PhilGEOS 2013, through its Technical Program Committee, is pleased to announce the list of abstracts accepted for oral and poster presentations during the technical sessions of the symposium.
Authors should have already received the notice of acceptance through email. The authors are requested to prepare their full paper and have it submitted on or before 15 November 2013 by email (email@example.com). The full paper guidelines and format is available here.
Geomatics for Agriculture
Assessment of the variability of yield of maize in Lilongwe district in relation to climate change using DSSAT model in Malawi country (Oral)
The study generates information on seasonal rainfall characteristics that will be vital in exploiting the possibilities offered by climatic variability and offers opportunities for adapting to seasonal distribution to improve and stabilize maize crop yields. The need to generate agronomically relevant seasonal rainfall and temperature characteristics to guide decision making for example in terms of adaptation and mitigation strategies in agriculture. DSSAT model was used to run the crop simulations for the cropping season of 1996/1997 to 2007/2008 for growth, development and yields of hybrid Maize at Chitedze Research Station, and to assess which agronomic management practices can help adapt to climate change. The DSSAT model was used to provide information concerning management options such as the timing of planting, specifically the impact on the yield with reference to different planting dates at Chitedze Research Station. The results show that planting maize early December increase yield other than late and early November, late December, and late and early January for Chitedze, supported by statistical values using the Index of Agreement of 0.861 (d-stat) which signifies the closeness of the relationship between the observed and the simulated yield, also the efficiency of DSSAT model to simulate yield with little Root Mean Square of Error (220.689 kg/ha). R2=0.770, mean difference of –143.41 kg/ha. The mean observed Maize yield was 1350 kg/ha and the mean simulated being 1206.59 kg/ha through regression analysis they are positively correlated. Planting date is directly related to the yield of maize with reference to rainfall received with minimal variability. Maize crop totally depends upon the amount and frequency of rainfall as well as its distribution on temporal and spatial scales, especially the reproductive and the vegetative phases are prone to rainfall variability.
Bunda College of Agriculture, Lilongwe, Malawi
GeoWEPP Application in Determining Runoff and Sediment Yield in Agriculturally Active Watershed of Mapawa (Oral)
The Geospatial Interface for Water Erosion Prediction Project (GeoWEPP) model was applied in the study to determine runoff and sediment yield in Mapawa watershed at Lantapan, Bukidnon. The watershed is actively cultivated with common agricultural corps raised like cereals, root crops, and vegetables. The average elevation of the area is 1,258 meters above sea level with a slope ranging from 0.5 to 75%. As an extension to leading GIS application, GeoWEPP can predict specific location of soil erosion onsite and can locate possible deposition areas offsite. The model can also generate map layers indicating sediments from the contributing hillslopes for site specification. It can also predict runoff and sediment yield on per rainfall event basis as in addition to annual values. Georeferenced datasets were prepared corresponding to the four main input files such as climate, slope, land management, and soil properties for the simulation run within GeoWEPP. Climate input file was processed from a one year localized weather dataset using a standalone program called the breakpoint climate data generator (BPCDG). Slope input file was derived from spurious-free 3-meter resolution digital elevation model (DEM). Soil and management input files were derived using primary data from the site. Separate database files were also created to link WEPP with the most common GIS application. After series of calibration, sediment yield at the main weir, and sub weirs 1, 2, 3, and 4 were predicted with values of 22.1, 3.7, 5.2, 3.5, and 39.0 t.ha-1yr-1, respectively. Similarly, runoff and sediment yield at the main weir for 20 rainfall events were predicted with an average value of 11,121.0 m3 and 11.2 tons, respectively. The predictive accuracy of the model was tested using the data collected from the five weirs within the watershed. Results show that the average root mean square errors (RMSE) between observed and predicted sediment yield values was 5.32 with an index of agreement (IA) and regression coefficient (R2) of 0.96 and 0.95, respectively. Model results on per rainfall event both for runoff and sediment yield for 20 rainfall events were also compared with data collected at the main weir. Results showed that the RMSE, IA and R2 values for runoff were 12,153.80, 0.55, and 0.93, respectively. Likewise, the RMSE, IA and R2 values for sediment yield were 5.00, 0.95, and 0.83, respectively. Overall, the model showed satisfactory performance despite limited number of datasets for validation. This implies applicability of GeoWEPP in watersheds with intensive agricultural activities and steeper hillslopes.
