Ariel Blanco - Academia.edu (original) (raw)

Papers by Ariel Blanco

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences

The Agricultural Resources Extraction from LiDAR Surveys (PARMAP) project component of the Nation... more The Agricultural Resources Extraction from LiDAR Surveys (PARMAP) project component of the Nationwide Detailed Resources Assessment using LiDAR (Phil-LiDAR 2) Program aims to produce detailed agricultural maps using LiDAR. Agricultural land cover at crop level was classified through object based image analysis using Support Vector Machine as classifier and LiDAR derivatives from point cloud (2 points per sq.m.) and orthophoto (0.5-meter resolution) as inputs. An accuracy of at least 90%, assessed using validation points from the field and through image interpretation, was required before proceeding to post-processing and map layout. Knowledge sharing and capacity development facilitated by the University of the Philippines Diliman (UPD) enabled partner universities across the Philippines to produce outputs for their assigned region. Considering output layers were generated by multiple teams working on different landscape complexities with some degree of data quality variability, quality checking is crucial to ensure accuracy standards were met. UPD PARMap devised a centralized and end-to-end scheme divided into four stepsland classification, GIS post-processing, schema application, and map layout. At each step, a block is reviewed and, subsequently, either approved or returned with documentation on required revisions. Turnaround time of review is at least one block (area ranging from 10 to 580 sq. km.) per day. For coastal municipalities, an additional integration process to incorporate mapped coastal features was applied. Common problems observed during quality checking include misclassifications, gaps between features, incomplete attributes and missing map elements. Some issues are particular to specific blocks such as problematic LiDAR derivatives. UPD addressed these problems through discussion and mentoring visits to partner universities. As of March 2017, a total of 336 municipal agricultural maps have been turned-over to various stakeholders. For the remaining months of the program, an additional 360 maps are expected to be distributed.

Present-day vertical land movement in San Fernando (La Union) and Currimao (Ilocos Norte), northwest Luzon, Philippines

<p>The northwestern coast of Luzon Island is located within the forearc region of t... more <p>The northwestern coast of Luzon Island is located within the forearc region of the Manila Trench where emergent coral reef platforms have been reported; and an uplift rate of 0.5 m/kyr has been estimated for the past 7,000 years in San Fernando and Currimao. This study examined the present-day vertical land movement (VLM) in both sites using tide gauge records and retracked Jason satellite altimeter missions. Both the tide gauge and satellite data were corrected for tides using the T_Tide algorithm and the difference between the tide gauge sea level (TGSL) and sea surface heights (SSH) from the satellite were calculated. The influence of VLM was inferred from the differences between the TGSL and SSH, then validated using available GNSS data.</p><p> </p><p>Hourly TGSL for San Fernando is available from 2002 to 2018 with a completeness index (CI) of 37%. The satellite products used were the 20 Hz MLE4 and 1Hz ALES retracked Jason satellite series downloaded from AVISO+ and OpenADB, respectively. The MLE4 product indicates subsidence with a rate of 0.43 ± 0.10 mm/yr, while ALES indicates uplift at 1.93 ± 0.42 mm/yr. GNSS observations at the San Fernando TG benchmark (TGBM) from 2017 to 2019 shows subsidence at 0.74 ± 0.40 mm/yr, which agrees well with the VLM estimate from the difference between TGSL and MLE4 SSH.    </p><p> </p><p>Currimao TG station has a CI of 90% from 2008 to 2016. Satellite products used were the 20 Hz MLE4 and 20 Hz ALES retracked Jason-2 downloaded from AVISO+, and both indicate uplift with a rate of 7.30 ± 0.17 and 6.24 ± 0.25 mm/yr, respectively. The present-day uplift agrees with the geological records, however, there are no GNSS data at the TGBM to validate the present-day vertical motion.</p><p> </p><p>The differences between the present-day vertical motion of San Fernando and Currimao may indicate the influence of other fault systems associated with the Philippine Fault or segmentation of the forearc. Subsidence in San Fernando could imply stress accumulation in the area and the observed uplift in the geological records are cumulative co-seismic vertical displacements.  </p>

Proceedings of the 11th International Conference on Simulation and Modeling Methodologies, Technologies and Applications

A massive decrease in seagrass coverage in the Philippines has been observed in the past several ... more A massive decrease in seagrass coverage in the Philippines has been observed in the past several years due to coastal eutrophication and typhoons. It is key to observe the changes and probable damage in seagrass habitat and develop a way to scientifically back up recovery strategies such as transplantation to increase the probability of rehabilitation success. This study describes the framework development of a transplantation scenario evaluation tool that performs Thalassia hemprichii growth simulation within an uproot site in Palawan as a case study. The growth parameters used include shoot leaf area, spacer length, plastochrone interval, and life expectancy, and horizontal apex density. Base scenario and three scenarios with varying combinations of transplantation density and distribution were applied to the three 4 x 4 grid plots with 24 x 24 cm cell size from classified drone imagery. Results show that transplantation distribution has a greater weight than density with respect to the percent cover responses. Based on the mean and standard deviation of percent cover responses, scenario 1 having 4 transplants with 24 cm intervals is the most suitable for plots 1 and 2, while scenario 2 having 8 transplants (2 per cell) with 24 cm intervals for plot 3.

