2023 Volume 79 Issue 17 Article ID: 23-17187
Both the shoreline recession by ground subsidence due to excess pumping of the underground water and that caused by wind waves incident from the easterly direction under the tropical monsoon weather were investigated, taking Pelalongan area on Java Island as a study area. In the study area, nine subareas were adopted on both sides of the Comal River delta and the shoreline changes in each area was investigated using the satellite images. Field observation was also carried out in Pekalongan area, and the ground subsidence was investigated on 19 August 2022. It was found that in this area, the ground subsidence reached approximately 1.6 m and the sinking area rapidly expanding. On the other hand, along the coast east of the Comal River delta, the mean wave incidence angle is as large as 22° clockwise, whereas on the west side, the angle increased up to 42°, causing the High-angle wave instability.