George R. Puno
Central Mindanao University, Musuan, Bukidnon
Mappping the starch-rich Sago palms through maximum likelihood classification of multi-source data (Oral)
An approach to map Sago palms using multi-source data is presented in this paper. The approach consisted of applying the Maximum Likelihood Classifier (MLC) to a stack of calibrated and co-registered ALOS AVNIR-2 image, NDVI, Envisat ASAR image, and an ASTER GDEM of the study area located in Agusan del Sur, Mindanao, Philippines. The MLC was applied to eight combinations of the ALOS AVNIR-2 reflectance bands, NDVI, Envisat ASAR and ASTER GDEM to derive classification maps. Results indicate that more than 90% overall classification accuracy and more than 90% Producer’s Accuracy for Sago Palm can be both achieved if MLC is applied to any of the 8 combinations. However, the User’s Accuracy for Sago palm is only 77% when using the ALOS AVNIR2 image alone as input which indicates overestimation of Sago palm classification due to high commission errors. Better User’s Accuracy of 91.37% was achieved when MLC was applied to a combination of ALOS AVNIR 2, NDVI, Envisat ASAR and ASTER GDEM. With this significant increase in User’s accuracy, the approach of applying MLC to a combination of these multi-source datasets shows potential in mapping Sago palms in other areas in the Philippines.
Jojene R. Santillan
Research Laboratory for Applied Geodesy and Space Technology, Training Center for Applied Geodesy and Photogrammetry, University of the Philippines, Diliman, Quezon City, Metro Manila
Utilizing Smartphone Potential for GPS Embedded Data Gathering Tool (Oral)
Timely data is very important in Research and Development operations for project evaluation. Data collection, transmission, storage and presentation from multi-location are tedious tasks. For wider coverage, it is more difficult, time-consuming, and expensive owing to the country’s archipelagic geography using the conventional ways. Hence, the use of currently available information and communications Technology (ICT) technologies and Information Systems (IS) may bring merits. Smartphone applications for field data collection to facilitate real-time field data collection and transmission was used in a pilot project in Central Luzon. A customized data collection form utilizing the device built-in GPS to geo-tag the farmer’s trading post, farm location and warehouse. Short messaging service (SMS) was used as data transmission channel because of wider signal coverage. The data collection application was directly interacted with the informant by filling up e-forms in the smartphone during farmer interview. The compact data was stored in the phone and when signal is available, it is simultaneously transmitted via SMS at current rate which is not network specific. Then data was received by a terminal modem and passed on to the server-based information systems for organization and storage to the database system. The management information system (MIS) provided window for the GIS-based map presentation with attribute data for review by experts and stakeholders. The data collection to storage was efficiently done in less than 1 hour provided that network provider has no problem. It is more economic than using paper survey forms because the cost per event is just 1 peso. The data collection can be activity-based for more accurate data capture by minimizing recall. This can replace, integrate or enhance the existing methods – a hybrid data collection, and transmission method.
Arturo Arocena, Jr., Henry D.C. Cayaban, Michael M. Malonzo, Luis Alejandri I. Tamani, Jovino L. De Dios
Philippine Rice Research Institute (PhilRice), Maligaya, Science City of Munoz, Nueva Ecija
Sugarcane nursery production and development program in Tarlac mill district (Oral)
The adverse effect of changing weather patterns is inevitable. It can affect the overall growth habit of the sugarcane crop. Thus, farmer’s productivity as well as profitability also may deem to decrease. As a result, reduction of area planted to sugarcane is presently observed. Furthermore, as a general picture of the sugar industry, our capability to maintain our sufficiency in sugarcane production will be at stake. In order to mitigate this risk and still have a chance to increase the productivity, variety programming is strongly recommended. Planting the most suited variety for a given season, specific location and agronomic characteristics that will complement the timing of all the farm activities for the whole growing period. Sugarcane varieties differ in their age of maturity due to their varying photosynthetic efficiency in response to climatic and cultural practices. The best time to plant and harvest a variety is essential in maximizing yield potential. It must be planted in the season it is most adaptable and harvested at the right age where the sucrose content and tonnage are high. This is why nursery establishment is carefully planned to have available planting materials at the optimum time of planting and at the right location. Through the aid of GIS, identification of the strategic locations for the nurseries can be established. Types of varieties to be planted will be based on the topography, soil type and time of harvest (also road accessibility).