Evaluation of the cooling effect of green and blue spaces on urban microclimate through numerical simulation: A case study of Iloilo River Esplanade, Philippines

Sustainable Cities and Society, 2021

The aggravating impacts of the urban heat island phenomenon in Philippine cities has motivated pl... more The aggravating impacts of the urban heat island phenomenon in Philippine cities has motivated planners to utilize urban green and blue spaces as a potential mitigation strategy. This study aims to assess the cooling effect (CE), heat reduction (HR), and energy saving potential (ESP) of trees and water along the Iloilo River Esplanade located in Iloilo City, Philippines. Microclimate modelling and simulation during summertime were performed using ENVI-met software and validated using field observations. Results of the study show that the urban park can provide a maximum CE of 2.63°C at 3:00 PM near the southern edge of the river, which is equivalent to a HR of 13,564 J and an ESP of 1.09 × 10−2 kWh. Meanwhile, a temperature increase of up to 0.16°C can be observed at night due to the nocturnal warming effect of water. In terms of spatial distribution, CE, HR, and ESP tend to gradually decrease as the horizontal distance from the park and altitude increases. Moreover, wind direction ...

An integrated use of Sentinel-1 Synthetic Aperture Radar (SAR) and Sentinel-2 multispectral image... more An integrated use of Sentinel-1 Synthetic Aperture Radar (SAR) and Sentinel-2 multispectral imagery is implemented in this study for the assessment of pine forest condition in Camp John Hay, Baguio City, Philippines. These assessments include: (1) the inspection of distribution of dead trees, (2) trends analysis of Sentinel-derived products, and (3) the generation of anomaly maps. Dead trees were identified using Google Earth Pro imagery – the trees were classified as such if they manifest brown or grey foliage with evident foliage loss. The products used for succeeding analyses are sigma naught VH (σ0VH) and sigma naught VV (σ0VV) backscatter derived from Sentinel-1, Sentinel-2 bands 2, 3, 4, 5, 6, 7, 8, 8a, 11, and 12, as well as Sentinel-2 derived vegetation indices S2REP (Sentinel-2 Red-Edge Position Index), NDWI (Normalized Difference Water Index), NDVI (Normalized Difference Water Index), NDII (Normalized Difference Infrared Index), MSI (Moisture Stress Index), IRECI (Inverted...

Change in Seagrass Fractional Cover in Bolinao and Anda , Philippines Derived from Landsat Imaages

Seagrass meadows have been drastically reduced in Bolinao and Anda in the Province of Pangasinan,... more Seagrass meadows have been drastically reduced in Bolinao and Anda in the Province of Pangasinan, Philippines. It is imperative to understand the patterns of seagrass cover change in order to be able to protect seagrasses from further loss. Landsat 7 and Landsat 8 images available for years 1993 to 2014 were processed to determine the spatial and temporal distribution of changes in seagrass coverage. The images were corrected for water column effects using the Lyzenga method. Fractional seagrasscoverages were estimated using the Mixture Tuned Matched Filtering (MTMF) technique on Minimum Noise Fraction (MNF) images. Pixels with high MTMF scores and low Infeasibility values were identified as seagrasses. Seagrass fractional cover was derived from the MTMF scores. The results were compared to seagrass cover maps derived from high resolution. Zonal analysis was performed to characterize seagrass changes in eight zones. In 1993, seagrasses, in varying densities, cover approximately 71.0...

Japan Geoscience Union, 2017

A dynamic model which reproduces the physical and biogeochemical environmental conditions and ass... more A dynamic model which reproduces the physical and biogeochemical environmental conditions and associated factors, can be an effective tool in determining coastal management strategies in an area influenced by intensive human activities. The outputs of the model suggest the need for proper assessment of the effectiveness of coastal management efforts which is made difficult by multiple environmental stressors such as pollutant discharge from rivers and from unregulated mariculture, the effects of which vary in space and time. Seagrass beds are found in many coastal areas and their responses are regarded as key indicators of ecosystem health, are nursery grounds for fishes and invertebrates, and are major sources of primary production in coastal waters. However, their recent disappearance along many coastal areas in the world caused by anthropogenic stressors has become a serious global concern. Our study site is located along the coastal towns of Bolinao and Anda in northwestern part...

Comparative Assessment of Water Column Correction Techniques for Seagrass Mapping Using Worldview-2 Image

Benthic cover mapping has always been challenging, primarily due to the compounding effects of th... more Benthic cover mapping has always been challenging, primarily due to the compounding effects of the overlying water column. While a number of algorithms have been developed to address these, research on the application and performance assessment of such methods to seagrass mapping using high-resolution satellite images is limited. This research dealt with seagrass mapping using WorldView-2 images with an emphasis on the evaluation of the relative performance of different water column correction methods and on the band combinations. A geometric correction was conducted using DGPS survey coordinates. Atmospheric correction was performed using the Fast Line-of-Sight Atmospheric Analysis (FLAASH) model as this produced image-derived spectra similar to field spectra. Three water column correction models were applied and compared, namely, Lyzenga’s Optical Model (LOM), Stumpf’s Ratio Model (SRM), and Simple Radiative Transfer Model (SRTM). Maximum Likelihood Classification (MLC) was used ...

