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Abstract. Cimanuk watershed is one of the national priority watersheds for rehabilitation considering its critical condition. In this area, Jatigede Reservoir operates, which is the second largest reservoir in Indonesia, after Jatiluhur Reservoir. The reservoir performs several functions, including flood control, irrigation for 90.000 ha of rice fields, water supply of 3.500 litres per second, and power generation of 110 MW. In 2004 the Jatigede Reservoir catchment area had a critical land area of 40.875 ha (28% of the catchment area). The sedimentation rate in Cimanuk River at Eretan station shows a high rate (5.32 mm/year), which potentially decreases the function of Jatigede Reservoir. Therefore, a strategy of Best Management Practice's (BMP's) is required to mitigate the problem by using SWAT hydrology modelling. The aim of this study is to examine the impact of BMP's on surface runoff and sediment yield in Jatigede Reservoir Catchment Area. Simulations were conducted using land use in 2011. The results of this study suggest that SWAT model is considered as a reasonable modelling of BMP's simulation concerning Nash-Sutcliffe Coefficients (0.71). The simulation is using terraces, silt pit, and dam trenches as BMP's techniques. The BMP's application can reduce surface runoff from 99.7 mm to 75.8 mm, and decrease sediment yield from 61.9 ton/ha/year to 40.8 ton/ha/year.

Coastal areas have very important roles and benefits. Unfortunately, most of them in the world are experiencing the effects of climatic changes such as rising sea levels, increasing coastal erosion, and marine intrusion. Meanwhile, there have been many studies on coastal vulnerability from various aspects and perspectives. Therefore, it is necessary to study the trend on coastal vulnerability from past historical records of several decades ago and also from the aspects that have not been studied. This study aims to identify gaps and opportunities related to coastal vulnerability to provide solutions to sustainability themes in the future. Also, there is a need for this study since it is not monotonous and contains a novel element. The method used in this review article is Web of Science (WoS) as the database source, while VOSviewer is used to visualize and analyze the Bibliometric maps. WoS is a website that provides subscription-based access to multiple databases that provide comprehensive citation data for many different academic disciplines, while VOSviewer is a software tool for constructing and visualizing bibliometric networks. The analysis shows that for over 20 years, topics related to coastal vulnerability around the world are divided into four categories, each of which shows the most frequently occurring themes, namely climate change, coastal vulnerability, sea level, and vulnerability. Subsequently, there is a gap in coastal vulnerability, which is a topic on climate change that has been rarely studied in Indonesia since 2015. This bibliometric approach is used to identify key themes in each study or scope of knowledge that has been conducted so far, which is beneficialin determining novel future research.

Lake Maninjau was one of the international tourist destinations before the 2000s. Aside from being used as a source of 66 MW hydroelectric power built in 1972, currently, this caldera lake is also used for aquaculture. Lake Maninjau ecosystem, which consists of water bodies and watersheds, has an area of 23,729.3 Ha. The surface area of Lake Maninjau at +461.5 m asl is 9,737.5 Ha. Calculation of water balance in the Lake Maninjau watershed becomes a necessity because of its multi-functional status. Maninjau watershed water balance is estimated using SWAT (Soil and Water Assessment Tools) model. Rainfall data from Climate Hazard Group InfraRed Precipitation with Station (CHIRPS) was reanalyzed and compared with local rainfall data. The simulation conducted for 1981 - 2019 on the sub-watershed scale produced NSE and R2 values of 0.61 and 0.7, respectively. The simulation was scaled up for the entire catchment of Lake Maninjau. Simulation results showed that an average annual rainfall of 2,483.9 mm/year produced a surface flow, interflow, base flow, and recharge to aquifer of 7.8 mm/year, 1397.4 mm/year, 273.4 mm/year and 14.7 mm/year, respectively.

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