Abstract
Water scarcity is a critical issue in semiarid regions; however, regional groundwater monitoring is extremely limited. This study evaluates the ability of the GRACE satellites to monitor groundwater storage in the semiarid High Plains aquifer, United States (450,000 km 2 area), which is subjected to intense irrigation. GRACE-derived terrestrial water storage (TWS) is highly correlated with the sum of soil moisture (SM) and groundwater storage (GWS) ( R = 0.96 for in situ measured SM from 78 stations and R = 0.95 for simulated SM with the Noah land surface model with root-mean-square difference of 38 mm and 36 mm, respectively). Correlation between seasonal GWS changes calculated from GRACE TWS minus SM and measured GWS (∼1000 wells per season) is also high ( R = 0.73 for in situ SM and R = 0.72 for simulated SM). Variability in SM is mostly restricted to the upper 2 m of the soil. Monitored SM compared favorably with simulated SM ( R = 0.82). Study results show the potential for using GRACE gravity measurements to monitor TWS and GWS over large semiarid regions subjected to intense irrigation.
Original language | American English |
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Journal | Water Resources Research |
Volume | 45 |
DOIs | |
State | Published - May 1 2009 |
Externally published | Yes |
Keywords
- GRACE
- groundwater
- soil moisture
Disciplines
- Life Sciences
- Marine Biology