Development of Decision Support Tools for Water Energy Food Infrastructure Management of Sri Lanka By Thushara De Silva Manikkuwahandi Dissertation Submitted to the Faculty of the Graduate School of Vanderbilt University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in Environmental Engineering January 31, 2020 Nashville, Tennessee Approved: George Hornberger Ph.D Hiba Baroud Ph.D Jonathan Gilligan Ph.D Douglas Adams Ph.D