Japan Geoscience Union, 2016

1.Mutsu Institute for Oceanography, Japan Agency for Marine-Earth Science and Technology , 2.Akke... more 1.Mutsu Institute for Oceanography, Japan Agency for Marine-Earth Science and Technology , 2.Akkeshi Marine Station, Hokkaido University, 3.Graduate School of Kuroshio Science, Kochi University, 4.Atmosphere and Ocean Research Institute, The University of Tokyo, 5.Marine Science Institute, University of the Philippines-Diliman, 6.Mindanao State University at Naawan, the Philippine, 7.College of Engineering, University of the Philippines, 8.School of Environment and Society, Tokyo Institute of Technology, 9.Present address: Hokkaido National Fisheries Research Institute, Fisheries Research Agency

Remapping the Philippine reefs: the Coral Reef Visualization and Assessment (CoRVA) program

As Filipinos are highly dependent on the coral reef ecosystem, the conservation of these natural ... more As Filipinos are highly dependent on the coral reef ecosystem, the conservation of these natural resources is crucial in contributing to the food security for the Filipino population. In the late 1970's, the first national coral mapping program highlighted that our reefs were generally in a fair condition. The Co ral R eef V isualization and A ssessment (CoRVA) program attempts to undertake the task of contributing to the re- evaluation of the state of the Philippine coral reefs, particularly the NIPAS sites. CoRVA is a comprehensive program focused on assessing the reef ecosystem by means of reef visualization and monitoring, associated habitat (seagrass & mangrove) assessment, reef fish assessment and deep reef exploration. This ecosystem assessment approach, along with outputs from the analysis of the coastal integrity, allows us to select sites which require additional protection and rehabilitation. By including ocean connectivity, we can establish or effectively strengthen ...

Soil erosion remains an environmental concern in the Laguna Lake watershed where land u se c hang... more Soil erosion remains an environmental concern in the Laguna Lake watershed where land u se c hanges have ca used increased sediment delivery into the lake ca using continued shallowing of the lake, underscoring the importance of an integrated watershed- lake management. However, soil erosion in the watershed has not been comprehensively assessed and approaches to doing this have not been explored fully. There is also a need to develop an assessment system which local government units within the watershed can use in d ealing with erosion p roblems. In this s tudy, three spatially distributed-type models - Universal Soil Loss Equation (USLE), Unit Stream Power Erosion/Deposition (USPED), and CASC2D - implemented in GIS were used to assess changes in the relative magnitude and p attern of soil erosion as a result of land use/land cover changes determined from Landsat images (1993-2002) and to examine their utility in identifying "hot spots", where soil conservation measures a...

Geovisualization of Land Use and Zoning Ordinances in Boracay Island, Malay, Aklan

Integrated Use of Electrical Resistance Tomography and Radon Monitoring for Characterizing Submarine Groundwater Discharge Dynamics in a Fringing Reef

Accurate information on mangrove forest extent is essential for both natural resources management... more Accurate information on mangrove forest extent is essential for both natural resources management and integrated land and sea use planning. In this study, we assessed the spatial distribution of mangrove forests in the provinces of Southwestern Luzon for the year 2015 using publicly available Landsat 8 images. The images were calibrated and atmospherically corrected using the FLAASH model. Support Vector Machine (SVM) was used to classify the images into four classes (i.e., mangroves, terrestrial non-mangroves vegetation, built-up plus bare soil, and cloud cover plus shadows). Results generated the following total areas of mangrove forest cover per province: 42,999 ha in Palawan; 398 ha in Batangas; 3,259 ha in Oriental Mindoro, 1,386 ha in Occidental Mindoro, 137 ha in Cavite and 10,570 ha in Quezon. In general, the mangrove areal estimates of our study were comparable to previous remote sensing studies conducted in the Philippines. Although there are some discrepancies with the re...

Seagrass biomass and sediment carbon in conserved and disturbed seascape

Ecological Research

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing

Chlorophyll-a (Chl-a) concentration, a crucial indicator of phytoplankton biomass, is sensitive t... more Chlorophyll-a (Chl-a) concentration, a crucial indicator of phytoplankton biomass, is sensitive to seasonality. The variations in trophic states regarding seasonality and the changes of spectral properties of water bodies pose uncertainties to the accuracy of remote sensing semi-empirical models. In particular, lakes in subtropical regions generally experience different trophic states in dry and wet seasons. In this study, a season-insensitive Chl-a retrieval model using multi-task convolution neural network with multiple output layers (MCNN) is proposed. A layersharing network combined with data augmentation is adopted to alleviate the issue of insufficient quantity of in situ samples. In addition, a hyperparameter optimization is performed to automatically refine the MCNN architecture. To evaluate the accuracy of proposed method, Laguna Lake, one of the largest lakes in Southeast Asia, is selected as the validation target. The lake is characterized by oligotrophic and mesotrophic states in wet season, whereas the states change to mesotrophic and lowlevel eutrophic states in dry season. A collection of Sentinel-3 Ocean and Land Colour Instrument Level-2 images and 409 in situ samples with the Chl-a concentration range 1.24-22.30 mg m −3 were used for model calibration and evaluation. Experimental results showed that MCNN with the performance of average R 2 =0.74, RMSE=2.06 mg m −3 , Pearson's r=0.86 outperforms related semi-empirical models including normalized difference chlorophyll index, two-band and three-band models, and WaterNet. The Chl-a prediction accuracy was improved by 7.19-14.6%, in terms of RMSE, compared with WaterNet.