Laverne C. Olalia
Sugar Regulatory Adminstration, North Avenue, Diliman, Quezon City
Geographic Information System (GIS) in identifying and monitoring root and tuber crops production areas in selected barangays in the province of Benguet, Cordillera Administrative Region
Arnel L. Tenorio, Office of the City Agriculturist, City Government of Tanauan, Batangas
Rhodora M. Gonzalez, Department of Geodetic Engineering, UP Diliman, Quezon City
This study utilized Geographic Information System (GIS) to develop a methodology to generate spatial data in identifying and monitoring root and tuber crops (RTC) area to provide more accurate and timely information to government, non-government organization, and local government units in planning food security and crafting relevant policies. It determined the location and estimated the area planted with RTC. It used a participatory mapping approach to determine the traditional RTC production area at barangay level. It compared the GIS generated and the community participatory maps on estimating RTC production areas. Lastly, it integrated the results of GIS-based and community-based techniques in developing a database for root crops data.The sources of information especially on root crops are limited or disaggregated. There are municipalities that have records of production data by municipality but none at barangay level. Among the provinces of Cordillera Administrative Region (CAR), only Abra and Benguet have provincial and municipal level data; however all of the provinces lack barangay level data. Based on DA-CAR data, Ifugao had the biggest production of sweet potato (7327.75MT) while Benguet had the biggest production area (792 Ha). In the province of Benguet based on Office of the Provincial Agriculturist 2011 data, the Municipality of Kabayan has the biggest area (146 Ha.) and production of sweet potato (6088 MT).RTC database structure is organized in the Entity-Relationship (ER) Diagram using the MS Access software. The ER diagram is composed of entities namely province, municipality, barangay, farmers, facility, farm and crops.It was observed that majority of the barangays did not have scaled barangay maps, only sketches and drawings. With this, Participatory Mapping methodology was conducted at barangay level. The study used printed satellite Google images in tarpaulin, where the community facilitated the transfer of information. There was a specific dimension in people’s cognitive maps of their community and the GIS researchers’ technical map. Both have its own cognition and perception of directions, scale, landmarks, slope, soil type, cropping pattern and social aspect.The output of the participatory mapping is the RTC maps with location of RTC areas in the barangay. Using spatial analysis function of QGIS, the area of the polygons is determined.
Geomatics for Forestry
Combining satellite and airborne mapping and data sets for forest monitoring and assessment of carbon stocks in the Philippines (Oral)
Satellite data obtained through remote sensing has been a common and widespread source of information for forest monitoring. This is, in part, due to its ability to cover large tracts of forest lands, and its accessibility, availability, and cost. However, its spatial resolution can be coarse and may not be adequate to meet certain level of accuracy and uncertainty. Airborne-generated data sets have higher spatial resolutions and better accuracy, but can be very costly to obtain. To monitor large forest areas for various purposes, including forest carbon assessment under the Reduced Emission from Deforestation and forest Degradation (REDD+) program of the UN Framework Convention for Climate Change (UNFCCC), it is imperative to develop tools and methodologies that are cost efficient and meets acceptable level of accuracy. This paper explores different tools and methodologies that combine data obtained from medium resolution imagery obtained from remote sensing and high resolution data sets obtained from airborne sensors such as LiDAR and radar. These tools will be applied and tested using data obtained from pilot REDD+ areas.
