scholarly journals Fishing Ground Mapping Model in The Semi-Enclosed Saleh Bay, West Nusa Tenggara

2021 ◽  
Vol 35 (1) ◽  
Author(s):  
Anang Dwi Purwanto ◽  
Ulung Jantama Wisha ◽  
Erick Karno Hutomo
Keyword(s):  
Southwest Monsoon ◽  
Fishing Ground ◽  
Northeast Monsoon ◽  
Statistical Regression ◽  
Thermal Front ◽  
Mapping Model ◽  
Fisheries Resources ◽  
Level 3 ◽  
Continued Use ◽  
Strategic Position

Saleh Bay is a semi-enclosed area of water in Nusa Tenggara Barat Province that is enriched by fisheries resources. The bay’s strategic position, surrounded by several small islands, makes it an area of fertile water. An area of water is considered a potentially ideal fishing ground if it contains several oceanographic phenomena, including thermal fronts and upwelling. Fishing activities in Saleh Bay have been found to be ineffective and inefficient due to local people’s continued use of traditional methods such as fishing by signs of nature (instincts), wind direction, astrological signs and previous experience. This study aimed to create a mapping model of the fishing grounds in Saleh Bay based on remote sensing satellite data. Spatial analysis of daily level 3 images from the Suomi-National Polar-Orbiting Partnership (SNPP) was conducted throughout January and August 2019. The image acquisition period was adapted based on the seasonal system of Indonesia. The study area was determined based on thermal front events as identified by sea surface temperature (SST) data analysed using statistical regression with a Non-Linear Multi-Channel SST (NLSST) approach. An ideal fishing ground is characterised by several oceanographic settings such as upwelling and thermal front occurrence. The average SST distribution in January 2019 was relatively high, ranging from 30.39 to 33.70 oC, while in August 2019, the temperature declined significantly, ranging from 25.09 to 29.30 oC. Concerning the fishing ground model, a plethora of potential fishing ground areas were identified in August compared to January 2019, at 144 and 42 points respectively. This reflected the density of the fishing grounds observed. The fishing grounds were most likely to be concentrated in the bay mouth during the southwest monsoon and within the bay near the plateau during the northeast monsoon. The seasonal variability of Saleh Bay played a significant role in the spatial extraction of the fishing ground data.

VARIABILITY OF CHLOROPHYLL-A DISTRIBUTION AROUND BELITUNG ISLAND WATERS OBSERVED BY AQUA-MODIS SATELLITE DATA

2018 ◽  
Vol 20 (2) ◽  
pp. 78
Author(s):  
Ulung Jantama Wisha ◽  
Hanah Khoirunnisa
Keyword(s):  
Chlorophyll A ◽  
Southern Oscillation ◽  
Geographical Location ◽  
Southwest Monsoon ◽  
Fishing Ground ◽  
Northeast Monsoon ◽  
Surface Distribution ◽  
Nutrient Runoff ◽  
Chl A ◽  
Sst Variability

<p>Belitung Island has a strategic geographical location, which is directly bordered with Sumatera and Kalimantan also Karimata and Malacca Straits. Those conditions make the waters productivity being high due to the support from the biogeochemical cycle, nutrient runoff, and upwelling. This study aims to determine the seasonal variability of chlorophyll-a (Chl-a) around Belitung waters. The method used in this study was spatial analysis with IDW (inverse distance weighted) to interpolate the Chl-a surface distribution. Sea Surface Temperature (SST) acquired from Aqua-MODIS were retrieved from NASA (National Aeronautics and Space Administration) and wind data were obtained from ECMWF (European Centre for Medium-Range Weather Forecasts), data were analyzed statistically and spatially. The Chl-a concentration in the northeast monsoon ranged 0.38-3.5 mg.m-3, in the southwest monsoon ranged 0.15-18.7 mg.m-3, and in the transitional season ranged 0.29-9.04 mg.m-3. The Chl-a concentration during southwest and 1st transitional monsoons were higher due to the maximum sunlight intensity stimulating photosynthesis of autotroph biota. The condition of SST is indicating the upwelling event that involves wind-driven motion of dense, cooler, and usually nutrient-rich water towards the ocean surface. Seasonal SST variability ranged 22.6-28.3oC, 27.3-32.1oC, 30.7-32.3oC, and  29.1-32.8oC during northeast, 1st transitional, southwest, and 2nd transitional monsoons respectively. The existence of ENSO (El-Nino Southern Oscillation) contributes to enhance the Chl-a concentration. During ENSO years, the Chl-a concentration was higher than non-ENSO years due to the great impact of ENSO inducing upwelling and higher nutrient availability. Chl-a and SST conditions can be used to predict fishing ground and upwelling area. </p>

