infiltration
Infiltration
Percolation Percolation
Hortonian overland flow
Ground surface
Ground
surface
Measurement of infiltration capacity
10
Manual measurement of IC
using a cylinder (Murai, 1970)
Double cylinders (rings)
infiltrometer (Tsujimura
et al., 1991)
Measurement of IC using a
sprinkler (Onda and Yukawa,
1995)
Measurement of IC using a
sprinkler on the tower of 12 m
height (Onda, Tsujimura et al.,
2006)
Water tank
Inner cylinder
Outer cylinder
Soil surface
Water tank
Sprinkler
Tipping bucket
Overland flow collector
Contrasting of forest situation and
infiltration capacity
11
• Contrasting between well maintained forest (right) and no
maintained forest (left) (upper-left).
• Un-perennial watershed without forest maintenance
•Observed runoff during a heavy rainstorm in an un-perennial
watershed
Measurement of infiltration capacity
� Calculation of IC using data of sprinkler
� I = P – Q
� I: IC, P: rainfall intensity, Q: overland flow intensity
12
Comparison of IC among three
different type infiltrometers
(cylinder, sprinkler, tower
sprinkler)
(Onda, Tsujimura et al., 2006)
Exercise 1
13
Time (min.) Infiltration (mL or cm3) IC (mm/hr)
0-1 30
1-2 30
2-3 10
3-4 20
4-5 25
5-6 15
6-7 5
7-8 10
8-9 15
9-10 5
10-12 15
12-14 12
14-16 16
16-18 18
18-20 26
20-25 22
25-30 22
30-35 26
35-40 27
40-45 24
45-50 23
The left table shows data
taken by an infiltration
measurement test using a
cylindrical infiltrometer in a
grassland of U Tsukuba.
Calculate infiltration capacity
at each time step and draw a
graph showing a temporal
change of IC.
Note: Diameter of the cylinder
is 5 cm.
Exercise 1 -Answer
14
15
y = 0.0126x2.3236
R2 = 0.9729
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
0 2 4 6 8 10Water level (cm)
Discharge (L/s)
Typical weir at stream in headwater
(Hewlett and Nutter, 1970) Example of water level -
discharge relation curve in a
headwater
Water level sensor
(a) A gauging station at Hubbard Brook Watershed
(USA)
(b) A gauging station at Sleepers River Watershed
(USGS)
A weir and parshall flume
at stream of Shiranui
Watershed in Kumamoto,
Japan
A parshall flume at
stream of Shiranui
Watershed in
Kumamoto, Japan
0
5
10
15
20
6-Sep 8-Sep 10-Sep 12-Sep 14-Sep 16-Sep
日付 (2001)
流量 (mm/h)
0
20
40
60
80
100
120
140
160
雨量 (mm/h)
流量
雨量
Date (2001)
Runoff (m
m/h
)
Rain
fall
(mm
/h)
Observed in a headwater, Nikko, Japan
Rainfall
Runoff
Hydrograph and hyetographRunoff characteristics reflecting hydrological processes
18
Urban watershed (0.4
ha) covered by
pavement
RR: 100%Runoff (m
3/h
)
Rain
fall
(cm
/h)
Runoff (m
3/h
)R
unoff (m
3/h
)R
unoff (m
3/h
)
Rain
fall
(cm
/h)
Rural watershed (58
ha) covered by grass
and cultivated area
RR: 3.6%
Forested watershed
(182 ha) covered by
birch and fir underlain
by silt
RR: 3 - 30%Rain
fall
(cm
/h)
Rain
fall
(cm
/h) Watershed in Kenya
(53 ha) by volcanic
ash (no vegetation
information)
RR: 2%
Time (min)
Time (hr)
Time (days)
Time (days)
RR: Runoff ratio
to rainfall in one
rainfall event
Kayane (1980)
19
(b) South western Japan (Kyushu Island)(a) Central Japan (Kanto Plain)Runoff
(mm d
-1)
0.1
1.0
10
100
300
□:Quat. Volc. rock
△:Tertial. Volc. rock
○:Granite
●:Mesozoic
■:Paleozpic
0.5
50
5.0
I II III IV V VI VII
□:Quat. Volc. rock
○:Granite
■:Paleozoic
I II III IV V VI VII
(I) annual maximum runoff, (II) 35-day runoff, (III) runoff with high water level, (IV) runoff with ordinary water level, (V) runoff with low water level, (VI) draught runoff, (VII) annual minimum runoff
20
Onda, Tsujimura et al. (2006)
Runoff
(L s
-1km
-2)
Rain
fall
(mm
h-1)
Days (Sep - Oct, 1993)
Schematic diagram showing
relationship between runoff
characteristics and subsurface
flow processes in shale and
granite watersheds. (Onda,
Tsujimura et al., 1999)
Shale Granite
Delayed response Quick response
Subsurface flow in bedrockSubsurface flow in soil layer
Runoff
Runoff
Rainfall
Soil
layer
Where does water come from?
