The use of AVHRR data to determine the concentration of visible and invisible tropospheric pollutants originating from a 1997 forest fire in Southeast Asia

A massive forest fire in Indonesia in 1997 affected the whole Asian region by producing a large smoke plume, with Malaysia bearing the brunt due to the wind direction and weather conditions and because of its proximity to the source. The five primary fire produced pollutants were carbon monoxide (CO), sulphur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3) and particulate matter less than 10 mm (PM10). The first four of these are, of course, invisible to conventional satellite-flown multispectral scanners operating in the visible and near infrared regions of the electromagnetic spectrum. The fifth, PM10, is present in the haze and therefore makes an observable contribution to the signal received by the Advanced Very High Resolution Radiometer (AVHRR). The haze in AVHRR channels 1 and 2 data for the fires of September 1997 has been used to study the concentration of PM10 directly. It has also been used to study the concentration indirectly—as a tracer or surrogate—for the four remaining materials, the gases CO, SO2, NO2 and O3. Data from ground observations have been used to calibrate the results and the distributions of the fire pollutants over Peninsular Malaysia have been plotted

Development of rapid low-cost lars platform for oil palm plantation

The need to produce high temporal remote sensing imagery for supporting precision agriculture in oil palm deserves a new low-altitude remote sensing (LARS) technique. Consumer over the shelf unmanned aerial vehicles (UAV) and digital cameras have the potential to serve as Personal Remote Sensing Toolkits which are low-cost, efficient, rapid and safe. The objectives of this study were to develop and test a new technique to rapidly capturing nadir images of large area oil palm plantation (1 km2 ~ 4 km2). Using 5 different multi-rotor UAV models several imagery missions were carried out. Multi-rotors were chosen as a platform due to its vertical take-off and landing (VTOL) feature. Multi-rotor’s VTOL was crucial for imagery mission success. Post processing results showed that for an area of 1 km2, it needs 2 to 6 sorties of quad-rotor UAV with 4000x3000 pixel digital cameras flying at altitude of 120m above ground level and an average of 50m cross-path distance. The results provide a suitability assessment of low-cost digital aerial imagery acquisition system. The study has successfully developed a decent workhorse quad-rotor UAV for Rapid Aerial Photogrammetry Imagery and Delivery (RAPID) in oil palm terrain. Finally we proposed the workhorse UAV as Low-Altitude Personal Remote Sensing (LAPERS) basic founding element

GIS and Multi-criteria Analysis for School Site Selection (Study Case: Malacca Historical City)

Abstract: A set of school suitability map would be very useful for education planners when making a complex decision within a short period of time. This study will utilize both spatial and non-spatial parameters to establish a systematic site selection process for primary schools in Melaka Tengah District. It was carried out by using Geographic Information System (GIS) and Multi-criteria Decision Analysis (MCDA). Three analysis namely demographic, safety and constrain analysis were used to identify the potential sites. Then accessibility analysis, using expertise and public opinion were used to further analyze the potential site. The resulted map showed 54.2% of the total area is highly not suitable, leaving 46% suitable for school sitting. The final safety model output was compared with field verification data from State Education Department (JPN Melaka) and Malacca Historical City Council (MBMBB).

GIS and multi-criteria analysis for school site selection (Study case: Malacca Historical City)

School sites selection is an essential process which needs information on various fields. The process includes scientific justification, judgment and a finding of suitable land, which consider financial, social, ecological and political perspectives, that limit conflicts and supports agreement among the decision makers. A set of school suitability map would be very useful for education planners when making a complex decision within a short period of time. This study will utilize both spatial and non-spatial parameters to establish a systematic site selection process for primary schools in Melaka Tengah District. It was carried out by using Geographic Information System (GIS) and Multi-criteria Decision Analysis (MCDA). Three analysis namely demographic, safety and constrain analysis were used to identify the potential sites. Then accessibility analysis, using expertise and public opinion were used to further analyze the potential site. The resulted map showed 54.% of the total area is highly not suitable, leaving 46% suitable for school sitting. The final safety model output was compared with field verification data from State Education Department (JPN Melaka) and Malacca Historical City Council (MBMBB)

Remote sensing of tropospheric pollutants originating from 1997 forest fire in Southeast Asia

The massive forest fire in Indonesia in 1997 affected the whole Asian region by transporting large quantity of smoke plume. Malaysia bore the brunt due to its proximity, wind direction and weather conditions. Therefore this study aims at using coarse spatial but high temporal resolution Advanced Very High Resolution Radiometer (AVHRR) data of NOAA-14 satellite to detect and subsequently map the five primary fire pollutants i.e. carbon monoxide (CO), sulfur dioxide (SO2), nirogen dioxide (NO2), ozone (O3) and particulate matter (less than 10 micron) (PM10) in Peninsular Malaysia. Regression analysis was used to establish a statistical relationship between above mentioned concentrations recorded at 5 stations around Peninsular Malaysia and reflectance values from AVHRR data. Among the 5 constituents, PM10 showed a moderate correlation (R2) of 0.51 whilst, other constituents revealed poor correlation with correlation of less than 0.5. This model, was then applied to all the pixels in the image covering the whole Peninsular Malaysia. The obtained values are in Air Pollution Index/API values

Non-destructive, laser-based individual tree aboveground biomass estimation in a tropical rainforest

