Priority analysis of mangrove land rehabilitation in coastal areas of Pati District with remote sensing

Abstract Pati District has a 60 km coastline, characterized predominantly by muddy physical conditions. This has led the local government to designate the area as a mangrove forest zone. However, there has been a decrease in the quantity of mangroves due to land use changes, converting the area into fishponds that are not in accordance with its designated purpose. The decline in the quality and quantity of the mangrove ecosystem can be observed through land-use changes detected by remote sensing. This involves identifying the density levels of the mangrove forest using Geographic Information Systems (GIS) through the NDVI method. There is a need for monitoring and identification of land cover changes that are not in accordance with its designated use. This serves as a basis for local government decision-making to determine priority areas for effective and sustainable mangrove rehabilitation. This research utilizes remote sensing and GIS methods with overlay processing techniques. The mangrove density class is obtained from the Landsat 8 NDVI image classification results, followed by raster data overlay analysis for each district with vector data overlay. The analysis of mangrove density classes using the NDVI method on Landsat imagery in 2020 indicates that the mangrove forest areas in Pati District are predominantly of medium density class, covering a total area of 151.74 hectares, or 88.57% of the total existing mangrove area of 171.34 hectares. The coastal area of Margoyoso Subdistrict is a priority area for mangrove rehabilitation with a coastline length of 7.2 km and has an existing mangrove area of only 5.80 ha (3.38%) which is the lowest with a sparse density category compared to Tayu Subdistrict and Trangkil Subdistrict which is directly adjacent to Margoyoso Subdistrict. Tayu Subdistrict on the north side has an existing mangrove area of 23.54 ha with moderate density of 8 km coastline and Trangkil Subdistrict on the south side has an existing mangrove area of 19.90 ha with moderate density with a coastline of 4.4 km.