Deepali Roy
Assistant Editor
Geospatial World
Owing to its location along the Pacific Ring of Fire, the Asia Pacific region is extremely susceptible to natural disasters. For long, countries in this region have been facing nature’s fury in the form of cyclones, volcanic eruptions, typhoons, earthquakes, tsunamis, floods, landslides and storms.
According to the International Disaster Database, between 1980-1989 and 1999-2009, the number of disaster events reported globally increased from 1,690 to 3,886. Over the whole period of 1980-2009, 45 percent of these were in the Asia Pacific. Further, according to a report by the United Nations Economic and Social Commission for the Asia and the Pacific (UNESCAP), people of the Asia Pacific region are four times more likely to be affected by natural disasters than those living in Africa, and 25 times more likely than those living in Europe or North America. Also, while the region generated one quarter of the world’s GDP, it accounted for a staggering 85 per cent of deaths and 38 per cent of global economic losses during 1980-2009.
The Asia Pacific region is being characterised by growing wealth and is emerging as a market to reckon with on the global economic map. These gains can slip out of the hand if they are not protected from the risks and impacts of disasters. It therefore becomes imperative to reduce disaster vulnerability and protect both the lives and development gains from impact of disasters. While countries in the region are making it a priority and sprucing up their efforts, , good efforts also need to be matched by new multidisciplinary policy approaches, as UNESCAP observes. One of the key tools in reducing risks and in ensuring that efforts before and after disasters are more effective and efficient, is geospatial technology.
Geospatial information and technology
Disaster management programmes are developed and implemented through the analysis of information pertaining to the event of the disaster. The majority of this information is spatial and can be mapped. Dr. Sutopo Purwo Nugroho, Head of Data, Information, and Public Relations, National Agency for Disaster Management (Badan Nasional Penanggulangan Bencana – BNPB), Indonesia explains that once the information is mapped and data is linked to the map, emergency management planning can begin. Dr. Surono, Head-Center for Volcanology and Geological Hazard Mitigation, Geological Agency, Indonesia adds that using GIS, information can be layered and analysed to understand natural disasters and therefore reduce impact of the disasters. Elaborating on the benefits of remote sensing, Dr. Surono says that satellite data is very useful in creating different kinds of maps such as topographic, land use, land cover and density (building, roadway, stream, etc) maps. Maps created through satellite imagery can be produced more easily on large scale and for wide areas in different resolutions, depending on the purpose.
Geospatial technology can address various stages of disaster management, including planning and mitigation, preparedness, response and recovery.
Planning and mitigation: As potential emergency situations are identified, mitigation needs can be determined and prioritised. In the case of an earthquake, which all infrastructure is within the primary impact zone of earthquake faults? Using geospatial information, officials can pinpoint hazards and evaluate the risk and consequences of potential emergencies or disasters. Values at risk can be displayed quickly and efficiently through a GIS. Utilising existing databases linked to geographic features in GIS makes this possible.
Preparedness: Preparedness includes those activities that prepare for actual emergencies. GIS can provide answers to questions such as how many paramedics and logistics units are required and where should they be located, informs Dr. Sutopo. GIS has potential to display “real-time” monitoring of aspects like earth movements, reservoir level at dam sights, radiation monitors and so forth. Dr. Surono says that geospatial technology is a tool for planning of evacuation routes, for the design of centres for emergency operations and for integration of satellite data with other relevant data in the design of disaster warning systems. Response: Geo-information can assist immediately in the event of a disaster by helping decision makers understand the scope of the damage and identify locations where people may be trapped or injured or require medical support and rescue, says Dr. Sutopo. It is essential to analyse critical infrastructure (facilities essential for the operation and sustainability of health services, food services and government operations) that is or could be damaged or destroyed to restore vital services and government operations. Decision makers can assign response resources to the highest life safety and facility repair priorities. Another critical mission that geospatial technology supports is establishment of emergency supply chain management, says Dr. Sutopo.
Recovery: A GIS can work in concert with GPS to locate each damaged facility, identify the type and amount of damage and help relief workers and decision makers to establish priorities for action. A GIS can display areas where services have been restored in order to quickly reallocate recovery work to priority tasks. Long-term plans and progress can be displayed and tracked utilising a GIS. Prioritisation for major restoration investments can be made using GIS.
