Hydrodynamical model during east season at Gosong Coastal West Borneo as candidate location of nuclear power plant in Indonesia

Indonesia planned to build the first nuclear power plant in Gosong Coast, Bengkayang Regency, West Kalimantan. This research examined the hydrodynamical conditions in the ocean of Gosong Coast during the eastern season. This hydrodynamic model can be considered in estimating the distribution of various radionuclide wastes that release to the ocean. It was simulated using the Delft3D flow module application for 15 days which included the neap and spring tide conditions. Base on the result of the hydrodynamical model, Gosong Coast had a mixed semidiurnal type of tide with low amplitude. The wind parameters involved higher impacts to the hydrodynamical conditions. The model result did not find significant differences between neap and spring tide periods. There was a flow collision between 2 opposite water currents which was occurred at Burung Archipelagic during flood tide and at the Coastal area of Singkawang City during ebb tide. Therefore, the ocean currents at Gosong Coast flowed directly offshore through Burung Archipelagic during ebb tide. Meanwhile during flood tide, these ocean currents moved to Singkawang and Sambas Coastal area before they deflected toward offshore.

Suspended sediment floc size in the Cam - Nam Trieu estuary (Hai Phong, Vietnam), in wet season

Median diameters (D50) of suspended particles were inferred in the wet season in the Cam - Nam Trieu estuary (Hai Phong, Vietnam) based on the particle size distribution measured by LISST-100X on five transects along the river from 23 to 26 September 2015. The results showed that floc diameters varied between 3.6 μm to 146.5 μm and averaged 49.14 μm. At high tide, the average floc size D50 was lowest (42.66 ± 11.55 µm). It reached the highest value in the ebb tide (62.87 ± 23.34 µm) and then decreased to intermediate values in the flood tide (48.75 ± 15.72 µm). The coefficient of variation of the mean floc size D50 was lowest in the high tide (27.05%), highest in ebb tide (37.13%), then intermediate in the flood tide (32.12%).

“We’re in the water!”

This chapter describes how, when the South Tower came down, boats of all kinds amassed along the water's edge, cramming their decks and interior spaces with evacuees, trying to deliver as many people off Manhattan as possible. This unregulated effort raised Coast Guard concerns that overcrowding would cause problems on the water. Although low water had hit the Battery at 8:50 a.m., the currents in this portion of the Hudson River were determined by more than just the tide. Sometimes the current continued to pull downstream even as the flood tide began. Such were the conditions on the morning of September 11; many mariners reported a “ripping” ebb well into the ten o'clock hour. This complicated the waterborne evacuation.

Sediment Movements in Estuary of Siak River, Riau Basin, Indonesia

Siak river has a long history as a transportation lane in the east of Sumatera. From traditional to timber transportations are dependent on this river. Now the river is a severe suffering pollutant spill from many sources. Anthropological activities were higher contributions in the degradation of river environments. Many works were reported about pollution in Siak river. But how the distribution of model sediment transport in the mouth of the river is less to be explained. We consider hydrodynamics model of the mouth of Siak river for modeling the sediment distribution. This simulation gives a fundamental and clear understanding of how total solid sediment (TSS) distribution when flood and ebb tide happens. At ebb tide, TSS dispersion is higher than at flood tide. There is found that the sediment is concentrated in the plume of Siak river in Bengkalis strait. The composition of the sediment is dominated by organic matters.

Spatiotemporal Distribution Characteristics of Nutrients in the Drowned Tidal Inlet under the Influence of Tides: A Case Study of Zhanjiang Bay, China

The tidal dynamics and the characteristics of pollutant migration in the drowned-valley tidal inlet, a typical unit of coastal tidal inlets, are strongly influenced by geomorphological features. Along with the development of society and the economy, the hydrodynamic and water quality environment of the tidal inlet is also becoming more disturbed by human activities, such as reclamation of the sea and the construction of large bridges. In this study, a typical drowned-valley tidal inlet, Zhanjiang Bay (ZJB), was selected for the establishment of a model via coupling of a tidal hydrodynamic model and water quality numerical model. This model can be used to simulate the migration and diffusion of pollutants in ZJB. The spatial and temporal variation processes of water quality factors of the bay under the influence of special geomorphic units was simulated at the tidal-inlet entrance, the flood/ebb tidal delta, and the tidal basin. The results show that ZJB has strong tidal currents that are significantly affected by the terrain. Under the influence of the terrain and tidal currents, the phosphorus and nitrogen concentration at the flood-tide and ebb-tide moments showed obvious temporal and spatial differences in the ebb-tide delta, tidal-inlet entrance, flood-tide delta, and tidal basin. In this study, we analyzed the response mechanism of the water quality environment to the drowned-valley tidal inlet, and this can provide theoretical guidance and a basis for decision-making toward protecting the ecology and water security of ZJB.

