Hydrology and Earth System Sciences
Hydrology and Earth System Sciences
HESS
Articles | Volume 19, issue 3
Articles | Volume 19, issue 3
https://doi.org/10.5194/hess-19-1487-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/hess-19-1487-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Articles | Volume 19, issue 3
Research article
 | 
24 Mar 2015
Research article |  | 24 Mar 2015

Identifying water mass depletion in northern Iraq observed by GRACE

G. Mulder, T. N. Olsthoorn, D. A. M. A. Al-Manmi, E. J. O. Schrama, and E. H. Smidt

Abstract. Observations acquired by Gravity Recovery And Climate Experiment (GRACE) mission indicate a mass loss of 146 ± 6 mm equivalent water height (EWH) in northern Iraq between 2007 and 2009. These data are used as an independent validation of lake mass variations and a rainfall-runoff model, which is based on local geology and climate conditions. Model inputs are precipitation from Tropical Rainfall Measurement Mission (TRMM) observations, and climatic parameters from Global Land Data Assimilation Systems (GLDAS) model parameters. The model is calibrated with observed river discharge and includes a representation of the karstified aquifers in the region to improve model realism. Lake mass variations were derived from Moderate Resolution Imaging Spectroradiometer (MODIS) in combination with satellite altimetry and some in situ data. Our rainfall–runoff model confirms that northern Iraq suffered a drought between 2007 and 2009 and captures the annual cycle and longer trend of the observed GRACE data. The total mass depletion seen by GRACE between 2007 and 2009 is mainly explained by a lake mass depletion of 75 ± 3 mm EWH and a natural groundwater depletion of 39 ± 8 mm EWH. Our findings indicate that anthropogenic groundwater extraction has a minor influence in this region, while a decline in lake mass and natural depletion of groundwater play a key role.

How to cite. Mulder, G., Olsthoorn, T. N., Al-Manmi, D. A. M. A., Schrama, E. J. O., and Smidt, E. H.: Identifying water mass depletion in northern Iraq observed by GRACE, Hydrol. Earth Syst. Sci., 19, 1487–1500, https://doi.org/10.5194/hess-19-1487-2015, 2015.
Received: 03 Sep 2014 – Discussion started: 17 Oct 2014 – Revised: 16 Feb 2015 – Accepted: 27 Feb 2015 – Published: 24 Mar 2015
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Short summary
From 2007 to 2009, northern Iraq suffered a severe drought and GRACE satellite observations indicate a water loss of about 146mm equivalent water height (EWH) in the same period. To identify the main causes of this water loss, we developed a model based on geology, remote sensing and stream flow data. Our findings indicate that anthropogenic groundwater extraction has a minor influence in this region, while a decline in lake mass and natural depletion of groundwater play a key role.
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