Your search found 10 records
1 Crow, W. T.; Ryu, D.; Famiglietti, J. S.. 2005. Upscaling of field-scale soil moisture measurements using distributed land surface modeling. Advances in Water Resources, 28(1):1-14.
(Location: IWMI-HQ Call no: PER Record No: H036661)
2 Rodell, M.; Famiglietti, J. S.. 1999. Detectability of variations in continental water storage form satellite observations of the time dependent gravity field. Water Resources Research, 35(9):2705-2723.
(Location: IWMI-HQ Call no: P 7474 Record No: H038081)
3 Rodell, M.; Famiglietti, J. S.. 2001. An analysis of terrestrial water storage variations in Illinois with implications for the Gravity Recovery and Climate Experiment (GRACE) Water Resources Research, 37(5):1327-1339.
(Location: IWMI-HQ Call no: P 7475 Record No: H038082)
4 Rodell, M.; Famiglietti, J. S.; Chen, J.; Seneviratne, S. I.; Viterbo, P.; Holl, S.; Wilson, C. R. 2004. Basin scale estimates of evapotranspiration using GRACE and other observations. Geophysical Research Letters, 31:4p.
Evapotranspiration ; Water balance ; Estimation ; Precipitation ; Runoff ; River basins ; Water storage ; Models ; Water budget ; Remote sensing / USA / Mississippi River
(Location: IWMI-HQ Call no: P 7476 Record No: H038083)
5 Rodell, M.; Velicogna, I.; Famiglietti, J. S.. 2009. Satellite-based estimates of groundwater depletion in India. Letter. Nature, 460:999-1002. [doi: https://doi.org/10.1038/nature08238]
Groundwater depletion ; Estimation ; Satellite surveys ; Water storage ; Soil water ; Time series analysis / India / Rajasthan / Punjab / Haryana / Delhi
(Location: IWMI HQ Call no: e-copy only Record No: H042301)
(0.35 MB)
Groundwater is a primary source of fresh water in many parts of the world. Some regions are becoming overly dependent on it, consuming groundwater faster than it is naturally replenished and causing water tables to decline unremittingly. Indirect evidence suggests that this is the case in northwest India, but there has been no regional assessment of the rate of groundwater depletion. Here we use terrestrial water storage-change observations from the NASA Gravity Recovery and Climate Experiment satellites and simulated soil-water variations from a dataintegrating hydrological modelling system to show that groundwater is being depleted at a mean rate of 4.061.0 cm yr21 equivalent height of water (17.764.5km3 yr21) over the Indian states of Rajasthan, Punjab and Haryana (including Delhi). During our study period of August 2002 to October 2008, groundwater depletion was equivalent to a net loss of 109 km of water, which is double the capacity of India’s largest surface-water reservoir. Annual rainfall was close to normal throughout the period and we demonstrate that the other terrestrial water storage components (soil moisture, surface waters, snow, glaciers and biomass) did not contribute significantly to the observed decline in total water levels. Although our observational record is brief, the available evidence suggests that unsustainable consumption of groundwater for irrigation and other anthropogenic uses is likely to be the cause. If measures are not taken soon to ensure sustainable groundwater usage, the consequences for the 114,000,000 residents of the region may include a reduction of agricultural output and shortages of potable water, leading to extensive socioeconomic stresses.
6 Richey, A. S.; Thomas, B. F.; Lo, M.-H.; Reager, J. T.; Famiglietti, J. S.; Voss, K.; Swenson, S.; Rodell, M. 2015. Quantifying renewable groundwater stress with GRACE. Water Resources Research, 51(7):5217-5238. [doi: https://doi.org/10.1002/2015WR017349]
Groundwater extraction ; Water stress ; Water use ; Water availability ; Satellite observation ; Aquifers ; Groundwater recharge ; Statistical methods ; Water storage ; Irrigated farming ; Water demand ; Remote sensing ; Farmland ; Anthropogenic factors
(Location: IWMI HQ Call no: e-copy only Record No: H047568)
http://onlinelibrary.wiley.com/doi/10.1002/2015WR017349/epdf
https://vlibrary.iwmi.org/pdf/H047568.pdf
https://vlibrary.iwmi.org/pdf/H047568.pdf
(2.71 MB) (2.71 MB)
Groundwater is an increasingly important water supply source globally. Understanding the amount of groundwater used versus the volume available is crucial to evaluate future water availability. We present a groundwater stress assessment to quantify the relationship between groundwater use and availability in the world’s 37 largest aquifer systems. We quantify stress according to a ratio of groundwater use to availability, which we call the Renewable Groundwater Stress ratio. The impact of quantifying groundwater use based on nationally reported groundwater withdrawal statistics is compared to a novel approach to quantify use based on remote sensing observations from the Gravity Recovery and Climate Experiment (GRACE) satellite mission. Four characteristic stress regimes are defined: Overstressed, Variable Stress, Human-dominated Stress, and Unstressed. The regimes are a function of the sign of use (positive or negative) and the sign of groundwater availability, defined as mean annual recharge. The ability to mitigate and adapt to stressed conditions, where use exceeds sustainable water availability, is a function of economic capacity and land use patterns. Therefore, we qualitatively explore the relationship between stress and anthropogenic biomes. We find that estimates of groundwater stress based on withdrawal statistics are unable to capture the range of characteristic stress regimes, especially in regions dominated by sparsely populated biome types with limited cropland. GRACE-based estimates of use and stress can holistically quantify the impact of groundwater use on stress, resulting in both greater magnitudes of stress and more variability of stress between regions.