Guillermo A. Mendoza
USAID B+WISER Program and Department of Natural Resources, University of Illinois, Urbana, Illinois, USA
USAID Office of Environment, Energy and Climate Change, Roxas Boulevard, Manila
Jose Don De Alban
Fauna & Flora International Philippines, Tagaytay City, Cavite, Philippines
Tree species diversity assessment and spatial analysis in a permanent monitoring plots of natural forest in Musuan, Bukidnon (Oral)
The study was conducted to understand the long-term dynamics and responses of natural forests to changes in climate particularly in terms of species diversity, composition and abundance with the aid of Geographic Information System (GIS) techniques. Initial findings, which would also serve as baseline information for long-term monitoring, showed that the species diversity in the chosen natural forest is relatively low (H = 1.21; D = 0.875; E = 1.063). However, some threatened species (15%) was observed such as Shorea almon and Afzelia rhomboidea suggesting the significance of the area as potential conservation site. Although the sampled area recorded more than 90% endemism, a number of dominant species (high Species Importance Value) such as Senna spectabilis which is an exotic one may have possible influence on the low diversity – a threat to forest regeneration. Analyzing its pattern spatially, S. spectabilis seems to be clustering (Nearest Neighbor Ratio = 0.89). Nevertheless, further studies on their ecology and control are necessary.
Alex S. Olpenda, Adrian M. Tulod, George R. Puno, Mark Jun A. Rojo, Ronald O. Villarta
College of Forestry and Environmental Science, Central Mindanao University, University Town, Musuan, Maramag, Bukidnon
Assessment of trees outside forest (TOF) in selected Makiling subwatersheds (Oral)
Trees outside Forest (TOF) are trees including shrubs that are found outside the Food and Agriculture Organization (FAO) forest and other wooded land classification that can be agricultural, urban, or non-agricultural/urban. TOF provide various environmental, economic, and socio-cultural services and functions but people are not fully benefiting from these services because TOF are neither well documented nor given enough attention. Hence, there is a need to identify and assess TOF in agriculture and urban areas outside Mt. Makiling as a means of promoting these resources. A SPOT satellite image (2010) covering the Cambantoc, Molawin-Dampalit, and Tigbi subwatersheds of Mt. Makiling in Laguna, Philippines was used in the supervised classification of forests, lakes, agriculture, urban areas and brush lands in GIS. Areas that qualify as other lands were extracted using the classified land types in vector format. Using GIS and Google Earth imagery, areas with TOF were digitized and assessed following the FAO decision tree algorithm for TOF. Field checking was conducted in areas with TOF to validate whether tree height fall within the TOF criteria. Based on the GIS and field assessment and checking, Tigbi and Molawin-Dampalit subwatersheds were found to have TOF on urban land, while Cambantoc subwatershed has TOF on agricultural land and TOF on non-agricultural/urban. TOF in Tigbi and Molawin-Dampalit are fruit trees cultivated for food, landscaping and trees near farms and roads. In Tigbi subwatershed, TOF on agricultural land are mostly agroforestry trees while non-agricultural TOF are trees used as farm windbreaks. Findings suggested that the assessed TOF contributed to the tree canopy cover in Makiling subwatersheds. Assessment of TOF can be used to account for the ecosystem services it provides which complement those that come from forests and other wooded lands. FAO also recognizes the importance of TOF for local and national food security. TOF, especially fruit trees, are important source of food products for the people. Some species of TOF also provide excellent source of fodder for livestock. TOF planted in agroforestry sites have, in many studies, demonstrated to increase farm yield.
