Carbon is an essential component in the regulation of climate systems through the global biogeochemical cycle. However, changes in land use/land cover (LULC) have reduced the capacity of terrestrial ecosystems like watershed to store carbon. This shows the need for a policy framework that balances conservative objectives with agricultural demands, as watersheds are required to support carbon storage and food production. Previous studies have generally assessed carbon dynamics or LULC change separately, with limited integration of policy-driven scenarios. Therefore, this study aimed to conduct multi-scenario carbon storage modeling to evaluate LULC protection strategies in the Cimanuk Watershed, Indonesia, an area experiencing significant LULC pressures. The method used consisted of Support Vector Machine (SVM)–Markov, the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST), Geodetector, and Getis-Ord Gi*. A total of four scenarios were used to project LULC and carbon storage in 2042, which included Business as Usual (BAU), Paddy Field Protection (PFP), Forest Protection (FOP), and Paddy Field and Forest Protection (PFFOP). The results showed that forest area declined by 39,400 ha between 2015 and 2025, thereby reducing carbon storage. The PFFOP scenario was identified as the most viable, combining the protection of paddy fields and forests to balance agricultural production and carbon sequestration. Among the factors analyzed, slope exerted the greatest influence on carbon storage. Spatial cluster analysis showed that carbon hotspots were predominantly located in the upper Cimanuk sub-watershed. These results offered valuable insights into scenario-based sustainable watershed management to optimize carbon storage and maintain agricultural function. Furthermore, the proposed framework showed promising potential for application in other tropical watersheds, serving as a reference for decision-makers in sustainable watershed management.

Oil spills have become serious problems for coastal and marine environment. Oil spills incidents often occur in Batam-Bintan and Karawang waters. During Northwest monsoon, oil spills often found littering Batam and Bintan north coastal area. In Karawang waters there are a lot of oil and gas activities that cause risk of oil spills. Remote sensing technology is a solution to monitor oil spills in the sea. Active remote sensing or radar and passive/optical remote sensing have their own advantages in detecting oil spills. By using multitemporal and multi sensor satellite data, monitoring of oil spill can be done in periodic time in area that are vulnerable to oil spills. This study used SAR and optical data to monitor waters area that are often found oil spills. This study aimed to detect oil spills in Batam-Bintan and Karawang waters using multi sensor and multitemporal satellite data in 2021, and to analyze spatiotemporal distribution of oil spill, and compare oil spill pattern of the two areas. The study used Sentinel-1A, Sentinel-2A and Sentinel-2B data from January to December 2021. Oil spill detection from SAR data used dark spot object detection method. Oil spill detection from Sentinel-2 used RGB composite of SWIR-NIR-Red band. Analysis of oil spill from Sentinel-1 and Sentinel-2 from January to December 2021, in Batam-Bintan waters mostly found from January to April, then decreased, and increase in November, and mostly found in north of Bintan to the north until east of Malay peninsula. In Karawang, oil spills mostly found in March-April, and July-August, but every month oil spills was found in this area. Oil spill in Karawang mostly located from near the coast up to around 20 km to the shore.

In this study, we observed the coastal condition caused by Jakarta Bay reclamation, which began in 2013, by the Total Suspended Solid (TSS) from remote sensing data. TSS is one of the key parameters for knowing the quality of waters of the region. Extraction of TSS information using remote sensing data is carried out by adopting an algorithm built using the red channel reflectance data of the Landsat satellite in the Mahakam Delta. Fifteen observation points were taken to see the dynamics of the development of TSS fluctuations along the reclamation area. The analysis shows that all observation points have increased with the highest value at point 3 which is adjacent to the location of the new island. The next observation point with a very significant TSS increase is the observation point that is in the bay position. This condition can be understood because of two large influences, namely the bay with its river basin and the effect of the reclamation activity itself. On the contrary, the four observation points that were in a position free from the effects of reclamation did not experience a significant increase, even found a decrease in TSS value. Because the image data used are taken in the same season, it can be concluded that reclamation activities have an impact on the increase in TSS around the Jakarta Bay.