Monitoring Groundwater Storage Depletion Using Gravity Recovery and Climate Experiment (GRACE) Data in Bakhtegan Catchment, Iran

The Bakhtegan catchment, an important agricultural region in south-western Iran, has suffered groundwater depletion in recent years. As groundwater is considered the main source of fresh water in the catchment, especially for agriculture, monitoring groundwater responses to irrigation is important. Gravity Recovery and Climate Experiment (GRACE) satellite data can help determine water mass changes in catchments and assess water volume changes. In this study, we compared GRACE-derived water mass data against groundwater volume variations measured in situ. We also assessed the efficiency of GRACE-derived data in catchments smaller than the 200,000 km2 recommended area when using GRACE. For the study period (January 2002 through December 2011), the GRACE data showed a 7.6 mm annual decline in groundwater level, with a total volume loss of 2.6 km3 during the period. The in situ monthly measurements of groundwater level showed an average depletion of 10 m in catchment aquifers during the study period. This depletion rate was supported by the recorded decrease in precipitation volume, especially in the post-drought period after 2007. These results demonstrate that GRACE can be useful tool for monitoring groundwater depletion in arid catchments.

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Monitoring Groundwater Storage Depletion Using Gravity Recovery and Climate Experiment (GRACE) Data in the Semi-Arid Catchments

10.5194/hess-2018-471 ◽

2018 ◽

Cited By ~ 1

Author(s):

Nizar Abou Zaki ◽

Ali Torabi Haghighi ◽

Pekka M. Rossi ◽

Mohammad J. Tourian ◽

Bjørn Klove

Keyword(s):

Groundwater Level ◽

Water Mass ◽

Groundwater Resources ◽

Water Volume ◽

Groundwater Depletion ◽

Drought Period ◽

Resources Management ◽

Grace Data ◽

Gravity Recovery

Abstract. The Bakhtegan catchment, an important agricultural region in south-western Iran, has suffered groundwater depletion in recent years. As groundwater is considered the main source of fresh water in the catchment, especially for agriculture, monitoring groundwater responses to irrigation is important. Gravity Recovery and Climate Experiment (GRACE) satellite data can help determine water mass changes in catchments and assess water volume changes, but have been under-used to date in water resources management. In this study, we compared GRACE-derived water mass data against groundwater volume variations measured in situ. We also assessed the efficiency of GRACE-derived data in catchments smaller than the 200,000 km2 recommended area when using GRACE. For the study period (January 2002 through December 2011), the GRACE data showed a 7.6 mm annual decline in groundwater level, with a total volume loss of 2.6 km3 during the period. The in situ monthly measurements of groundwater level showed an average depletion of 10 m in catchment aquifers during the study period. This depletion rate was supported by the recorded decrease in precipitation volume, especially in the post-drought period after 2007. These results demonstrate that GRACE can be useful in groundwater resources management of catchments facing groundwater depletion and increasing water demand.

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Improving estimates of water resources in a semi-arid region by assimilating GRACE data into the PCR-GLOBWB hydrological model

10.5194/hess-2016-354 ◽

2016 ◽

Author(s):

N. Tangdamrongsub ◽

S. C. Steele-Dunne ◽

B. C. Gunter ◽

P. G. Ditmar ◽

E. H. Sutanudjaja ◽

...

Keyword(s):