Recent methods for detailed and accurate biomass and carbon stock estimation of forests have been driven by advances in remote sensing technology. The conventional approach to biomass estimation heavily relies on the tree species and site-specific allometric equations, which are based on destructive methods. This paper introduces a non-destructive, laser-based approach (terrestrial laser scanner) for individual tree aboveground biomass estimation in the Royal Belum forest reserve, Perak, Malaysia. The study area is in the state park, and it is believed to be one of the oldest rainforests in the world. The point clouds generated for 35 forest plots, using the terrestrial laser scanner, were geo-rectified and cleaned to produce separate point clouds for individual trees. The volumes of tree trunks were estimated based on a cylinder model fitted to the point clouds. The biomasses of tree trunks were calculated by multiplying the volume and the species wood density. The biomasses of branches and leaves were also estimated based on the estimated volume and density values. Branch and leaf volumes were estimated based on the fitted point clouds using an alpha-shape approach. The estimated individual biomass and the total above ground biomass were compared with the aboveground biomass (AGB) value estimated using existing allometric equations and individual tree census data collected in the field. The results show that the combination of a simple single-tree stem reconstruction and wood density can be used to estimate stem biomass comparable to the results usually obtained through existing allometric equations. However, there are several issues associated with the data and method used for branch and leaf biomass estimations, which need further improvement

Revising digital elevation models generation from Sentinel-1 synthetic aperture radar and interferometric technique in densely-vegetated humid tropical environment

Generation of digital elevation models (DEM) over densely vegetated humid tropics using Sentinel-1 data and Interferometry synthetic aperture radar (InSAR) technique is revised based on recommended optimum perpendicular baselines, and accuracy assessment based on coherence cells is introduced. Six pairs of Sentinel-1 data within the optimum perpendicular baseline of 150 − 400 m and different temporal baselines acquired between 2015 and 2021 were processed using Sentinel Application Platform. Results revealed: that due to the extreme difficulty of achieving good coherence, interferograms are characterized by noise, generated DEMs are dominated by artefacts, higher elevation accuracy can be achieved within coherence cells, and within the recommended optimum perpendicular baseline range, elevation accuracy within coherence cells is mainly determined by the perpendicular baseline compared to temporal baseline. Therefore, this study can provide practical guide for InSAR generated DEMs evaluation in densely vegetated environments, and remote sensing method for regional-scale measurement and mapping of spots heights

THE STUDY ON THE DURABILITY OF SUBMERGED STRUCTURE DISPLACEMENT DUE TO CONCRETE FAILURE

Concrete structures that exposed to marine environments are subjected to multiple deterioration mechanisms. An overview of the existing technology for submerged concrete, pressure resistant, concrete structures which related such as cracks, debonds, and delamination are discussed. Basic knowledge related to drowning durability such as submerged concrete structures in the maritime environment are the durability of a concrete and the ability to resist to weathering, chemical attack, abrasion or other deterioration processes. The measuring techniques and instrumentation for geometrical monitoring of submerged structural displacements have traditionally been categorized into two groups according to the two main groups, namely as geodetic surveying and geotechnical structural measurements of local displacements. This paper aims to study the durability of submerged concrete displacement and harmful effects of submerged concrete structures

Parameterization of aerodynamic roughness length and zero plane displacement over tropical region using airborne LiDAR data

Airborne LiDAR data has been one of the reliable data for individual tree properties estimation. High density airborne LiDAR data has been used previously for detailed reconstruction of tree geometry. The aim of this study is to estimate aerodynamic roughness over specific height (Zo/H) and zero plane displacement (do) over forest area using airborne LiDAR data. The results of this study will be very useful as a main guideline for related applications to understand the role of carbon and hydrological cycles, land cover and land use change, habitat fragmentation, and biogeographical modeling. The airborne LiDAR data is first classified into ground and non-ground classes. The ground points are interpolated for digital terrain model (DTM) generation and the non-ground points are used to generate digital surface model (DSM). Canopy height model (CHM) is then generated by subtracting DTM from DSM. Individual tree delineation is carried out on the CHM and individual tree height is used together with allometric equation in estimating height to crown base (HCB) and diameter at breast height (DBH). Tree crown delineation is carried out using the Inverse Watershed segmentation approach. Crown diameter, HBC and DBH are used to estimate individual tree frontal area and the total frontal area over a specific ground surface is further calculated by subtracting the intersected crowns and trunks from the total area of tree crowns and trunks. The considered ground area i.e. plants area determined the final spatial resolution of the Zo/H and do. Both parameters are calculated for different wind directions that were assumed to be originated from North/South and East/West. The results show that the estimated Zo/H and do have similar pattern and values with previous studies over vegetated area

Development of rapid low-cost lars platform for oil palm plantation

The need to produce high temporal remote sensing imagery for supporting precision agriculture in oil palm deserves a new low-altitude remote sensing (LARS) technique. Consumer over the shelf unmanned aerial vehicles (UAV) and digital cameras have the potential to serve as Personal Remote Sensing Toolkits which are low-cost, efficient, rapid and safe. The objectives of this study were to develop and test a new technique to rapidly capturing nadir images of large area oil palm plantation (1 km2 ~ 4 km2). Using 5 different multi-rotor UAV models several imagery missions were carried out. Multi-rotors were chosen as a platform due to its vertical take-off and landing (VTOL) feature. Multi-rotor’s VTOL was crucial for imagery mission success. Post processing results showed that for an area of 1 km2, it needs 2 to 6 sorties of quad-rotor UAV with 4000x3000 pixel digital cameras flying at altitude of 120m above ground level and an average of 50m cross-path distance. The results provide a suitability assessment of low-cost digital aerial imagery acquisition system. The study has successfully developed a decent workhorse quad-rotor UAV for Rapid Aerial Photogrammetry Imagery and Delivery (RAPID) in oil palm terrain. Finally we proposed the workhorse UAV as Low-Altitude Personal Remote Sensing (LAPERS) basic founding element