14 Jul 2017 05:54am IST
Being bordered by a mighty ocean on the western side and majestic hill ranges along the eastern boundary, Goa is found in an environmentally delicate setup but also in a highly vulnerable situation from a hydro-meteorological perspective. A sea shore is the site of a tremendous release of ocean energy, particularly when higher wind speeds generate high waves that generally overshoot the beach. The coast is the realm where the sea water comes to rest and is therefore the ultimate playing field of the ocean. As such, the response of any coast to oncoming waves solely depends of the natural geomorphic disposition of the coastal landscape, the type of vegetation it supports, and also the natural and anthropogenic impacts a coast might have suffered.
Time and again we have reiterated that the coast of Goa is under assault. Tourism and related human activities are a major cause. The frontal dune fields and associated vegetation have suffered severely; these geomorphic features are highly degraded and are rapidly disappearing. The recent judgment of July 3, 2017 by the National Green Tribunal regarding human interference on sand dunes at Colva-Sernabatim is yet another grim warning that our coastal ecosystems are treated with impunity. The court has confirmed that dunes were altered, and ordered the restoration of damaged dunes, in addition to heavy penalties on the offenders.
Can degraded natural ecosystems be repaired or rejuvenated? Yes. Globally, sandy areas have been replenished creating wider beaches, and sand nourishment with plantations has produced fatter dunes. The Coastal Regulation Zone (CRZ) laws guarantee protection of dune fields as human interference is forbidden. However, this instrument neither proposes strategies for restoration of landforms nor does it guarantee the conservation of coastal vegetation. India does not have a beach preservation strategy. Hence, there is an imperative need for a comprehensive policy for the conservation and restoration of dune belts of India.
Some initial basic observations are enumerated below: (A) Mapping of sand dunes was first conducted by Survey of India (SoI) in 1964. The toposheets published by SoI comprise colored maps wherein the dune fields of the entire country are demarcated. These official maps depict a scenario that existed in 1960-1964 period. For Goa, the presence of dunes that back the entire sandy coast of Goa is therefore officially known for more than 50 years. (B) Subsequently, in 1980, a senior NIO scientist Dr BG Wagle mapped the entire Goa coast based on aerial photographs. Active dunes and stable dunes are differentiated; at places, dune fields extend two kilometres inland. Wagle lives in Dona Paula and is ready to discuss his findings on dune mapping with any interested person. (C) Later, in 1998, Mascarenhas gave a field based account on the anthropogenic impacts on the dune belts of Goa. Tourism related activities, construction of dwellings, roads and beach shacks in particular were identified as major causes for the degradation of dune complexes. Except the above, there are no other reports on the scientific aspects of sand dunes of Goa. Lately however, some press reports have indicated that sand dunes have been mapped by an agency from Chennai; the report is not accessible for public.
A dune management policy will also have to abide by the following major topics: (1) Restoration of the original dune line (1964): The toposheets of 1964 have the high water line marked in blue colour. This line in fact corresponds to the High Tide Line (HTL) as mentioned in the CRZ notification. It also matches with the vegetation line and hence the dune line. If the 1964 high water line can be digitised and plotted on a modern map, the shift, if any, in the HTL or the vegetation line over the last 50 years can be identified. In such a case, the line whichever is seaward has to be considered as a new dune line. (2) Deployment of sand fences for the rebuilding of new and rejuvenation of degraded dunes: For the first time in India, a dune building experiment was conducted at Miramar in 2007. Sponsored by CCP, a series of wooden sand fences were deployed on the beach so as to stop and trap wind-blown sand. Accreted sand grows into mounds that stabilize with time. A highly successful initiative, the dune fashioned artificially but growing naturally is still prominently identified (despite footfalls) at Miramar. (3) Aggressive afforestation on/along damaged dunes: Never attempted in the country, plantation of frontal ‘ipomoea’ creepers needs to be undertaken on a war footing. A small pilot area where vegetation is sparse can be adopted. A vegetated dune implies coastal stability. (4) Establishment of dune parks: A proposal to designate four coastal sites of Goa (Mandrem, Morjim, Agonda, Galgibaga) as coastal sand dune parks is already approved by GCZMA and GSBB. Goa would be the first littoral state to have officially approved dune parks. (5) Monitoring and research: Routine monitoring from a research perspective is essential so as to ensure the growth and evolution in space and time of specific dune fields. Local scientific bodies can easily pledge their expertise as a part of their research and societal obligation. (6)Awareness / societal participation in affairs of the coast: Without public enthusiasm, success of such coastal initiatives is rather hard to achieve.
As a former member of GCZMA and presently a member of GSBB, this author has been raising critical coastal issues of societal importance on a routine basis at every possible forum - to no avail. Ecological principles are clearly ignored mostly due to a lack of political will as well as an absence of societal commitments. heard.
(Dr Antonio Mascarenhas is a former Scientist, NIO, Goa)