Rosmadi Ghazali

Delineation of tree crown and canopy height using airborne LiDAR and aerial photo

Airborne LiDAR has good potential in giving accurate height of canopy in forestry area and measuring variable characteristics of detected trees This is essentially accomplished by subtracting the last return altitude (ground) from the first corresponding altitude (canopy surface). This research is intended to extract tree crowns and estimate its height by combining both spatial and spectral information from airborne LiDAR and digital aerial photo. Contouring techniqs were adopted in order to extract the tree crown information from digital aerial photo. LiDAR data was used to estimate tree height from Canopy Height Model (CHM). LiDAR data and digital aerial photo were acquired on the 20th September 2009 at Sungai Ayer Tawar plantation using Optech ALTM3070 and DCS digital camera. The results show that low statistical performance in estimating the tree height due to low density of LiDAR points and less of sampling data taken from field observations.

MyGeoHealth: GIS-based cholera transmission risk system in Sabah, Malaysia

Malaysian Geographical or Geospatial Health (MyGeoHealth) is a term used to describe innovative method for monitoring environmental risk factors on human health. There are possible spatial relationship between environment and cholera outbreaks in Tawau, Sabah due to the recent outbreaks are hard to predict. Cholera is a diarrhoeal disease caused by Vibrio cholerae (Vc), which occurs naturally in coastal phytoplankton (Chl-a) related with sea surface temperature (SST), shellfish and man. This study adapts the MyGeoHealth by emphasizing the potential of geographical information system (GIS), satellite remote sensing (RS) and global positioning system (GPS) to develop an introduced cholera transmission risk system in Tawau, Sabah. Spatio-temporal pattern and effect of SST, Chl-a, and cholera cases were determined using integrated geospatial technologies (GIS, RS and GPS), statistics and epidemiological approaches. Although the results of the effect were only statistically minimum correlation, the disease could outbreak at anywhere and anytime particularly at high population, unhygienic environment, close to the contaminated water supply, and during the hot or the wet season. These spatial characteristics of outbreak could be used as a cholera transmission risk indicator and an efficient control plan in Sabah as required in the MyGeoHealth.

Evaluating the relationship between scanning resolution of laser scanner with the accuracy of the 3D model constructed

A 3D laser scanner is an active image capturing instrument that has the ability to accurately send a signal and capture it back in x, y and z dimension. The then can be used to produce the real surface condition in relevant processing software which is suitable for direct measurement on the image or constructing DTM (Digital Terrain Model) the as what is possible in photogrammetry. A 3D laser scanner captured image the same as photogrammetric camera that capture x and y coordinates and z value measured by distance from the instrument to the object. As the development of computer technology become so advanced the capability of software to handle images captured with certain overlapping coverage to produced 3D model has been proven capable of producing a high quality surface model as the raw data captured in 3D with instrument coordinates system. The principal used in laser scanning technology is the same in photogrammetry but the different is the laser scanner can measure distance from the object to the centre of the instrument as well as it offer a different scanning resolution and wider angle of coverage which is not available in normal camera used in close range photogrammetry. When the laser scanner scan a object it actually calculate the a 3 dimensional coordinate for each pixel on the object based on the principal of 3D triangulation since it measure distance, angle and high of instrument provided by user. A surveying technique for acquiring positional data to construct DTM (Digital Terrain Model) such as laser scanner should be evaluate the impact of scanning resolution in order to relate the scanning resolution and the accuracy of the surface model for a GIS or any other application. The technique of producing 3D model and the size of spatial pixel captured during observation must relevant to the cost of producing and accuracy requirement of the client. This paper will study the impact of scanning resolution on the accuracy of the points on the ground by comparing the coordinate obtained with 3D scanner with GPS static observation.