Emerging technologies
GIS, remote sensing and GNSS have been the traditionally used geospatial technologies in disaster management. However, various other technologies are increasingly contributing to various aspects of disaster management.
One such technology is LiDAR that is finding application in areas like flood readiness through creation of flood risk maps. Mohaizi Mohamad, CEO, Geomatika Technology, says that LiDAR technology is needed to create a highly accurate GIS-based topographic layer for automated hydrological systems analysis and flood plan delineation for flood readiness. Elaborating on the benefits of this technology for flood readiness and speeding up the projects related to flood analysis, Mohaizi says that official solutions for flood control are engineering based which are ineffective in combating extensive monsoon floods. He observes that a highly accurate, 10 cm topographic height data is the requirement for hydrological spatial analysis and LiDAR survey is one of the quickest and most accurate methods to produce the requisite digital elevation model (DEM). Using the LiDAR-derived DEM, hydrologists can predict the extent of flooding and accordingly plan mitigation and remediation strategies. Citing the instance of Malaysia that has been witnessing floods at an alarming level in recent years, Mohaizi informs that LiDAR data was used over the MADA territory in Kedah area in Malaysia for the analysis of data accuracy for flood detection and prevention. The main purpose of the LiDAR data was to design new drainage system to enhance the existing drainage and irrigation systems for all paddy areas in MADA. Optimum accuracy of LiDAR data can be further achieved through use of real time kinematic (RTK) GPS surveying, says Mohaizi. RTK surveying utilises short observations times and enables surveyors to move between stations. The use of a network of reference stations, instead of a single reference station, allows modelling of systematic errors in the region, thereby reducing errors. RTK GPS collected ground data in a designated area is then compared with LiDAR data. This technique ensures that all LiDAR data achieve the accuracy of up to 5 cm on clear ground, explains Mohaizi.
Another technology is IfSAR (interferometric synthetic aperture radar) which has a significant role to play in processes like establishment of early warning systems, a crucial element of disaster management since preparedness saves lives. David Hisdall, Vice President Asia Pacific & Australia, InterMAP points out instances of two tsunamis that hit different countries in the Asia Pacific region. On 26 December, 2004 a major tsunami hit south western Sumatra in Indonesia, causing damage across the Indian Ocean. Over 250,000 people died. Much of the damage was in locations far from the epicentre, where there would have been sufficient time to be warned of the potential disaster. On March 11, 2011 a tsunami of similar size and magnitude took place off the east coast of Japan. While this event produced even larger waves, it resulted in a loss of life of less than 25,000 people. David says that much of the reduction in loss of life can be directly attributed to preparedness, making warning system an important element in the efforts to save lives in case of occurrence of tsunami. To be effective, safe areas for each community must be selected and evacuation routes prepared and signs posted. This planning requires detailed information based on accurate predictions of where the water will go during an event. This data is gathered from coastal modelling software that uses accurate 3D information to predict the probable paths that inundation will take once it makes landfall. Following this modelling and route planning, regular tsunami evacuation drills need to be carried out so that the local population is well versed in responding to the warnings. IFSAR technology provides cloud free imagery and high resolution digital elevation data that can aid planners in selecting safe areas and planning access routes. Elaborating on the benefits of IfSAR data in disaster management, David says that since IfSAR is not affected by smoke, fog, cloud or darkness, it allows more complete coverage over large areas, making it a suitable source of geospatial data for selection of tsunami safe areas and evacuation routes. In many areas not just in Asia Pacific but across the world, IfSAR data offer the only viable means of monitoring active volcanoes or mapping strain building up around faults, detecting earthquakes and modelling risk, says David.
Recent initiatives
Realising the inherent role of geospatial information and the contribution of geospatial technology, countries in the region are taking initiatives in giving due cognizance to the geospatial information and incorporating the technology to strengthen their disaster management mechanisms.
