33 Application of Geospatial Technology in Disaster Management

Dr. Puneeta Pandey

 

1. Learning Objectives

 

The purpose of this module is to familiarize the readers regarding Disasters and application of geospatial technology (remote sensing and geographical information system) in disaster management.

 

2. Introduction

 

For mankind, disasters are unavoidable in nature and have been recurrent events despite problematic ever since time immortal. The disasters mostly natural likely to hit without warning and are supposed to have high magnitude, frequency, complexity and economic impact worldwide. The disasters cause threats to humans, settlements, economic assets and are supposed to have high risk proportions in areas of dense population. It is for the reason that most of the world’s nastiest disasters tend to occur between the Tropic of Cancer and the Tropic of Capricorn (Sharma, 2014). This vast belt from both sides of equator is inhabited by the developing countries of the world, where the problems of disaster management are exclusive due to the apparently competing needs between basic requirements for people and economic growth (Sharma, 2014).

 

In 2015, Asia-Pacific belt remained as the world’s most disaster prone region. Around 160 disasters out of world’s 344 recorded ones were reported in the region, which account 47% of that total. The total population affected by such calamities was about 59.3 millions with a total of more than 16,046 deaths in the region. South Asia went through highest percentage of fatalities with a total of 14,647 deaths (around 64% of the total) due to 52 disasters that took place in the year 2015 and out of which the maximum deaths (around 8,790) were reported from Nepal earthquake tragedy. The total economic loss in Asia and the Pacific was more than US$ 45.1 billion in the year 2015, besides much more losses indirectly. About 90 storms were recorded worldwide that took place in 2015, out of which half of the storms occurred in Asia-Pacific, affecting 9 million inhabitants with a loss of US$ 11.8 billion. Two-fifth of all disasters was related to floods, responsible for 37% damage to human lives and 25% economic loss. (ESCAP, 2015)

 

Indian Scenario

 

As is well documented, the Indian subcontinent is susceptible to various natural disasters such as droughts, cyclones, tsunamis, floods, earthquakes, forest fire, landslides and avalanches. Out of 35 total states/ Union Territories in the country, 25 are prone to disasters. In the country, on an average, about 50 million people are affected by disasters every year, besides million dollars loss to property (Sharma, 2014).

 

Literally, a disaster is a sudden accident or a natural calamity that leads to serious damage to property or lives of living beings. According to World Health Organization (W.H.O), a disaster can be defined as “any occurrence that cause damage, ecological disruption, loss of human life, deterioration of heath and health services on a scale, sufficient to warrant an extraordinary response from outside that affected community or area”. A natural disaster owes its origin to the natural processes occurring on the Earth. A disaster is a major adverse event or disruption, occurring over a relatively short time, resulting from natural or human induced activities, causing heavy damage to human lives, material, environment or economy, thus, making it difficult to combat such losses. During such calamity developing countries go through much more costs compared to developed ones, more than 95% of all deaths caused by calamities in developing countries, and losses due to natural events are 20 times greater (as GDP %) in developing countries than in developed countries (Sharma, 2014).

 

2.1 Types of Disasters

 

Broadly, disasters can be natural or man-made which occur in many different forms with different magnitude of destruction and range of time duration.

 

A natural disaster is a type of that happens due to natural process or phenomenon, causing damage to lives, health, property, environment and economy of the region. This type of disaster includes earthquakes, volcanoes, landslides, floods, storms (hurricanes and tornadoes), tsunamis, and cyclones, killing people on large scale and costs billion of dollars damage to property and the environment every year worldwide. Today, however, due to population explosion and urbanization, there is a sharp increase in severity of damage due to frequent disasters. There are some disasters that happen without any warning such as earthquakes and tornadoes, causing much more damage unexpectedly to infrastructure and other productive capacity (Sharma, 2014). Storms like hurricanes and typhoons are considered as one of the most seriously damaging natural calamities because of their size and magnitude. Disasters like floods and cyclones cause damage to a larger extent to both infrastructure and agriculture (Sharma, 2014).

 

Man- made disasters are the end results of technological hazards or human error. Fires, stampedes, industrial accidents, oil spills, transport accidents, war and nuclear explosions/radiation are some of the examples of man-made disasters. Like natural disasters, these events also cause serious damage to human lives, property and economy of the state.

