Tuesday, August 20, 2019

Forest Fire Danger Modelling Environmental Sciences Essay

Forest Fire Danger Modelling Environmental Sciences Essay Forests constitute a large part of the earths renewable natural resources. Besides serving as an important source of food, fuel wood, fodder, timber etc, it also plays a pivotal role in maintaining a near ideal environmental condition for life sustenance (Biswadip Garia et al., 2007). Forest fires are natural or manmade disasters that occur throughout the world. Controlled forest fire is a useful, efficient and legitimate tool for environmental management such as forest clearance, field preparation, regrowth for livestock, and reduction of fire hazard. If the forest fire is un-controlled then it becomes a disaster. It adversely affects on humans, animals and plants. Annual fires may decrease the growth of the grasses, herbs and shrubs, which may result in increased soil erosion (Kandya et al., 1998).Forest fires cause wide ranging adverse ecological, economic and social impacts. In a nutshell, fires cause: indirect effect on agricultural production and loss of livelihood for the trib als (Biswadip Gharai et al., 2008). In 1982-1983, fires burned 3.6 M ha of scrub and forests in East Kalimantan, Indonesia, alone. These fires caused local extinction of some plants and animals and economic losses in forestry, non-timber forest products and agriculture of approximately $9 billion (Kinnaird and OBrien 1998). Chemical reactions of the gases released by fire leads to an increase in atmospheric ozone and the deposition of acidic compounds downwind from fires, which in turn can affect the physiology of plants and ecosystems in these areas. The ecological and socio-economic consequences of wild land fires in India include -Loss of timber, loss of bio-diversity, loss of wildlife habitat, global warming, soil erosion, loss of fuel wood and fodder, damage to water and other natural resources, loss of natural regeneration (IFFN Report: 2002). Forest fires also pose serious health hazards by producing smoke and noxious gases. The burning of vegetation gives off not only carbon dioxide but also a host of other, noxious gases (Green house gases) such as carbon monoxide, methane, hydrocarbons, nitric oxide and nitrous oxide, that lead to global warming and ozone layer depletion. Consequently, thousands of people suffered from serious respiratory problems due to these toxic gases. Burning forests and grasslands also add to already serious threat of global warming. Recent measurement suggest that biomass burning may be a significant global source of methyl bromide, which is an ozone depleting chemical. In 1997 up to 5 M ha got burned in Indonesia. The smoke of these fires affected the health of 70 million people and disrupted the economies of Indonesia, Malaysia and Singapore causing a total economic loss estimated at $4.4 billion (Kinnaird and OBrien, 1998). Fires affect animals mainly through effects on their habitat. Fires often cause short-term increases in wildlife foods that contribute to increases in populations of some animals. These increases are moderated by the animals ability to thrive in the altered, often simplified, structure of the post fire environment. The extent of fire effects on animal communities generally depends on the extent of change in habitat structure and species composition caused by fire (Smith et al., 2000). Forest ecosystems are capable of storing large quantities of carbon in trees, other organic matter, and soil. Forests may also reduce the amount of carbon dioxide in the atmosphere through increases in biomass and organic matter accumulation. Forest fires add the pool of carbon dioxide into the atmosphere. Thus, Forest fires contribute to increasing atmospheric CO2 concentration and, therefore, intensifying the greenhouse effect. The perturbation of atmospheric chemistry induced by global biomass burning is comparable in magnitude to the effect of fossil fuel burning (Lindesay et al., 1996). In June and July 1998 catastrophic wildfires had an estimated impact of $600-800 million in north eastern Florida, valuing the economic effects associated with category-2-hurricanes (Butry et al. 2001). Government policies: According to the Constitution of India, the central and state governments in the country are enabled to legislate on forestry issues. The implementation part of the forest policy/programmes lies with the state government. Thus, fire prevention, detection, and suppression activities are the responsibility of the state governments forest departments. The policy, planning, and financing are the primary responsibility of the Central Government (Ministry of Environment and Forests Report: 2007). Forest fire and its management have long history in Indian