Development of a Rapid Mangrove Zonation Mapping Workflow Using Sentinel 2-Derived Indices and Biophysical Dataset

Frontiers in Remote Sensing

Moderate to high resolution satellite imageries are commonly used in mapping mangrove cover from ... more Moderate to high resolution satellite imageries are commonly used in mapping mangrove cover from local to global scales. In addition to extent information, studies such as mangrove composition, ecology, and distribution analysis require further information on mangrove zonation. Mangrove zonation refers to unique sections within a mangrove forest being dominated by a similar family, genus, or species. This can be observed both in natural and planted mangrove forests. In this study, a mapping workflow was developed to detect zonation in test mangrove forest sites in Katunggan-It Ibajay (KII) Ecopark (Aklan), Bintuan (Coron), Bogtong, and Sagrada (Busuanga) in the Philippines and Fukido Mangrove Park (Ishigaki, Japan) using Sentinel-2 imagery. The methodology was then applied to generate a nationwide mangrove zonation map of the Philippines for year 2020. Combination of biophysical products, water, and vegetation indices were used as classification inputs including leaf area index (LAI...

ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences

Monitoring the progress of building's construction is critical in construction management. Howeve... more Monitoring the progress of building's construction is critical in construction management. However, measuring the building construction's progress are still manual, time consuming, error prone, and impose tedious process of analysis leading to delays, additional costings and effort. The main goal of this research is to develop a methodology for building construction progress monitoring based on 3D as-built model of the building from unmanned aerial system (UAS) images, 4D as-planned model (with construction schedule integrated) and, GIS analysis. Monitoring was done by capturing videos of the building with a camera-equipped UAS. Still images were extracted, filtered, bundle-adjusted, and 3D as-built model was generated using open source photogrammetric software. The as-planned model was generated from digitized CAD drawings using GIS. The 3D as-built model was aligned with the 4D asplanned model of building formed from extrusion of building elements, and integration of the construction's planned schedule. The construction progress is visualized via color-coding the building elements in the 3D model. The developed methodology was conducted and applied from the data obtained from an actual construction site. Accuracy in detecting 'built' or 'not built' building elements ranges from 82-84% and precision of 50-72%. Quantified progress in terms of the number of building elements are 21.31% (November 2016), 26.84% (January 2017) and 44.19% (March 2017). The results can be used as an input for progress monitoring performance of construction projects and improving related decision-making process.

Modeling seagrass bed dynamics under environmental impacts of intensive mariculture activities in Bolinao and Anda, the Philippines

Estuarine, Coastal and Shelf Science

Scaling relations and substrate conditions controlling the complexity of Rhizophora prop root system

Estuarine, Coastal and Shelf Science

Abstract The complex structures of the prop root system of the mangrove genus Rhizophora attenuat... more Abstract The complex structures of the prop root system of the mangrove genus Rhizophora attenuate storm surges and tsunamis and promote sedimentation. While quantification of the mangrove's drag force is essential for assessing the mangroves' ability to reduce the risk of disaster and vulnerability to rising sea-level, the projected area of prop root system having multiple orders of prop roots (e.g., first-, second-, and third-order prop roots, where the root order indicates the level of branching from the stem) are still unexplored. To contribute to the quantitative evaluation of the mangrove's drag force, we investigated the vertical profile of whole-tree prop root projected area and the number of prop roots of 156 trees sampled from Indonesia, the Philippines, and Japan. Our results showed that prop roots above the first-order contribute up to 80% of the whole-tree prop root projected area, highlighting the importance of the presence of second-, third-, and even higher-order prop roots on the drag force exerted by mangroves. Based on field data, an empirical model for the prop root system, described by a scaling factor (S), and maximum and minimum root heights (HRmax, HRmin), was developed by assuming that the size distribution of prop roots follows a constant scaling factor S. S and HRmax showed significant correlations with stem diameter at breast height suggesting the scaling relations in the prop root system. The model, which employs the site- and species-specific regression models for S and HRmax, reproduced the vertical distribution of the number of prop roots – a good predictor of the prop root projected area – with reasonable accuracy. However, the site- and species-specific scaling relations are highly variable depending on the environment, suggesting morphological plasticity in the prop root system. Rhizophora trees that grow on a shallow sediment layer (around 0.1 m thickness) tend to produce more prop roots compared with those on a thicker sediment layer suggesting a morphological response of the prop root system to increase below-ground root biomass where below-ground root development is physically constrained. Multivariate analysis indicated that hard substrate also possibly contributes to higher complexity of prop root system. However, prediction of the site- and species-specific scaling relations from these environmental variables still needs to be improved. Further research is needed to explain the mechanisms of morphological response of prop root systems to environmental gradients and to establish a generalized model for predicting the prop root system in various environments.

