Variability and trend of sea level in southern waters of Java, Indonesia

Abstract

The coastal area of Java has become a centre of new economic growth. The southern coast of Java, which is directly adjacent to the tropical Indian Ocean, is very vulnerable to sea level rise caused by climate change. Information on variability and trends in sea level are therefore very important for adaptation and disaster mitigation efforts. This research was conducted to determine the variability and trend of sea level in the southern sea of Java. Data used were from satellite altimeter from 1993 to 2018 and tide gauges from 2007 to 2015. The rate of sea level rise was analysed using linear regression. The results showed that the sea level variability in the southern waters of Java was influenced by the Asian-Australian monsoon, eddy currents and the Indian Ocean Dipole (IOD). During June-November, there was a very significant decrease in sea level, especially in the south of East Java and Central Java, which was caused by upwelling and eddy currents. When there was a positive phase of IOD and an El Niño event, sea level decreased; conversely, when the IOD was in a negative phase, sea level increased. For the period 1993-2018, the sea level in the southern waters of Java increased by about 4.7 mm/year.

Relative and Absolute Sea Level Change Variability in The Palabuhanratu Bay Waters

“…Based on the relative and absolute sea level time series, the slope value of positive sea level changes with a linear trend line rise, which means there has been a sea level rise in the waters of Palabuhanratu Bay based on the two sea level observations. Previous research has seen sea level rise south of Java [13,18]. In the same period data 2013-2022, there is a difference in SLR values between relative SLR and absolute SLR.…”

“…Monitoring sea level variability and trends is crucial to responding to global warming and for disaster adaptation and mitigation [12,13]. This information can be obtained from tidal measurements along the coastline and satellite altimetry observations, which provide different sea level information [14,15].…”

“…The southern waters of Java are more dynamic due to their direct connection with the Indian Ocean [18]. [13] calculated the variability and trend of sea level changes in the waters of southern Java based on altimetry data and tidal stations in Cilacap, Central Java, and Prigi, East Java. The results showed an SLR of 4.7 mm/year.…”

“…Palabuhanratu Bay is part of the coast of Sukabumi Regency, West Java, which is to be affected by sea level rise because it is in the southern waters of Java, which is directly influenced by waters with intense wave energy from the Indian Ocean and local solid influences [19]. It is on the Sunda shelf, which experiences yearly plate movement [13]. This study uses tide gauge observation and altimetry data to analyze the variability and trend of sea level changes in Palabuhanratu Bay to detect sea level rise.…”

Maintaining Carbon Storage Does Not Reduce Fish Production from Mangrove-Fish Pond System: A Case Study in Coastal Area of Subang District, West Java, Indonesia

“…Many Indonesian coastal areas face complex environmental problems [1][2][3], which include the widespread occurrences of beach abrasion, seawater intrusion, soil subsidence, and flooding [4][5][6][7]. The current trend of sea-level rise [8] also worsens the situation [9]. Meanwhile, the coastal environmental problems are highly related to deforestation and degradation of mangrove forests [10,11], which are the natural shields of coastal areas.…”