7 Bhanja, S. N.; Mukherjee, A.; Saha, D.; Velicogna, I.; Famiglietti, J. S.. 2016. Validation of GRACE based groundwater storage anomaly using in-situ groundwater level measurements in India. Journal of Hydrology, 543(Part B):729-738. [doi: https://doi.org/10.1016/j.jhydrol.2016.10.042]
Water resources ; Groundwater table ; Water storage ; Water levels ; Models ; River basins ; Aquifers ; Wells ; Satellite observation ; Hydrogeology ; Precipitation ; Estimation / India
(Location: IWMI HQ Call no: e-copy only Record No: H047897)
(4.00 MB)
In this study, we tried to validate groundwater storage (GWS) anomaly obtained from a combination of GRACE and land-surface model based estimates, for the first time, with GWS anomaly obtained from a dense network of in-situ groundwater observation wells within 12 major river basins in India. We used seasonal data from >15,000 groundwater observation wells between 2005 and 2013, distributed all over the country. Two recently released GRACE products, RL05 spherical harmonics (SH) and RL05 mascon (MS) products are used for comparison with in-situ data. To our knowledge, this is the first study of comparing the performance of two independent GRACE products at a sub-continental scale. Also for the first time, we have created a high resolution (0.10 0.10 ) map of specific yield for the entire country that was used for calculating GWS. Observed GWS anomalies have been computed using water level anomalies and specific yield information for the locale of individual observation wells that are up-scaled to basin-scale in order to compare with GRACE-based estimates. In general GRACE-based estimates match well (on the basis of the statistical analyses performed in the study) with observed estimates in most of the river basins. On comparing with observed GWS anomaly, GRACE-SH estimates match well in terms of RMSE, while GRACE-MS estimates show better association in terms of correlation, while the output of skewness, kurtosis, coefficient of variation (CV) and scatter analyses remain inconclusive for inter-comparison between two GRACE estimates. We used a non-parametric trend estimation approach, the Hodrick-Prescott (HP) filter, to further assess the performance of the two GRACE estimates. GRACE-MS estimates clearly outperform GRACE-SH estimates for reproducing observed GWS anomaly trends with significantly (>95% confidence level) strong association in 10 out of 12 basins for GRACE-MS estimates, on the other hand, GRACE-SH estimates show significantly (>95% confidence level) strong association in 6 out of 12 basins. On the basis of the study output, we recommend using GRACE-MS estimates for groundwater studies over the region and other regions of the globe with similar climatic, hydrogeologic or groundwater withdrawal conditions.
8 Nanteza, J.; de Linage, C. R.; Thomas, B. F.; Famiglietti, J. S.. 2016. Monitoring groundwater storage changes in complex basement aquifers: an evaluation of the GRACE satellites over East Africa. Water Resources Research, 52(12):9542-9564. [doi: https://doi.org/10.1002/2016WR018846.]
Groundwater ; Water storage ; Monitoring ; Aquifers ; Satellite observation ; Surface water ; Soil moisture ; Water balance ; Models ; Lakes ; Wells ; Water use ; Hydroclimatology ; Climate change ; Precipitation ; Rain ; Estimation / East Africa / Kenya / Uganda / Tanzania / Burundi / Rwanda / Upper Nile Basin / Lake Victoria / Lake Tanganyika / Lake Malawi / Lake Turkana / Lake Albert / Lake Mweru / Lake Edward
(Location: IWMI HQ Call no: e-copy only Record No: H048049)
(3.24 MB)
Although the use of the Gravity Recovery and Climate Experiment (GRACE) satellites to monitor groundwater storage changes has become commonplace, our evaluation suggests that careful processing of the GRACE data is necessary to extract a representative signal especially in regions with significant surface water storage (i.e., lakes/reservoirs). In our study, we use cautiously processed data sets, including GRACE, lake altimetry, and model soil moisture, to reduce scaling factor bias and compare GRACE-derived groundwater storage changes to in situ groundwater observations over parts of East Africa. Over the period 2007–2010, a strong correlation between in situ groundwater storage changes and GRACE groundwater estimates (Spearman's = 0.6) is found. Piecewise trend analyses for the GRACE groundwater estimates reveal significant negative storage changes that are attributed to groundwater use and climate variability. Further analysis comparing groundwater and satellite precipitation data sets permits identification of regional groundwater characterization. For example, our results identify potentially permeable and/or shallow groundwater systems underlying Tanzania and deep and/or less permeable groundwater systems underlying the Upper Nile basin. Regional groundwater behaviors in the semiarid regions of Northern Kenya are attributed to hydraulic connections to recharge zones outside the subbasin boundary. Our results prove the utility of applying GRACE in monitoring groundwater resources in hydrologically complex regions that are undersampled and where policies limit data accessibility.
