Environmentally friendly shore protection using geosynthetic tubes, A case study from East coast of India

Coastal erosion is a major problem faced by the coastal population. Kadalur villages located in the South East coast of India are one such coastal site subjected to large scale erosion. National Institute of Ocean Technology (NIOT) has monitored the shoreline changes along this coast for more than 5 years and analysis of the field data indicates that the high waves generated during cyclones primarily causes erosion of coast resulting in significant beach loss. The frequency and intensity of cyclones affecting this coast is found to have increased since 2003. Based on the analysis of site behavior and extensive field and numerical model studies, an offshore detached segmented submerged breakwater made of geosynthetic tubes has been designed for protecting the coast. The experimental project was implemented by NIOT during the period 2016-18. Construction of the offshore submerged breakwater using geosynthetic tubes was carried out by pumping sand slurry with the help of simple dredge pumps through floating HDPE pipelines thereby reducing the use of heavy equipment and marine spread, thereby making it economically feasible for implementation by the local authorities. The use of geosynthetic tubes has reduced the environmental impact of the breakwater structure since conventional rock or concrete units have not been used for construction. The submerged breakwater has facilitated beach formation on the seaward by reducing the energy of waves reaching the shore. Performance of submerged breakwater is being monitored for seasonal variations in beach growth, structure stability, durability and environment effects.