scholarly journals GOATFISH (MULLIDAE) RESOURCES IN VIETNAM SEA BASED ON BOTTOM TRAWL SURVEY IN THE PERIOD 2012 - 2013

2018 ◽  
Vol 17 (4) ◽  
pp. 459-468
Author(s):  
Vo Trong Thang ◽  
Tran Van Cuong ◽  
Mai Cong Nhuan ◽  
Nguyen Van Hai
Keyword(s):  
Monsoon Season ◽  
Southwest Monsoon ◽  
Current Status ◽  
Total Output ◽  
Total Biomass ◽  
Trawl Survey ◽  
Northeast Monsoon ◽  
Fisheries Resources ◽  
Bottom Fish ◽  
Gulf Of Tonkin

During 2012 - 2013, under the project “The current status and movements of fisheries resources in Vietnam sea” two surveys were conducted to investigate bottom fish resources with 494 hauls. Based on the research results, 16 species belonging to 3 genera of goatfishes were analyzed. The goatfish output accounted for 0.34 - 4.31% compared to the total output of bottom fish in the survey time. The species Upeneus japonicus comprised 62 - 94% of the output of the goatfishes. The average exploitation yield of goatfishes in the Northeast monsoon season was 1.035 kg/h and that in the Southwest monsoon season was 1.446 kg/h. The exploitation yield had a tendency of decrease compared with the previous studies. The distribution density was the highest in the Southwestern region areas and the lowest in the Gulf of Tonkin; Meanwhile according to spatial distribution the density of goatfishes was the highest in the depth < 20 m and the lowest in the depth from 30 - 50 m. The estimation for the total biomass of goatfishes in the Northeast monsoon season was 13,450 tons and in the Southeast monsoon season was 15,321 tons.

scholarly journals Threadfin bream (Nemipteridae) resources in the sea of Vietnam based on the bottom trawl surveys

2020 ◽  
Vol 19 (4) ◽  
pp. 579-588
Author(s):  
Tran Nhat Anh ◽  
Tran Van Cuong
Keyword(s):  
Southwest Monsoon ◽  
Northern Region ◽  
Bottom Trawl ◽  
Depth Range ◽  
Northeast Monsoon ◽  
Catch Per Unit Effort ◽  
Number Of Species ◽  
Fisheries Resources ◽  
The Family ◽  
Trawl Surveys

The threadfin bream (Nemipteridae) resources in the sea of Vietnam were analysed using the results of  bottom trawl surveys conducted by the assessment of living marine resources project in Vietnam (ALMRV) in period 2000–2005 and comprehensive investigation of marine fisheries resources project in Vietnam sea during 2012–2013. Results showed that a total of 23 species belonging to 4 genera of Nemipterus, Parascolopsis, Pentapodus and Scolopsis were recorded. The Southeast region has the highest number of species encountered with 26 species, and the lowest number in Central waters with 16 species. The highest number of species was encountered at 50–100 m depth range with 25 species and the lowest number at the depth of less than 20 m with 9 species. Catch of threadfin bream comprised more than 1% of total catch of surveys. In threadfin bream family, genus Nemipterus was the most abundant, the catch of this genus contributed from 75.1% to 88.4% of the family catch. The catch per unit effort decreased from Northern region to Southern region, while the catch in the Northeast monsoon was higher than in the Southwest monsoon. The biomass of threadfin bream in Vietnamese water was estimated to be 7,534 to 12,229 tons depending on the monsoon patterns.