Jan Joseph V. Dida, Joseph C. Paquit, Cheamson Garret K. Boongaling,Gemmalyn E. Magnaye, Nathaniel C. Bantayan
College of Forestry and Natural Resources, University of the Philippines Los Banos, College, Laguna
Mapping canopy crown density of forests in relation to assessing their potential for carbon emissions or removals (Poster)
Forest cover mapping in the Philippines entail classifying land cover according to the Land Cover Classification System (LCCS) developed by FAO and embodied, as standard, in the Department of Environment and Natural Resources memorandum circular 2005-005. Map products derived from using this LCCS have reflected canopy characteristics in terms of two categories, namely: open canopy and closed canopy forests. Open canopy refers to a crown cover of forests between 10 and less than 40 percent, while closed canopy denotes forests with crown cover from 40 percent and above. However, map products within the country have not gone to the extent of displaying categories of forests based on percentages of crown cover. Crown cover might better reflect the degree of degradation of forests, as this can be related to the amount of carbon stock within forest stands. In this study, we explored the possibility of deriving canopy density from both digital and visual interpretation using interpretation keys arising from training sets and published data. Initial results showed that visual interpretation outputs comes close to digital interpretation, but this will be dependent on resolution and time factor. Alternatively, digital interpretation will require different sets of training data according to the crown cover percentages. There is a promising direction by which we can automate the process of interpreting crown cover density from establishing relationships between the visually-derived results and those being interpreted digitally through an image-processing software. However, this still remains to be tested and further investigation to establish the appropriate steps in the automation.
Ernie D. Urriza, Oliver G. Coroza, Margaux A. Cruz
Conservation International – Philippines, Teachers Village, Diliman, Quezon City
Support to enhancing the capacity of DENR to use geospatial technologies for sustainable forest management (Oral)
Forests in the Philippines provide a number of ecosystem services (e.g., water supply, food production, raw materials, genetic resources) that translate to better human well-being and improved national economic development (Costanza et al., 1997). However, the sustainability of these ecosystem services are under serious threat primarily due to the over-extraction of natural resources in forests and their unplanned conversion to other land uses (Liu et al., 1993; Maohong, 2012). Sustainable forest management has been proposed as an approach to address these negative practices (Dugan, 1997; Grainger & Malayang, 2006). Geospatial technologies such as satellite remote sensing, geographic information systems (GIS), and satellite-based positioning systems are tools that enable the sustainable management of forests (Bone et al., 2007; Franklin, 2001; Li & Zhao, 2006). Cognizant of this, the United States Agency for International Development (USAID) and the United States Forest Service entered into a partnership to support capacity enhancement activities for the Philippine Department of Environment and Natural Resources (DENR) on the use of geospatial technologies for sustainable forest management. These activities, which represent one facet of USAID’s work on natural resource management and biodiversity conservation in the Philippines, involve the following: 1) technical assistance to the GIS and Remote Sensing Unit of DENR’s Forest Management Bureau, 2) provision of in-country training on the use of remote sensing for forestry applications, intermediate digital image processing methods, and GIS for forest land use planning, 3) facilitation of training opportunities in the United States on the use of remote sensing for forest monitoring, 4) facilitation of long-term partnerships between FMB and local universities on remote sensing, and 5) technical assistance on the design of the National Forest Inventory. This paper describes these activities in detail and how these contribute to the development of DENR’s capacity to sustainably manage forests.
Randy John Vinluan (USAID-PH), Calderon, Ricardo (Forest Management Bureau); Rabang, Bonifacio (Forest Management Bureau); Agoncillo, Oliver (USAID/Philippines); Nunez, Ma. Aleta (US Forest Service); Lebow, Elizabeth (US Forest Service)
Assessment of diversity of plants and diversity mapping in the forest ecosystems of Carranglan, Nueva Ecija, Philippines (Oral)
A study was conducted to assess the diversity of plants present in the forest ecosystems of Carranglan, Nueva Ecija. Plants that were found in the study areas were collected, preserved, described, identified and classified. Data were gathered using the quadrat sampling method. Ten(10) stations were selected, wherein 5 stations were located at Barangay Gen. Luna and the other five stations were situated at Barangay Burgos. Ten(10) quadrats measuring 10m by 12m per station were used to survey the plants. The site of the 100 quadrats used to assess the plants were identified and mapped through the application of Global Positioning System (GPS).The ecological parameters were also computed to determine the population, dominance and diversity values of the plants. A total of 294 different plant species were surveyed from the study areas. Two hundred forty four (244) were identified and 50 were still unidentified. These were classified under 81 families. Family Moraceae, Myrtaceae, Araceae and Dipterocarpaceae are so far the most represented families. Trees, shrubs and vines were the most common plants in the area, with some ferns, mosses, herbs, grasses, sedges and epiphytes. Shannon’s Diversity Index showed that the study area exhibited very high diversity. There were twenty five (25) plants which are listed in the IUCN Red List of 2013. Four species were listed as critically endangered, two of which are endemic species (Shorea sp.) in the Philippines. There were also near threatened (2), endangered(1), vulnerable(7) and least concern(9) plants recorded. There were also twenty five (25) endemic plants and 13 introduced/invasive species observed. Problems/threats identified in the forest ecosystems include fire, timber poaching, kaingin practices, soil erosion, and introduced species.
