Detection of Changes in Surface Water Bodies Urban Area with NDWI and MNDWI Methods

Land surface water bodies, an essential part of the Earth’s water cycle such as rivers, lakes, swamp, and reservoirs, influence the global ecosystem and climate global significantly. Makassar, one of the most populated cities in Indonesia, recently experiences massive development that affects the existence of vegetation area and urban aquatic ecosystem. This study attempts to detect the urban surface water bodies and to monitor the change by using Landsat OLI TIRS. In order to extract the high accuracy of data, the image data utilized in this study was acquired by Landsat 8 OLI TIRS sensor on 14 December 2000, 27 December 2009 and 06 January 2019 from the United States Geological Survey (USGS) portal analyzed by Normalized Difference Water Index (NDWI) and Modified Normalized Difference Water Index (MNDWI). These methods are scientifically used to classify the data into two categories consisted of water and non-water objects. The result shows that in the last nine years, urban surface water bodies increased around 129.8 ha distributed mostly in Manggala area. Due to rapid urban development such as housing, makes the urban runoff concentrating in low land and creates giant swamp as well as an urban wetland. In coastal areas however decline of the water body due to dominantly by massive reclamation, housing and factory settlement. The increase of urban surface water bodies can lower the urban heat while massive development in the built-up area can worsen the urban heat.