scholarly journals Human Impacts on Estuarine Erosion-Deposition in Southern Central Vietnam: Observation and Hydrodynamic Simulation

2021 ◽  
Vol 13 (15) ◽  
pp. 8303
Author(s):  
Vu Tuan Anh ◽  
Pham Ba Trung ◽  
Kim-Anh Nguyen ◽  
Yuei-An Liou ◽  
Minh-Thu Phan
Keyword(s):  
Deposition Process ◽  
Southwest Monsoon ◽  
North Coast ◽  
Northeast Monsoon ◽  
Southern Coast ◽  
Erosion Processes ◽  
The North ◽  
Central Vietnam ◽  
Southern Central ◽  
Deposition Processes

This paper aims to identify the causes and sources of erosion and deposition at small estuaries in southern central Vietnam under human intervention. The jetty built at the Tam Quan river mouth (Binh Dinh Province, Vietnam) serves as the base for the study. After its completion at the end of 2009, the hydrodynamic and erosion-deposition processes in the region have been significantly altered. Inside the estuary, the waves are not influenced, but the currents are increased during the ebb tide period and decreased during the flood tide timeframe. During the southwest monsoon, the jetty could cause an increase in the deposition process in both frequency and area, whereas the erosion process tends to narrow the area and increase the frequency on the north coast. In contrast, both deposition and erosion processes are increased on the southern coast. About 5859 m3 of sediments are deposited in the channel gate mainly by local sources. During the northeast monsoon, both deposition and erosion processes are located over a narrow area with frequency increased on the north coast, whereas the deposition process is narrowed with higher frequency on the southern coast. The total amount of sediment deposited at the estuary is 56,446 m3, of which 74.2% is from the onsite erosion material, 15.8% from the river and 10% from the longshore transportation. Generally, due to mainly erosion-deposition processes, sediment volume is accumulated during the northeast monsoon with amount 9.6 times more than that the southwest monsoon. The erosion-deposition processes are contributed to by poor practical management and local human activities inland and in the coastal regions, as well as the natural situation, resulting in serious impacts on society, the economy and the environment. Hence, the governance of the erosion-deposition processes and sediment load in small estuaries appear to contribute to the master plan for the local sustainable development of society and the economy.

scholarly journals Sensitivity Study of WRF Numerical Modeling for Forecasting Heavy Rainfall in Sri Lanka

Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 378 ◽  
Author(s):  
Channa Rodrigo ◽  
Sangil Kim ◽  
Il Jung
Keyword(s):  
Sri Lanka ◽  
Heavy Rainfall ◽  
Weather Prediction ◽  
Wrf Model ◽  
Heavy Rain ◽  
Heavy Precipitation ◽  
Sensitivity Study ◽  
Southwest Monsoon ◽  
Northeast Monsoon ◽  
Pressure System

This study aimed to determine the predictability of the Weather Research and Forecasting (WRF) model with different model physics options to identify the best set of physics parameters for predicting heavy rainfall events during the southwest and northeast monsoon seasons. Two case studies were used for the evaluation: heavy precipitation during the southwest monsoon associated with the simultaneous onset of the monsoon, and a low pressure system over the southwest Bay of Bengal that produced heavy rain over most of the country, with heavy precipitation associated with the northeast monsoon associated with monsoon flow and easterly disturbances. The modeling results showed large variation in the rainfall estimated by the model using the various model physics schemes, but several corresponding rainfall simulations were produced with spatial distribution aligned with rainfall station data, although the amount was not estimated accurately. Moreover, the WRF model was able to capture the rainfall patterns of these events in Sri Lanka, suggesting that the model has potential for operational use in numerical weather prediction in Sri Lanka.

scholarly journals SPATIO-TEMPORAL ESTIMATION OF INTEGRATED WATER VAPOUR OVER THE MALAYSIAN PENINSULA DURING MONSOON SEASON