 

Disasters have also been categorized into different sub-groups depending on their source/ origin (Sharma, 2014). These five subgroups are as follows:

 

Sub-Group I- Water and Climate Related Disasters

 

This sub-group includes cyclones, tornadoes and hurricanes, heat wave and cold wave, avalanches, floods, droughts, hailstorm, sea erosion, thunder, cloud burst and lightning.

 

Sub-Group II- Geologically related disasters

 

This includes landslides, mudflows, dam failures/ dam bursts, mine fires and earthquakes.

 

Sub-Group III- Chemical, Industrial & Nuclear related disasters

 

In this sub-group the chemical, industrial and nuclear disasters have been accounted.

 

Sub-Group IV- Accident related disasters

 

This category includes oil spill, building collapse, bomb blasts, festival related disasters, electrical disasters and fires, forest fires, urban fires and transport related accidents.

 

Sub-Group V – Biologically related disasters

 

This sub-group includes pest attacks, biological disasters and epidemics, cattle epidemics and food poisoning.

 

 

3. Disaster Management and application of Geospatial Technology

 

Disaster Management can be defined as the organization and management of resources and responsibilities (activities) while dealing with emergency situations with all humanitarian aspects during different stages viz., preparedness, response and recovery in order to reduce the impact and damage caused during disasters. In this process, the objectives of the concerned experts are to monitor the condition, simulate the disaster occurrence to have better models for prediction, propose suitable contingency plans and finally preparation of spatial databases.

 

The management of calamities either natural or man-made requires both manual as well as technological efforts. So far as technological aspect is concerned, the management of disasters can be done using technology like remote sensing (RS) and geographical information system (GIS). A large amount of multi -temporal spatial data is required for the management of natural disasters. RS and GIS are very effective tools in management of disasters. These techniques can be used effectively for the assessment of disaster severity and subsequent impact of destruction. Together with the growing applications of RS, the use of GIS has become equally important for the purpose of cartography (map composition) and enumeration tasks. In disaster management, the satellite data can be used during various phases of the management, such as preparedness, prevention, preparedness, relief and reconstruction; mostly used for monitoring and warning tasks. During the past few decades the RS technique has been an effective operational tool in preparedness and warning phases for floods, droughts and cyclones. In preventive phase, the GIS are used in assessing the severity and impact of destruction due to disasters. Integrated with global positioning system (GPS), the GIS in disaster relief stage, is very useful in search and rescue operations in areas devastated by calamity. And in preventive phase, the GIS can be used to manage large amount of data needed for the assessment of vulnerability of the hazard. It can also be used for better planning, emergency operations designing, evacuation means during preparedness stage and for the incorporation of satellite data with other significant data in proper design of warning system. This technology can also be used in search and rescue operations during relief stage. The GIS can be used to organize the information related to damage due to disaster and after disaster for census report preparation during rehabilitation phase.

 

 

3.1 Principles of Disaster Management

  • The management of disasters is the duty of all spheres of government.
  • Resources should be used efficiently that are available for daily purpose.
  • All related organizations should work as an extension from their core business.
  • Each individual is responsible for his/her safety during disaster.
  • A better planning should focus on large scale events during management practices. The planning should significantly recognize the differences between disasters and incidents.
  • The planning should take into account the type of physical environment and the population structure.
  • The arrangements should recognize the cordial role of non-government organizations.

 

3.2 Phases of Disaster Management

 

Disaster Preparedness: All those actions that are implemented before the occurrence of a disaster.

 

For example: Preparedness plans; emergency exercises/training; warning systems.

 

Disaster Impact: This phase includes all the damages and negative consequences on human lives, property, environment and their economy.

 

Disaster Response: This phase includes activities during the occurrence of a disaster. For example:

 

Public warning systems; emergency operations; search and rescue.

 

Rehabilitation: All those actions that are meant to rebuild lives and livelihoods during disaster for long term sustainable development. It accounts all those measures which assist in increasing the resilience of food, water systems and other resources in case of future disasters and emergencies.

 

Mitigation: It includes those activities that reduce the effects of disasters. For example: building codes and zoning; vulnerability analysis; public education.

