Assessment of Coastal Erosion and recommendation for suitable Interventions Green Coastal Infrastructure

 / Research / National / Green Coastal Infrastructure

The Project

Coastal process studies play a vital role in identifying erosion hotspots and in understanding the prime causes of erosion along the coast of India.  Recent impacts from climate change have made coastal zones more vulnerable to increased intensity of wave action and sea level rise with consequent effects resulting in increased erosion.  Other negative impacts of erosion and sea level rise are salt water intrusion and likely submergence of deltaic areas and low-lying coastal land.

In recent years, continuous increase in human pressure and unusual development over the coastal regions has led to changes in shoreline and eventually causes to high erosion along the coast. The extent of erosion along the coast of India has also been determined by the National Centre for Sustainable Coastal Management (NCSCM) using long-term satellite data from 1975 to 2011. It is estimated that about 500 km of the coast is facing severe erosion, and about 464 km of the coast is covered with rubble mound or revetment type cement seawall.  Approximately 100 sq.km of the beach/ coastal land area have been lost in the past. Estimates indicate that the annual economic losses due to coastal erosion at ~450 ha per year can be valued at about Rs. 1000 crores of protection work and mitigation measures including their maintenance expenses are therefore exorbitant. The causative factors for shoreline changes need to be identified through a comprehensive coastal process study and by developing and implementing a robust Shoreline Management Plan.

It is proposed to develop living shoreline infrastructure at two suitable locations of highly eroding coast along the Indian coast. This involves a five-step scientific strategy, mentioned below.

Green Coastal Infrastructure

Aim

The aim is to expand on the available shoreline solutions involving protection of the coast using nature-based solutions and promoting green coastal infrastructures to the extent possible.

Objectives

  • Identify hotspots of highly eroding coastline of India based on the economic and social conditions along the coast

    • Siting of high erosion areas
    • Sediment budget, coastal sediment cells and strategy for coastal protection
    • Hazard Line – demarcation of risk zones
    • Demographic and social aspects
    • Ecologically Sensitive Areas
    • Land use and Land cover for the coast of India
  • Development of criteria for the implementation of green coastal infrastructures along the highly eroding coastline

    • Assessment of coastline for Living Shoreline Suitability Factors
    • Siting and design considerations
    • Primary and Secondary Data – coastal process study
  • Design of conceptual green coastal protection measures to control the erosion and to enhance the coastal ecosystems

    • Evaluation of Design of green, grey and hybrid coastal structures
    • Numerical Modelling
    • Evaluation of designed green coastal infrastructure
    • Stability testing of the conceptually designed coastal protection measure using index and process-based models
  • Cost Benefit Analysis for pilot interventions

  • Implementing green coastal infrastructure at 2 pilot sites along with coastal States/ UTs with State/UT Budget.

Expected Outcomes

  • High/Medium eroding stretches of the coastline to suggest suitable soft protection structures, wherever applicable identified
  • Suitable interventions for green coastal infrastructure or hybrid structures in case of high wave energy for highly eroding hotspots suggested
  • Riparian buffers to regulate storm overflows, reed beds for localized waste treatment and restoration of ecosystems flows designed
  • Suitable actions towards better safety and security of the coastal community and infrastructure formulated
  • Better protection of the coastal community using climate resilient infrastructure suggested