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences

The Agricultural Resources Extraction from LiDAR Surveys (PARMAP) project component of the Nation... more The Agricultural Resources Extraction from LiDAR Surveys (PARMAP) project component of the Nationwide Detailed Resources Assessment using LiDAR (Phil-LiDAR 2) Program aims to produce detailed agricultural maps using LiDAR. Agricultural land cover at crop level was classified through object based image analysis using Support Vector Machine as classifier and LiDAR derivatives from point cloud (2 points per sq.m.) and orthophoto (0.5-meter resolution) as inputs. An accuracy of at least 90%, assessed using validation points from the field and through image interpretation, was required before proceeding to post-processing and map layout. Knowledge sharing and capacity development facilitated by the University of the Philippines Diliman (UPD) enabled partner universities across the Philippines to produce outputs for their assigned region. Considering output layers were generated by multiple teams working on different landscape complexities with some degree of data quality variability, quality checking is crucial to ensure accuracy standards were met. UPD PARMap devised a centralized and end-to-end scheme divided into four stepsland classification, GIS post-processing, schema application, and map layout. At each step, a block is reviewed and, subsequently, either approved or returned with documentation on required revisions. Turnaround time of review is at least one block (area ranging from 10 to 580 sq. km.) per day. For coastal municipalities, an additional integration process to incorporate mapped coastal features was applied. Common problems observed during quality checking include misclassifications, gaps between features, incomplete attributes and missing map elements. Some issues are particular to specific blocks such as problematic LiDAR derivatives. UPD addressed these problems through discussion and mentoring visits to partner universities. As of March 2017, a total of 336 municipal agricultural maps have been turned-over to various stakeholders. For the remaining months of the program, an additional 360 maps are expected to be distributed.

Present-day vertical land movement in San Fernando (La Union) and Currimao (Ilocos Norte), northwest Luzon, Philippines

<p>The northwestern coast of Luzon Island is located within the forearc region of t... more <p>The northwestern coast of Luzon Island is located within the forearc region of the Manila Trench where emergent coral reef platforms have been reported; and an uplift rate of 0.5 m/kyr has been estimated for the past 7,000 years in San Fernando and Currimao. This study examined the present-day vertical land movement (VLM) in both sites using tide gauge records and retracked Jason satellite altimeter missions. Both the tide gauge and satellite data were corrected for tides using the T_Tide algorithm and the difference between the tide gauge sea level (TGSL) and sea surface heights (SSH) from the satellite were calculated. The influence of VLM was inferred from the differences between the TGSL and SSH, then validated using available GNSS data.</p><p> </p><p>Hourly TGSL for San Fernando is available from 2002 to 2018 with a completeness index (CI) of 37%. The satellite products used were the 20 Hz MLE4 and 1Hz ALES retracked Jason satellite series downloaded from AVISO+ and OpenADB, respectively. The MLE4 product indicates subsidence with a rate of 0.43 ± 0.10 mm/yr, while ALES indicates uplift at 1.93 ± 0.42 mm/yr. GNSS observations at the San Fernando TG benchmark (TGBM) from 2017 to 2019 shows subsidence at 0.74 ± 0.40 mm/yr, which agrees well with the VLM estimate from the difference between TGSL and MLE4 SSH.    </p><p> </p><p>Currimao TG station has a CI of 90% from 2008 to 2016. Satellite products used were the 20 Hz MLE4 and 20 Hz ALES retracked Jason-2 downloaded from AVISO+, and both indicate uplift with a rate of 7.30 ± 0.17 and 6.24 ± 0.25 mm/yr, respectively. The present-day uplift agrees with the geological records, however, there are no GNSS data at the TGBM to validate the present-day vertical motion.</p><p> </p><p>The differences between the present-day vertical motion of San Fernando and Currimao may indicate the influence of other fault systems associated with the Philippine Fault or segmentation of the forearc. Subsidence in San Fernando could imply stress accumulation in the area and the observed uplift in the geological records are cumulative co-seismic vertical displacements.  </p>

Proceedings of the 11th International Conference on Simulation and Modeling Methodologies, Technologies and Applications

A massive decrease in seagrass coverage in the Philippines has been observed in the past several ... more A massive decrease in seagrass coverage in the Philippines has been observed in the past several years due to coastal eutrophication and typhoons. It is key to observe the changes and probable damage in seagrass habitat and develop a way to scientifically back up recovery strategies such as transplantation to increase the probability of rehabilitation success. This study describes the framework development of a transplantation scenario evaluation tool that performs Thalassia hemprichii growth simulation within an uproot site in Palawan as a case study. The growth parameters used include shoot leaf area, spacer length, plastochrone interval, and life expectancy, and horizontal apex density. Base scenario and three scenarios with varying combinations of transplantation density and distribution were applied to the three 4 x 4 grid plots with 24 x 24 cm cell size from classified drone imagery. Results show that transplantation distribution has a greater weight than density with respect to the percent cover responses. Based on the mean and standard deviation of percent cover responses, scenario 1 having 4 transplants with 24 cm intervals is the most suitable for plots 1 and 2, while scenario 2 having 8 transplants (2 per cell) with 24 cm intervals for plot 3.