 

3.3 Management of Disasters

 

The UN General Assembly Resolution declared the period of 1990- 2000 as International Decade for Natural Disaster Reduction. In response to this, the Government of India has undertaken several initiatives, shifting the focus from post-disaster approach to pre-disaster preparedness, including preparation of Vulnerability Atlas of India; to minimize the loss to life and property as a result of these disasters. Besides, the Disaster Management Act, 2005 lays down institutional and coordination mechanism at national, state and district level.

 

3.3.1 Management of EARTHQUAKE using geospatial technologies (remote sensing and geographical information system):

 

To provide rapid and reliable assessment report of the destruction caused by earthquakes, the analysis of RS imagery in particular high-resolution aerial imagery has been a very effective technology. The techniques like Photogrammetry and GIS are considered as modern tools in exploring the earthquake and other associated phenomena (Altan, 2005). The methods like terrestrial photogrammetry was first time used to document and report the earthquake damages caused in Friaul, Italy. There are several efforts to use RS, photogrammetry, and other information sciences and systems in the areas damaged by earthquake. Some of them are associated with long term and short term prediction, and some are linked with recording and assessment of the damage caused (Altan, 2005).The maps related to epicentre of the earthquake are being used to generate seismic hazard maps. The seismic zoning map happens to be a basic informative tool in the code for designing resistant structures related to earthquake. Figure 1 describes the seismic zones of India.

Figure 1: Seismic zones map of India (Source: www.isr.gujarat.gov.in)

 

Along with the data associated with earthquake, structural design, geological factors, soil data etc., are very useful for the preparation of building codes which aid in designing earthquake resistant structures. The Building Materials & Technology Promotion Council, Ministry of Housing & Urban Poverty Alleviation, Government of India, collaborates with national and international agencies/organizations for vulnerability analysis and mitigation practices.

 

3.3.2 Management of LANDSLIDES using geospatial technologies (remote sensing and geographical information system)

 

Landslides occur in a wide range, depending on speed of movement, type of movement (slide, fall, flow, spread, topple), material involved (debris, rock, soil), and also the triggering mechanism (rainfall, earthquake). The use of satellite data, aerial photos and RS techniques helps in the data collection during the disaster. The computerized techniques and other systems would help in storage, retrieval and analysis of the data. In the preventive phase of disaster, satellite imagery can be used for landslide inventory and the mapping of factors related landslide occurrence, such as faults, lithology, geo-morphological setting, slope, land use and vegetation. The dimension of the landslide features relative to the ground resolution of the RS data, landslide inventory mapping has been very essential. Satellite imagery with better spatial resolution and stereo capability (SPOT, IRS) are very helpful in recording and documentation of the past landslides. In future, it is expected that Very High Resolution (VHR) imagery, such as from IKONOS-2, might be very useful for landslide inventory. The imagery of satellite data can also be used to have data on the parameters (soils, geology, slope, geomorphology, landuse, hydrology, rainfall, faults etc.) related to landslide assessment. For the classification of lithology, land use and vegetation, multispectral images are significantly important. Also for geo-morphological mapping or terrain classification, Stereo SPOT imagery has been widely used (Soeters et al., 1991). SPOT or IRS images can be used to prepare digital elevation models (DEM). The techniques like GPS, photogrammetry and Radar interferometry have been essential during disaster preparedness stage. Landslide hazard zonation map included a map separating the draw out varying degrees of predictable slope stability. The landslide hazard zonation map has an inbuilt factor of forecasting, consists of map showing varying degree of slope stability and therefore, probabilistic in nature. A landslide hazard zonation map has ability to aid in some of the following individual factor maps based on methodology and input data: Landslide location, Slope steepness, Land use/ land cover, Geology, Density of drainages and Rainfall.

Figure 2 describes the landslide zonation map of India.

Figure 2: Landslide zonation map of India (Source: http://www.bmtpc.org)

 

There is a wide range of applications of the hazard zonation maps which include preparation of development plans for dams, roads, cities etc., master plan and land use plans, decision making in rescue and relief operations.

 

3.3.3 Management of FLOODS using geospatial technologies (remote sensing and geographical information system)

 

Floods are considered to be most devastating hazard among all natural hazards worldwide, causing more deaths and property damage than any other. It may be defined as any relatively high water flow that overflows the banks in any portion of a river or stream beyond it capacity to hold. Different types of flooding (e.g. river floods, flash floods, dam-break floods or coastal floods) have different characteristics with respect to the time of occurrence, the magnitude, frequency, duration, flow velocity and the areal extension. Many factors play a role in the occurrence of flooding, such as the intensity and duration of rainfall, snowmelt, deforestation, land use practices, sedimentation in riverbeds, and natural or man-made obstructions. Figure 3 represents the flood hazard zonation map of India.

