Abstract
Global warming is hitting all parts of the world for the last fifty years due to Global Climate Change and it is expected to continue in the future in an increasing trend unless the present mode of CO2 emission is limited or reversed. This is manifested in the rising temperature over land and the changes induced in the general weather circulation patterns over land and oceans. The Tigris River catchment as most of other parts in the world is suffering from increased temperatures and reduced precipitation contributing to reduced water resources elements all over it and reduction of the river stream flow itself. Studies using the soil and water assessment tool SWAT were performed on the five Tigris River tributaries basins in Iraq in order to assess these impacts. This paper summarizes the results of those studies, the characteristics of each of the five basins, and illustrates the application of SWAT as a tool for future predictions. Moreover, it explains in more details the work done on one of the basins as an example, summarizes the results of the five studies and then analyzes these results and discusses the expected future outcomes. The final conclusion which can be drawn is that severe shortage in all water resources elements will occur over the five basins and the Tigris River stream flow will suffer a considerable decline. This situation demands that policy makers in Iraq should take steps immediately to improve water and soil management practices to try and reduce as much as possible the expected damage that will hit all water using sectors.
Keywords: Climate Change, Global warming, CO2 emission, SWAT model.