Mon Aug 24, F. Flechtner
• Sorted by Date • Sorted by Last Name of First Author •
Arifin, Taylor, Richard G., Shamsudduha, Mohammad, and Ramdhan, Agus M., 2026. Limits to GRACE–based groundwater storage monitoring in a 23 000 km2 coastal basin: evidence from the Lower Kutai Basin, Indonesia. Hydrology and Earth System Sciences, 30(14):4771–4797, doi:10.5194/hess-30-4771-2026.
• from the NASA Astrophysics Data System • by the DOI System •
@ARTICLE{2026HESS...30.4771A,
author = {{Arifin} and {Taylor}, Richard G. and {Shamsudduha}, Mohammad and {Ramdhan}, Agus M.},
title = "{Limits to GRACE-based groundwater storage monitoring in a 23 000 km2 coastal basin: evidence from the Lower Kutai Basin, Indonesia}",
journal = {Hydrology and Earth System Sciences},
year = 2026,
month = jul,
volume = {30},
number = {14},
pages = {4771-4797},
abstract = "{Groundwater is considered a climate-resilient source of freshwater yet
its long-term response to climate variability remains poorly
understood in environments with limited ground-based monitoring
networks. In the Lower Kutai Basin where Indonesia's new capital
(Nusantara) is under development, we examine the limitations to
Gravity Recovery and Climate Experiment (GRACE) satellite data
to estimate groundwater storage changes
({\ensuremath{\Delta}}GWS) over the last two decades using
evidence of other water storage changes from global-scale
models. We identify potential ocean signal leakage, inferred
from residual correlations (r up to 0.68) between paired land-
ocean grids, which can propagate errors into
{\ensuremath{\Delta}}GWS estimates and result in physically
implausible {\ensuremath{\Delta}}GWS values. GRACE-derived
terrestrial water storage anomalies ({\ensuremath{\Delta}}TWS)
exhibit strong seasonal and interannual variability that is
consistent across different spatial scales (r=0.78-1) and are
dominated by changes in root-zone soil moisture storage
({\ensuremath{\Delta}}SMS). Across 54 realizations, only 21
\%--60 \% (mean: 42 \%) of {\ensuremath{\Delta}}GWS estimates per
realization are physically plausible. Validation of plausible
{\ensuremath{\Delta}}GWS values critically relies on robust
storage coefficients. Correlations between GRACE-derived
{\ensuremath{\Delta}}GWS and groundwater-level anomalies
({\ensuremath{\Delta}}GWL) are generally weak and reflect
discrepancies between GRACE's basin-scale signals and localized
aquifer dynamics influenced by heterogeneity and groundwater
abstraction. Statistical analyses show weak-to-moderate coupling
of {\ensuremath{\Delta}}TWS and {\ensuremath{\Delta}}SMS with
ENSO indices (r=-0.4 to -0.6) whereas {\ensuremath{\Delta}}GWS
is less responsive. Drought conditions associated with the
2015--2016 El Ni{\~n}o are a notable exception as
{\ensuremath{\Delta}}TWS deficits (-2.4 to -4.6cmmonth-1)
correspond with plausible {\ensuremath{\Delta}}GWS declines
(-1.1cmmonth-1). High-frequency (hourly) groundwater-level
observations indicate that episodic, high-intensity rainfall
events (>90th percentile) disproportionately contribute to
groundwater recharge. These findings demonstrate that only a
subset of {\ensuremath{\Delta}}GWS values can be plausibly
estimated from GRACE so that, without expanded in situ
monitoring, {\ensuremath{\Delta}}GWS estimates in this small
coastal basin will remain highly uncertain.}",
doi = {10.5194/hess-30-4771-2026},
adsurl = {https://ui.adsabs.harvard.edu/abs/2026HESS...30.4771A},
adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
Generated by
bib2html_grace.pl
(written by Patrick Riley
modified for this page by Volker Klemann) on
Mon Aug 24, 2026 17:14:25
GRACE-FO
Mon Aug 24, F. Flechtner