Wutthichai Tengchaisun creator Sutat Weesakul Chairperson Shrestha, Sangam Co-Chairperson Kawasaki, Akiyuki Examination Committee Somchai Chonwattana Examination Committee Babel, Mukand S. Examination Committee Panya Consultants, Thailand Scholarship donor text series technical report th Pathum Thani, Thailand Asian Institute of Technology 2015 continuing eng 104 leaves : ill. (some col.) The Bangpakong - Prachinburi Basin was flood frequently . Then Royal Irrigation Department planned to enlarge some existing canal and create a new canal to be the diversion for reduce flood in Prachinburi city but these canal is locate in retention area . So this study w as study about effect of enlarging canal to be diversion in retention area. The study has done by using MIKE 11 to simulated flow in river and floodplain. After applied the case of enlarge existing canal together with created new canal then the results ha ve come out. The effective of this case is it can reduce flood depth at Prachinburi city about 4 cm. and reduced flood day by 1 - 2 days. The discharge flow through diversion canal about 400 MCM with the peak d ischarge at Khumon canal is 97 cms . By compare e nlarged canal case with existing canal case the enlarge canal can drain about 130 MCM. The enlarging canal can drain more water but there is still have flood in the area. Eventually, it can reduce depth and flood time but it just a little value. The sugge stions are enlarge some canal more such as Khumon up to 100 cms and Sanampho up to 70 cms. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Water Engineering and Management Thesis (M.Eng.) - Asian Institute of Technology, 2015 Flood damage prevention Bangpakong - Prachinburi Basin (Thailand) Floodplain management Bangpakong - Prachinburi Basin (Thailand) Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B04412 http://203.159.5.9/ait-thesis/detail.php?q=B04412 170220 20260818114032.0