Detection of Changes in Water Surface Area in Limboto Lake Using Landsat Data From 1990 to 2020

Abstract

Lake Limboto is included in the fifteen priority lakes due to its increasingly critical condition. Long-term observations of changes in the lake water surface area are carried out to understand the impact of changes better and protect the ecosystem of water resources. The use of remote sensing technology products in Landsat 4 TM, Landsat 5 TM, Landsat 7 ETM +, and Landsat 8 OLI satellite images and Google Earth Engine is a suitable combination to study the dynamics of Lake Limboto. The water index used are NDWI (Normalized Difference Water Index), MNDWI (Modified Normalized Difference Water Index), and AWEI (Automated Water Extraction Index). The water surface area of Lake Limboto changes every year, starting in 1990 with an area of 1,976 Ha, increasing in 2000 to 2,039 Ha, and the widest inundation of water surface in 2002 was 2,889 Ha, a decrease occurred in 2009 to 2,498 Ha, to become 1,843 Ha in 2020. The objects above the water surface also change yearly, from 6% in 1990-2000, increasing to 10% in 2009, reaching a 16% increase in 2014, and decreasing to 9% in 2020. This changing trend can be used as the basis for government policies in the management of Limboto Lake.