2017 ◽  
Vol XLII-4/W5 ◽  
pp. 165-175
Author(s):  
S. Salihin ◽  
T. A. Musa ◽  
Z. Mohd Radzi
Keyword(s):  
Water Vapour ◽  
Monsoon Season ◽  
Temporal Distribution ◽  
Southwest Monsoon ◽  
Northeast Monsoon ◽  
Path Delay ◽  
Zenith Path Delay ◽  
Temporal Estimation ◽  
Integrated Water Vapour ◽  
Spatio Temporal

This paper provides the precise information on spatial-temporal distribution of water vapour that was retrieved from Zenith Path Delay (ZPD) which was estimated by Global Positioning System (GPS) processing over the Malaysian Peninsular. A time series analysis of these ZPD and Integrated Water Vapor (IWV) values was done to capture the characteristic on their seasonal variation during monsoon seasons. This study was found that the pattern and distribution of atmospheric water vapour over Malaysian Peninsular in whole four years periods were influenced by two inter-monsoon and two monsoon seasons which are First Inter-monsoon, Second Inter-monsoon, Southwest monsoon and Northeast monsoon.

scholarly journals Projected changes in temperature and precipitation over mainland Southeast Asia by CMIP6 models

2021 ◽  
Author(s):  
S. Supharatid ◽  
J. Nafung ◽  
T. Aribarg
Keyword(s):  
Climate Change ◽  
Coupled Model ◽  
Southwest Monsoon ◽  
Future Climate Change ◽  
Boreal Summer ◽  
Northeast Monsoon ◽  
Adaptation Measures ◽  
Mitigation And Adaptation ◽  
Temperature And Precipitation ◽  
Projected Changes

Abstract Five mainland SEA countries (Cambodia, Laos, Myanmar, Vietnam, and Thailand) are threatened by climate change. Here, the latest 18 Coupled Model Intercomparison Project Phase 6 (CMIP6) is employed to examine future climate change in this region under two SSP-RCP (shared socioeconomic pathway-representative concentration pathway) scenarios (SSP2-4.5 and SSP5-8.5). The bias-corrected multi-model ensemble (MME) projects a warming (wetting) over Cambodia, Laos, Myanmar, Vietnam, and Thailand by 1.88–3.89, 2.04–4.22, 1.88–4.09, 2.03–4.25, and 1.90–3.96 °C (8.76–20.47, 12.69–21.10, 9.54–21.10, 13.47–22.12, and 7.03–15.17%) in the 21st century with larger values found under SSP5-8.5 than SSP2-4.5. The MME model displays approximately triple the current rainfall during the boreal summer. Overall, there are robust increases in rainfall during the Southwest Monsoon (3.41–3.44, 8.44–9.53, and 10.89–17.59%) and the Northeast Monsoon (−2.58 to 0.78, −0.43 to 2.81, and 2.32 to 5.45%). The effectiveness of anticipated climate change mitigation and adaptation strategies under SSP2-4.5 results in slowing down the warming trends and decreasing precipitation trends after 2050. All these findings imply that member countries of mainland SEA need to prepare for appropriate adaptation measures in response to the changing climate.

scholarly journals PERIKANAN PELAGIS KECIL DI DAERAH TELUK: STUDI KASUS DI TELUK SAPE NUSA TENGGARA BARAT

2002 ◽  
Vol 4 (1) ◽  
Author(s):  
Suadi Suadi
Keyword(s):  
The State ◽  
Fishing Ground ◽  
Fisheries Resources ◽  
Intensive Exploitation ◽  
Integrated Policy ◽  
Resources Exploitation ◽  
Relationship Of ◽  
The Relationship ◽  
Pelagic Fishery ◽  
Pelagic Fisheries

