The Influence of Amplitude Stability Index Values in Mapping Land Movements on Sipora Island

Abstract

Sipora Island in the Mentawai Islands Regency is prone to land movement disasters that can damage and cause losses to the people who live on Sipora Island, plus very little data base related to land movement maps on the island. To reduce the risk that will arise, it is necessary to map land movement using the PS-InSAR method, using 48 scenes of Sentinel-1A images and comparing the amplitude stability index parameters 0.65, 0.75, and 0.85 to get differences in the distribution of land movement points and the number of land movement points on the island of Sipora, to see the relationship between the value of the amplitude of the stability index is done fisher test, amplitude stability index parameters 0.65 and 0.75 can map points with subsidence value up to -99mm / year while the amplitude stability index parameter 0.85 can map points with subsidence value -87mm / year all parameters have a maximum uplift value of 5mm / year. The number of points obtained with an amplitude stability index of 0.65 is 27561, 0.75 is 961 and 0.85 is 255. The distribution of land movement points parameter value amplitude stability index 0.65 covers the entire surface of the island of Sipora, the distribution of land movement points amplitude stability index 0.75 focuses on the north and south of the island and the distribution of land movement points amplitude stability index 0.85 in the northern part of the island. The difference parameters of amplitude stability index 0.65, 0.75 and 0.85.