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A. Güntner | Hydrogravimetry 1
• Sub-humid climate (Mediterranean)
• Mean annual precipitation: 1200 mm, (highly seasonal)
• Elevation: 160 m amsl
Early results at Concepción / Chile
SG gravity residuals (tides, atmosphere, polar motion removed)Gravimetric response of near-surface soil moisture
A. Güntner | Hydrogravimetry 2
Non-tidal ocean loading effect: Concepción
• Distance to the coastline: 11 km• Ocean bottom pressure models:
• The Ocean Model for Circulation and Tides (OMCT)• Water column + atmospheric pressure (6 h)
• Estimation of the Circulation and Climate of the Ocean (ECCO1)• Gravity response: GGP Loading service (12 h, http://loading.u-strasbg.fr/GGP/)
A. Güntner | Hydrogravimetry 3
Global hydrological effect• Attraction and loading effect of hydrological mass variations
beyond 0.1° (approx. 11 km)
Sutherland
Concepción
Relatively small amplitude in comparison to SG sites in Central Europe(e.g. amplitude for Wettzell is about 2 µGal)
A. Güntner | Hydrogravimetry 4
• Relatively small amplitude in comparison to European SG sites – Smaller regional integration area
SutherlandConcepción WettzellGravity response to 1 kg/m2 (logarithm)
log(m.s-2) log(m.s-2) log(m.s-2)
Global hydrological effect
A. Güntner | Hydrogravimetry 5
-
+ +
+ --
+
kg/m2 :
+
SutherlandConcepción Wettzell
• Relatively small amplitude in comparison to European SG sites – Smaller regional integration area– Seasonally compensating continental-scale effects
Global hydrological effect
WGHM Total water storage anomaly: 08/2003 – average(2000-2012)
A. Güntner | Hydrogravimetry 6
Groundwater well Soil moisture sensors Climate station
Groundwater well (since 04/12)
Gravity variations at Concepción - Local hydrology -
TDR cluster with about 40 sensors up to 3.5m in depth
A. Güntner | Hydrogravimetry 7
Soil depth [m]
Soil moisture variations
Vol
%
Local hydrology in Concepción (Chile)
A. Güntner | Hydrogravimetry 8
Soil depth [m]
Local hydrology in Concepción (Chile)
Soil moisture and groundwater variations
Gro
undw
ater
(m
bel
ow s
urfa
ce)
Vol
%
A. Güntner | Hydrogravimetry 9
Silty loamClayey loam3,5m
WeatheredGranite
22m
Granite
SG gravity residuals
Gravity variations at Concepción - Local hydrology - G
ravi
ty (
μG
al)
SG038
A. Güntner | Hydrogravimetry 10
Soil moisture Silty loamClayey loam3,5m
WeatheredGranite
22m
Granite
SG gravity residualsSoil moisture (observed)
Gravity variations at Concepción - Local hydrology - G
ravi
ty (
μG
al)
SG038
A. Güntner | Hydrogravimetry 11
Groundwater
Silty loamClayey loam3,5m
WeatheredGranite
22m
Granite
Gravity variations at Concepción - Local hydrology -
SG gravity residualsSoil moisture (observed)Soil moisture + groundwater (observed)
Soil moisture
Gra
vity
(μ
Gal
)
SG038
A. Güntner | Hydrogravimetry 12
Vadose Zone
Silty loamClayey loam3,5m
WeatheredGranite
22m
Granite
Gravity variations at Concepción - Local hydrology -
SG gravity residualsSoil moisture (observed)Soil moisture + groundwater (observed)Soil moisture + groundwater (observed) + vadose zone (simulated by hydrological model)
Soil moisture
Groundwater
Gra
vity
(μ
Gal
)
SG038
A. Güntner | Hydrogravimetry 13
Gravity variations at Concepción - Local hydrology -
What causes the large seasonal gravity signal?
1) Variations of station elevation can be excluded based on GPS data
2) Non-tidal ocean loading effects are too small
3) Global hydrological effects are too small
Local water storage variations in deep unsaturated zone
A. Güntner | Hydrogravimetry 14
TIGOGlobal hydrological effect
• Local effect: observed SM variation (integration radius ≤ 0.1°)• Global effect: WGHM TWS (integration radius > 0.1°)
A. Güntner | Hydrogravimetry 15
WETTZELLGlobal hydrological effect
• Local effect: modeled TWS variation (Creutzfeld et al., 2012)• Global effect: WGHM TWS (integration radius > 0.1°)
A. Güntner | Hydrogravimetry 16
Geodetic Observatory Wettzell
Gravimeter building
Hydro-meteorological monitoring network
A. Güntner | Hydrogravimetry 17
Snow Top soil
Saprolith
Groundwater Gravimeter signal
Creutzfeldt et al. (2010), WRR
Gravity signals of different storage compartments in Wettzell
Soil
A. Güntner | Hydrogravimetry 18
(hydrological monitoring)
(gravimeter)
Creutzfeldt et al., 2010 (GJI)
Gravimeter signal (SG) and gravity response of local water storage variations (from independent hydrol. measurements)
A. Güntner | Hydrogravimetry 19
Hydrological extremes and their impact on the water cycle
Creutzfeldt et al. 2012, JGR
Water storage derived from Superconducting gravimeter (Wettzell, Bavarian Forest, Germany)
Wat
er s
tora
ge (
mm
)
Drought in Central Europe (2003)
A. Güntner | Hydrogravimetry 20
0
5
10
15
20
25
30
35
40
45
0
100
200
300
400
500
600
2001 2002 2003 2004 2005 2006 2007 2008 2009
Soil
moi
stur
e (V
ol%
)
Gra
vim
eter
-bas
ed
wat
er st
orag
e (m
m)
Hydrological extremes and their impact on the water cycle
Water storage in Wettzell (Germany)
Drought in Central Europe (2003)
Soil moisture
Gravimeter-based water
storage
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