Projected ecosystem response to the anticipated effects of sea level rise

Abstract

The impact of sea level rise (SLR) on a mangrove island ecosystem was investigated by projecting future increase in tidal inundation at the island. The aims of this study is to simulate the potential mangrove response under several conditions of SLR scenarios for the year 2050 and 2100. Processed WordView-2 and IFSAR images were used in the analysis. Segmentation and classification process were conducted using SPRING 5.2 software while inundation was simulated using ArcGIS 9.3. A series of mangrove migration map for 2050 and 2100 SLR scenarios showed an adjustment to tidal inundation classification due to the increased seawater level. Mangroves from the higher zone (Z4) migrated into the lower zone (Z2 and Z3) as a response to SLR. In the worst-case scenario, more than 25% of the mangrove forest is predicted to be permanently submerged due to a 1.3 m sea level rise. The total land loss in the year 2100 was estimated at 73.52ha (Case study 1) and 148.92ha (Case study 2). The worst-case scenarios will possibly lead to the extinction of Xylocarpus moluccensis when Z4 starts to be completely inundated during the 2050 SLR projection. In conclusion, the findings showed that the tolerance to seawater inundation of different mangrove species determines its responses and migration pattern.