Land Use Changes Analysis in Jakarta Bay Coastal Area Between 1998, 2008 and 2018

As the national capital and one of the largest cities in the world, environmental conditions and land use in Jakarta have changed a lot in the last twenty years. Economic growth and high population growth in Jakarta have resulted in massive development of infrastructure and residential areas in Jakarta. Economic growth and an increase in population are become problems, especially with the decreasing of green areas due to the development process carried out without paying attention to the surrounding environment. Environmental problems such as water pollution, land subsidence, coastal erosion and flooding often occur in the Jakarta area, especially in the coastal areas of North Jakarta. The research from 1998 to 2018 show that from the observations area of mangrove land cover has increased by 79 hectares during that period. The same trend applied on area of built and open land that increased by 292 hectares and 887 hectares respectively. Meanwhile, the area of land for vegetation, water bodies, and fishpond has decreased from 1998 to 2018 by 393 hectares, 797 hectares and 309 hectares respectively. Development and reclamation have changed land use in the Northern area of Jakarta. However, it is also necessary to pay attention to the impact of development on environmental and social conditions in the North Jakarta area.

Assessing Mandeh Region as the Center of Marine Ecotourism in West Sumatra Province, Indonesia: Mass Tourism Issue and Vulnerability Aspects

Nowadays, Mandeh Region has developed significantly as the center of marine ecotourism in West Sumatra Province. Many local and international tourists were visiting this site. Due to those conditions, many threats emerged, such as mass tourism evoking damages and pollutions. This study aimed to examine the feasibility of the Mandeh Region for tourism activity and identify the impacts of mass tourism. A direct survey has been conducted. We assessed water quality, accessibility, and social conflicts using a scoring method. A modified matrix categorizing some parameters as the underlying data for marine tourism sustainability was used. We also developed Smartline and CVI model to assess the vulnerability level along Mandeh coastal bay. Local zonation was recommended to reduce more environmental damages. We examined the feasibility of the Mandeh region as a place for ecotourism that reached 71.12 %, indicating this area is sufficiently feasible. The absence of local regulations before the Mandeh region was established as the center of marine ecotourism resulted in mass tourism phenomena that elevated marine litter accumulation. Moreover, the development of many resorts near the coast has recently played a role in triggering pollution and damage. Advanced regulation and management are necessary to diminish negative impacts on both the environment and society.

Distribution of Tide Type in Indonesian Waters Based on 7 Days Data Measurement of Ipasoet-BIG Station

Tidal data is needed in the field of energy, marine navigation, coastal construction and other activities related to the oceans. Tidal phenomena occur due to the interaction of the earth with space objects. The sea level rise in coastal waters can be modeled by a harmonic function containing tidal constant numbers. From the constants formed can be calculated a Formzahl number that shows the type of tides that occur at the observation station. This paper tries to describe the distribution pattern of tidal types that exist in Indonesian waters based on data observation collected at station belong to the Geospatial Information Agency. The result is that there are 4 types of tides in Indonesian waters, with the most dominant distribution are mixed tide, prevailing semi diurnal typel.

Hydro-Oceanographic Characteristics In Karimunjawa Coastal Waters During The 1st Transitional Season

This study aims to determine oceanographic characteristics such as tides, waves, and currents in Karimunjawa Coastal Waters during the 1st transitional season and to update the oceanographic database for spatial management evaluation in the region. The tidal characteristics were obtained from the least square method analysis using World Tide software based on Matlab programming language, while wave and current characteristics obtained from 2-dimensional numerical modeling using Mike 21 software on the flow model and spectral wave module. The primary data used were the significant wave height (Hs), wave peak period (Tp), and ocean current components (u and v velocity) on 13-26 May 2016 using the Sontex Argonaut XR type Acoustic Doppler Current Profiler (ADCP) equipment. Tide data were predicted for the Kemujan Islands station from 1-31 March 2020. Secondary data for additional numerical model input were obtained from ERA5-reanalysis in the form of Hs, Tp, u, and v wind velocity data for May 2020 with a temporal resolution of 20 minutes, while bathymetry data derived from GEBCO Satellite Derivated Bathymetry (SDB) data. The tide analysis results showed that Karimunjawa waters are a single daily mixed tidal type. The wave characteristic moves from east to west with high waves reached 0.9 meters and a peak period of 7 seconds. The eastern side of Karimunjawa Island, Kemujan Island, and the western area have a calmer wave. The current characteristic moves northeastward with a speed of 5-28 cm/s, which concludes that in several locations, such as the Menjangan Besar-Menjangan Kecil strait, the currents depend on the tidal conditions.