Carbon and nutrient cycling between estuarine and adjacent coastal waters

<p>Seasonal and annual nitrate and phosphate loads were determined from FerryBox measurements to investigate the high seasonal and inter-annual variability of carbon and nutrient exchange between the Elbe estuary and North Sea. At the inner continental shelf, high biological activity is driven by riverine nutrient inputs, which can contribute to the net carbon dioxide (CO<sub>2</sub>) uptake. It is possible that in tidal systems this newly formed phytoplankton is transported back into the estuary over the flood tide, and this organic matter can be remineralized in the intertidal region. At present, the influence of this tidally driven mechanism on the nutrient exports and primary production in the coastal zone is not fully characterized, hence carbon sources and sinks at the estuary-coastal boundary may not be well accounted for.</p><p>The coupling between nutrient inputs from the Elbe estuary to adjacent coastal waters and the subsequent biological activity are now being investigated with a high-frequency dataset provided by a FerryBox situated at the mouth of the estuary. The FerryBox continuously measures physical and biogeochemical parameters every 10 to 60 minutes. Prelimary seasonal and nutrient (nitrate and phosphate) loads from the Elbe estuary to the coastal waters were calculated with FerryBox data between 2014 and 2017. The nutrient loads exhibited high seasonal and inter-annual variability. For example, in summer 2014 nitrate loads reached 100 x 10<sup>7</sup> mol yr<sup>-1</sup> whereas, in summer 2017 nitrate loads were 50 x 10<sup>7</sup> mol yr<sup>-1</sup>, which cannot be explained by river discharge alone. Such changes in nutrient loads are likely to influence primary production rates in the adjacent coastal waters and impact CO<sub>2</sub> uptake and therefore carbon cycling.</p><p>Time-series analysis is employed to determine patterns in oxygen changes in relation to photosynthesis and respiration, along with nutrient fluctuations, between 2014 and 2017. Salinity is used to differentiate between the coastal and estuarine end members, with low and high salinity representing flood tide (estuarine waters) and ebb tide (coastal waters), respectively. Changes in dissolved oxygen concentrations are used to estimate primary production (P) and community respiration (R) rates in the water column. The P/R ratio provides the ability to classify the community into autotrophic and heterotrophic systems. Results of this analysis will show the role of varying nutrient loads in supporting primary production in the coastal waters, along with estimating net ecosystem metabolism, and therefore give us a better understanding of nutrient and carbon cycling. </p>

Monitoring of Fine-Scale Warm Drain-Off Water from Nuclear Power Stations in the Daya Bay Based on Landsat 8 Data

Monitoring the drain-off water from nuclear power stations by high-resolution remote sensing satellites is of great significance for ensuring the safe operation of nuclear power stations and monitoring environmental changes. In order to select the optimal algorithm for Landsat 8 Thermal Infrared Sensor (TIRS) data to monitor warm drain-off water from the Daya Bay Nuclear Power Station (DNPS) and the Ling Ao Nuclear Power Station (LNPS) located on the southern coast of China, this study applies the edge detection method to remove stripes and produces estimates of four Sea Surface Temperature (SST) inversion methods, the Radiation Transfer Equation Method (RTM), the Single Channel algorithm (SC), the Mono Window algorithm (MW) and the Split Window algorithm (SW), using the buoy and Minimum Orbit Intersection Distances (MOIDS) SST data. Among the four algorithms, the SST from the SW algorithm is the most consistent with the buoy, the MODIS SST, the ERA-Interim and the Optimum Interpolation Sea Surface Temperature (OISST). Based on the SST retrieved from the SW algorithm, the tidal currents calculated by the Finite-Volume Coastal Ocean Model (FVCOM) and winds from ERA-Interim, the distribution of the warm drain-off from the two nuclear power stations is analyzed. First, warm drain-off water is mainly distributed in a fan-shaped area from the two nuclear power stations to the center of the Daya Bay. The SST of the warm drain-off is about 1–4 °C higher than the surrounding water and exceeds 6 °C at the drain-off outfall. Second, the tide determines the shape and distribution characteristics of the warm drain-off area. The warm drain-off water flows to the northeast during the flood tide. During the ebb tide, the warm drain-off water flows toward the southwest direction as the tide flows toward the bay mouth, forming a fan-shaped area. Moreover, the temperature increase intensity in the combined discharge channel during the flood tide is lower than that during the ebb tide, and the low temperature rising area during the flood tide is smaller than that during the ebb tide.