This research of the Segara Anakan Estuary, Java Island, Indonesia, is carried out with the aim of developing a salinity intrusion model and investigating the adaptation scheme to mitigate the impact of sea level rise. The study includes topography, water level and current velocity field data acquisition to provide the required information for modeling. The bathymetry data are obtained from secondary data. The model uses the Surface-water Modeling System (SMS) developed by the US Army Corps of Engineers. The flow model within the SMS (RMA2 module) results in current velocity distribution in the domain, which is validated by field data. The validated flow model is developed into a water quality model (RMA4 module). It is found that the current velocity and salinity trend is highly correlated with Citanduy River discharge, which at the lowest value, the tide is able to propagate over 10 km into the Citanduy River. The simulation period is until 2050, in which the results show a sea level rise of 23.2 cm (referred to 2018). The model also shows that the saline water moves farther inland in 2050, impacting a salinity increase of ~0.5-2.5 ppt along the Citanduy River. In 2050, with check dam protection, an area of ~16.16 km from the mouth of the Citanduy River is only able to yield 75% productivity from October to December. The top elevation of the check dam becomes the determining point for mitigation.

No abstract

Ciapus Sub Watershed is part of the Cisadane watershed which passes through 3 (three) sub-districts in Bogor Regency, namely Dramaga District, Ciomas District, and Tamansari District. From 2011 to 2020 housing construction in Dramaga, Ciomas and Tamansari sub-districts increased. High enough rainfall and continuous land changes will result in water infiltration not functioning properly and will cause an increase in surface runoff. Therefore, it is necessary to know how much influence changes in land cover have on the runoff discharge of rainwater in the Ciapus sub-watershed. The purpose of this study was to identify changes in land cover in the Ciapus sub-watershed and to determine the magnitude of the increase in runoff due to changes in land cover in the Ciapus sub-watershed. The results of the analysis of the Ciapus sub-watershed have 8 types of land cover, namely water bodies, primary dry land forest, secondary dry land forest, gardens, dry land agriculture, mixed dry land agriculture, rice fields and settlements. The biggest change in land cover area between 2011 and 2020 is the increase in residential area of ​​2441.59 ha. Meanwhile, dry land agriculture experienced the largest reduction in area of ​​1288.68 ha. Based on the calculation of runoff discharge using the rational method, the amount of discharge that occurred in 2011 was 153.31 mm/second while in 2020 it was 214.99 mm/second

<p><em>Fly ash dan bottom ash  merupakan limbah B3 yang dihasilkan dari proses pembakaran batu bara.</em><em> </em><em>Di Indonesia, batu bara banyak digunakan sebagai bahan bakar pada pembangkit listrik tenaga uap (PLTU). Salah satu PLTU di Indonesia yaitu PLTU Sulawesi Utara II, yang terletak di Provinsi Sulawesi Utara, Kabupaten Minahasa Selatan. Jumlah limbah yang dihasilkan cukup banyak sehingga dibutuhkan cara untuk mengurangi penumpukan fly ash dan bottom ash. Fly ash dan bottom ash dapat digunakan sebagai material stabilisasi tanah dasar. Dalam penelitian ini, diambil dua sampel tanah yang berbeda dengan komposisi penambahan fly ash dan bottom ash yang bermacam-macam. Pengujian CBR dilakukan pada tanah dengan komposisi yang paling optimum menurut klasifikasi AASHTO, yaitu tanah yang termasuk ke dalam kelas A-1 dan A-2 dengan kondisi kuat dukung tanah sangat baik hingga baik. Hasil pengujian CBR pada tanah yang telah dicampur dengan fly ash dan bottom ash adalah sebesar 19,66%, 52,22%, 21,33%, dan 40,88%. Dari hasil pengujian tersebut dapat disimpulkan bahwa penambahan fly ash dan bottom ash pada tanah dapat meningkatkan nilai CBR pada tanah asli yang semula hanya memiliki nilai sebesar 11,2% dan 5,35%.</em><em></em></p>