The Philippines, for example, which is one of the most susceptible countries in the region, has been strengthening its pool of geospatial information and adopting geospatial technology. The Department of Science and Technology (DOST) is undertaking the micro mapping Disaster Risk Exposure Assessment and Mitigation (DREAM) project. Under the project, the Department will acquire geospatial data with LiDAR and airborne radar interferometry (INSAR) technologies. The project will produce detailed topographic information that will enable the creation of more accurate flood inundation maps. The Department of Environment and Natural Resources’ Mines and Geosciences Bureau has conducted densification or geo-hazard assessment and mapping with a scale of 1:10,000 on 49 barangays (administrative units). This activity determined each barangay’s vulnerability to coastal erosion, storm surges and coastal flooding. Areas in Metro Manila at high risk during natural disasters may now be known through an accurate hazard map. The Australian government has formally handed over the 3D maps of the capital to the Philippines government. The map uses LiDAR technology to identify areas severely at risk during natural disasters.
Geospatial initiatives in disaster management in the Philippines have been strengthened through the top down approach of the government, with President Benigno Aquino III getting involved in the process. The President has directed the release of PHP 1.6 billion (PHP: Philippine Peso) to DOST to tap state-of-the-art technology for more accurate weather and disaster information and improving the government’s disaster planning and response system. 65,000 geo-hazard maps identifying disaster-prone areas have been distributed to local governments in the Philippines. In addition, the National Disaster Risk Reduction and Management Council would also soon come out with multihazard maps in 13 provinces.
For efficient use of geospatial information in disaster management, it is important that timely information is available to those who need it. Indonesia’s National Agency for Disaster Management (BNPB) has established Geospasial, a Web-based spatial information system that provides spatial information such as administrative boundaries at provincial and national levels and topographical maps at 1:250,000 scale in PDF format that can be downloaded for free, informs Dr. Sutopo. This can be beneficial for preliminary description of an area that can be used in emergency response. Users can download over 1000 maps. The website also features Disaster Watch which provides information related to a disaster when it strikes, in real time. The agency is also developing a mechanism to estimate the impact of a disaster, which was recently put to use in the case of an earthquake off Bali. This was created within an hour of the earthquake and available from BNPB’s website.
Thailand, which witnessed one of its most severe floods in recent times, too has utilised geospatial information in relief and rescue efforts. The Information and Communication Technology Ministry of Thailand has introduced an online mapping application to let users find flood status of different locations. The system features data evaluation from all state agencies, including the Royal Thai Survey Department and the Department of Highways. The Ministry is looking to further develop the application on top of the government’s GIS for future flood planning and drought prevention measures.
Challenges
Even though the countries in the region have been strengthening the use of geospatial information and technology in their disaster management initiatives, certain gaps still exist. Some of them were highlighted at the United Nations International Conference on Space‐based Technologies for Disaster Risk Management ‐ “Best Practices for Risk Reduction and Rapid Response mapping,” recently concluded in Beijing, China. The conference, held in collaboration with the Asia Pacific Space Cooperation Organisation, especially focussed on the use of geospatial information in disaster management in the Asia Pacific region. A general problem is that data is available, but centralised repositories recording datasets are often not in place.
In the Pacific, regional organisations like SOPAC have been using space-based information at the regional level, but not at any national level. There is no capacity at national levels to access or use satellite images, and it takes weeks to obtain needed information which is too late for the response window, observed the conference.
Other challenges include lack of technical expertise; lack of awareness of GIS and its benefits as it is seen only as a tool for producing maps; and bureaucracy to make provision to obtain the required data. The application of remotely sensed data for regional risk assessment is needed to translate to the ground level. Challenge is not only across technical communities, but also across political set-up. Authorities (bureaucrats and politicians) who are in power and in a position to help people affected by disaster, do not often know what the data means, much less how it can be used to create appropriate policies.
Conclusion
An unfortunate reality for the residents of many locations on the Pacific Ring of Fire is that it is not a matter of “if” a natural disaster strikes, but “when” it will happen next. While the occurrence of such events cannot be controlled, the damage to life and property can be prevented or reduced by judicious planning and use of resources such as geospatial technology. Countries in the Asia Pacific region are fast realising the potential of the technology in mitigating the impact of natural disasters and are gearing up to be prepared to safeguard their people.