Annie Melinda Paz-Alberto, Shirly C. Serrano, Paul Henric P. Gojo Cruz
Institute for Climate Change and Environmental Management, Central Luzon State University, Science City of Muñoz, Nueva Ecija, Philippines
Assessment of MODIS NDVI data as alternative source of information for forest cover monitoring (Oral)
Periodic observation of the country’s forest cover is a must for proper planning and management of this important natural resource. Remote sensing technology has long been providing the world the means for mapping and monitoring natural resources for a variety of purposes. Notwithstanding the growing applications and benefits of this technology, the acquisition cost of remote sensing data is still the main problem that has to be addressed. In view of the characteristics of freely-available MODIS data, this study focused on the premise that this can be a potential source of information on forest condition. As vegetation reflects much radiation in the near-IR, Normalized Difference Vegetation Index (NDVI) can be used to identify vegetation and its broad classes. In this study, unsupervised classification using the ISODATA algorithm and supervised classification by endmember spectra techniques and regression analysis were utilized in order to assess the usefulness of the MODIS Vegetation Indices. ISODATA technique was found to be superior in assessing the usefulness of Sav-Golay-filtered 250 meter MODIS NDVI time series image covering the Cagayan River Basin (CRB), Northern Luzon, Philippines. Through zonal analysis, mean NDVI Spectral Profile and amount of estimated per-cent cover from the Landsat-derived Land Cover/Land Use Map were generated and the relationship was established to interpret the unknown classes. The final classified image showed significant improvement as the overall, producer’s, and user’s accuracies as well as the kappa coefficient have increased by classifying the misclassified pixels in the second iteration. The overall accuracy and kappa coefficient have increased by 9% and 0.1405 respectively. In addition, confidence interval for forest land category was computed by taking random samples from the CRB subset of 2010 Land Cover Map of the Philippines. The computation obtained a very small amount of variance wherein at 90% confidence level, the confidence limits are 82.15% and 84.19%. Results showed that the method developed and described in this study can be used to extract forest land class from a 250 meter MODIS NDVI time series image and can therefore become valid as alternative source of information for forest cover monitoring.
Alita D. Sangalang
Resource Data Analysis Branch, National Mapping and Resource Information Authority, Fort Bonifacio, Makati City
Ariel C. Blanco
Department of Geodetic Engineering, UP Diliman, Quezon City
Assessing the applicability of GPS-GLONASS-BDS ready GNSS Receivers in mapping under forest canopy (Oral)
Louie P. Balicanta, Edison P. Paraiso, Patricia Kristen A. Dela Cruz
Department of Geodetic Engineering, UP Diliman, Quezon City
Global Navigation Satellite System (GNSS) has been widely used in many applications related to mapping. For almost four decades the U.S. NAVSTAR GPS was used as the main satellite technology used in most of these applications. The Russian GLONASS satellite system was upgraded and made available to commercial use in the past decade. Recently, the Chinese BeiDou Satellite Navigation System (BDS) was made available to mainland China and its neighbouring countries. Because of this several GNSS receivers manufactured in China were made capable of obtaining and reading satellite signals coming from the three satellite systems (GPS, GLONASS and BDS). In relation to GNSS application, researches were done to evaluate the performance of GPS under forest canopies. The result of one of the researches showed that GPS performance was significantly degraded under heavy canopies (Zheng et.al., 2005). This research aimed to test and assess the applicability of using a GNSS receiver (GPS, GLONASS and BDS ready) in forest canopy with increased observation accuracy. Initial results show that with a GNSS receiver capable of reading GPS, GLONASS and BDS, position was fixed with high accuracy and a maximum fixing time of two (2) minutes in Real Time Kinematic Mode.