Evaluation of the cooling effect of green and blue spaces on urban microclimate through numerical simulation: A case study of Iloilo River Esplanade, Philippines

Sustainable Cities and Society, 2021

The aggravating impacts of the urban heat island phenomenon in Philippine cities has motivated pl... more The aggravating impacts of the urban heat island phenomenon in Philippine cities has motivated planners to utilize urban green and blue spaces as a potential mitigation strategy. This study aims to assess the cooling effect (CE), heat reduction (HR), and energy saving potential (ESP) of trees and water along the Iloilo River Esplanade located in Iloilo City, Philippines. Microclimate modelling and simulation during summertime were performed using ENVI-met software and validated using field observations. Results of the study show that the urban park can provide a maximum CE of 2.63°C at 3:00 PM near the southern edge of the river, which is equivalent to a HR of 13,564 J and an ESP of 1.09 × 10−2 kWh. Meanwhile, a temperature increase of up to 0.16°C can be observed at night due to the nocturnal warming effect of water. In terms of spatial distribution, CE, HR, and ESP tend to gradually decrease as the horizontal distance from the park and altitude increases. Moreover, wind direction ...

An integrated use of Sentinel-1 Synthetic Aperture Radar (SAR) and Sentinel-2 multispectral image... more An integrated use of Sentinel-1 Synthetic Aperture Radar (SAR) and Sentinel-2 multispectral imagery is implemented in this study for the assessment of pine forest condition in Camp John Hay, Baguio City, Philippines. These assessments include: (1) the inspection of distribution of dead trees, (2) trends analysis of Sentinel-derived products, and (3) the generation of anomaly maps. Dead trees were identified using Google Earth Pro imagery – the trees were classified as such if they manifest brown or grey foliage with evident foliage loss. The products used for succeeding analyses are sigma naught VH (σ0VH) and sigma naught VV (σ0VV) backscatter derived from Sentinel-1, Sentinel-2 bands 2, 3, 4, 5, 6, 7, 8, 8a, 11, and 12, as well as Sentinel-2 derived vegetation indices S2REP (Sentinel-2 Red-Edge Position Index), NDWI (Normalized Difference Water Index), NDVI (Normalized Difference Water Index), NDII (Normalized Difference Infrared Index), MSI (Moisture Stress Index), IRECI (Inverted...

Change in Seagrass Fractional Cover in Bolinao and Anda , Philippines Derived from Landsat Imaages

Seagrass meadows have been drastically reduced in Bolinao and Anda in the Province of Pangasinan,... more Seagrass meadows have been drastically reduced in Bolinao and Anda in the Province of Pangasinan, Philippines. It is imperative to understand the patterns of seagrass cover change in order to be able to protect seagrasses from further loss. Landsat 7 and Landsat 8 images available for years 1993 to 2014 were processed to determine the spatial and temporal distribution of changes in seagrass coverage. The images were corrected for water column effects using the Lyzenga method. Fractional seagrasscoverages were estimated using the Mixture Tuned Matched Filtering (MTMF) technique on Minimum Noise Fraction (MNF) images. Pixels with high MTMF scores and low Infeasibility values were identified as seagrasses. Seagrass fractional cover was derived from the MTMF scores. The results were compared to seagrass cover maps derived from high resolution. Zonal analysis was performed to characterize seagrass changes in eight zones. In 1993, seagrasses, in varying densities, cover approximately 71.0...

Japan Geoscience Union, 2017

A dynamic model which reproduces the physical and biogeochemical environmental conditions and ass... more A dynamic model which reproduces the physical and biogeochemical environmental conditions and associated factors, can be an effective tool in determining coastal management strategies in an area influenced by intensive human activities. The outputs of the model suggest the need for proper assessment of the effectiveness of coastal management efforts which is made difficult by multiple environmental stressors such as pollutant discharge from rivers and from unregulated mariculture, the effects of which vary in space and time. Seagrass beds are found in many coastal areas and their responses are regarded as key indicators of ecosystem health, are nursery grounds for fishes and invertebrates, and are major sources of primary production in coastal waters. However, their recent disappearance along many coastal areas in the world caused by anthropogenic stressors has become a serious global concern. Our study site is located along the coastal towns of Bolinao and Anda in northwestern part...

Comparative Assessment of Water Column Correction Techniques for Seagrass Mapping Using Worldview-2 Image

Benthic cover mapping has always been challenging, primarily due to the compounding effects of th... more Benthic cover mapping has always been challenging, primarily due to the compounding effects of the overlying water column. While a number of algorithms have been developed to address these, research on the application and performance assessment of such methods to seagrass mapping using high-resolution satellite images is limited. This research dealt with seagrass mapping using WorldView-2 images with an emphasis on the evaluation of the relative performance of different water column correction methods and on the band combinations. A geometric correction was conducted using DGPS survey coordinates. Atmospheric correction was performed using the Fast Line-of-Sight Atmospheric Analysis (FLAASH) model as this produced image-derived spectra similar to field spectra. Three water column correction models were applied and compared, namely, Lyzenga’s Optical Model (LOM), Stumpf’s Ratio Model (SRM), and Simple Radiative Transfer Model (SRTM). Maximum Likelihood Classification (MLC) was used ...

