| Report by OrissaDiary.com correspondent; Bhubaneswar:The World Bank funded Integrated Coastal Zone Management Project (ICZMP) in Orissa envisages a soft engineering technique to be executed on a pilot basis at vulnerable sea-erosion-hit Pentha coast in Kendrapara district.
ICZM Project has planned to deploy the geo-synthetic tubes at a depth of 4 to 5 m in the sea bed to dampen the wave force and to protect the coast. As a result of the deployment, the wave energy at coast would be minimized and settlement of sand would take place between stretch of 4m depth and the shore. Over the years, the lost beach would be regained. Initially this will be implemented at Pentha Coast which comes under the ICZM Project area. The geo-synthetic tube is a soft-engineering technique in contrast to the hard engineering options like sea-wall. The coastal protection measure component of the ICZMP is executed by the state water resources department. The disadvantages of the hard engineering structures are high cost, compromise with the aesthetics of the sea-scape.
Recently, ICZMP has selected IIT, Chennai to provide technical inputs, consultancy for providing design, estimation, bid document preparation and construction supervision in respect of construction of geo-tube embankment. A comprehensive scientific modeling study and field investigation has been undertaken by the Indian Institute of Technology, Chennai along the erosion-hit shorelines of Pentha. IIT, Chennai’s team of oceanographic experts made a preliminary assessment on geological feature and different riverine systems located around Pentha coast. The next step of activities depends upon the detailed survey and generation of data on oceanographic parameters and coastal processes to prepare the exact site specific design and layout of geo-tube embankment. The last component of this deployment is to guide the quality control of geo-tube and the materials to be filled from the extensive scientific study. Scientific studies on various parameters related to quality of geo-tube such as permeability criteria, retention capacity and resistance to pressure of filling and active load, physical properties of geo-tube such as mechanical, hydraulic and endurance under UV radiation etc will be taken up. “This method has been successfully tried in a number of locations world over. Under the project, additional preventive measures such as vegetative cover as a bio shield is also proposed in order to stabilize the coast,”said Dr. Ajit Kumar Pattnaik, Project Director of ICZMP – Odisha.
The ICZMP proposes following activities in phased manners for this pilot application at Pentha in Kendrapara district. (a) Laying of geo-synthetic tubes in the seabed over a stretch of 700 m after deciding the depth and alignment through modeling studies, to dampen the wave energy on the coast and also facilitating settlement of sand between the tubes and the coast. This would act as a first layer defense to the coast against strong wave action which is responsible for erosion.
(b) Coastal afforestation as the next layer of protection (from the present beach towards the land) to stabilize the beach and to act as a second line of defense.
(c) Construction of the embankment in the landward side, keeping top level 7.4 m above MSL with top width of 5.0 m filling with compacted earth fill. This forms as a last line of defense against sea water intrusion into the agriculture field. The budget of this sub-component is 18.91 crore. Looking at the success of this pilot application it would be replicated in other erosion prone stretches of Orissa coast. |
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