Estimation of Water Surplus and Natural Groundwater Recharge in Iraq

يقسم علم الهيدرولوجيا الى مكونين اساسيين هما المياه السطحية والمياه الجوفية. يهدف البحث الى تقدير الجريان السطحي والتغذية الطبيعية للمياه الجوفية في العراق اعتماداً على معادلة التوازن المائي وبيانات الارصاد الجوية التي يمكن من خلالها حساب التبخر – نتح كامن والحقيقي بطريقة ثورنثويت . قورنت قيم التبخر – نتح كامن مع مجموع المعدل السنوي للامطار في (32) محطة انواء جوية لغرض الحصول على قيم التبخر – نتح الحقيقي باستخدام معادلة التوازن المائي . انقسم الفائض المائي المتحقق إلى جريان سطحي وتغذية طبيعية للمياه الجوفية بعد استخدام طريقة معامل الجريان السطحي لحساب الجريان السطحي المتحقق من الزيادة المائية. اشارت النتائج إلى أن الفائض المائي ازداد باتجاه الشمال الشرقي للعراق ، في حين أن الحد الأدنى لقيم الجريان السطحي والمياه الجوفية تواجدت في منطقة الصحراء الغربية. لقد كان للظروف المناخية الصحراوية التأثير الرئيسي على انخفاض معدلات الساقط المطري وارتفاع درجة الحرارة مما أدى إلى انخفاض الفائض المائي والجريان السطحي والتغذية الطبيعية للمياه الجوفية.The hydrology section is divided into two main components, surface water and groundwater.  Estimation of water surplus and natural groundwater recharge in Iraq meteorological data was the aim of this research. In thirty two meteorological stations, the corrected potential evapotranspiration (PEc) was compared with monthly and annual rainfall in order to estimate actual evapotranspiration (AE) using water balance equation. Water surplus was divided into runoff and natural groundwater recharge where runoff coefficient method was used to estimate runoff. The obtained mathematical relationship between rainfall with both water surplus and actual evapotranspiration can be used to estimate these two parameters directly from rainfall. The results indicate that water surplus increased towards north-east direction of Iraq, while the minimum values of runoff and groundwater recharge located in western desert of Iraq. The climate conditions of desert was the major influence on reducing rainfall and rising temperature resulting decreasing water surplus, runoff and groundwater recharge. &nbsp

Meteorological Water Balance of Khan Al-Baghdadi and surrounding area within Anbar Governorate – West of Iraq.

The water balance equation for any natural area or water body indicates the relative values of inflow, outflow and change in water storage for the area or water body. Analysis of watersheds and drainage patterns of the studied area plays a vital role in understanding the hydrogeological behavior and expressing the prevailing climate, geomorphology and structural antecedents of terrains. This research will study the climate characteristics and meteorological water balance to calculate runoff and groundwater recharge as water surplus. The research used the meteorological parameters recorded in Hit station during the period (1995-2010) to describe climate conditions as well as calculating water surplus using Thorntwaite formula. The climate of area classified as hot dry in summer and cold low rainfall in winter as a continental semi-dry to dry climate class. The calculated potential evapotranspiration was (1174.3) mm, while calculated actual evapotranspiration was (69.59) mm. The amount of water surplus was (31.71) mm, divided into (20.26) mm as runoff and (11.45) mm as groundwater recharge. The average annual of groundwater recharge in the area was (72,020,500) cubic meters. The estimated percent of the water surplus and deficit from the annual rainfall was (31.3%) and (68.69%) respectively