An estimation of the frequency of historic wind speeds of typhoons in an open-source Geographical Information System (GIS) for Region 8 in the Philippines (Oral)
This study was carried out to analyze the frequency of historical typhoons for Region 8 in the Philippines in order to quantify the occurrence of different wind speed categories following the Saffir-Simpsons-Scale (SSS) for cyclones. The aim was to develop an open-source method that can be utilized and updated by Local Government Units (LGUs). The calculations are based on data from observations of historical cyclones (1945-2012), downloaded from the “JTWC Tropical Cyclone Best Track Data Site”. The data were processed with the help of PostGIS and integrated into QuantumGIS to estimate wind speed buffers along the cyclone tracks using the parametric model by HOLLAND (1980). Since only recent cyclone observations (2001- 2012) included all needed parameters, multiple regression analysis were performed on the complete datasets in order to derive the missing parameters for the older data. Adapted from PEDUZZI ET AL. (2012), the speed of the eye of cyclone was added to Holland’s equation to take the translatory motion of the cyclone into consideration. On the basis of the Saffir-Simpson-Scale thresholds for the five wind speed categories were identified: SSS1: >33-43 m/s, SSS2: 43-50m/s, SSS3: 50-58m/s, SSS4 58-69m/s, SSS5 >69m/s. Following Holland’s slightly modified equation the area affected by a given Saffir-Simpson wind speed category could be approximated numerically. To avoid duplications, for every typhoon only the maximum wind speed category affecting a certain area around the track was used. For every Saffir-Simpson category the calculated wind speed buffers were overlaid to count intersections. These counts of intersected areas were used to calculate the historic frequencies per wind speed class and their spatial distribution. Statistics for the last one hundred years do not reveal significant changes in the number of typhoons making landfall in the Philippines but other parameters linked to human induced climate change show significant changes (e.g. atmospheric temperature). Therefore it appears likely that historic wind speed patterns will continue into the next decades, though there are indications that tropical cyclones are getting stronger. The advantage of this approach is that it is open-source and the results are easily applicable by LGUs in Region 8. Some parameters, particularly the radius of maximal wind speed, were not recorded before 2001 and therefore had to be deduced and estimated from complete records of a period of only ten years. This reduced the quality of the output. Also, only symmetric wind speed buffers could be calculated in this study, which are possible but rather rare in typhoons. The resulting maps displaying the historic frequency of certain wind speed categories can be an important and useful tool in disaster risk management and spatial planning by identifying areas that are prone to different categories of wind speeds generated by tropical cyclones.
Hannah Fuchs, University of Bonn, Germany
Olaf Neussner, GIZ, Philippines
The effects of the changing landscape along the Mandulog River to lowland flood risk (Oral)
The area surrounding the Mandulog River in northern Mindanao has been experiencing changes due to both conversion of forestland to agricultural lands and due to infrastructure and community development in the area. This changing landscape, and the possible effects of a changing climate in Mindanao, may have been factors to the destructive flooding suffered by the lowland areas during the rage of tropical storm Washi (“Sendong”) particularly in Iligan City. This article pieces together observations and researches on the general state of the Mandulog River from the past and the present.
