Shoreline Dynamics in East Java Province, Indonesia, from 2000 to 2019 Using Multi-Sensor Remote Sensing Data

Abstract

Coastal regions are one of the most vulnerable areas to the effects of global warming, which is accompanied by an increase in mean sea level and changing shoreline configurations. In Indonesia, the socioeconomic importance of coastal regions where the most populated cities are located is high. However, shoreline changes in Indonesia are relatively understudied. In particular, detailed monitoring with remote sensing data is lacking despite the abundance of datasets and the availability of easily accessible cloud computing platforms such as the Google Earth Engine that are able to perform multi-temporal and multi-sensor mapping. Our study aimed to assess shoreline changes in East Java Province Indonesia from 2000 to 2019 using variables derived from a multi-sensor combination of optical remote sensing data (Landsat-7 ETM and Landsat-8 OLI) and radar data (ALOS Palsar and Sentinel-1 data). Random forest and GMO maximum entropy (GMO-Maxent) accuracy was assessed for the classification of land and water, and the land polygons from the best algorithm were used for deriving shorelines. In addition, shoreline changes were quantified using Digital Shoreline Analysis System (DSAS). Our results showed that coastal accretion is more profound than coastal erosion in East Java Province with average rates of change of +4.12 (end point rate, EPR) and +4.26 m/year (weighted linear rate, WLR) from 2000 to 2019. In addition, some parts of the shorelines in the study area experienced massive changes, especially in the deltas of the Bengawan Solo and Brantas/Porong river with rates of change (EPR) between −87.44 to +89.65 and −18.98 to +111.75 m/year, respectively. In the study areas, coastal erosion happened mostly in the mangrove and aquaculture areas, while the accreted areas were used mostly as aquaculture and mangrove areas. The massive shoreline changes in this area require better monitoring to mitigate the potential risks of coastal erosion and to better manage coastal sedimentation.

Spatio-Temporal Analysis of Wulan Delta in Indonesia: Characteristics, Evolution, and Controlling Factors

“…This is due to the less deposited shoreline length during 2011-2015 (17.76 km) compared to other years, i.e., between 22.98-29.83 km. The shoreline change rate in this area during 25 years is more significant than what has happened in Yogyakarta and East Java (Mutaqin, 2017;Arjasakusuma et al, 2021).…”

“…We used multi-temporal images of Landsat 5 TM (1995, 2000, and 2011) and Landsat 8 OLI/TIRS (2015 and 2020) from USGS (https://earthexplorer.usgs.gov/) as the database to recognize the evolution of Wulan Delta ( Table 1). The spatio-temporal monitoring in the coastal area using remote sensing data could help understand the erosion distribution and quickly predict coastal evolution trends with extensive coverage area (Wahyunto et al, 1995;Cracknell, 1999;Zhang, 2011;Mutaqin, 2017;Wicaksono and Wicaksono, 2019;Costantino et al, 2020;Arjasakusuma et al, 2021).…”

“…The land loss and the land accumulation in Section-B are imbalanced. Land accretion tends to be higher since it is located in the river estuary (Arjasakusuma et al, 2021). The most extensive land accumulation was 1.62 km 2 during 2000-2011, whereas the severest land loss was 0.16 km 2 during 2000-2011 and 2011-2015.…”

“…Furthermore, one-third of the world population was living in the coastal area, and the numbers always increase year by year. This situation can inflict an increasing hazard level in the coastal areas since this area is very dynamic due to its natural and human processes (Mujabar and Chandrasekar, 2013;Mutaqin, 2017;Mutaqin et al, 2019;Arjasakusuma et al, 2021).…”

Coastal Morphodynamic Analysis in Buleleng Regency, Bali - Indonesia

“…Coastal areas form at the interface of three major natural systems on earth: atmosphere, ocean, and land surface, which continually change in response to human and natural forces in the form of both physical and non-physical processes, such as storms, currents, erosion, and sedimentation (Weill and Tessier 2016;Mutaqin 2017;Fan et al, 2018;Arjasakusuma et al, 2021). Developing countries, including Indonesia, have reported the most cases of severe natural disaster impacts.…”