21
Time
Rainfall
Runoff
Time
Kirchner et al (2001)
Mass balanceEnd Members Mixing Analysis (EMMA)
23
Qn, Cn
Qo, Co
Qt, Ct
Qo, Co
oonntt
ont
QCQCQC
QQQ
+=
+=
t
no
nt
o QCC
CCQ
−
−=
24
Tracer concentration C
Tra
cer concentration C
End member a
Mixture (total discharge)
100
0Contrib
ution ratio o
f end m
em
ber b to
tota
l dis
charg
e (%
)
1000Contribution ratio of end member b to
total discharge (%)
End member b
X%
100-X
%
X% 100-X%
oonntt
ont
QCQCQC
QQQ
+=
+=
t
no
nt
o QCC
CCQ
−
−=
25
Concentration of tracer 1: C1
Concentration of tracer 2: C2
End member aMixture(total discharge)
End member b
End member c1=++ cba QQQ
tccbbaa CQCQCQC 1111 =++
tccbbaa CQCQCQC 2222 =++
Exercise 2
26
Time Runoff
Event water (rainfall)
Pre-event water (groundwater)
The data in the left table shows temporal change of δ18O in stream water (runoff: L/s/km2) during a rainstorm in a small headwater basin, Seto, Aichi, Japan. Calculate contribution rate of pre-event water to runoff water using EMMA and show the results by graph.
t
no
nt
o QCC
CCQ
−
−=
Exercise 2 -Answer
27
Total runoff
Pre-event water component
Granite Watershed
Shale Watershed
28
Case in a headwater� Contrasting runoff components separation using 18O
between the watersheds underlain by shale and granite� Shale watershed: >98% coming from pre-event water
� Granite watershed: 64% coming from pre-event water
Shale Granite
δ18O
(‰)
Runoff (l/s/k
m2)
Rain
fall
(mm
/h)
Shale Watershed
Granite Watershed
31
Stream
Saturation
Divide
Weir
Overland flow
Spring
Stream
Saturation
Divide
Weir
Rain gauge
Observation line
Saturation area: 5% of watershed
Saturation in valley bottom
Observation line on slope
Weir at outlet of watershed
33
0.0
2.0
4.0
6.0
8.0Rainfall (mm/5 min)
285 mm
0 .0
2 .0
4 .0
6 .0
Cl- conc. (m
g/L
)
R a infall: 0 .3 m g/L
0
20
40
60
80
100
Ratio of pre-event water (%)
0
2000
4000
6000
8000
0:00 Sep11 12:00
Sep11
0:00 Sep12 12:00
Sep12
0:00 Sep13 12:00
Sep13
Specific discharge (L/s/km
2)
Pre-event water
2000
(a) Heavy rainstorm (265 mm)
降水量
(mm)
Cl-濃度
(mg L
-1)
地下水成分割合
(%)
比流量
(L s-1km
-2)
地下水成分
降水濃度 0.3
0.0
0.5
1.0
1.5
2.0Rainfall (mm/5 min)
16 mm
0.0
2.0
4.0
6.0
Cl- co
nc. (m
g/L)
Rainfall: 0.7 mg/L
0
20
40
60
80
100
Ratio of pre-event water (%)
0
20
40
60
80
6:00
Oct27
12:00
Oct27
18:00
Oct27
0:00
Oct28
6:00
Oct28
12:00
Oct28
Specific discharge (L/s/km
2)
P re-event water
1999
(b) Small rainstorm (16 mm)
降水量
(mm)
Cl-濃度
(mg L
-1)
地下水成分割合
(%)
比流量
(L s-1km
-2)
地下水成分
降水濃度 0.7
Rain
fall
(mm
)
Rain
fall
(mm
)
Cl-
conc
(mg/L
)
Cl-
conc
(mg/L
)
Gro
undw
ate
r
Ratio (%
)
Gro
undw
ate
r
Ratio (%
)
Runoff (L/s
/km
2)
Runoff (L/s
/km
2)
Groundwater
component Groundwater
component
Rain water: 0.3Rain water: 0.7
Asai (2001)
34
Groundwater tableEqui-potential line
Direction of subsurface
flow
比流量
(L s-1km
-2)
降水量
(mm)
比流量
(L s-1km
-2)
降水量
(mm)
Runoff (L
/s/k
m2)
Runoff (L
/s/k
m2)
Rain
fall
(mm
)
Rain
fall
(mm
)
35
Asai (2001)
y = 0.05x
r2 = 0.84
0.0
1.0
2.0
3.0
4.0
0.0 4.0 8.0 12.0
Peak rainfall (mm/10 min)
Runoff of event water (mm/10 m
in) 総降雨量 265 mmTotal rainfall: 265 mm
Role of bedrock groundwater in
runoff
40
Iwagami, Tsujimura et al. (2010)
Role of bedrock groundwater in
runoff
41
Role of bedrock groundwater in
runoff
42
Iwagami, Tsujimura et al. (2010)
Role of bedrock groundwater
in runoff
43Iwagami, Tsujimura et al. (2010)
Aquitard
不透
水層
Confined aquiferConfined aquifer
Acuitard
Unconfined aquiferUnconfined aquifer
GW table
River Spring
Recharge area
Well
Residence time
1940 1990
CF
Cs
con
cen
tra
tio
n
CFCs in atmosphere
Age in spring / GW
Present
Residence time
in spring / GW
Age Present
Aq
uitard
CFCs (chlorofluorocarbons)CFCs (chlorofluorocarbons)
�CFC-11 (CCl3F, trichlorofluoromethane)
�CFC-12 (CCl2F2, dichlorodifluoromethane)
�CFC-113 (C2Cl3F3, trichlorotrifluoroethane)
0
100
200
300
400
500
600
700
1940 1950 1960 1970 1980 1990 2000
Year
Tra
cer concentration (pptv
) CFC-12CFC-11CFC-113SF6×100
� CFCs is stable in the atmosphere.