Japan Geoscience Union, 2016

1.Mutsu Institute for Oceanography, Japan Agency for Marine-Earth Science and Technology , 2.Akke... more 1.Mutsu Institute for Oceanography, Japan Agency for Marine-Earth Science and Technology , 2.Akkeshi Marine Station, Hokkaido University, 3.Graduate School of Kuroshio Science, Kochi University, 4.Atmosphere and Ocean Research Institute, The University of Tokyo, 5.Marine Science Institute, University of the Philippines-Diliman, 6.Mindanao State University at Naawan, the Philippine, 7.College of Engineering, University of the Philippines, 8.School of Environment and Society, Tokyo Institute of Technology, 9.Present address: Hokkaido National Fisheries Research Institute, Fisheries Research Agency

Remapping the Philippine reefs: the Coral Reef Visualization and Assessment (CoRVA) program

As Filipinos are highly dependent on the coral reef ecosystem, the conservation of these natural ... more As Filipinos are highly dependent on the coral reef ecosystem, the conservation of these natural resources is crucial in contributing to the food security for the Filipino population. In the late 1970's, the first national coral mapping program highlighted that our reefs were generally in a fair condition. The Co ral R eef V isualization and A ssessment (CoRVA) program attempts to undertake the task of contributing to the re- evaluation of the state of the Philippine coral reefs, particularly the NIPAS sites. CoRVA is a comprehensive program focused on assessing the reef ecosystem by means of reef visualization and monitoring, associated habitat (seagrass & mangrove) assessment, reef fish assessment and deep reef exploration. This ecosystem assessment approach, along with outputs from the analysis of the coastal integrity, allows us to select sites which require additional protection and rehabilitation. By including ocean connectivity, we can establish or effectively strengthen ...

Soil erosion remains an environmental concern in the Laguna Lake watershed where land u se c hang... more Soil erosion remains an environmental concern in the Laguna Lake watershed where land u se c hanges have ca used increased sediment delivery into the lake ca using continued shallowing of the lake, underscoring the importance of an integrated watershed- lake management. However, soil erosion in the watershed has not been comprehensively assessed and approaches to doing this have not been explored fully. There is also a need to develop an assessment system which local government units within the watershed can use in d ealing with erosion p roblems. In this s tudy, three spatially distributed-type models - Universal Soil Loss Equation (USLE), Unit Stream Power Erosion/Deposition (USPED), and CASC2D - implemented in GIS were used to assess changes in the relative magnitude and p attern of soil erosion as a result of land use/land cover changes determined from Landsat images (1993-2002) and to examine their utility in identifying "hot spots", where soil conservation measures a...

Geovisualization of Land Use and Zoning Ordinances in Boracay Island, Malay, Aklan

Integrated Use of Electrical Resistance Tomography and Radon Monitoring for Characterizing Submarine Groundwater Discharge Dynamics in a Fringing Reef

Accurate information on mangrove forest extent is essential for both natural resources management... more Accurate information on mangrove forest extent is essential for both natural resources management and integrated land and sea use planning. In this study, we assessed the spatial distribution of mangrove forests in the provinces of Southwestern Luzon for the year 2015 using publicly available Landsat 8 images. The images were calibrated and atmospherically corrected using the FLAASH model. Support Vector Machine (SVM) was used to classify the images into four classes (i.e., mangroves, terrestrial non-mangroves vegetation, built-up plus bare soil, and cloud cover plus shadows). Results generated the following total areas of mangrove forest cover per province: 42,999 ha in Palawan; 398 ha in Batangas; 3,259 ha in Oriental Mindoro, 1,386 ha in Occidental Mindoro, 137 ha in Cavite and 10,570 ha in Quezon. In general, the mangrove areal estimates of our study were comparable to previous remote sensing studies conducted in the Philippines. Although there are some discrepancies with the re...

Seagrass biomass and sediment carbon in conserved and disturbed seascape

Ecological Research

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing

Chlorophyll-a (Chl-a) concentration, a crucial indicator of phytoplankton biomass, is sensitive t... more Chlorophyll-a (Chl-a) concentration, a crucial indicator of phytoplankton biomass, is sensitive to seasonality. The variations in trophic states regarding seasonality and the changes of spectral properties of water bodies pose uncertainties to the accuracy of remote sensing semi-empirical models. In particular, lakes in subtropical regions generally experience different trophic states in dry and wet seasons. In this study, a season-insensitive Chl-a retrieval model using multi-task convolution neural network with multiple output layers (MCNN) is proposed. A layersharing network combined with data augmentation is adopted to alleviate the issue of insufficient quantity of in situ samples. In addition, a hyperparameter optimization is performed to automatically refine the MCNN architecture. To evaluate the accuracy of proposed method, Laguna Lake, one of the largest lakes in Southeast Asia, is selected as the validation target. The lake is characterized by oligotrophic and mesotrophic states in wet season, whereas the states change to mesotrophic and lowlevel eutrophic states in dry season. A collection of Sentinel-3 Ocean and Land Colour Instrument Level-2 images and 409 in situ samples with the Chl-a concentration range 1.24-22.30 mg m −3 were used for model calibration and evaluation. Experimental results showed that MCNN with the performance of average R 2 =0.74, RMSE=2.06 mg m −3 , Pearson's r=0.86 outperforms related semi-empirical models including normalized difference chlorophyll index, two-band and three-band models, and WaterNet. The Chl-a prediction accuracy was improved by 7.19-14.6%, in terms of RMSE, compared with WaterNet.

