Wednesday, July 23, 2014

New water balance calculation for the Dead Sea

A press release from the Helmholtz Centre for Environmental Research: The drinking water resources on the eastern, Jordanian side of the Dead Sea could decline severe as a result of climate change than those on the western, Israeli and Palestinian side. This is the conclusion reached by an international team of researchers that calculated the water flows around the Dead Sea. The natural replenishment rate of groundwater will reduce dramatically in the future if precipitation lowers as predicted, say the scientists, writing in the journal Science of the Total Environment. Even now, the available groundwater resources in the region are not sufficient to meet the growing water requirements of the population and agriculture. If the situation worsens, it could therefore have serious social, economic and ecological consequences for the region.

A reliable inventory of existing water resources around the Dead Sea, on the border between Israel, Palestine and Jordan, forms the basis for sustainable water management. The lowest lake on earth is not only one of the biggest tourist attractions in the Middle East; more than four million people rely on the groundwater resources in its catchment basin. For a long time, the complex hydrology of this region presented major unknown factors in the local water balance equation. To some extent it still does. Thanks to improved computer simulations, the researchers were able to
work out – on an international scale for the first time – how much water actually infiltrates from rainfall and replenishes the groundwater reservoir: around 281 million cubic metres per year. This means that we now also know what the maximum withdrawal limit should be if this resource is to be managed sustainably.

... Using the models, the scientists were able, for the first time, to make predictions about possible future changes in the groundwater resources that are so vital for this region: the western (Israeli–Palestinian) side of the lake receives almost twice as much rainfall as the eastern (Jordanian) side. As a result, groundwater replenishment rates are currently around 50 per cent higher on the western side. Climate scenarios predict a decrease in annual rainfall of around 20 per cent. However, the water that currently ends up underground and replenishes these important groundwater resources would be halved. The decrease on the western Israeli–Palestinian side is expected to be around 45 per cent, whereas the water available for the Jordanian (eastern) side would fall by nearly 55 per cent. The social and economic situation could therefore worsen, in Jordan in particular.

Saving and reusing water could therefore be a solution, and the UFZ researchers are developing this concept further with colleagues from Israel, Palestine and Jordan. For instance, the SMART project researched ways of stabilising water supply in the Middle East. The UFZ developed new concepts for decentralised wastewater treatment and made a significant contribution to the water master plan of Jordan, one of the world’s most arid countries. Great importance was attached to adapting the wastewater treatment concept to local conditions, and to collaborating with local scientists and authorities. A special implementation office was set up in Jordan’s Ministry of Water in Amman....

Sinkholes and surface springs in Samar (Western Dead Sea), the Jordan flank of the Dead Sea is visible in the background. Photo: Dr. Christian Siebert/UFZ

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