THE CONCEPT OF SUSTAINABLE DEVELOPMENT WITH THE MANGROVE AVICENNIA MARINA AS A REDUCTOR OF WAVE ENERGY

Coastal building construction is considered risky of abrasion by sea waves. One alternative that can be used as an effort to prevent abrasion is to take advantage of pneumatophore and litter of the Avicennia marina mangrove. The purpose of this study was to determine the effectiveness of Avicennia marina pneumatophore and litter for attenuating sea waves. The applied research methods were Transect-squared, Spot-check, and Sondani methods. The measurement of wave data employed SBE 26Plus and RBRDuo T.D. They were carried out at 5 stations with thicknesses of 3 m, 5 m, 10 m, 20 m, and 50 m respectively. The obtained raw data was then processed and the largest value of pneumatophore was produced at STA 1. The mangrove was able to attenuate the energy as much as 50% with the ratio of pneumatophore + litter + other factors = 14,93% + 16,44% + 18,63%. At STA 2, the attenuated energy was 54% with a ratio of 10,36% + 7,08% + 36,55%. At STA 3, the attenuated energy was 83% with a ratio of 5,43% + 2,29% + 75,28%. At STA 4, 91% of the energy was attenuated with a ratio of 4,22% + 1,05% + 85,73%. The farthest mangrove, at STA 5, attenuated the energy as much as 92%, with a ratio of 3,90% + 0,48% + 87,62%. It is safe to infer that the suppression of wave energy by pneumatophore and litter on the coast has the greatest effectiveness as the pneumatophore releases optimal bending power and the litter bears the smallest porosity value, while such other factors as large trees, core trees, seedlings, piles, sedimentation, and twigs dominate are more dominant as the mangrove thickness increases.