|Chart taken from Voss et al|
Unfortunately, international water law fails to provide a guiding principle for water resource allocation and management of water across national borders. As a result, there are not legally binding water allocation agreements among the nations and Turkey, located up river of the others, acted unilaterally to construct over 20 dams on both the Tigris and Euphrates rivers. This intensive infrastructure development not only increased political tensions in the regions it has significantly altered the Tigris and Euphrates Basins in many ways. Turkish, Syrian, and Iraqi water managers now dictate the river flows with timed releases from the reservoirs. Turkey used their water infrastructure to ensure their water supply during the drought period from 2007-2009. The result was the Euphrates River flow had decreased to approximately 70% of its normal flow by the time it crossed into Iraq. This forces Iraq to increase their use of groundwater to supplement the depleted river flow.
Observing the groundwater buried beneath layers of soil and rock was almost impossible until, the twin satellites known as the Gravity Recovery and Climate Experiment, or GRACE, were launched in March 2002. At the time few believed the satellites could measure changes in groundwater, but thanks to work of Dr. Jay Famiglietti and his graduate student Matt Rodell, who were working at that time at the University of Texas at Austin (UT-Austin) the techniques for measuring groundwater using the GRACE satellites were developed and proven. Expanding on this earlier work is a new study lead by Kate Voss and Jay Famiglietti and is the first comprehensive hydrological assessments of the entire Tigris-Euphrates-Western Iran region.
GRACE data is providing a global picture of water storage trends and could be an invaluable tool for understanding water resource availability when hydrologic data and observations are not collected or shared beyond political boundaries. This information someday could be used to develop a unifying principal of cross border water resource allocation. Now, though, the first use has been to study the consequences of Turkey’s diversion of the lions’ share of the water on the Tigris and Euphrates rivers during a period of drought.
Over the first 7 years of data collected ( January 2003 through December 2009) from GRACE, water stored in the 291,000-square-mileTigris and Euphrates basin shrunk by an average of 16 million acre feet a year, among the largest liquid freshwater losses on the planet (as recorded by GRACE). Meanwhile, the region’s demand for fresh water continues to grow. These nations are using their water unsustainably and using water beyond what should be their water budget. Drs. Voss, Frmiglietti et al used the GRACE data to calculate that nearly 144 km3 of water was lost in the Tigris and Euphrates water basin from 2003 to 2009. Approximately 91 km3 of the total amount of water lost during this time came from groundwater.
|Chart taken from Voss et al|
The Tigris-Euphrates water basin is already facing severe water scarcity. The analyses presented by Drs. Voss, Famiglietti et al shows that groundwater depletion accounts for approximately 60% of the total water volume lost over the seven year period. Land subsidence due to over pumping of groundwater near Tehran, Iran, was documented by studies done by others. Once the land subsides it can no longer store water. A Brookings Institution report in 2012 (Michel et al) highlighted the displacement of hundreds of thousands of people from northern Iraq due to lack of water.
The consequences of this lack regional water allocation and management have left the downstream nation of Iraq with little surface water flow and to survive the government drilled more than 1,000 well over the period that have resulted in the observed depletion of the nonrenewable groundwater reserves. After the drought began in 2007, agricultural productivity for the region declined, but Turkey controlling the dams upstream was least affected. However, downstream in Syria and Iraq, significant, larger declines occurred in all crops, particularly barley production. Agricultural output and water availability significantly influence economic stability and in turn peace in the region.
Advances in hydrologic remote sensing using satellites, and hydrological models, make it possible to construct accurate and holistic picture of freshwater availability, for this region or across the globe. The challenge is to use this information to manage water resources sustainably. Unless we learn to live within the water budget available, the more arid portions of the globe may descend into water and food wars.
All this information is from a recently published article “Groundwater depletion in the Middle East from GRACE with implications for trans-boundary water management in the Tigris-Euphrates-Western Iran region” by K. A. Voss, J. S. Famiglietti, M. Lo, C. de Linage, M. Rodell, and S. C. Swenson, and published in Water Resources Research in 2013. Like all scholarly, peer reviewed articles this one took several years to go from data gathering to publication so the data collection was from January 2003 through December 2009.