Abstract
DRAINMOD is a field and watershed scale water management simulation model that has been used to design subsurface drainage systems and characterize drainage and water table control practices in poorly drained soils. DRAINMOD is also used as a research tool to investigate the performance of drainage and sub irrigation systems and their effects on water use, crop response, land treatment of wastewater, and pollutants transport from agricultural fields. The model is based on a water balance in the profile to quantify hydrologic components such as infiltration, subsurface drainage, surface runoff, deep and lateral seepage and evapotranspiration. The objective of this research is to examine the capability of DRAINMOD to obtain an optimal drainage systems design for Iraqi conditions using the information of Dujailah project. This is done by obtaining the minimum drain depth and maximum spacing that meet the criteria for water table control. The results obtained from DRAINMOD for the drainage systems design show a good agreement with those previously obtained for Dujailah project. Therefore DRAINMOD is a suitable simulation model which can be used to simulate the performance of drainage and water table control systems in Iraq. Keywords :DRAINMOD, optimal drainage design, drainage in Iraq
