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Consideration of the Recommendations of the Expert Team Meeting on Reducing the Impact of Natural Disaster and Mitigation of Extreme Events by H. P. Das Division of Agricultural Meteorology India Meteorological Department
H. P. Das
Division of Agricultural Meteorology
India Meteorological Department
Current definitions of natural disasters are primarily meant to address socio-economic management issues related to natural disasters. It is important to develop a more comprehensive definition of natural disasters for applications in agriculture, rangelands, forestry, and fishery sectors.
Magnitude : 7.5 RS
Focal depth : 60 km
Type of faulting: Crustling movement (vertical / horizontal)
2. Assessment of the impact of natural disasters on agriculture, rangelands, forestry, and fisheries requires the design of a comprehensive database in accordance with the users needs. There is a need for an integrated data management system including adequate collection, quality control, analysis and presentation of data specific to certain kinds of disaster, e.g., lightning incidence, soil moisture, and fire danger indices. Presentation should make use of best available technology, e.g., GIS and Internet.
3.Effective management of and preparedness for natural disasters requires free and unlimited access to relevant databases that will allow monitoring, assessment, and prediction. It is recommended that all agencies responsible for these databases develop good collaborating links for the exchange of information included in these databases.
4 A number of modern tools and methodologies for the monitoring and prediction of natural disasters, such as storm surges, tropical cyclones, drought, floods, etc., are now available. Agricultural risk zoning is an essential component of natural disaster mitigation and preparedness strategies. Given the complex nature of databases, GIS and remote sensing should be employed to facilitate strategic and tactical applications at the farm and policy levels.
5 Current natural disaster management is largely crisis driven. There is an urgent need for a more risk-based management approach to natural disaster planning in agriculture, rangelands, forestry, and fisheries. An effective risk management approach would include a timely and user-oriented early warning system with rapid dissemination of information to users.
It is also felt to include more indicators and information in monitoring drought. Some of the parameters are dry spells, very high temperature during crop growing period, critical stages of the main crops and cultural practices needed in these stages, soil moisture in the crop root zone and outbreak of crop pests and diseases.
The remote sensing can also play a good role to provide information on various drought indicators (viz. rainfall, soil moisture etc.) The NDVI and other indices are found to vary with the magnitude of greenness. Moisture stress in vegetation due to continued rainfall deficiency is reflected with lowering of value of vegetation indices. Microwave sensors can provide estimate of soil moisture only in surface layers upto 10 cm thickness
It is also important to transmit this information promptly via a suitable telecommunication system
Recognizing that early warning is an important component of preparedness, it is recommended that:
India Meteorological Department (IMD) prepares aridity anomaly maps for the country as a whole in order to monitor droughts over the country on a real time basis. In addition , IMD prepares rainfall maps every week throughout the year which show rainfall received during a week and the corresponding departures from normal, thus indicating the development of drought and its termination.
Another method of monitoring drought is to use standardised precipitation index (SPI) which could be adopted on operational basis in the form of map.
Remote sensing can also play a good role to monitor the drought by the vegetative index map which indicates the vegetative status during the fortnight period. The NDVI and other related indices are found to carry with magnitude of green foliage brought about by phenological changes. The temporal pattern of NDVI is useful in diagnosting vegetative condition.
Methodology for preparation of drought map
Aridity Index = Water Deficit = Actual Evaporation – Potential Evaporation
Water Need Potential Evaporation
Various categories of Agricultural drought
Drought CategoryAridity Anomaly Value
Mild Drought upto 25%
Moderate Drought 26-50%
Severe Drought > 50%
SPI classification scale
SPI ValueDrought Category
0 to 0.99 Mild Drought
-1.00 to –1.49 Moderate Drought
-1.00 to –1.99 Severe Drought
-2.00 or less Extreme Drought
When NIR and VIS are measured radiation in near infrared and visible bands.
Moisture stress in vegetation resulting from prolonged rainfall deficiency is reflected by lower NDVI values.
7.There is an urgent need to assess the forecasting skills for natural disasters to determine those where greater research is needed. Lack of good forecast skill in drought, for example, is a constraint to improved adaptation, management, and mitigation.
For the qualitative analysis of event forecast skill score and ratio score tests have been used, which are based on 2x2 contingency table. The results are as follows :-
Table 6(a) The ratio and skill score for the year 1992-2000
April 99 to March 2000)
Event 12 (YY) 6 (NY)
No event 10 (YN) 119 (NN)
8 Given the regional and global nature of natural disasters, it is essential to promote and foster the use of international and regional programs to enhance collaboration and building of partnerships and through virtual networks with distributed functions to enhance cooperation on issues related to improved management of and preparedness for natural disasters.
9 Given the importance of storm surges to coastal lowlands, it is essential that WMO, in collaboration with other international and regional agencies, develop an integrated coastal management approach in reducing the impacts of natural disaster on agriculture, rangelands, forestry, and fisheries.
10. The growing frequency of natural disasters requires effective use of the media to better inform and educate the general public and policymakers about the potential impacts of natural disaster and the need to adopt preparedness strategies. Community involvement and education is essential in preparedness and mitigation. The “Community Fireguard” example for bushfire- prone areas in Australia is a good example. Feedback from user community is crucial for agencies responsible for mitigation and relief.
Use of media for educating the public about the disasters - community involvement
11 There is a need to recognize the importance of understanding glacial lake outburst floods (GLOFS) as a new natural disaster and develop appropriate assessment and preparedness strategies.
