A. Güntner | Hydrogravimetry 1 Sub-humid climate (Mediterranean) Mean annual precipitation: 1200...

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


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/)


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)


• 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


-

+ +

+ --

+

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)


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


Soil depth [m]

Soil moisture variations

Vol

%

Local hydrology in Concepción (Chile)


Soil depth [m]

Local hydrology in Concepción (Chile)

Soil moisture and groundwater variations

Gro

undw

ater

(m

bel

ow s

urfa

ce)

Vol

%


Silty loamClayey loam3,5m

WeatheredGranite

22m

Granite

SG gravity residuals

Gravity variations at Concepción - Local hydrology - G

ravi

ty (

μG

al)

SG038


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


Groundwater


WeatheredGranite

22m

Granite


SG gravity residualsSoil moisture (observed)Soil moisture + groundwater (observed)

Soil moisture

Gra

vity

(μ

Gal

)

SG038


Vadose Zone


WeatheredGranite

22m

Granite


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



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


TIGOGlobal hydrological effect

• Local effect: observed SM variation (integration radius ≤ 0.1°)• Global effect: WGHM TWS (integration radius > 0.1°)


WETTZELLGlobal hydrological effect

• Local effect: modeled TWS variation (Creutzfeld et al., 2012)• Global effect: WGHM TWS (integration radius > 0.1°)


Geodetic Observatory Wettzell

Gravimeter building

Hydro-meteorological monitoring network


Snow Top soil

Saprolith

Groundwater Gravimeter signal

Creutzfeldt et al. (2010), WRR

Gravity signals of different storage compartments in Wettzell

Soil


(hydrological monitoring)

(gravimeter)

Creutzfeldt et al., 2010 (GJI)

Gravimeter signal (SG) and gravity response of local water storage variations (from independent hydrol. measurements)


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)


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

A. Güntner | Hydrogravimetry 1 Sub-humid climate (Mediterranean) Mean annual precipitation: 1200...

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