Estimation of nypa (Nypa fruticans) biomass using Sentinel 2A satellite data

Abstract

Nypa (Nypa fruticans) is a palm that is commonly found along rivers and around ponds, and is including in the mangrove vegetation category because its distribution is influenced by the tidal regime. Plant biomass is organic material produced from photosynthesis. Information on plant biomass is still limited for many vegetation types, including nypa (Nypa fruticans). Biomass estimation is generally done through field measurements, but this is expensive and requires a lot of time and manpower. Therefore, the use of remote sensing technology is certainly van attractive option for estimating plant biomass. This study aimed to estimate the biomass potential of nypa palms, calculate the relationship between vegetation index and palm biomass content, and compare the vegetation indices NDVI and GNDVI. Field biomass estimation involved destructive sampling methods, harvesting the midrib and palm leaves above ground level. Remote sensing technology used to estimate the palm biomass potential used Sentinel-2A satellite imagery, applying atmospheric correction and transformation using the NDVI and GNDVI vegetation indices. The measurement of above ground biomass yielded an average nypa biomass of approximately 22 tons/Ha. The regression analysis showed a positive correlation between measured field biomass and the vegetation indices, where the NDVI vegetation index coefficient of determination was R2 = 0.79 and the GNDVI vegetation index coefficient of determination was 0.88. The results show that the GNDVI vegetation index performed better than the NDVI index, explaining approximately 94% of the observed variation in nypa palm biomass.