Remote Sensing and GIS Application for Sedimentation Modeling in Porong River Estuary as an Impact of Lapindo Mudflow, Sidoarjo

Abstract

Lapindo mudflow that has occurred since May 2006 in Porong, Sidoarjo have raised thorny issue. One of the consequences that turned up physically was the alteration that has occurred in Porong River estuary. Porong River estuary has undergone drastic morphological change since 2006 to 2016 that became interesting phenomenon studied using remote sensing imagery. Landsat 7 ETM+ and Landsat 8 OLI/TIRS images were used to observe the changes that occurred in Porong River estuary. Porong River estuary had additional land area of 149.4 Ha in 2000-2006, 93.79 Ha in 2006-2010 and 100.24 Ha in 2010-2016. This addition was largely due to the change of land use in the sub-watershed, input from Lapindo mudflow, as well as human activities in the development of a new delta called Sarinah Island. There were several algorithms that were used in the calculation of the sediment concentration value (SSC), such as blue, green, near infrared band, also Doxaran, NDSSI, and the red/near infrared band ratio. However, the SSC of pixel value did not have strong correlation with the SSC field value. The dynamic of object and accuracy of the algorithm became the most influential factor that must be considered in calculating the value of SSC.