The aims of this research were to know the state of small pelagic fishery and social economic aspect of resources exploitation. To examine these issues, the research combined survey and descriptive analytic methods. Gordon-Schaefer model was applied to analyze the state of fishery and analytical descriptive to explained the relationship of the phenomena's. Data collection was based on indepth interview and recording of District Fishery Service's. Samll pelagic fisheries that been analyzed were anchovies (Stolephorus sp.), squids (Loligo sp.), and mackerels (Rastrelliger sp.).There are two main problems of fisheries in the area, firstly, the conflict on coastal zone between marine capture fisheries and mariculture. The second one is the intensive exploitation of fisheries resources. Pelagic fisheries at Sape Bay have been exploited above maximum TAC mainly 80% of MSY. MSY of anchovies (Stolephorus sp.) reached 2324,9 ton at number of effort 56534 trip and MEY 2172,3 ton at number of effort 42144 trips. MSY of squids (Loligo sp.) is 455,0 ton at number of effort 12183 trip and MEY 449,0 ton at number of effort 10780 trips equal to Bagan Perahu  trips. The model was not applicable to predict the MSY and MEY of mackerels (Rastrelliger sp.). The continuing increase of effort will depleted the stock and decreased economic rent. In addition, the increasing of competition on fishing ground with pearl culture, have resulted fishermen stress. The integrated policy and management are needed to solve these problems and to avoid social riots. 

scholarly journals KARAKTERISTIK KONSENTRASI CH4 (METANA) DI BEBERAPA KOTA BESAR DAN KOTA KECIL DI INDONESIA

2017 ◽  
Vol 19 (2) ◽  
pp. 167
Author(s):  
Indah Susanti ◽  
Lilik Slamet S ◽  
Waluyo Eko Cahyono
Keyword(s):  
El Niño ◽  
El Nino ◽  
Anthropogenic Activities ◽  
Small Towns ◽  
Statistical Regression ◽  
Friedman Test ◽  
Large Cities ◽  
Infra Red ◽  
Level 3 ◽  
Using Data

<p class="JudulABSInd"><strong>ABSTRAK</strong></p><p class="abstrakindo">Keberadaan konsentrasi CH<sub>4</sub> di atmosfer berasal dari sumber emisi CH<sub>4</sub> di permukaan bumi baik asal antropogenik maupun alami. Bobot molekul CH<sub>4</sub> yang ringan mengakibatkan CH<sub>4</sub> dapat bergerak vertikal sampai ke stratosfer. Konsentrasi CH<sub>4</sub> yang tak terkendali berakibat pada pemanasan global dan perubahan iklim, sehingga perlu dipahami karakteristik CH<sub>4</sub> terutama di beberapa kota besar (Jakarta, Medan, Makassar) dan kota kecil (Ambon, Biak Numfor, Pangkal Pinang) di Indonesia. Dengan menggunakan data <em>Atmospheric Infra Red Soundings</em><em> </em>(AIRS) level 3 yang memiliki resolusi spasial satu derajat dan resolusi temporal bulanan, untuk periode waktu 2003-2015, dikaji kecenderungan konsentrasi CH<sub>4</sub> di enam kota  dan anomalinya pada beberapa ketinggian atmosfer serta analisis pengaruh kategori kota (kota besar dan kota kecil berdasarkan jumlah penduduk) terhadap konsentrasi CH<sub>4</sub>. Metode yang digunakan pada penelitian ini adalah analisis spasial horizontal dan vertical dengan bantuan <em>Software Grads</em> untuk mengetahui daerah mana dan pada level ketinggian mana terjadi perubahan konsentrasi CH<sub>4</sub>, serta ditunjang oleh analisis statistik regresi dan uji Friedman serta uji Tukey untuk mengetahui apakah ada pengaruh kategori kota terhadap konsentrasi CH<sub>4</sub> di atmosfer. Hasilnya menunjukkan adanya penurunan konsentrasi CH<sub>4 </sub>terhadap ketinggian atmosfer dengan pola logaritmik (eksponensial) yang sebagian besar berasal dari kegiatan di permukaan bumi. Fluktuasi konsentrasi CH<sub>4</sub> di atmosfer disebabkan salah satunya oleh <em>El Nino Southern Oscilation</em> (ENSO). Kondisi ini tampak dari kesamaan pola nilai indeks ENSO dan konsentrasi CH<sub>4</sub>. Berdasarkan penelitian dengan menggunakan uji Friedman dan uji Tukey dihasilkan bahwa klasifikasi kota menjadi kota besar dan kota kecil tidak berpengaruh pada konsentrasi CH<sub>4</sub>.</p><p><strong>Kata kunci</strong>: profil, metana, AIRS, statistik, klasifikasi, kota</p><p class="judulABS"><strong>ABSTRACT</strong></p><p><em>C</em><em>oncentration of CH<sub>4</sub> in the atmosphere comes from the source of CH<sub>4</sub> emissions on the earth's surface either natural or anthropogenic activities. </em><em>The light m</em><em>olecular weight resulting CH<sub>4</sub>  can move vertically up into the stratosphere. Unbridled CH<sub>4</sub> concentration resulted in global warming and climate change</em><em>. So, it’s</em><em> important to understand CH4 characteristics, especially in large cities (Jakarta, Medan, Makassar) and small towns (Ambon, Biak Noemfoor, Pangkal Pinang) in Indonesia. Using data Atmospheric Infra Red Soundings (</em><em>AIRS</em><em>) level 3 which has a spatial resolution of one degree and monthly temporal resolution, for time period from 2003 to 2015, we analyzed the tendency of concentration of CH<sub>4</sub> in 6 cities  and its anomalies in some altitude atmosphere as well as analysis of the influence of the city category (cities and towns based on population) </em><em>towards</em><em> the CH<sub>4 </sub>concentration. The method used in this research is the analysis of spatial horizontal and vertical </em><em>using</em><em> Grads to know </em><em>region</em><em> and altitude levels which </em><em>have </em><em>change the concentration of CH<sub>4</sub>. In additon, supported by statistical regression analysis and Friedman test and Tukey test to determine whether there is any relation between  city category against concentration of CH<sub>4</sub> in the atmosphere. The results indicate a decrease in the height of atmospheric CH<sub>4</sub> concentrations with  the pattern of logarithmic (exponential) is mostly derived from activities in the Earth's surface. Fluctuations in the concentration of CH<sub>4</sub> in the atmosphere caused among other is by </em><em>El Nino Southern Oscilation</em> (<em>ENSO</em><em>)</em><em>. This condition appears on the similarities of the ENSO index values and CH<sub>4</sub> concentrations. Based on research by using the Friedman test and Tukey's test result that classification of  cities and towns has no effect on the concentration of CH<sub>4</sub>.</em></p><p><strong><em>Keywords:</em></strong><em> profile, </em><em>CH<sub>4</sub>, AIRS, statistic, classification, city </em></p>