Figure 3: Flood Hazard Zonation map of India (Source: www.mapsofIndia.com)

 

In flood evaluation procedure, there are certain parameters that need to be taken into consideration which include depth of flood water, the rate of rise and decline, the duration, the flow velocity and the frequency of occurrence. During the stages of preparedness/warning and response/monitoring the earth observation satellites are widely used. These earth observation satellites provide data for mapping geomorphologic elements, historical events and sequential inundation phases, including depth, duration, and direction of current during prevention stage of disaster. The monitoring of flood is carried out by using RS satellite imagery from global scale to storm scale. In most of the disaster management phases, the satellite data has been effectively and operationally used (CEOS, 1999). It is frequently used in the storm scale to monitor the movement, intensity and precipitation spread to determine how much, when, and where the heavy precipitation is going to shift during the next zero to three hours (called NOWCASTING) through hydrodynamic models. Synthetic Aperture Radar (SAR) has been regularly observing the earth’s surface, even in a bad weather situation or thick cloud cover. The mapping and monitoring of flood can also be done by using NOAA AHVRR, in near real time. From GOES and POES satellites, the multi channel and multi sensor data are used for meteorological evaluation, interpretation, validation, and assimilation into numerical prediction models to assess hydro-geological risks (Barrett, 1996).

 

For flood forecasting and subsequent warning, the Quantitative precipitation estimates (QPE) and forecasts (QPF) use satellite data as informative source. For the mapping of flood inundated areas, the Synthetic Aperture Radar (SAR) from ERS and RADARSAT have been verified as very effective even in bad weather conditions. In India since 1993, ERS-SAR has been used effectively in flood monitoring besides Radarsat since 1998 (Chakraborti, 1999). For the management of floods, the RS should always be associated with other data in a GIS, especially the integration of a large number of hydrological and hydraulic factors on the local scale. The GIS technique can contribute in generation of topographic information using digital elevation model (DEM), obtained from SPOT, aerial photography, geodetic surveys, LiDAR (Light detection And Ranging) or SAR (Corr, 1983 ). All these data incorporated in 2D or 3D finite element models, have been very useful in flood prediction in floodplains and river channels (Gee et al., 1990).

 

4. Conclusions

 

At the end of the module, the reader would have gained an insight into the types of disaster, principle of disaster management and the role played by remote sensing and GIS in managing the disasters, especially in terms of preparedness and mitigation measures.

 

5. References

  • Altan, O. (2005). Use of photogrammetry, remote sensing and spatial information technologies in disaster management, especially earthquakes. Geo-information for Disaster Management, 4, 311-322.
  • Barrett, E. (Ed.). (1996). The storm project: using remote sensing for improved monitoring and prediction of heavy rainfall and related events. Remote Sensing Reviews, vol 14, 282 pp.
  • CEOS/IGOS (1999): CEOS/IGOS disaster management support project. http://www.ceos.noaa.org/ Chakraborti, A. K. (1999, October). Satellite remote sensing for near-real-time flood and drought impact assessment-Indian experience. In Workshop on Natural Disasters and their Mitigation-A Remote Sensing & GIS perspective (pp. 11-15).
  • Corr, D. (1983). Production of DEM’s from ERS-1 SAR data. Mapping awareness, 7, 18-22.
  • ESCAP (2015). Disasters in Asia and the Pacific – 2015 Year in Review.
  • Gee, D. M., Anderson, M. G., & Baird, L. (1990). Large‐scale floodplain modelling. Earth surface processes and landforms, 15(6), 513-523.
  • Sharma, V. K. (2014). Natural disaster management in India- Environment and development view point.
  • Soeters, R., Rengers, N., & Van Westen, C. J. (1991). Remote sensing and geographical information systems   as   applied   to   mountain   hazard   analysis   and   environmental   monitoring.   In Thematic Conference on Geologic Remote Sensing, 8th, Denver, CO (pp. 1389-1402).
  • http://www.bmtpc.org
  • www.isr.gujarat.gov.in
  • www.mapsofIndia.com