Water Resources ◽

Hydrological Model ◽

Hexi Corridor ◽

Accurate Estimation ◽

Groundwater Depletion ◽

Correlated Errors ◽

Grace Data ◽

The Impact ◽

Semi Arid

Abstract. An accurate estimation of water resources dynamics is crucial for proper management of both agriculture and the local ecology, particularly in semi-arid regions. Imperfections in model physics, uncertainties in model land parameters and meteorological data, as well as the human impact on land changes often limit the accuracy of hydrological models in estimating water storages. To mitigate this problem, this study investigated the assimilation of Terrestrial Water Storage (TWS) estimates derived from the Gravity Recovery And Climate Experiment (GRACE) data using an Ensemble Kalman Filter (EnKF) approach. The region considered was the Hexi Corridor of Northern China. The hydrological model used for the analysis was PCR-GLOBWB, driven by satellite-based forcing data from April 2002 to December 2010. In this study, EnKF 3D scheme, which accounts for the GRACE spatially-correlated errors, was used. The correlated errors were propagated from the full error variance-covariance matrices provided as a part of the GRACE data product. The impact of the GRACE Data Assimilation (DA) scheme was evaluated in terms of the TWS, as well as individual hydrological storage estimates. The capability of GRACE DA to adjust the storage level was apparent not only for the entire TWS but also for the groundwater component, which had annual amplitude, phase, and long-term trend estimates closer to the GRACE observations. This study also assessed the benefits of taking into account correlations of errors in GRACE-based estimates. The assessment was carried out by comparing the EnKF results, with and without taking into account error correlations, with the in situ groundwater data from 5 well sites and the in situ streamflow data from two river gauges. On average, the experiments showed that GRACE DA improved the accuracy of groundwater storage estimates by as much as 25 %. The inclusion of error correlations provided an equal or greater improvement in the estimates. No significant benefits of GRACE DA were observed in terms of streamflow estimates, which reflect a limited spatial and temporal resolution of GRACE observations. Results from the 9-year long GRACE DA study were used to assess the status of water resources over the Hexi Corridor. Areally-averaged values revealed that TWS, soil moisture, and groundwater storages over the region decreased with an average rate of approximately 0.2, 0.1, and 0.1 cm/yr in terms of equivalent water heights, respectively. A substantial decline in TWS (approximately −0.4 cm/yr) was seen over the Shiyang River Basin in particular, and the reduction mostly occurred in the groundwater layer. An investigation of the relationship between water resources and agriculture suggested that groundwater consumption required to maintain the growing period in this specific basin was likely the cause of the groundwater depletion.

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Quantifying Vertical Deformation in the Tigris–Euphrates Basin Due to the Groundwater Abstraction: Insights from GRACE and Sentinel-1 Satellites

Water ◽

10.3390/w11081658 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1658 ◽

Cited By ~ 5

Author(s):

Ashraf Rateb ◽

Chung-Yen Kuo

Keyword(s):

Groundwater Depletion ◽

Groundwater Abstraction ◽

Groundwater Levels ◽

In Situ Data ◽

Depletion Rate ◽

Small Baseline Subset ◽

Small Baseline ◽

Remote Sensing Techniques ◽

Sbas Insar ◽

Gravity Recovery

This study explores the occurrences of land subsidence in response to dropping groundwater levels in the central part of the Tigris–Euphrates basin. We estimated the groundwater depletion related to human and climate drivers between 2003 and 2017 based on estimates from the Gravity Recovery and Climate Experiment (GRACE) and two global hydrological models (NOAH-3.3 and WGHM-2.2d). The cumulative displacement was calculated using Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) for 96 interferograms, which were generated by 31 images acquired by the Sentinel-1 satellite. The results show that the basin is experiencing a decline in groundwater storage at a rate of −7.56 km3/year with a total loss of 106.81 km3. This depletion rate has led to inelastic compaction and has resulted in subsidence near the city of Baghdad at a rate of −10 mm/year. The measured coherence phase between the two signals is ~0.67, and the depletion precedes the subsidence by ~1.5 months. The new data from GRACE-Follow on, Sentinel-1, and the piezometric water level could help to constrain the rate of depletion and displacements in the basin. Combining these remote sensing techniques provides an independent tool for water management in areas where in-situ data are scarce.

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Improving the Accuracy of Groundwater Storage Estimates Based on Groundwater Weighted Fusion Model

Remote Sensing ◽

10.3390/rs14010202 ◽

2022 ◽

Vol 14 (1) ◽

pp. 202

Author(s):

Kai Su ◽

Wei Zheng ◽

Wenjie Yin ◽

Litang Hu ◽

Yifan Shen

Keyword(s):