� CFCs concentration in the atmosphere is increasing since 1950.
Long trend of CFCs in atmosphere (USGS)
Atmosphere (Fa)
Groundwater (Fg)
Soil surface
Water table
Air in soil (Fs)
Fa
Fs
Fg
iHi pKC = (1)
Ci: CFCs concentration, KH: Henry’s law constant
( )OHii pPxp2
−= (2)
ip : pressure of gas, xi: CFCs mol ratio in atmosphere, P: atmospheric
pressure, pH2O: vapor pressure (Warner and Weiss, 1985)
+
++
+
+=2
321321100100100
ln100
lnT
bT
bbST
aT
aaKH (3)
T: absolute temperature, S: chloride concentration (vol %).
The parameters of a1,a2,a3,b1,b2,b3 are taken from Warner and Weiss
(1985).
Excess air throughfissurs of bedrock Decomposition by microorganism
Aquitard
不透
水層
Confined aquifer
Aquitard
Unconfined aquiferUnconfined GW
CFCs contamination
River Spring
Recharge altitude
Recharge temperature
Well
Urban airThickness of unsaturated zone
Aq
uitard
Age of spring and GW in Mt. TsukubaAge of spring and GW in Mt. Tsukuba(Matsumoto, T., 2009)(Matsumoto, T., 2009)
Geological map (Miyazaki et al., 1996)
Granite
Gabbro
Deposit
Metamorphic
CFC-11(pg/kg)
100
500
1000
CFC-11 concentration
Spatial distribution of CFCs and chemical componentsSpatial distribution of CFCs and chemical components
Chemical characteristics
0
100
200
300
400
500
600
700
1940 1950 1960 1970 1980 1990 2000
Year
Tra
cer concentration (pptv
) CFC-12CFC-11CFC-113SF6×100
Age of spring and GWAge of spring and GW
Granite
Gabbro
Deposit
Metamorphic
Western slope
Southern slope
Age of spring and GW in a mountainous watershed facing ocean Age of spring and GW in a mountainous watershed facing ocean ((OhtaOhta, K., 2008), K., 2008)
Hokuto city,
Yamanashi Pref.
800
1000
1200
1400
1600
18002000
2200::::降水降水降水降水::::大気大気大気大気サンプルサンプルサンプルサンプル
Headwater of R Jingu
←Spring
(J-1)
Main stream→ (J-10)
SpringMain stream
BranchWatershed
boundary
R. Jingu
R. Kamanashi
R. OjiraR. Tazawa
R. Matsuyamazawa
Precipitation
Atmosphere
17
18
14
20
J-1
17
1410
14
14
7
12
8
13 10
Branch
Main
stream
Spring
2km
松山沢川 神宮川
田沢川 尾白川
釜無川
:湧水:河川水(本流)
:河川水(支流):流域界
Age of spring / river waters in low flow
10
19
Spring:14~20 years
Branch:
10~17 years
Main stream:
7~19 years
y = 1.1958x - 8.3709
R2 = 0.7888
0
5
10
15
20
25
0 10 20 30
SiO2 [mg/L]
Resi
dence tim
e [
year
s]
Spring
Main stream
BranchWatershed
boundary
2km
松山沢川 神宮川
田沢川 尾白川
釜無川
:湧水:河川水(本流)
:河川水(支流):流域界
Age of spring / river waters in high flowAge of spring / river waters in high flow
12
11
7
12
J-1
11
1110
13
11
6
8
11
10 8
Branch
Main
stream
Spring
11
6
15
16J-0
15
15
18
19
Spring:
7~16 years
Branch:
10~19 years
Main stream:
6~18 years
Spring
Main stream
BranchWatershed
boundary
Spring: 14 - 20 years
Branch: 10 - 17 years
Main stream: 7 - 19 years
Spring: 7 - 16 years
Branch: 10 - 19 years
Main stream:
6 - 18 years
Behavior of subsurface Behavior of subsurface
water and residence time water and residence time
in mountainous watershedin mountainous watershed
High flow season
Low flow season
Summary
� Rainfall-runoff characteristics suggest subsurface flow processes occurring in hillslope.
� Groundwater is dominant in runoff during rainstorms in warm humid regions.
� Role of bedrock groundwater is important in runoff during rainstorms in headwater catchments.
� Residence time of groundwater and spring water varies dynamically according with hydrological regime in headwaters.
57