A study on school location suitability using AHP in GIS approach

The National Education System at school level under the government education institution category consists of preschool, primary, secondary and post-secondary education. Ministry of education has many departments and division with a lot of aim, objective and task to produce Malaysian citizens who will be knowledgeable and competent, possess high moral standards, responsible and capable of achieving high level of personal well-being for harmony and betterment of the family, the society and nation contribution. This research is focus on i). The suitability study of existing school distribution/location and ii). The determination of new school location at Negeri Perlis Indera Kayangan. Perhap with the increments number of population nowadays, this is the right time for a school suitability location determination study in order to determine i). The Most Suitable, ii). Suitable and iiii). Less Suitable location for existing and new school in Negeri Perlis Indera Kayangan. The use of AHP (Analytical Hierarchy Process) in GIS approach was implemented and the results show that the most, suitable and less suitable has been successfully presented for Perlis State.

Potential of single orthorectified of high resolution satellite image (Ikonos) for large scale mapping

High and accelerating rates of the urban changes and the urban area growth especially in developing countries needs for efficient and fast techniques for map production and revision with the appropriate accuracy. The used of high resolution with ground resolution had changed mapping perception due to its unique characteristics and have a good potential as a data sources for map production. Thus, the mapping potentials of the single IKONOS image had been thoroughly examined on 2D geometric accuracy assessment. Based on overall evaluation, it is found the amount of error and the entire image is have a good geometric planimetric accuracy that regardless to its standard requirement and it is suggested and recommended to be used for large scale map production. Otherwise, the experience gain from this research will eventually highlight the future role of existing technology towards the mapping production in large scale specification for various mapping applications and also may contribute significantly to the topographical data collection process.

Integrating Cadastral GIS Database into GPS Navigation System for Locating Land Parcel Location in cadastral surveying

Cadastral surveys deal with one of the oldest and most fundamental facets of human society, which is ownership of land. They are the surveys that create, mark, define, retrace, or reestablish the boundaries and subdivisions of the public lands in Malaysia. Knowing exactly where the boundary lines are is important for many different activities. If there any consideration of constructing a building on the property, conducting a cadastral survey is a requirement to avoid any possibility of encroaching into a neighboring land. This type of survey can ensure that fences and other improvements are located in exactly the right position within the boundary. Originally used to ensure reliable land valuation and taxation, today these surveys are mainly used to solve boundary disputes. The boundary mark is important in starting a Cadastral survey job. This is because the coordinate as well as bearing and distance is a necessity to start the survey job in determining all the boundary of a new or existing parcel. One of the common issues in starting a new cadastral survey job is finding the location of the work site or lot parcel. It may take a long time to refer on the certified plan and locate the site manually. The surveyor may take time to go and find the location of the work site only by referring the certified plan especially in the area that not really familiarize with it. They may take a few days in locating the area. They also need to find the land owner to conform the location of the lot parcel. Therefore, using this new portable GPS that has been integrated with cadastral GIS database, it can help surveyor to save their time to reach at lot parcel. This automatically saves their time in locating the boundary mark. It helped surveyor when the lot parcel now can also be navigated in this portable GPS. Therefore, in this paper will study on the integration of land parcel data in the Malaysian Cadastral database (PDUK) into GPS system to assist surveyor in locating parcel location based lot number of the land.

Integrating open source GIS and Google Earth™ for managing rural waterborne outbreaks

Limitation of cost and staff skill in using GIS technologies for health sectors are common barriers in developing countries. Cholera is the life-threatening disease that gives a major problem to the global region. This study demonstrates the potential applications open source GIS software and Virtual globes technology (e.g. Google Earth™) in local waterborne outbreaks mapping and analysis. This integrated technologies showed the disease database and map could dynamically display and qualitatively create a model hypothesis regarding relationship between the disease and its potential risk factors. Quantum GIS (QGIS) as the Open Source GIS software used to create geodatabase and map of cholera risk distribution, and then the software was combined with Google Earth™ to analyze the cholera spatial-temporal pattern in the high risk areas (e.g. populous and coastal areas). The technologies are not only strengthen local public health capacity but also assist policy makers and health practitioners to implement GIS and mapping technologies in their disease control programme and research.