Human Factors ◽

River Basin ◽

Groundwater Level ◽

Efficiency Coefficient ◽

Fusion Model ◽

Groundwater Storage ◽

Effective Measure ◽

Weighted Fusion ◽

Grace Data

It is an effective measure to estimate groundwater storage anomalies (GWSA) by combining Gravity Recovery and Climate Experiment (GRACE) data and hydrological models. However, GWSA results based on a single hydrological model and GRACE data may have greater uncertainties, and it is difficult to verify in some regions where in situ groundwater-level measurements are limited. First, to solve this problem, a groundwater weighted fusion model (GWFM) is presented, based on the extended triple collocation (ETC) method. Second, the Shiyang River Basin (SYRB) is taken as an example, and in situ groundwater-level measurements are used to evaluate the performance of the GWFM. The comparison indicates that the correlation coefficient (CC) and Nash-Sutcliffe efficiency coefficient (NSE) are increased by 9–40% and 23–657%, respectively, relative to the original results. Moreover, the root mean squared error (RMSE) is reduced by 9–28%, which verifies the superiority of the GWFM. Third, the spatiotemporal distribution and influencing factors of GWSA in the Hexi Corridor (HC) are comprehensively analyzed during the period between 2003 and 2016. The results show that GWSA decline, with a trend of −2.37 ± 0.38 mm/yr from 2003 to 2010, and the downward trend after 2011 (−0.46 ± 1.35 mm/yr) slow down significantly compared to 2003–2010. The spatial distribution obtained by the GWFM is more reliable compared to the arithmetic average results, and GWFM-based GWSA fully retain the advantages of different models, especially in the southeastern part of the SYRB. Additionally, a simple index is used to evaluate the contributions of climatic factors and human factors to groundwater storage (GWS) in the HC and its different subregions. The index indicates that climate factors occupy a dominant position in the SLRB and SYRB, while human factors have a significant impact on GWS in the Heihe River Basin (HRB). This study can provide suggestions for the management and assessments of groundwater resources in some arid regions.

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Groundwater storage dynamics in the world's large aquifer systems from GRACE: uncertainty and role of extreme precipitation

Earth System Dynamics ◽

10.5194/esd-11-755-2020 ◽

2020 ◽

Vol 11 (3) ◽

pp. 755-774 ◽

Cited By ~ 2

Author(s):

Mohammad Shamsudduha ◽

Richard G. Taylor

Keyword(s):

Land Surface ◽

Global Scale ◽

Groundwater Depletion ◽

P Value ◽

Groundwater Storage ◽

Aquifer Systems ◽

Surface Models ◽

Gravity Recovery

Abstract. Under variable and changing climates groundwater storage sustains vital ecosystems and enables freshwater withdrawals globally for agriculture, drinking water, and industry. Here, we assess recent changes in groundwater storage (ΔGWS) from 2002 to 2016 in 37 of the world's large aquifer systems using an ensemble of datasets from the Gravity Recovery and Climate Experiment (GRACE) and land surface models (LSMs). Ensemble GRACE-derived ΔGWS is well reconciled to in situ observations (r=0.62–0.86, p value <0.001) for two tropical basins with regional piezometric networks and contrasting climate regimes. Trends in GRACE-derived ΔGWS are overwhelmingly non-linear; indeed, linear declining trends adequately (R2>0.5, p value <0.001) explain variability in only two aquifer systems. Non-linearity in ΔGWS derives, in part, from the episodic nature of groundwater replenishment associated with extreme annual (>90th percentile, 1901–2016) precipitation and is inconsistent with prevailing narratives of global-scale groundwater depletion at the scale of the GRACE footprint (∼200 000 km2). Substantial uncertainty remains in estimates of GRACE-derived ΔGWS, evident from 20 realisations presented here, but these data provide a regional context to changes in groundwater storage observed more locally through piezometry.

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Annual sea level variations in the Red Sea observed using GNSS

Geophysical Journal International ◽

10.1093/gji/ggaa032 ◽

2020 ◽

Vol 221 (2) ◽

pp. 826-834

Author(s):

A O Alothman ◽

M Bos ◽

R Fernandes ◽

Ali M Radwan ◽

M Rashwan

Keyword(s):