Halaman Depan Jurnal Segara Vol 17 No 1

Halaman Depan Jurnal Segara Vol 17 No 1

Analysis Of Salt Production Location Using The Salt Location Suitability Index To Apply The Continuously Dynamic Mixing In The Greenhouse Salt Tunnel In North Aceh And East Aceh

One of the main potentials of marine resources in Indonesia is salt. Salt production locations are located in various regions of Indonesia. Aceh Province is one of the leading salt-producing areas on the island of Sumatra. Salt production in Aceh faces various challenges, such as the production system and salt production locations' suitability. Therefore, to develop salt production in Aceh, analysis of the production system and suitability of salt production sites are fundamental. This study aims to analyze the production system and the suitability of salt production locations in North Aceh Regency and East Aceh Regency as salt production centers in Aceh Province. This research uses a combination of qualitative and quantitative methods (mixed method) with a descriptive approach. Production system analysis is carried out through direct observation and in-depth interviews with the stakeholders (government and salt farmers). Analysis of the salt location's suitability level was carried out using the Salt Suitability Index (SSI) method. This study shows that the production system in North Aceh and East Aceh districts uses three production methods consisting of boiling seawater, solar evaporation, and a combination of boiling and solar evaporation. The main obstacle to salt production in Aceh is the weather, such as high rainfall and fluctuations throughout the year. Analysis of the suitability of the location of salt production shows the value of the SSI at the salt ponds site in the North Aceh and the East Aceh Regencies is 80% which indicates that the locations are sufficiently appropriate as a salt production site. The results of this study show that the application of the Continuously Dynamic Mixing (CDM) method in Greenhouse Salt Tunnel (GST) technology may be used to improve the quality and quantity of salt production in Aceh.

Seagrass Condition at Some Small Islands in The Taka Bonerate National Marine Park, South Sulawesi Indonesia

The assessment of seagrass bed condition in Indonesia still refers to the Decree of the State Minister for the Environment (KMNLH) no. 200 of 2004, which considers only one variable, namely the percentage of seagrass cover. To assess the seagrass beds condition to be more in-depth and meaningful, it is necessary to consider the addition of several variables, such as the biotic variables (seagrass species diversity including macroalgae and macro-benthos components) as well as the abiotic variables (reef flat areas and the substrate components). The purpose of this study is to determine the seagrass beds condition in several small islands in the Taka Bonerate National Marine Park by considering the additional analysis using both biotic and abiotic variables as mentioned above. The methodology used in this study is a combination of the use of the standard seagrass transect method, interpretation of satellite imagery related to the seagrass bottom habitat area, and its components on the reef flat of a particular island, as well as weighting and scoring based on those considered additional variables. By applying the criteria in the method, the seagrass bed conditions were then classified into three categories, namely seagrass in good, moderate, and unfavorable conditions, respectively. The results of the total score assessment on several small islands in Taka Bonerate Islands show that the seagrass bed in Latondu Besar Island is in good conditions with the highest score of (316) compared to Tarupa Besar, Jinato, Rajuni Kecil, and Tinabo Besar Islands with an average score of (173). The results of this study indicate that the assessment of seagrass conditions is more meaningful in terms of seagrass ecology than based on seagrass cover alone. However, this study requires a lot of validation for its application in assessing the condition of seagrass beds in other islands in Indonesia.

Identification of Floating Marine Debris in The Banda Aceh Estuary

The coastal area of Banda Aceh City have the potential to be polluted by waste from the mainland as much as 45.41 tons/day. One source of land waste is the Krueng Aceh river, the river has dense residential areas and high community activities such as ports, ship repairs, traditional markets, recreation and fishing activities. This study aims to identify floating debris in the Krueng Aceh estuary. Data collection was carried out at the mouth of the river using a debris trap mounted on the ship that moves periodically and the research time was based on tidal charts. The results showed that type of marine debris found is plastic, cloth, processed wood, rubber and metal. Plastic debris is the most common debris found by 89 % on the surface of the Krueng Aceh estuary at spring tide and neap tide. The highest amount of debris is found in the morning 09.50 AM and 03.32 PM in the evening.

Identification of Reclamation Area in Ancol of North Jakarta Using Resistivity Method

The coastal reclamation area is an expansion of coastal areas through technical engineering to develop new land areas. Identification of the reclamation area can be performed by detecting subsurface imaging using the resistivity method. This study used a multi-electrode (multichannel) resistivity imaging method. The resistivity imaging results show a good response of subsurface resistivity and successfully identified reclamation area with low resistivity <27.8 Ωm in almost the study area. Its depth varies from 4 meters to 30 meters. The reclamation results are composed of loose rock that has not been fully compacted, so it has not been well consolidated. As a result, it will experience land subsidence if overload.

Evolution of Subsurface Temperatures in West Sumatra - Southern Java Waters During 2010–2014 Indian Ocean Dipole Events

The temperature anomaly formation in the West Sumatra and South Java Waters plays an important role in the formation of the Indian Ocean Dipole (IOD). There have not been many detailed studies on the evolution of temperature anomalies in the subsurface layers in the area during the IOD events. In this study, temperature data from the HYCOM were used to examine the evolution of temperature anomalies on the surface and subsurface in the event of negative IOD (nIOD) 2010 and positive IOD (pIOD) 2012). The analysis was done using a cross-section plot and a Hovmöller diagram. It has shown that in the negative IOD 2010, a positive temperature anomaly in the subsurface layer was started four months earlier than the surface layer and ended six months after the IOD event. In contrast to positive IOD 2012, a negative temperature anomaly formed in the surface layer seven months earlier, and then move to the deeper layer coincide with the onset of the positive IOD event. The negative anomaly in both layers was simultaneously over two months after the positive IOD event over. The La-Niña phase that coincides with the positive or negative IOD event, influences the process of forming temperature anomalies in the subsurface layer, which in this case supports (inhibits) the formation of positive (negative) temperature anomalies in negative (positive) IOD event. The temperature anomaly in the subsurface layer can be an alternative indicator in identifying and predicting IOD events.