3004 Bowman-Oddy Laboratories
University of Toledo
Toledo, Ohio 43606

Department Info:

University of Toledo
Dept. of Environmental Sciences
2801 Bancroft Street,
Mail Stop 604
Toledo, OH 43606
Tel: (419) 530-2009
Fax: (419) 530-4421

Surface and Groundwater Fluctuations in the Aral Sea Watershed

The Aral Sea located in Kazakhstan and Uzbekistan is the focal point of one of the worst environmental tragedies in modern history. The Aral Sea is a closed basin and its major contributing rivers, the Amu Darya and the Syr Darya, drain a watershed area of 1.8 million square kilometers. Both rivers are glacially fed and begin in water rich regions in the southeast part of the basin, moving to a much more arid region in the northwest. Large irrigation projects in the region have significantly altered the water balance of the area, most notably the Kara-Kum canal which was constructed in the early 1960s. These large diversions of water for agriculture have significantly reduced surface water inputs from both rivers so much that the Amu Darya now only reaches the sea by groundwater flow. Many restoration projects have been proposed, but the recovery of the sea to 1960 levels is unlikely. As climate change predicts this already stressed region will get drier, it is necessary to understand the water balance of the Aral Sea watershed at a regional scale. GRACE (Gravity Recovery and Climate Experiment) gravity data was coupled with TRMM (Tropical Rainfall Measuring Mission) precipitation estimates to observe season oscillations in rainfall source and storage as well as inter-annual trends.Aral Watershed Gravity Anomaly Monthly time steps (111 total) were used for each GRACE and TRMM data and a spectral density function was used throughout the basin to determine when and where rainfall occurred and compare how the equivalent water thickness signal from the gravity data responded to precipitation events. Data was used from 191 climate (precipitation and temperature) stations to assess the ability of GRACE data to monitor water storage and predict future water balance variability and determine the short-term outlook for basin-wide water resources.

JPL wrote up a nice summary of this work

Results are avialble in:

Zmijewski, K.*, Becker, R.H.2014, Estimating the effects of anthropogenic and climate change on water balance in the Aral Sea watershed using GRACE: 2003-2012, Earth interactions, v18,no3,pp-16,doi:10.1175/2013EI000537.1