Sea Level ◽

Red Sea ◽

Water Mass ◽

Satellite System ◽

Vertical Loading ◽

Grace Data ◽

Sea Level Variations ◽

Global Navigation Satellite ◽

Level Loading ◽

Gravity Recovery

SUMMARY Annual sea level variations in the Red Sea have amplitudes of 15–20 cm as observed using various techniques such as tide gauges, satellite altimetry and recently Gravity Recovery and Climate Experiment (GRACE) satellite data. In this study, we demonstrate that Global Navigation Satellite System (GNSS) observations can also be used to measure the effect of these sea level variations. The extra water mass presses on the seafloor, which causes horizontal and vertical deformations. Using time-series from 10 coastal GNSS stations, we observe annual horizontal and vertical loading displacements with amplitudes of 2–5 mm. When correcting for atmospheric, hydrological and surface water loading and a residual geocentre motion, significant annual signals of approximately 0.5 and 2 mm are still observed for the horizontal and vertical components, respectively. In the northern Red Sea, the observed annual signals and predicted annual sea level loading show good agreement. This confirms that the signal is mostly a result of the variations in water mass and thermal expansion. Furthermore, we conclude that the uncertainties in the hydrological model over Ethiopia and Eritrea influence the loading over the southern Red Sea, which was underestimated in previous studies using GRACE data.

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Improved Understanding of Groundwater Storage Changes under the Influence of River Basin Governance in Northwestern China Using GRACE Data

Remote Sensing ◽

10.3390/rs13142672 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2672

Author(s):

Xin Liu ◽

Litang Hu ◽

Kangning Sun ◽

Zhengqiu Yang ◽

Jianchong Sun ◽

...

Keyword(s):

River Basin ◽

Groundwater Level ◽

Regional Scale ◽

Water Storage ◽

Northwestern China ◽

In Situ Observation ◽

Observation Data ◽

Groundwater Storage ◽

Grace Data

Groundwater is crucial for economic development in arid and semiarid areas. The Shiyang River Basin (SRB) has the most prominent water use issues in northwestern China, and overexploited groundwater resources have led to continuous groundwater-level decline. The key governance planning project of the SRB was issued in 2007. This paper synthetically combines remote-sensing data from Gravity Recovery and Climate Experiment (GRACE) data and precipitation, actual evapotranspiration, land use, and in situ groundwater-level data to evaluate groundwater storage variations on a regional scale. Terrestrial water storage anomalies (TWSA) and groundwater storage anomalies (GWSA), in addition to their influencing factors in the SRB since the implementation of the key governance project, are analyzed in order to evaluate the effect of governance. The results show that GRACE-derived GWS variations are consistent with in situ observation data in the basin, with a correlation coefficient of 0.68. The GWS in the SRB had a slow downward trend from 2003 to 2016, and this increased by 0.38 billion m³/year after 2018. As the meteorological data did not change significantly, the changes in water storage are mainly caused by human activities, which are estimated by using the principle of water balance. The decline in GWS in the middle and lower reaches of the SRB has been curbed since 2009 and has gradually rebounded since 2014. GWS decreased by 2.2 mm EWH (equivalent water height) from 2011 to 2016, which was 91% lower than that from 2007 to 2010. The cropland area in the middle and lower reaches of the SRB also stopped increasing after 2011 and gradually decreased after 2014, while the area of natural vegetation gradually increased, indicating that the groundwater level and associated ecology significantly recovered after the implementation of the project.

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Downscaling GRACE total water storage change using partial least squares regression

Scientific Data ◽

10.1038/s41597-021-00862-6 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Bramha Dutt Vishwakarma ◽

Jinwei Zhang ◽

Nico Sneeuw

Keyword(s):

Water Mass ◽

Spatial Scales ◽

Water Storage ◽

Temporal Variations ◽

Least Squares Regression ◽

Total Water ◽

Satellite Mission ◽

Grace Data ◽

Gravity Recovery ◽

Storage Change

AbstractThe Gravity Recovery And Climate Experiment (GRACE) satellite mission recorded temporal variations in the Earth’s gravity field, which are then converted to Total Water Storage Change (TWSC) fields representing an anomaly in the water mass stored in all three physical states, on and below the surface of the Earth. GRACE provided a first global observational record of water mass redistribution at spatial scales greater than 63000 km2. This limits their usability in regional hydrological applications. In this study, we implement a statistical downscaling approach that assimilates 0.5° × 0.5° water storage fields from the WaterGAP hydrology model (WGHM), precipitation fields from 3 models, evapotranspiration and runoff from 2 models, with GRACE data to obtain TWSC at a 0.5° × 0.5° grid. The downscaled product exploits dominant common statistical modes between all the hydrological datasets to improve the spatial resolution of GRACE. We also provide open access to scripts that researchers can use to produce downscaled TWSC fields with input observations and models of their own choice.

