Research on solutions of planting grass in coir mats to protect dike slope against overtopping

Abstract

Earth dikes are very vulnerable to breaking when the water overflows the dike crest (due to waves or
floods). Waves or overflow water are generally the primary cause of surface erosion of inner slopes and
in many cases can lead to dike breaking. It is the fact that many dikes in Vietnam have become more
vulnerable to the overflows due to insufficient dike crest elevations and intensified floods in recent
years. Therefore, research on solutions to respond, prevent, and ensure the safety of the river deltas
against overtopping is necessary. Protecting the inner slopes of dikes with coir grass mats can be an
effective, low-cost solution preventing surface erosion caused by overflow in the short time when the
overflow has low depth and velocity or can also reduce the evolution of dike breaching to permit
evacuation of people and property prior to the complete failure by high-velocity overflow. This paper
presents the results of a case study applying plantation of grass in coir mats to protect the dike slope
against waves and overflow for dike improvement and upgrading.