IOC-UNEP-WMO Pilot Activity on Sea-Level Changes and Associated Coastal Impact in the Indian Ocean

Satish Shetye, National Institute of Oceanography, Goa, India

Sea-level is an easily measurable variable which can provide important insights into the physical oceanography of a region. This is the basic tenet of a project "IOC-UNEP-WMO Pilot Activity on Sea-level Changes and Associated Coastal Impacts in the Indian Ocean," which has recently been launched by the IOC.

Recent interest in possibility of climate change due to enhanced greenhouse warming and consequent sea level rise has helped to focus attention of the world community on the need to measure sea level on a long-term basis. It has also been appreciated that the sea level at a location contains signals due to a variety of processes that encompass geology and physical oceanography of the region. Of all these processes in action, the physical oceanographic processes (tides, storm surges, impact of coastal circulation, etc.) generally dominate the variability in the short time-scale (a few hours to a few years). It is therefore important to understand these before attempting to isolate the long-term effects including the possible sea level rise.

Most coastal countries of the world maintain a tide-gauge network to monitor sea level along the coast. Use of data from these stations to understand the physical oceangoraphy of the region requires skills that many countries do not possess. It is important that these countries are encouraged to develop such skills so that important clues contained in the data collected by their monitoring stations do not go unused. Such analysis of data is also helpful in enhancing consciousness regarding data quality. These considerations form the basis of the Pilot Activity in the Indian Ocean. One of its primary objectives is to enhance the capabilities of the countries of the Indian Ocean to collect and analyse sea-level data. The project envisages setting up of a network of Cells for Monitoring and Analysis of Sea Level (CMAS). The task of the scientists associated with each CMAS will be to secure high quality sea level data recorded in their region of responsibility and to analyze these data to understand the variability seen in the data. The details concerning implementation of the project are summarized in the IOC Document IOC/INF-908 (Draft Action Plan for implementation in the Indian Ocean).

The following eight countries have now formally set up CMAS: Bangladesh, India, Keny, Madagascar, Malaysia, Republic of Maldives, Mauritius and Mozambique. Tanzania and Sri Lanka are expected to join soon. Seychelles has agreed to support the actities propsed under the Pilot Activity by making sea-level data from its stations available to interested researchers. Australia has offered to provide assistance in CMAS activities. Each CMAS is expected to identify the research problems of its interest and use sea-level data to address them. The Pilot Activity provides a framework for cooperation amongst CMASs, the IOC, UNEP and WMO so that the goals set by each CMAS are met within a time-bound programmes.

The activities planned under the Pilot Programme were discussed at the IOC-UNEP-WMO-SAREC Planning Workshop on an Integrated Approach to Coastal Erosion, Sea Level Changes and their Impacts held at the Institute of Marine Sciences (University of Dar-es-Salaam), Zanzibar, United Republic of Tanzania, 17-21 January 1994. Capacity building was identified as a primary need of the Pilot Activity. Short-term and long-term needs of CMAS towards building capabilities in operating tide-gauge installations and in data analysis for physical oceanographic studies were identified. As a follow-up to the recommendations of this Workshop, a "hands-on" training workshop on sea level data analysis will be held during 21 November - 1 December 1995 at the Geodetic & Research Branch, Survey of India, Dehra Dun, India. The trainees, nominated by different CMAS, will be exposed to modern techniques of sea-level data analysis by faculty drawn from the Permanent Service for Mean Sea Level (Bidston, UK), University of Hawaii Sea Level Centre (Hawaii, USA), the National Tidal Facility (Adelaide, Australia) and the Survey of India. The trainees are expected to analyse, with assistance of the faculty members, the data collected in their countries. The Workshop will also review progress made so far in this Pilot Activity and decide on the future course of actions.