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ANALYSIS OF WATER MASS VARIATIONS AT WETLANDS REGIONS FROM GRACE: THE PANTANAL CASE

Brazilian Journal of Geophysics ◽

10.22564/rbgf.v35i4.786 ◽

2018 ◽

Vol 35 (4) ◽

pp. 307

Author(s):

Cecilia Cornero ◽

AYELEN PEREIRA ◽

MARÍA CRISTINA PACINO

Keyword(s):

Water Mass ◽

Spatial Scales ◽

Water Storage ◽

Transport Processes ◽

Satellite Gravity ◽

The North ◽

Paraguay River ◽

Gravity Recovery ◽

Gravity Mission

ABSTRACT. The natural heritage of biodiversity of the Paraguay river basin is subject to potential impacts due to climate change. To monitor these environments at large spatial scales, the satellite gravity mission GRACE (Gravity Recovery and Climate Experiment) provides time-variable Earth’s gravity field models that reflect the variations due to mass transport processes, like continental water storage changes. The purpose of this work is to analyze the spatial and temporal water storage changes for period 2003-2014 using the Equivalent Water Height (EWH) derived from the GRACE solutions in the Pantanal region, one of the most biologically rich environments of the planet. The comparison with EWH and river gauge data at different stations distributed over the Pantanal area was carried out. In order to validate the satellite results, the correlation analysis between the water mass changes and river gauge measurements was obtained, and also the phase differences were analyzed. High correlations were detected at the north, and lower ones towards the south of the Pantanal. The EWH were also contrasted with soil moisture and rainfall data models. The results showed a good agreement between the signals for the area under study.Keywords: water storage, satellite gravity mission, river gauge, rainfall. RESUMO. O patrimônio natural de biodiversidade da bacia do rio Paraguai está sujeito a potenciais impactos das mudanças climáticas. Para monitorar esse ambiente em escala espacial, a missão satelital GRACE (Gravity Recovery and Climate Experiment) fornece modelos do campo de gravidade da Terra variáveis no tempo devido ao processo de transporte de massa, como as variações de armazenamento de água continentais. O objetivo deste artigo é analisar a variabilidade espacial e temporal de armazenamento de água para o período 2003-2014 através da altura equivalente d’água (EWH) derivada das soluções deGRACE na região do Pantanal, um dos ambientes biologicamente mais ricos do planeta. Comparações dos dados de EWH e alturas d’água in-situ foram feitas para diferentes estações distribuídas na região do Pantanal. Com a finalidade de validar os resultados de satélite, foi feita a análise de correlação entre as mudanças de massa d’água e as medições das réguas linimétricas fixadas nas margens dos rios. As diferenças de fase também foram analisadas. Ao Norte do Pantanal foram detectadas altas correlações entre as duas alturas (EWH versus in-situ), e baixas em direção ao sul. O EWH também foi validado com modelos de umidade do solo e precipitação. Os resultados mostraram uma boa concordância entre os sinais para a área em estudo. Palavras-chave: armazenamento de água, missão satelital, cotas do nível d’água, precipitação.

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Groundwater storage dynamics in the world's large aquifer systems from GRACE: uncertainty and role of extreme precipitation

10.5194/esd-2019-43 ◽

2019 ◽

Author(s):

Mohammad Shamsudduha ◽

Richard G. Taylor

Keyword(s):

Land Surface ◽

Global Scale ◽

Groundwater Depletion ◽

P Value ◽

Groundwater Storage ◽

Aquifer Systems ◽

Surface Models ◽

Gravity Recovery

Abstract. Under variable and changing climates groundwater storage sustains vital ecosystems and enables freshwater withdrawals globally for agriculture, drinking-water, and industry. Here, we assess recent changes in groundwater storage (ΔGWS) from 2002 to 2016 in 37 of the world's large aquifer systems using an ensemble of datasets from the Gravity Recovery and Climate Experiment (GRACE) and Land Surface Models (LSMs). Ensemble GRACE-derived ΔGWS is well reconciled to in-situ observations (r = 0.62–0.86, p value 0.5, p value 90th percentile, 1901–2016) precipitation and is inconsistent with prevailing narratives of global-scale groundwater depletion. Substantial uncertainty remains in estimates of GRACE-derived ΔGWS, evident from 20 realisations presented here, but these data provide a regional context to changes in groundwater storage observed more locally through piezometry.

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