scholarly journals Influence of the ENSO and Monsoonal Season on Long-Term Wind Energy Potential in Malaysia

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2965 ◽  
Author(s):  
Aliashim Albani ◽  
Mohd Ibrahim ◽  
Kim Yong
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
El Nino ◽  
Southwest Monsoon ◽  
Capacity Factor ◽  
Wind Data ◽  
Northeast Monsoon ◽  
Energy Potential ◽  
Wind Energy Potential

This paper assesses the long-term wind energy potential at three selected sites, namely Mersing and Kijal on the east coast of peninsular Malaysia and Kudat in Sabah. The influence of the El Niño-Southern Oscillation on reanalysis and meteorological wind data was assessed using the dimensionless median absolute deviation and wavelet coherency analysis. It was found that the wind strength increases during La Niña events and decreases during El Niño events. Linear sectoral regression was used to predict the long-term wind speed based on the 35 years of extended Climate Forecast System Reanalysis data and 10 years of meteorological wind data. The long-term monthly energy production was computed based on the 1.5 MW Goldwind wind turbine power curve. The measured wind data were extrapolated to the selected wind turbine default hub height (70 m.a.s.l) by using the site-specific power law indexed. The results showed that the capacity factor is higher during the Northeast monsoon (21.32%) compared to the Southwest monsoon season (3.71%) in Mersing. Moreover, the capacity factor in Kijal is also higher during the Northeast monsoon (10.66%) than during the Southwest monsoon (5.19%). However, in Kudat the capacity factor during the Southwest monsoon (36.42%) is higher compared to the Northeast monsoon (24.61%). This is due to the tail-effect of tropical storms that occur during this season in the South China Sea and Pacific Ocean.

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