Analysis of Abrasion Rate and Effect of Mangrove Vegetation Density on Sea Water Intrusion in Coastal Area Subang Regency

• Main Author: SUBRATA (NIM 11513043), DANU
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/21572
• Institution: Institut Teknologi Bandung

Mangrove is a forest with characteristic coastal areas. The existence of mangroves plays an important role in resisting sea waves to prevent coastal abrasion and water system to prevent sea water intrusion. This study aims to determinate the rate of abrasion and determinate the level of damage due to abrasion, the correlation between the density of mangrove vegetation to sea water intrusion, and the feasibility of ground water from salinity aspect. The location of the research was in mangrove vegetation in management of Perum Perhutani KPH Purwakarta (Plot 21D). methods of measuring abrasion rates for 2010 – 2011 and 2012 – 2017 periods based on data from Perum Perhutani for past land positions and field measurements for current conditions. The rate of damage due to abrasion is determinated by the criteria of Litbang PU Pengairan. Intrusion of sea water is detected by measuring ground water salinity. Measurements of groundwater salinity values were performed with four repetitions over a 30 day period. The value of groundwater salinity is measured on stands with rare densities (903,53 trees/ha), medium (1145,37 trees/ha), and very densely (1770,73 trees/ha) in three zones based on the distance from the shoreline marine zone, pond zone, and residential zone. Pearson correlation test conducted determine the relationship between the density of mangrove vegetation with salinity. The salinity value in pond zone and residental zone is then compared with the value of freshwater quality standard, pond water for shrimp and bandeng fish. The result showed that the abrasion rate of 2010 – 2011 was 69,3 ha or 34,65 ha/year, while the abrasion rate of 2012 – 2017 was 2,21 ha or 0,31 ha/year. Based on the level of damage, the research area is classified as a very heavy abrasion. Pearson correlation test results showed correlation coefficient value of -1 for marine zone, -0,85 for pond zone, and -0,96 for residential zone. The negative correlation coefficient (-) in all zones shows the higher the mangrove density, the lower the salinity. Groundwater in the pond zone based on its salinity is suitable for shrimp and bandeng fish farming, while groundwater in residential zones including unfit for freshwater, drinking water or other consumption water.