Article Per Year (5 Year)
p-Index From 2020 - 2025
0
P-Index
This Author published in this journals
All Journal INTERNATIONAL JOURNAL OF ENVIRONMENT AND GEOSCIENCES
Takahiro Osawa
Graduate School of Science and Engineering, Yamaguchi University, Ube Shi Tokiwadai 2-16-1, 7550092, Japan
Agriculture, Biological Sciences & Forestry Earth & Planetary Sciences Environmental Science

Published : 9 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 9 Documents
Search

 1 
Estimation of Carbon Sequestration in Tropical Peat Swamp Forest in Central Kalimantan Using Satellite Based on Primary Productivity Dewa Ayu Mery Agustin; Takahiro Osawa; I Putu Gede Ardhana
International Journal of Environment and Geosciences Vol 2 No 2 (2018)
Publisher : Graduate Study of Environmental Sciences, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/ijeg.2018.v02.i02.p01

Abstract

One of approach that can be used to estimate the carbon sequestration by vegetation is to calculate the Gross Primary Productivity (GPP) in Central Kalimantan. GPP is total carbon that can be absorbed by vegetation to be used in the process of photosynthesis. The purpose of this study is to estimate the value of GPP using Vegetation Photosynthesis and Respiration Model (VPRM) and analyze the data comparison between GPP value data derived from flux tower and GPP value data from MODIS data. The field data from flux tower was taken by Hirano et al. (2007) from January 1, 2004 to December 31, 2005. The MODIS data is used MODIS Surface Reflectance Level 3 data year 2004 to 2005. According to the result of this study, the maximum GPP value year 2004 and 2005 showed 302.365 gC m-2 per month (February 2004) and 366.841 gC m-2 per month (June 2005). The minimum GPP value year 2004 and 2005 was 166.003 gC m-2 per month (November 2004) and 187.663 gC m-2 per month (March 2005). The total value of GPP in year 2004 was 1,134.231 gC m-2 yr-1 and in year 2005 the value was 1,109.001 gC m-2 yr-1. The correlation coefficient between GPP value from flux tower and GPP value from MODIS – VPRM showed in dry season, r = 0.766 and in rainy season, r = 0,839.
Coral Reef and Shallow Water Benthic Identification Using Landsat 7 ETM+ Satellite Data in Nusa Penida District Arief Reza Fahlevi; Takahiro Osawa; I Wayan Arthana
International Journal of Environment and Geosciences Vol 2 No 1 (2018)
Publisher : Graduate Study of Environmental Sciences, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/ijeg.2018.v02.i01.p03

Abstract

This study aims to investigate the feasibility of Landsat 7 ETM+ to identify coral reefs and shallow water benthic at Nusa Penida district in 2009 and 2012, comparison with the Reef Health Monitoring (RHM) results conducted by the Coral Triangle Center (CTC) using the Point Intercept Transect (PIT) method in the same periods. This study also aims to determine the changes of coral reefs and shallow water benthic cover during this period and the distribution at Nusa Penida districk. Shallow water benthic classification refers to English et al. (1997), with a modified by the addition of vegetation classes (seagrass and seaweed). The classification result using confusion matrix between the Reef Health Monitoring (RHM) with the classification of satellite image in 2009 obtained an accuracy rate of 65.85% with a kappa coefficient value of 0.525, while in 2012 the accuracy value obtained of 74.81% with kappa coefficient value of 0.650, which shows the results of that classification of satellite images of Landsat 7 ETM+ with the results of in-situ research is in a moderate level.
Forest and Industrial Plantation Mapping with Multi-Temporal Dual Polarization by ALOS PALSAR Data In Riau Province Elis Molidena; Takahiro Osawa; Putu Gede Ardhana; Abd. Rahman As-syakur
International Journal of Environment and Geosciences Vol 2 No 1 (2018)
Publisher : Graduate Study of Environmental Sciences, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/ijeg.2018.v02.i01.p04

