Author
ZHANG, Y. - Kansas State University | |
LIN, X. - Kansas State University | |
Gowda, Prasanna | |
Brown, David | |
ZAMBRESKI, Z. - Kansas State University | |
KUTIKOFF, S. - Kansas State University |
Submitted to: Journal of the American Water Resources Association
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/9/2019 Publication Date: 9/4/2019 Citation: Zhang, Y., Lin, X., Gowda, P.H., Brown, D.P., Zambreski, Z., Kutikoff, S. 2019. Recent Ogallala aquifer region drought conditions as observed by terrestrial water storage anomalies from GRACE. Journal of the American Water Resources Association. 1-12. https://doi.org/10.1111/1752-1688.12798. DOI: https://doi.org/10.1111/1752-1688.12798 Interpretive Summary: The Gravity Recovery and Climate Experiment (GRACE) is a useful, satellite-based approach for capturing extreme climatic events, such as droughts and floods, on a regional scale. GRACE offers an alternative and independent method to monitor changes in surface and groundwater systems, and to better understand their underlying hydrological dynamics. For those locations and situations where on-the-ground observations are limited, GRACE data can be especially useful for water resource monitoring and management applications. In this study, the application of GRACE to recent drought events in the Ogallala Aquifer Region is demonstrated as a proof-of-concept to show its applicability for understanding hydrological and climatologic variations that affect this highly productive agricultural region. Technical Abstract: Recent severe drought events occurred over the northern Ogallala aquifer region (OAR) in 2012 and over the southern OAR during the period 2011-2015. The terrestrial water storage (TWS) change during these events, provided by the Gravity Recovery and Climate Experiment (GRACE), reveals a detailed picture of temporal and spatial evolution of these events. The GRACE data indicate the worst drought conditions occurred in September 2012, with an average TWS deficit of ~8 cm in the northern OAR and ~11 cm in the southern OAR. The TWS changes are consistent with accumulated precipitation data from the Global Precipitation Climatology Project (GPCP) and the National Climate Assessment – Land Data Assimilation System (NCALDAS), although the latter overestimated drought conditions in the northern OAR after 2010. Comparing TWS change with GPCP precipitation data shows that the TWS change can be attributed to precipitation variations. A power spectral analysis indicates a significant correlation between TWS change and the El Nino-Southern Oscillation (ENSO), and an analysis of squared wavelet coherence shows that the influence of ENSO 3.4 sea surface temperatures (SST) on TWS change is much stronger in the southern OAR than the northern OAR. The results of this study illustrate the value of using GRACE in the diagnosis of significant drought events, with implications for improved water resources management applications on a regional scale. |