Analysis of Land Cover and Building Damage Due to The 21th November 2022 Cianjur Earthquake using Sentinel-2

The Cianjur region is an area that has the potential for tectonic earthquakes caused by fault movements. The Cianjur earthquake that occurred on November 21, 2022 was caused by the emergence of a new fault, namely the Cugenang Fault. Judging from the depth of the earthquake, which was around 10km, earthquake activity in Cianjur district was included in the shallow category with a magnitude of 5.6 which claimed around 600 lives and resulted in more than 56,000 damaged housing units.Therefore monitoring is needed to see the impact of the Cianjur earthquake on changes in land cover and changes in vegetation and built-up land in Cianjur district. This monitoring utilizes remote sensing technology or remote sensing using Sentinel-2 satellite imagery data. The data obtained will later be analyzed and classified using the Supervised Classification method to obtain land cover maps before and after the earthquake, and the use of the NDBI index algorithm to see the density of buildings or settlements in areas affected by the earthquake. The data that has been collected from Sentinel – 2 data is in July 2022 and January 2023.After the Supervised Classification was carried out using the Maximum Likelihood method, land cover maps were obtained for the earthquake-affected areas before and after the earthquake. The accuracy test results were also carried out on the results of this classification and the results obtained were 90.11% accuracy. From the results of land cover, it can be seen that there was a decrease in the area of built-up land and vegetation land after the earthquake. An analysis of taking the NDBI index value has been carried out on Sentinel-2 satellite imagery which has been cropped with the area of built-up land. Classification of each NDBI class has been carried out to see the density of buildings in the earthquake affected areas. From the results of the analysis, it was found that there was a decrease in density from before the earthquake and after the earthquake. Then a calculation of the estimated number of damaged buildings has been carried out using the enumeration method on the NDBI value, especially for built-up land. After obtaining the results from the enumeration analysis, they are compared with data on building damage in the field. The comparison results show an accuracy of 76.45%.