Software Development for Hydrology and Hydraulics of Highway Drainage

In this book [thesis work], general watershed modeling concepts with relevance to road drainage, such as the rational method (IDF curve approach as well as rainfall frequency analysis approach), SCS Unit hydrograph, East African Flood Model etc. are reviewed. Their theoretical backgrounds as well as their limitations in contemporary highway engineering practice are discussed in adequate detail with special emphasis to practical application in the Ethiopian context. The most common methods of road drainage design in current practice are evaluated for their applicability in the Ethiopian context. Although disproportionate importance has been attached to the hydrologic analysis part in the thesis, hydraulic design methods are also established through mathematical techniques. The software is tested with a real project and the output compared with that from a manual design. Both hydrographs are included in this volume for comparison. Outcomes rely appreciably on a number of decisions that are at the exclusive discretion of the drainage designer, and it must be noted that the software is primarily a a vehicle of these decisions.