Utilizing Landsat Satellite Data (1990-2018) to Detect Water Inundation for the Management of Human Settlements in Coastal Zones

摘要

Objective: This study investigates waterinundation in Semarang and Demak and Kendalregencies in Java, Indonesia, utilizingLandsat 5, 7 and 8 satellite imagery, in combination withthe Seamless Digital Elevation Model and National Bathymetry (DEMNAS) data for 50, 100 and 150 year projections. Methods: Water inundation detection using optical methods (passive sensors) such as Landsat is an effective tool, more so when combined with the Normalized Difference Water Index (NDWI) method in Green Near Infrared (NIR) bands. Combining imagery from these remote sensing sources with DEMNAS land elevation data may strengthen future water inundation predictions and gauge land loss or degradation in regions subject to land inundation and sea level rise. Findings/Application: Semarang is currently subjected to coastal water inundation associated with losses of coastal infrastructure, resulting in the relocation of human settlements to more elevated areas. Sayung is a sub-distric, the most severely affected sub-district has previously expierienced an increase of water inundationfrom 1434.7ha (1990), 3489.1ha (2002) to4923.8ha (2002), an approximate 1.5 % of land loss annually. This average water inundation increase equivalent to 32 cm annually is based on DEMNAS data from 1990 to 2018, which may be due to coastal infrastructure which supports inundationin surrounding coastal areas such as Sayung, Demak regency.