Abstract

Backscattering characteristics of land use has been analyzed using ALOS PALSAR data. The purpose of this research are mapping of land use by five categories such as forest, acacia, oil palm, open area and water, and to identify the changes of environmental. Analysis Pixel-by-pixel average of ALOS PALSAR level 1.5 backscattering used from five of category land use was to estimate the spectral characteristic of each object in difference HH and HV polarization. Ground truth data was taken from 169 locations which used for classification, 119 locations and 50 locations used for validation. Two different times of ALOS PALSAR level 1.0 2009 and 2010 data, was used for changes detection by multi temporal color composite combination. The accuracy result for classification map shows 62% of ground truth database, and multi temporal analysis showed the possibility of changes.
Study Of Albacore Tuna (Thunnus alalunga) Abundance Using Regional Ocean Modeling System (ROMS) Data In Indian Ocean Dian Novianto; Takahiro Osawa; I Wayan Nuarsa
International Journal of Environment and Geosciences Vol 2 No 2 (2018)
Publisher : Graduate Study of Environmental Sciences, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/ijeg.2018.v02.i02.p03

Abstract

First, we analysed alabcore catch data based on time, positions, and layer alabcore caught and ROMS result data monthly climatology data for temperature, salinity. current velocity, and sea surface height for 2005–2008. Then, we analyzed the relationship between catch data and ROMS data by combining the statistical method of regression trogh origin (RTO) and geographic information system (GIS). Three model RTO were generated with the abundance of albacore tuna as a response variable, and temperature, salinity. current velocity, and sea surface height as predictor variables. All of the predictors of temperature, salinity. current velocity, and sea surface height were highly significant (P < 0.001) to the number of albacore tuna. Values of temperature, salinity. current velocity, and sea surface height in albacore tuna preferences ranged from 220 to 230 C, 34.79 to 34.84 Psu, 0.01 to 0.03 m/s and 0.66 to 0.70 m, respectively. Validation of the predicted number ofalbacore tuna with the observed value was significant (P < 0.05, r2 = 0.60). sea surface height was the most important environmental variable to the number of albacore tuna caught, followed by temperature, salinity and current velocity.
Mapping of Soil Fertility Using Landsat Data in Lautém District, Timor-Leste Romaldo Da Costa Ximenes; Takahiro Osawa; I Wayan Nuarsa
International Journal of Environment and Geosciences Vol 2 No 1 (2018)
Publisher : Graduate Study of Environmental Sciences, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/ijeg.2018.v02.i01.p05

Abstract

A single paragraph of about 250 words maximum. For research articles, abstracts should give a pertinent overview of the work. We strongly encourage authors to use the following style of structured abstracts, but without headings: 1) Background: Place the question addressed in a broad context and highlight the purpose of the study; 2) Methods: Describe briefly the main methods or treatments applied; 3) Results: Summarize the article's main findings; and 4) Conclusion: Indicate the main conclusions or interpretations. The abstract should be an objective representation of the article, it must not contain results which are not presented and substantiated in the main text and should not exaggerate the main conclusions.
Study of Land Use Change from 1997 To 2014 Using Landsat Data In Bangli Regency Nuranita Naningsi; Takahiro Osawa; I Nyoman Merit
International Journal of Environment and Geosciences Vol 2 No 2 (2018)
Publisher : Graduate Study of Environmental Sciences, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/ijeg.2018.v02.i02.p04

Abstract

Bangli Regency is one of Regency in the Bali Province. The total area of Bangli Regency is 52,081 hectares (9.24%) of total area of Bali Province (563,666 ha). The Growth and the development of the region Bangli Regency the positive impacts on the economy of the community, and the negative impacts on the environment. Land use change is one of the negative issue of development Bangli Regency. This study conduted the calculation of land use change from 1997 to 2014 using Landsat data in Bangli Regency. Landsat 5 TM, Landsat 7 ETM+ and Landsat 8 OLI/TIRS imageries were used to determine the land use map based, on using supervised classification method. The field data set the nine classes were classtuded based, on the classification were fresh water, bare land, forest, residential, bushes, irrigated paddy field, non irrigated paddy field, dry land and plantation. There results showed in land use changes from 1997 to 2014 that plantation increased (19,486.33 ha (36.89%)), and residential increased (1,872.00 ha (3.47%)), there is also a vast to reduction in dry land (-10,868.90 ha (-21.21%)), forest (-6,333.34 ha (-12.24%)), irrigated paddy field (-1,619.50 ha (-3.17%)), bushes (-1,637.30 ha (-3.27%)), bare land (-63.00 ha (-0.17%)), non irrigated paddy field (-113.59 ha ( -0.26%)) and fresh water (-2.70 ha (-0.05%). The results accuracy rate was 89.45%. Anslyse of land use showed that the significant decrease of plantation area in Bangli Regency hill due to rapid development of infrastrusture of tourism and extensive residential area has increased particularly in sub district of the Kintamani District.
Estimation of Green Land to Urban Change Based on Cellular Automata (CA) Method in Singaraja City and its Surrounding Areas Nyoman Arto Suprapto; Takahiro Osawa; I Dewa Nyoman Nurweda Putra
International Journal of Environment and Geosciences Vol 2 No 1 (2018)
Publisher : Graduate Study of Environmental Sciences, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/ijeg.2018.v02.i01.p01