Development of a Rapid Mangrove Zonation Mapping Workflow Using Sentinel 2-Derived Indices and Biophysical Dataset

Frontiers in Remote Sensing

Moderate to high resolution satellite imageries are commonly used in mapping mangrove cover from ... more Moderate to high resolution satellite imageries are commonly used in mapping mangrove cover from local to global scales. In addition to extent information, studies such as mangrove composition, ecology, and distribution analysis require further information on mangrove zonation. Mangrove zonation refers to unique sections within a mangrove forest being dominated by a similar family, genus, or species. This can be observed both in natural and planted mangrove forests. In this study, a mapping workflow was developed to detect zonation in test mangrove forest sites in Katunggan-It Ibajay (KII) Ecopark (Aklan), Bintuan (Coron), Bogtong, and Sagrada (Busuanga) in the Philippines and Fukido Mangrove Park (Ishigaki, Japan) using Sentinel-2 imagery. The methodology was then applied to generate a nationwide mangrove zonation map of the Philippines for year 2020. Combination of biophysical products, water, and vegetation indices were used as classification inputs including leaf area index (LAI...

ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences

Monitoring the progress of building's construction is critical in construction management. Howeve... more Monitoring the progress of building's construction is critical in construction management. However, measuring the building construction's progress are still manual, time consuming, error prone, and impose tedious process of analysis leading to delays, additional costings and effort. The main goal of this research is to develop a methodology for building construction progress monitoring based on 3D as-built model of the building from unmanned aerial system (UAS) images, 4D as-planned model (with construction schedule integrated) and, GIS analysis. Monitoring was done by capturing videos of the building with a camera-equipped UAS. Still images were extracted, filtered, bundle-adjusted, and 3D as-built model was generated using open source photogrammetric software. The as-planned model was generated from digitized CAD drawings using GIS. The 3D as-built model was aligned with the 4D asplanned model of building formed from extrusion of building elements, and integration of the construction's planned schedule. The construction progress is visualized via color-coding the building elements in the 3D model. The developed methodology was conducted and applied from the data obtained from an actual construction site. Accuracy in detecting 'built' or 'not built' building elements ranges from 82-84% and precision of 50-72%. Quantified progress in terms of the number of building elements are 21.31% (November 2016), 26.84% (January 2017) and 44.19% (March 2017). The results can be used as an input for progress monitoring performance of construction projects and improving related decision-making process.

Modeling seagrass bed dynamics under environmental impacts of intensive mariculture activities in Bolinao and Anda, the Philippines

Estuarine, Coastal and Shelf Science

Scaling relations and substrate conditions controlling the complexity of Rhizophora prop root system

Estuarine, Coastal and Shelf Science

Abstract The complex structures of the prop root system of the mangrove genus Rhizophora attenuat... more Abstract The complex structures of the prop root system of the mangrove genus Rhizophora attenuate storm surges and tsunamis and promote sedimentation. While quantification of the mangrove's drag force is essential for assessing the mangroves' ability to reduce the risk of disaster and vulnerability to rising sea-level, the projected area of prop root system having multiple orders of prop roots (e.g., first-, second-, and third-order prop roots, where the root order indicates the level of branching from the stem) are still unexplored. To contribute to the quantitative evaluation of the mangrove's drag force, we investigated the vertical profile of whole-tree prop root projected area and the number of prop roots of 156 trees sampled from Indonesia, the Philippines, and Japan. Our results showed that prop roots above the first-order contribute up to 80% of the whole-tree prop root projected area, highlighting the importance of the presence of second-, third-, and even higher-order prop roots on the drag force exerted by mangroves. Based on field data, an empirical model for the prop root system, described by a scaling factor (S), and maximum and minimum root heights (HRmax, HRmin), was developed by assuming that the size distribution of prop roots follows a constant scaling factor S. S and HRmax showed significant correlations with stem diameter at breast height suggesting the scaling relations in the prop root system. The model, which employs the site- and species-specific regression models for S and HRmax, reproduced the vertical distribution of the number of prop roots – a good predictor of the prop root projected area – with reasonable accuracy. However, the site- and species-specific scaling relations are highly variable depending on the environment, suggesting morphological plasticity in the prop root system. Rhizophora trees that grow on a shallow sediment layer (around 0.1 m thickness) tend to produce more prop roots compared with those on a thicker sediment layer suggesting a morphological response of the prop root system to increase below-ground root biomass where below-ground root development is physically constrained. Multivariate analysis indicated that hard substrate also possibly contributes to higher complexity of prop root system. However, prediction of the site- and species-specific scaling relations from these environmental variables still needs to be improved. Further research is needed to explain the mechanisms of morphological response of prop root systems to environmental gradients and to establish a generalized model for predicting the prop root system in various environments.