PEMETAAN MORFOLOGI DASAR PERAIRAN UNTUK PEMANTAUAN SEDIMENTASI DI DERMAGA PERIKANAN ULEE LHEU MENGGUNAKAN SINGLE BEAM ODOMETER DUA FREKUENSI

ABSTRACTUlee Lheu Fishing Port Jetty is an important port in Banda Aceh City which functions as a crossing, loading and unloading port. The issue of sedimentation is the main problem. This study aims to determine the morphology of the seabed as the basis for monitoring sedimentation at the Ulee Lheu Fishing Port Jetty. Bathymetric surveys were carried out in the dock pool using a single beam echotrack odometer. Tides were obtained using the IOC Sea Level Monitoring for 29 days and analyzed using the admiralty method. The results of the processing showed that there was sedimentation in the area of the Ulee Lheu Fishing Port Jetty. The depth of the wharf pool ranges from 0-7,7 meters with a sediment volume of 250.117,15 m3. Meanwhile, the tidal water type is included in the double daily tidal type with a value of F = 0,15 and the tidal distance is 2,38 meters and is included in the micro tidal range category and there is sedimentation in the Ulee Lheu Fishing Port Jetty.Keywords: Bathymetry, sedimentation, morphology, Ulee Lheu Port, tidal rangeABSTRAKDermaga Perikanan Ulee Lheu merupakan pelabuhan penting di Kota Banda Aceh yang difungsikan sebagai pelabuhan penyeberangan maupun sebagai pelabuhan bongkar muat. Isu sedimentasi menjadi masalah utama di dermaga ini. Penelitian ini bertujuan untuk mengetahui morfologi dasar laut sebagai dasar pemantauan sedimentasi di Dermaga Perikanan Ulee Lheu. Survei batimetri dilakukan di kolam dermaga menggunakan echotrack odometer single beam. Pasang surut diperoleh menggunakan dari IOC Sea Level Monitoring selama 29 hari serta dianalisa menggunakan metode admiralty. Hasil pengolahan menunjukan terjadi sedimentasi di areal Dermaga Perikanan. Kedalaman kolam dermaga berkisar antara 0-7,7 meter dengan volume sedimen berkisar 250.117,15 m3. Sementara tipe pasang surut perairan termasuk dalam tipe pasang surut harian ganda dengan nilai F=0,15 serta jarak tunggang pasut sebesar 2,38 meter dan termasuk dalam kategori mikro tidal range dan terdapat sedimentasi di bagian Dermaga Perikanan Ulee Lheu.Kata Kunci : Batimetri, Sedimentasi, Morfologi, Dermaga Perikanan Ulee Lheu, tunggang pasang surut

PEMBANGKIT LISTRIK TENAGA GELOMBANG LAUT DENGAN MENGGUNAKAN TEKNOLOGI OSCILATING WATER COLUMN (OWC) DI PERAIRAN MARANA

The alternatives to overcome electricity shortage in Indonesia is wave generating. One of the methods conducted in this research is OWC (Oscilating Water Column) based on study area criteria (Marana Village). OWC method can convert ocean wave energy atwave columnoscillationto generate electricity. To be able to produce electricity, this OWC device will train the wave energy through the OWC door hole. This research determine the amount of waves that can be utilized in Marana waters to be converted into units of electricity (watts). The amount of wave height that can be used, depends on the amount of wind that is in the waters of Marana. In addition to wave height, tidal is also needed to know the placement of Oscilating Water Column (OWC) is so that when the tidal water occurs, OWC is still in the condition of the wave. In addition, the bathymetry of the sea is also needed to know at the depth of how placed this OWC. Based on the results obtained from wave forecasting using the 2002-2006 wind data obtained maximum wave height for 5 years is 0.204 m in Year 2003. Which can generate electricity of 0.688 watts. Where from concluded in Marana waters do not have the potential to build Sea Wave Power Plant.

