Vegetation covers change and its impact on Barchan Dune morphology in Parangtritis Coast, Indonesia

Abstract

Barchan dune is a peculiar type of dune that forms in wind corridors at the Inner Zone of Parangtritis Sand Dune. Their existence is increasingly threatened by land-use changes, especially vegetation coverage. This research illustrates the dynamics of vegetation cover change at the Inner Zone with the NDVI value approach using Sentinel-2 imagery. We also conduct field surveys to determine the actual condition of barchan dunes and compare it to previous morphology data. We only used the slip face height as a parameter of the barchan morphometric. The result showed that the vegetation coverage changed annually in different parts of the Inner Zone from 2015 until 2019. This vegetation covers controlled by restoration program in 2015 and 2016. The vegetation density on the transport zone more significantly affected the morphology of barchan than vegetation density which grow on the barchan body. Based on field data, mostly barchan dunes (10 barchans) experienced a decrease of slip face height than increased slip face height (4 barchans). All of the decreased barchans located in the middle of the Inner zone. The most decreased slip face height as low as 29.3 meters.