EFFECTS OF CLIMATE CHANGE ON WATER AVAILABILITY AND ON CROP PRODUCTION IN IRAQ BY USING A HYDROLOGICAL MODEL UTILIZING GEOGRAPHICAL INFORMATION SYSTEM TECHNIQUE

摘要

Climate change is going to be the biggest environmental threat in the world. The incrementin temperature has great regional effects; some benefi cial but mostly detrimental. The mainobjective of this paper is to study the climate change (temperature, wind speed, humidity, andsunshine duration) in fi fty years in Diyala River basin (1960-2010), and study the effect ofwater reduction caused by climate change on crop production.A hydrological model was implemented using HEC-HMS software for the fi fty years withdaily time step to simulate the rainfall-runoff relationship depending on Soil Moisture Accountformula. Manual calibration was performed until the Nash-Sutcliffe test gave the best results.Climate data for this period were analyzed to conclude its effects on the generated runoff fromprecipitation and then its effect on the irrigation projects in Diyala basin. The result showedthat the decrement of the generated runoff was about 443.94 Mm3 per year as an averagein the last 20 years (6.48 %), and about 1230,585 and 120,340 ton of wheat and barley,respectively are lost each year in Diyala basin due to climate change.