Development of integrated Infectious Disease Information System (IDIS): Geospatial-based components for Malaria Information System (GeoMIS)

Introducing a Geospatial Based Infectious Disease Information System (IDIS) in Malaysia as an innovative initiative to control the disease is essential due to local environmental risk factor and public health awareness. Malaria is one of the major disease concerns in rural areas, requiring an efficient system to manage the disease. Most of the current disease information systems used by the local health authorities are non-spatial based method, which has not consisted of spatial features and functions. This study adapted the Geographical Information System (GIS) technology to develop an integrated Geospatial-Based Malaria Information System. The proposed system could enhance malaria surveillance programme in Malaysia to achieve zero malaria cases by 2015.

Spatial epidemiological techniques in cholera mapping and analysis towards a local scale predictive modelling

Cholera spatial epidemiology is the study of the spread and control of the disease spatial pattern and epidemics. Previous studies have shown that multi-factorial causation such as human behaviour, ecology and other infectious risk factors influence the disease outbreaks. Thus, understanding spatial pattern and possible interrelationship factors of the outbreaks are crucial to be explored an in-depth study. This study focuses on the integration of geographical information system (GIS) and epidemiological techniques in exploratory analyzing the cholera spatial pattern and distribution in the selected district of Sabah. Spatial Statistic and Pattern tools in ArcGIS and Microsoft Excel software were utilized to map and analyze the reported cholera cases and other data used. Meanwhile, cohort study in epidemiological technique was applied to investigate multiple outcomes of the disease exposure. The general spatial pattern of cholera was highly clustered showed the disease spread easily at a place or person to others especially 1500 meters from the infected person and locations. Although the cholera outbreaks in the districts are not critical, it could be endemic at the crowded areas, unhygienic environment, and close to contaminated water. It was also strongly believed that the coastal water of the study areas has possible relationship with the cholera transmission and phytoplankton bloom since the areas recorded higher cases. GIS demonstrates a vital spatial epidemiological technique in determining the distribution pattern and elucidating the hypotheses generating of the disease. The next research would be applying some advanced geo-analysis methods and other disease risk factors for producing a significant a local scale predictive risk model of the disease in Malaysia.

GIS in management of landscape trees: Determining, monitoring and implementing safety measures on potentially hazardous trees

Trees located in the vicinity public areas such as roadsides, recreation areas, and around building should be monitored regularly for structural weakness. Certain conditions can cause a tree to be structurally weakened so that parts or all of it are likely to collapse Landscape trees do not only contribute to the enhancement of scenery but might also become potential hazards risks if, there is no proper management. Nature elements such as heavy rains and strong winds could further increase risks thus endangering public safety and contributing to property damage. A proper management approach to monitor the maintenance of the landscape trees can help to reduce these risks. The development of an effective system for landscape tree management within University Technology MARA (UiTM) Shah Alam campus has been developed in this study. Potentially hazardous landscape trees were identified using the professional Arborist inventory. The condition of trees based on the tree hazard evaluation form modified from the International Society of Arborists (ISA). Geographical database was constructed that include tree location, species, and diameter breast height (DBH), condition, and growth recordings. It was also based on the inventory and later integrated into a system that can be used for the maintenance of trees. The identification of potentially hazardous trees is targeted along the roadside areas of the campus main entrance. They are to be used as a sampling unit in this Study. The selected trees include 61 Peltophorum pterocarpum spp, trees that were planted for over 30 years and that now pose a hazard due to their size, conditions and location of the trees along the road side. The Geographical Information System (GIS) was developed using Visual Basic (VB) software as user interface. The design of GIS software that allow user to capture manipulate and analyze spatial database give a significant help in assisting the documentation and decision making of potential hazard trees.