Julius Noah H. Sempio, Czar Jakiri S. Sarmiento, Enrico C. Paringit
Department of Geodetic Engineering, College of Engineering, UP Diliman, Quezon City
Comparative analysis of elevation acquired using RTK GPS versus differential leveling for obtaining Digital Elevation Models
Raquel Raiza T. Francisco, Louie P. Balicanta
Department of Geodetic Engineering, UP Diliman, Quezon City
Many Engineering practices require a significant investment. Therefore, having an accurate record of an original surface is vital for engineers in order to accurately calculate the amount of earthwork that might be needed for a piece of land that is about to undergo land development activity. Leveling provides a means of accurately measuring height differences and elevations of a particular point on the ground. Leveling instruments like digital level are the commonly used devices in carrying out this kind of field survey. However, using such instrument over a large area is costly and at the same time requires a substantial amount of time to finish. As the technology advances, the use of GPS specifically RTK GPS can be considered and tested in doing level field works. This research reports on the assessment of accuracy for Real Time Kinematic GPS derived height with derived elevation from leveling. These two surveying instruments provide us with precise measurements. However, varying field conditions will always affect the instruments’ accuracy. In this research, it is shown that for the precision of the values from RTK GPS, as the epoch or time of observation is increased, the better the precision of the elevation and that for the accuracy, there is no significant difference among the observations with different epochs. For the relationship between the distances of baseline to the accuracy of the measured elevation, it was found there is no correlation based from the data obtained.
Geomatics in hydrological simulations: The Iligan experience
Czar Jakiri S. Sarmiento, Enrico C. Paringit
Department of Geodetic Engineering, UP Diliman, Quezon City
In the midst of climate change debates and the increasing occurrence of extreme events, control measures and estimation systems play an increasingly critical role in disaster preparedness through improving flood alleviation procedures. From our own experience during Typhoon “Ondoy” and especially Typhoon “Pepeng” events of 2009, the maturity of estimation and forecasting of parameters in both weather and catchment inflow can improve the reaction time for evacuation and improve preparedness for rescue operations. Recently, the Philippine Government, through its agencies and state universities have been investing in the use of Geomatics to aid in flood disaster risk management. This paper presents the role of Geomatics in developing the Hydrological Simulations for Iligan City as a support for the LGU’s disaster risk management efforts.
ArcGIS customization using VBA for the City Planning and Development Office of Butuan City (Poster)
Arthur M. Amora
College of Engineering and Information Technology, Caraga State University, Butuan City
The operations in the City Planning and Development Office (CPDO) of Butuan City on the Real Property Unit (RPU) mapping and computerization involve the use of the GIS Software known as the ArcGIS. Nevertheless, these personnel still lack expertise in handling this software. Due to this, a customized ArcMap (main component of ArcGIS suite of geospatial processing programs) interface was created for the simplification of these operations or processes in relation to RPU mapping. This customized interface involves commands that would shorten several processes of ArcMap and is very user-friendly. Some of these commands can do direct loading of thematic maps, parcel searching and spatial filtering. Direct loading of thematic map or feature layers are done by just clicking the custom button representing a particular layer. A search button enables the user to find the desired RPU by just inputting the Parcel Identification Number (PIN). By RPU searching, the selected parcel’s information are shown in a custom window such as the owner’s name, lot area, barangay, class, land value as well as the pictures of the parcel’s title and the structure erecting on it. After the searching, the extent will zoom in to the selected RPU at a fixed ratio showing also its neighboring parcels. Another command is the spatial filter which is considered as a combined function of ‘Select by Location’ and ‘Select by Attributes’. Spatial filter loads a custom window that lets the user choose a particular thematic map from the table of contents (TOC) and its specific attribute. This selection will then be used as the feature layer that will select the parcels which intersects on it. Also, buffered search coverage is one of the options in spatial filter. Attribute table of selected features can also be open immediately after filtering. All of the customizations were done using Visual Basic for Application (VBA).
Development of a land property registry system application and dynamic database management for web-based GIS mapping: a case of Butuan City, Philippines (Poster)
Engr. Alexander Demetillo
College of Engineering and Information Technology
Caraga State University, Ampayon, Butuan City
Integrating SMS and application programming interface (API) for web-based GIS mapping of real property units of Butuan City, Philippines (Poster)
Engr. Michelle V. Japitana
College of Engineering and Information Technology
Caraga State University, Ampayon, Butuan City