Mangrove Phenology and Water Influences Measured with Digital Repeat Photography

The intertidal habitat of mangroves is very complex due to the dynamic roles of land and sea drivers. Knowledge of mangrove phenology can help in understanding mangrove growth cycles and their responses to climate and environmental changes. Studies of phenology based on digital repeat photography, or phenocams, have been successful in many terrestrial forests and other ecosystems, however few phenocam studies in mangrove forests showing the influence and interactions of water color and tidal water levels have been performed in sub-tropical and equatorial environments. In this study, we investigated the diurnal and seasonal patterns of an equatorial mangrove forest area at an Andaman Sea site in Phuket province, Southern Thailand, using two phenocams placed at different elevations and with different view orientations, which continuously monitored vegetation and water dynamics from July 2015 to August 2016. The aims of this study were to investigate fine-resolution, in situ mangrove forest phenology and assess the influence and interactions of water color and tidal water levels on the mangrove–water canopy signal. Diurnal and seasonal patterns of red, green, and blue chromatic coordinate (RCC, GCC, and BCC) indices were analyzed over various mangrove forest and water regions of interest (ROI). GCC signals from the water background were found to positively track diurnal water levels, while RCC signals were negatively related with tidal water levels, hence lower water levels yielded higher RCC values, reflecting brownish water colors and increased soil and mud exposure. At seasonal scales, the GCC profiles of the mangrove forest peaked in the dry season and were negatively related with the water level, however the inclusion of the water background signal dampened this relationship. We also detected a strong lunar tidal water periodicity in seasonal GCC values that was not only present in the water background, but was also detected in the mangrove–water canopy and mangrove forest phenology profiles. This suggests significant interactions between mangrove forests and their water backgrounds (color and depth), which may need to be accounted for in upscaling and coupling with satellite-based mangrove monitoring.

Introducing winter rice cropping by using non-saline tidal water influx in western basins of South 24 Parganas, India

A population exceeding 3.8 million people in the western region of 24-Parganas (South) is directly or indirectly reliant on agriculture as their primary source of livelihood. The agricultural trend shows a clear lack of multi-cropping with a drop of nearly 30% in rice cultivation during the winter season. Nearly 50% of the region is directly dependent on canals. The introduction of tidal water in the canal network provides an exceptionally economical and highly effective mode of irrigation water supply. The primary aim of the study was to identify the cartographic characteristics and channel hydraulics in the summer season. It was noted that the canals have a wide discharge range of 0.03–540.03 m3/s, average evaporation loss of 9.07 mm/day with a seepage loss ranging from 0.04 to 6.36 m3/s. The tidal water ingress quantity was calculated to be 4.17 Mm3, 5.32 Mm3, 1.88 Mm3 at Diamond Harbour sluice (Sl.), Kulpi Sl. and Kholakhali Sl. respectively. It was denoted that the augmentation of tidal backwater six times monthly would suffice the winter crop water requirement for the majority of the basins. This would result in the production of 172.13 kt which was previously 17.6 kt resulting in an increase of production by 878.01%. The per capita income would also be increased by nearly 978% for the season, resulting in the macro-socioeconomic upliftment of the region.

Pollination Ecology of Indian Tulip Tree, Thespesia Populnea (L.) Sol. Ex Correa (Malvaceae), a Valuable Evergreen Tree Species for Coastal Ecorestoration

Thespesia populnea is a coastal evergreen tree species which flowers seasonally. The flowers are hermaphroditic, self-compatible, self-pollinating, and principally melittophilous. The fruits are indehiscent, turban-shaped, capsules, which release seeds in tidal water upon the decay of their pericarp. Both fruits and seeds are buoyant and typically hydrochorous. This species is a source of wood, dye, food, traditional medicine, being also used as an ornamental and avenue tree. Therefore, it is important in coastal eco-restoration and carbon sequestration.