Abstract

Singaraja city is the second largest city in Bali which have a fairly rapid growth. Growth and development of the region in urban areas of Singaraja give the positive impact on the economy of the community but also give the negative impact on the environment. Land use change and land conversion into one of the negative issues of the development of urban areas in Singaraja. This study intends to calculate the amount of land conversion occur on the green land into urban areas within 14 years (2001-2015) and predict land use change in 2020 and 2025 in Singaraja City and Its Sorrounding Areas. Landsat 7 and Landsat 8 imageries were used to determine the land use map. Land use map obtained through the process of image classification using supervised method then verified using data field. Land use maps in 2015 and 2001 used to obtain the amount of change of urban areas and green land during the period of 14 years. This results show increasing amount of urban areas as 11,37% (3.153,74 ha) whereas green land decreased by 11,17% (3.097,68 ha). Land use change was predicted by Markov method. The projection results show the amount of urban areas in 2020 was 27,40% (7.598,45 ha) and 35,97% (9.974,55 ha) in 2025. The results obtained with this prediction accuracy rate of 0.91.
Analysis Of Land Use In The Southern Part Of Bali Using Fusion Techniques I Kadek Adiana Putra; Takahiro Osawa; Made Sudiana Mahendra
International Journal of Environment and Geosciences Vol 2 No 2 (2018)
Publisher : Graduate Study of Environmental Sciences, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/ijeg.2018.v02.i02.p05

Abstract

The southern part of Bali is a central region of tourism, especially in the Sub District of North Kuta, Kuta and South Kuta. The rapid development of tourism is with increasing infrastructure development. Monitor and analyze need to the land use. In this study a fusion technique with HSV method as the combination with ALOS AVNIR-2 2008 and ALOS PRISM in 2008, to estimate of the level of accuracy of image fusion with ALOS AVNIR-2 and subsequent for the analysis of land use in southern part of Bali. Results of the accuracy test with Google Earth showed land use result fusion has high accuracy with overall accuracy of 83. 5%. Analyze of land use showed that significant decrease of moor area in Jimbaran hill, due to rapid development of infrastructure of tourism is very rapid and then extensive residential areas have increased particularly in Sub district of the North Kuta.
Studi of Environmental Optimum for Pearl Oyster (Pinctada maxima) Aquacuolture Using Marine GIS and Remote Sensing Case Study of Buleleng Regency, North Bali, Indonesia Mohan Budiman; Takahiro Osawa; I Wayan Arthana
International Journal of Environment and Geosciences Vol 2 No 1 (2018)
Publisher : Graduate Study of Environmental Sciences, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/ijeg.2018.v02.i01.p02

Abstract

Oyster aquaculture is one of priorities for development and promotion of aquaculture activities in Buleleng Regency and since 2010 the production always increase and supports coastal communities. The selection of aquaculture structure system and farm site are importance. The selection should be based on an appraisal of the life history, habits, environmental parameters and socio-infrastructure. This study focused on obtaining the aquaculture structure system and site selection for Pearl Oyster (Pinctada maxima) in Buleleng Regency with seven attributes Chl-a, SST, bathymetry, and currents, distance to town, distance to pier, and distance to laboratory. The model structure for identifying culture structure and suitable sites for oyster aquaculture in coastal of Buleleng Regency was built on MCE (Multi Criteria Evaluation), the final result for suitable site outputs were compared with pearl production in Buleleng Regency in 2009, 2010, and 2011. The result of this study is that most areas at Buleleng coastal had medium suitability scores.
Co-Authors Abd. Rahman As-syakur Arief Reza Fahlevi Dewa Ayu Mery Agustin Dian Novianto Elis Molidena I Dewa Nym. Nurweda P., I Kadek Adiana Putra I NYOMAN MERIT I Putu Gede Ardhana I Wayan Arthana I Wayan Nuarsa M. Sudiana Mahendra Mohan Budiman Nuranita Naningsi Putu Gede Ardhana Romaldo Da Costa Ximenes Suprapto, Nyoman Arto