Impact of tsunami on the forest and biodiversity richness in Nicobar Islands (Andaman and Nicobar Islands), India

Abstract

Occurrences of extreme events are likely to cause major decline in global biodiversity. In one such event, on December 26, 2004 tsunami caused extensive damage and irreparable losses to the ecology and biodiversity of low-lying areas of the countries located around the Indian Ocean region. Archipelago of Andaman and Nicobar Islands, one of the richest centre of endemism and biodiversity in the Indo-Malayan region, suffered great loss of forests and coastal biodiversity owing to its closeness to the epicenter of tsunami, i.e. just off the coast of Indonesia. There is little insight into the resilience and rate of recovery pattern of tropical coastal habitats consequent to catastrophic impacts of tsunami. It's important to study the impacts of tsunami on the forest and biodiversity in order to suggest mitigation, restoration measures and long-term conservation planning. Here we have assessed the immediate after-effects of December 26, 2004 tsunami on the forests and areas prioritized for biodiversity conservation analyzing pre and post tsunami satellite imageries. The effect of topographic patterns of Island's coastal areas and their distance from the epicenter of tsunami with respect to changes in the forests and different levels of biologically rich areas modeled for prioritization for different groups of Islands in Nicobar has been studied. Great Nicobar accounted for higher proportion of total forest area damaged and submerged in Nicobar, followed by Central Nicobar and Car Nicobar. Mangroves, littoral forest, beach forest and low land swamps and Syzygium swamps were most affected. Study brings out spatially explicit scenario of damaged, submerged and lost forest areas and corresponding area statistics, vital for understanding and mitigating medium and long term effects of tsunami an extreme event.

The charms and challenges of climate change biodiversity in a warming world

“…The study highlights the potential contribution of geoinformatics to biodiversity assessments . Porwal et al (2012) highlighted the role of the existing baseline geospatial data for the detection of change in an extreme weather event, the tsunami that hit the Andaman and Nicobar islands on 26 December 2004. Raha et al (2012) analysed land transformation on a few islands in the Indian Sunderbans using maps and satellite images from 1924 to 2008, again demonstrating the utility of geoinformatics for the study of climate change induced sea level rises.…”

“…In coastal areas, plants have adapted to tolerate diurnal tidal effects through physiological and morphological trait modifications, thereby developing a specialized and complex ecosystem by evolution over tens of thousands of years; those modifications can be eliminated by a tsunami in just a few seconds. Porwal et al (2012) estimated the extent and magnitude of destruction/alteration, and linked this to distance from the epicentre, coastal topography, and vulnerability to powerful wave actions.…”

Assessment and Monitoring of Deforestation and Land-Use Changes (1976-2014) in Andaman and Nicobar Islands, India Using Remote Sensing and GIS

“…The earth quake (9.0 Richter scale) which struck Andaman and Nicobar Islands on 26 December 2004 and the consequent tsunami had caused considerable change on the mangrove stands of Andaman Islands. The mangroves of south Andaman was affected in various degrees based on their physiological response to the continuous inundation/exposure under the changed scenario; whereas, in the North Andaman due to the elevation of land, the sea water did not affect some of the mangrove stands 28 27 . It has been established through peer-reviewed literature and the present study that Andaman and Nicobar Islands has a high level of deforestation.…”

“…forest and non-forest) and 11 classes at level II. Forests were split into four classes to increase their 7,27 . Area-wise analysis indicates overall deforestation was very high in Andaman Islands with forest cover loss of 426.8 sq.…”

Sonneratia ovata Backer (Lythraceae): status and distribution of a Near Threatened mangrove species in tsunami impacted mangrove habitats of Nicobar Islands, India

“…The post tsunami research work in the Nicobar Islands on mangroves are almost all based only on remote sensing and GIS (Ramachandran et al 2005;Sridhar et al 2006;Porwal et al 2012). A single field based study that described the mangrove plant species diversity in the NFH of Central Nicobar Group of Islands was by Nehru & Balasubramanian (2011).…”