9 Fisher, J. B.; Melton, F.; Middleton, E.; Hain, C.; Anderson, M.; Allen, R.; McCabe, M. F.; Hook, S.; Baldocchi, D.; Townsend, P. A.; Kilic, A.; Tu, K.; Miralles, D. D.; Perret, J.; Lagouarde, J.-P.; Waliser, D.; Purdy, A. J.; French, A.; Schimel, D.; Famiglietti, J. S.; Stephens, G.; Wood, E. F. 2017. The future of evapotranspiration: global requirements for ecosystem functioning, carbon and climate feedbacks, agricultural management, and water resources. Water Resources Research, 53(4):2618-2626. [doi: https://doi.org/10.1002/2016WR020175]
Evapotranspiration ; Weather forecasting ; Models ; Satellite observation ; Water resources ; Ecosystems ; Carbon cycle ; Climate change ; Agriculture ; Water use ; Drought
(Location: IWMI HQ Call no: e-copy only Record No: H048201)
http://onlinelibrary.wiley.com/doi/10.1002/2016WR020175/epdf
https://vlibrary.iwmi.org/pdf/H048201.pdf
https://vlibrary.iwmi.org/pdf/H048201.pdf
(1.18 MB) (1.18 MB)
The fate of the terrestrial biosphere is highly uncertain given recent and projected changes in climate. This is especially acute for impacts associated with changes in drought frequency and intensity on the distribution and timing of water availability. The development of effective adaptation strategies for these emerging threats to food and water security are compromised by limitations in our understanding of how natural and managed ecosystems are responding to changing hydrological and climatological regimes. This information gap is exacerbated by insufficient monitoring capabilities from local to global scales. Here, we describe how evapotranspiration (ET) represents the key variable in linking ecosystem functioning, carbon and climate feedbacks, agricultural management, and water resources, and highlight both the outstanding science and applications questions and the actions, especially from a space-based perspective, necessary to advance them.
10 Xu, L.; Famiglietti, J. S.. 2023. Global patterns of water-driven human migration. WIREs WATER, 25p. (Online first) [doi: https://doi.org/10.1002/wat2.1647]
Climate change ; Water pollution ; Water scarcity ; Migration ; Livelihoods ; Socioeconomic aspects ; Political aspects ; Flooding ; Drought ; Food security ; Communities ; Freshwater ; Conflicts ; Case studies
(Location: IWMI HQ Call no: e-copy only Record No: H051930)
https://wires.onlinelibrary.wiley.com/doi/epdf/10.1002/wat2.1647
https://vlibrary.iwmi.org/pdf/H051930.pdf
https://vlibrary.iwmi.org/pdf/H051930.pdf
(6.35 MB) (6.35 MB)
Environmental change is growingly reported as an important driver of human migration. Among all environmental variables, water crises are the most critical factors. To date, patterns of interconnections between changes in water and migration are not yet clearly understood. Here, we explore these patterns through a systematic review that combined a quantitative text-mining approach with qualitative thematic analysis. Our results generally concur with those of previous studies, which found that water-driven migration usually occurs internally and that the population in low- and middle-income countries and in dry regions are the most vulnerable and more likely to migrate or be displaced in the face of water-related events. However, our causal network analysis highlights that water is not the only reason for migration: Its related problems could be major triggers driving people-at-risk to leave their original place. Based on observed evidence, water-driven migration can be generally divided into four patterns: variability in water quantity, damaging water hazards and extremes, physical disturbances to water systems, and water pollution. These patterns are not independent but interconnected through multifaceted factors affecting people's livelihoods and their decisions to migrate. Understanding water-migration dynamics requires systematic thinking of the interconnections between changes in water and in migration patterns, the investigation of interactions between fast and slow water variables and their dynamic link to other socioeconomic variables, an integrated water-migration database to help identify early-warning signals of damaging water hazards that may result in undesirable migration, and targeted water policies that focus on building the resilience of vulnerable regions and population to climate change.
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