A monthly tidal envelope classification for semidiurnal regimes in terms of the relative proportions of the S₂, N₂, and M₂ constituents

Daily tidal water level variations are a key control on shore ecology, on access to marine environments via ports, jetties, and wharves, on drainage links between the ocean and coastal hydrosystems such as lagoons and estuaries, and on the duration and frequency of opportunities to access the intertidal zone for recreation and food harvesting purposes. Further, high perigean spring tides interact with extreme weather events to produce significant coastal inundations in low-lying coastal settlements such as on deltas. Thus an understanding of daily through monthly tidal envelope characteristics is fundamental for resilient coastal management and development practices. For decades, scientists have described and compared daily tidal forms around the world's coasts based on the four main tidal amplitudes. Our paper builds on this “daily” method by adjusting the constituent analysis to distinguish between the different monthly types of tidal envelopes occurring in the semidiurnal coastal waters around New Zealand. Analyses of tidal records from 27 stations are used alongside data from the FES2014 tide model in order to find the key characteristics and constituent ratios of tides that can be used to classify monthly tidal envelopes. The resulting monthly tidal envelope classification approach described (E) is simple, complementary to the successful and much used daily tidal form factor (F), and of use for coastal flooding and maritime operation management and planning applications in areas with semidiurnal regimes.

THE EFFECT OF TIDAL WATER ON WELL WATER QUALITY IN NORTHERN COAST ROAD

Ulujami Sub-district is one of the sub-districts in Pemalang Regency, Central Java. Ulujami Sub-district is around 2305 ha, covering 18 urban villages. The 18 villages are: Ambowetan, Blendung, Botekan, Bumirejo, Kaliprau, Kertosari, Ketapang, Limbangan, Mojo, Padek, Pagergunung, Pamutih, Pesantren, Rowosari, Samong, Sukorejo, Tasikrejo, Wiyorowetan. It’s a densely populated region. Some urban villages are located at the northern coastline of Java and along rivers, and are often hit by tidal floods. Therefore, a study on the effect of tidal water on the quality of well water at the coastline of Pemalang Regency, specifically Ulujami Sub-district, is necessary. The data required by the present study were administrative map and well water quality parameters from the Decision of the Minister of Health No.416/MenKes/Per/XI/2010. The instruments were GPS, stationary, and Water Quality Checker. The well water sampling used stratified random sampling technique. The analysis included quality test of well water in tidal flood areas. The research result showed that in general the well water quality in Ulujami Sub-district was unqualified for daily needs. However, some locations near the coast showed high salt content, so well water wasn’t recommended for drinking, especially water from dug well. The well condition in Ulujami Sub-district is generally not fit for use. Of 36 tested well water in Ulujami Sub- district, 88.89% of the wells had odorless water, and 11.11% had slightly odored water, 11.1% had salty water, 3.89% had slightly salty water, and 75% had non-salty water, 44.44% had clear water, 33.33% had slightly cloudy water, and 22.22% had cloudy water.

The Contribution of Forerunner to Storm Surges along the Vietnam Coast

Vietnam, located in the tropical region of the northwest Pacific Ocean, is frequently impacted by tropical storms. Occurrence of extreme water level events associated with tropical storms are often unpredicted and put coastal infrastructure and safety of coastal populations at risk. Hence, an improved understanding of the nature of storm surges and their components along the Vietnam coast is required. For example, a higher than expected extreme storm surge during Typhoon Kalmegi (2014) highlighted the lack of understanding on the characteristics of storm surges in Vietnam. Physical processes that influence the non-tidal water level associated with tropical storms can persist for up to 14 days, beginning 3–4 days prior to storm landfall and cease up to 10 days after the landfall of the typhoon. This includes the forerunner, ‘direct’ storm surge, and coastally trapped waves. This study used a continuous record of six sea level time series collected over a 5-year period (2013–2017) from along the Vietnam coast and Hong Kong to examine the contribution of the forerunner to non-tidal water level. The forerunner is defined as the gradual increase in mean water level, 2–3 days prior to typhoon landfall and generated by shore parallel winds and currents that result in a mean higher water level at the coast. Results indicated that a forerunner was generated by almost all typhoons, at least at one station, with a range between 20 and 50 cm. The forerunner contributed up to 50% of the water level change due to the storm. Combination of forerunner and onshore winds generated storm surges that were much higher (to 70 cm). It was also found that the characteristics of the typhoon (e.g., path, speed, severity and size) significantly influenced the generation of the forerunner. It is recommended that the forerunner that is not currently well defined in predictive models should be included in storm surge forecasts.