Climate Change Impacts on Water Resources of Greater Zab River, Iraq

Abstract

igh variability in rainfall amount and occurrence are the main constraints for crop production in rainfed arid and semi-arid areas. Precipitation data analysis focusing on rainfall amount, distribution and dry spells is of a great importance to mitigate the drought impact on crop production. In this study, we used the very, easily accessed daily data from the National Center for Environmental Prediction; Climate Forecast System Reanalysis (NCEP/CFSR) for a period of 35 years (1979-2014) over the North Western Coast (NWCZ) of Egypt at four locations: Ras El Hekma, Matrouh, El Neguilla and Barrani. The data of total annual rainfall, maximum daily data and the number of rainy days based on 0.1,5,10,15 mm of rain, long and short dry spells and the start of the rainy season were presented. The analysis of the dry spells showed that there are at least 6 to 7 dry spells of 10 days or longer each year with a probability exceeding 20% in all the locations studied. Data also showed that Barrani has the highest total annual precipitation and maximum daily precipitation of 182 mm and 45 mm, respectively. A number of the rainy days of the four examined thresholds of 0.1,5,10 and 15 mm were higher in Barrani as compared to the other three locations. It is quite clear that the productivity of wheat, barley and other crops in the NWCZ is highly dependent on the amount and distribution of rainfall as well as the dry spells distribution. Therefore, available water management practices such as supplemental irrigation and water harvesting techniques should be implemented to reduce the potential drought developed for dry spells and to improve the productivity of the cultivated crops.