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All Journal Science and Technology Indonesia International Journal of Remote Sensing and Earth Sciences (IJReSES) SRIWIJAYA JOURNAL OF ENVIRONMENT
Wijaya Mardiansyah
Universitas Sriwijaya
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Earth & Planetary Sciences Energy Environmental Science Materials Science & Nanotechnology Physics Public Health

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INDENTIFYING PATTERNS OF SATTELITE IMAGERY USING AN ARTIFICIAL NEURAL NETWORK Iskhaq Iskandar; Azhar Affandi; Dedi Setiabudidaya; Muhammad Irfan; Wijaya Mardiansyah; Fadli Syamsuddin
International Journal of Remote Sensing and Earth Sciences (IJReSES) Vol 9, No 1 (2012)
Publisher : National Institute of Aeronautics and Space of Indonesia (LAPAN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (620.1 KB) | DOI: 10.30536/j.ijreses.2012.v9.a1824

Abstract

An artificial neural network analysis based on the self-organizing map (SOM)  was used  to  examine  patterns  of  satellite  imagery.  This  study  used  3  ×  4  SOM  array  to  extract patterns  of  satellite-observed  chlorophyll-a  (chl-a)  along  the  southern  coast  of  the  Lesser Sunda Islands from 1998 to 2006. The analyses indicated two characteristic spatial patterns, namely the northwest and the southeast monsoon patterns. The northwest monsoon pattern was characterized by a low  chl-a concentration. In contrast, the southeast monsoon pattern was  indicated  by  a  high  chl-a  distributed  along  the  southern  coast  of  the  Lesser  Sunda Islands.  Furthermore,  this  study  demonstrated  that  the  seasonal  variations  of  those  two patterns  were  related  to  the  variations  of  winds  and  sea  surface  temperature  (SST).  The winds  were  predominantly  southeasterly  (northwesterly)  during  southeast  (northwest) monsoon, drived  offshore (onshore) Ekman transport and  produced  upwelling (downwelling) along  the  southern  coasts  of  the  Lesser  Sunda  Islands.  Consequently,  upwelling  reduce dSST  and  helped  replenish  the  surface  water  nutrients,  thus  supporting  high  chl-a concentration. Finally, this study demonstrated that the SOM method was very useful for the identifications of patterns in various satellite imageries.
A Comparative Assessment of Vegetation Diversity Under Coffee Plantations Inside and Outside Protected Forest Areas Ifran Imanda; Sabaruddin Kadir; M. Umar Harun; Wijaya Mardiansyah
Sriwijaya Journal of Environment Vol 7, No 2 (2022): ENVIRONMENTAL CARE AND PROTECTION
Publisher : Program Pascasarjana Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22135/sje.2022.7.2.73-79

Abstract

The existence of tree vegetation planted in coffee plantations as shade trees is believed to have a positive influence on the growth and production of coffee plants. This study aims to analyze the diversity of coffee plant vegetation in three age classes planted inside and outside protected forest areas included in the administrative area of North Dempo and Central Dempo Districts, Pagar Alam City, South Sumatra Province. The results of observations and calculations of Value IVI found that Albizia sumatrana was the dominant species in all coffee plantations at various age levels. The IVI values of Albazia Sumatrana in coffee plants aged < 5 years were 157.32 (inside PF) and 720.92 (outside PF), in coffee plants aged < 10 years, were 84.30 (inside PF) and 155.51 (outside PF), while in coffee aged > 10 years is 75.46 (inside PF) and 95.92 (outside PF). Assessment using the Shanon Index and Simpon Index showed the same results; coffee plantations at all age levels had a moderate diversity index, except for vegetation in coffee plantations aged < 5 years which were outside protected forest areas and had low diversity index values. Through the availability of this information, it is hoped that it will be used as initial information for selecting vegetation types that will be used to support restoration activities in areas around protected forests.
Characteristics of Diurnal Rainfall over Peatland Area of South Sumatra, Indonesia Puad Maulana Mandailing; Wijaya Mardiansyah; Muhammad Irfan; Arsali Arsali; Iskhaq Iskandar
Science and Technology Indonesia Vol. 5 No. 4 (2020): October
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (4064.787 KB) | DOI: 10.26554/sti.2020.5.4.136-141

Abstract

The peak time of rainfall occurrence over an area has certain characteristics in which the difference in time and intensity of rainfall varies depending on its location and distance from the sea. This variation can be determined based on the phase and amplitude obtained using harmonic analysis. In this study, combined data from in-situ observation, satellite remote sensing and reanalysis were used to analyze spatial and temporal variations of peak rainfall events over peatland area of the South Sumatra Province. The results show that most of the South Sumatra Province has a diurnal peak of rainfall during afternoon ranging from 16.00 to 19.00 Western Indonesian Time. In addition, the results also indicate that the analysis on the in situ data revealed seasonal variation both in amplitude and time of maximum diurnal rainfall, while the reanalysis data only indicated a weak seasonal variation on the amplitude of the diurnal rainfall. Furthermore, spatial analysis shows that the time of maximum diurnal rainfall has spatial variation. Over the ocean, the time of maximum diurnal rainfall occurs during night time/early morning. Over the lowland or coastal area, the time of maximum diurnal rainfall occurs during afternoon, while over the high altitude (mountain) it occurs during late night.
Co-Authors Arsali Arsali Azhar Affandi Dedi Setiabudidaya Fadli Syamsuddin Ifran Imanda Iskhaq Iskandar M. Umar Harun Muhammad Irfan Puad Maulana Mandailing Sabaruddin Kadir