Valley glaciers and small ice caps represent storages of water over long time scales. Many rivers are supported by glacier melt, which maintains flows through the summer season. The state of a glacier is characterized by the relationship between the rate of accumulation of ice (from winter snowfall) and the rate of ablation or melt.
In higher mountains, floods induced by the glaciers i.e. Glacier Lake Outburst Floods (GLOF) sometimes occur.
12The WMO Technical note on drought and agriculture published in 1975 should be updated to include the major advancements in understanding these complex interrelationships. This revision should emphasize early warning, monitoring, and prediction techniques; vulnerability and impact assessment tools; preparedness and mitigation strategies. Case studies of China and India should be included in the revision. The publication could be published in hard copy, CD-ROM, and made accessible on Internet.
13 Given the growing incidence of dust and sand storms around the world, it is essential to include measurements of aeolian sedimentation loads in the standard agrometeorological stations of NMHSs. It is also essential to include a routine and comprehensive analysis of wind speed and direction data and disseminate this info to the users. These data should be applied to analyze the impact of sand storms on agriculture. Use of air quality networks to aid in data collection on dust and sand storms may also be examined.
Wind speed and direction is measured around the world but very few analyse the data. We should process the data and produce analytical diagrams. These data should be disseminated to the users who may apply it to analyse the impact of sand storm on agriculture.
14 It is recommended that strategies for education training address the needs at national, regional, and international levels in order to exploit the synergies and share experiences. Best practice strategies for developing and implementing education and training programs in support of drought preparedness policies should be documented from the experiences of countries such as Australia, China, India, and the United States. Elements of this could include consulting the users; developing skills in an influential “target group,” user-producer workshops; and adequate feedback channels.
15It is recommended that countries develop policies aimed at effective natural disaster management. Such policies should emphasis preparedness and incentives over insurance, insurance over relief, and relief over regulation.
One of the difficulties in promoting disaster insurance is that those who are at highest risk have the least capacity to pay the premiums. Possibilities of group/community insurance should also be available, particularly for marginalized communities. The insurance agency may promote a Community Rating System to encourage communities to go beyond the required standards of minimum safety. The incentive can be a reduction in insurance premium for policyholders within communities that take appropriate actions to reduce disaster losses.
Repeated relief allocation and use have not brought about region-wise improvements in the quality and standards of relief in the voluntary or the government sectors. Poor relief means poor recovery and rehabilitation. It also implies continued vulnerability of the poor.
Development that conforms to regulations is less prone to damage. Regulation is a largely local government responsibility. Effective enforcement often requires more training, personnel, and financial resources which many communities can not possibly provide. Regulations cannot provide full protection when they have a limited impact on existing buildings and infrastructure prone to hazards.
16There is a need and opportunity for agrometeorologists to supply design requirements for new satellite sensors. This implies in particular to drought and rangeland, forest fires from a disaster mitigation viewpoint.
Satellite remote sensing has been applied to the forest fire problem with some successes in locating large fires, mapping the large area burned and tracking smoke plumes. In many parts of the southwest pacific region, the use of remote sensing along with Geographic Information System and computer models have helped to achieve considerable success in detecting fires and mapping fire areas.
The visible and near infrared bands on the satellite multi-spectral scanners gives an indication of greenness of vegetation and approximate biomass. This property is used in the case of monitoring drought.
The estimation of forest fire danger from satellite remote sensing data is an important research area with potential great practical application and fuel moisture is an important index for fire danger estimation. The accurate estimation of fuel moisture using remote sensing data is very difficult, most of the approaches use proxy variables as indices of fuel moisture.
Moderate Resolution Imaging Spectraradiometer (MODIS) provide global high resolution products like NDVI and surface temperature which have shown close relationship with fuel moisture status.
Fire smoke is also an issue of high concern. For practical planning, there is a need for a tool which would give some indication of when smoke is likely to go once a fire is ignited. Finally for the operational application, there is a need for real time forecast of smoke impacts from individual and group of potential fires.
Better rainfall estimation by satellite remote sensing and thus improved rainfall forecast could significantly enhance drought monitoring capabilities, as well as short-term management. Soil moisture management is yet another aspect that is yet to take off at an operational level. Efforts are being made to use microwave remote sensing data to see to what extent soil moisture could be estimated.
Sensor for directly measuring evapotranspiration is also a necessity for understanding water requirement of the specific crop.
17 There is a need to integrate more fully simulation models, remote sensing, and ground based measurements. It is recommended that new efforts be started to develop this integration and capitalize on improved technology implementation strategies.
If good data bases are available, it is possible to design and develop powerful simulation models which can simulate the ground reality and this integration of information with remote sensing data and GIS may further enhance the policy analysis option.
18. There should be more research into the physical behaviour of crop growth and moisture regimes to develop better agricultural mitigation strategies.
Research and development initiatives especially in area with understanding the moisture regime in crop root zone, water requirement of the crop etc. have since contributed substantially to the knowledge base on drought management. These advancements have contributed in the development of useful technological outputs and also infused dynamism in agricultural production strategies and development of appropriate farming systems. These effects thus enable the farmers to tide over difficulties created by the drought simulation.
19More attention should be given to the impacts of potentially increasing frequency and severity of extreme events associated with global change and appropriate mitigation strategies and to minimizing damage due to extreme events of infrastructure underpinning agriculture, rangelands, fishery and forestry.