forestry. Forest fire occurs quite frequently during summer season. The conventional methods of fire protection cover an elaborate network of fire lines, fire watchtowers, block lines and guidelines (Roy et al., 2005). The monitoring and management of forest fires is very important in tropical countries such as India, where forests are prone to fires annually causing adverse ecological, economic and social impacts (Kiran Chand et al. 2006). Indian fire scenario: Forest fire is a major cause of degradation of Indias forests. It is estimated that the proportion of forest areas prone to forest fires annually ranges from 33% in some states to over 90% in others. According to the recent State of Forests report, the forest cover in India is 67.5 M ha, constituting 20.5 % of its geographical area, represented by 41.68 M ha (12.68 %) of dense forest and 25.87 M ha (7.87%) of open forest (FSI, 2003). Studies carried out by Forest Survey of India reveals that on an average 53 percent forest cover of the country is prone to heavy to light fire (State of Forest Report, 1997) and 6.17% of the forests are prone to severe fire damage.. Forest Survey of India estimated that about 1.45 million hectares of forest are affected by fire annually. In India there are very few cases of fire due to natural causes. The majority of the forest fires in the country are human caused. For getting information on forest fires in India in real time basis, Forest Survey of India is using satellite data procured on daily basis by the Forest Fire group of University of Maryland, USA. Forest Fire Group in association with NASA uploads information on active forest fires of the whole world on the Web Fire Mapper (http://maps.geog.umd.edu) on the daily basis. The updated information for the current date is available at around 10.30 AM for India on this website. U.S. based this group obtains information on global fires from the MODIS (Moderate Resolution Imaging Spectro-radiometer) sensors that are on the board of their Terra and Aqua Satellites. In India we have our own space programme in place for detecting forest fires in real time basis. Indian Space Research Organization (ISRO) through its array of IRS satellites, Environment Satellite (ENVISAT) and through its Defense Meteorological Satellite Program-Operational Line scan System (DMSP-OLS)a programme that helps in detecting fires during night, is helping the field mangers in identifying forest fire recurrence zones, forest fire risk assessment, potential areas for fire line alignment, fire watch towers locations, fire recovery analysis, monitoring fire progression, assessing near real time damage and in mitigation planning etc issues. As part of Disaster Management Support Programme of Department of Space, Decision Support center (DSC) is established at NRSC for working towards effective management of disasters in India. Under DSC activities of NRSC, considering the importance of forest fire management in India, a comprehensive system Indian Forest Fire Response and Assessment System (INFFRAS) integrating multi sensor satellite data and ground data through spatially and temporally explicit GIS analysis frame work is planned (NRSA Report: 2006). The INFFRAS is designed to meet the requirements of the forest department at following three levels. Pre fire : Preparatory planning for fire control; During fire : Near real time active fire detection and monitoring; Post fire: Damage and recovery assessment and mitigation planning. Information of fire locations on daily basis with in 1-2 hours of the satellite ground pass can be viewed on their web site (www.nrsa.gov.in) Fire Danger Rating Index: Fire danger is the resultant of factors affecting the inception, spread and difficulty of control of fires and the damage they cause (Chandler et al. 1983). If any of these factors are absent, then there is no fire danger (Cheney and Gould1995). the various factors of fuels, weather, topography and risk are combined to assess the daily fire potential on an area. Fire Danger is usually expressed in numeric or adjective terms. Fire danger indices are an important tool for fire and land managers. Effective Forest-fire management is based on sound knowledge of the potential for ignition, behaviour, difficulty of control, and impact of fire in a given situation. Forest-fire danger-rating systems provide a framework for organizing and integrating scientific knowledge and operational experience, and they are a cornerstone of modern fire management (S.W. Taylor et al 2001.) Fire danger rating systems are used by fire and land management agencies to determine levels of preparedness, to issue public warnings, and to provide an appropriate scale for management, research, and law for fire related matters (Cheney and Gould 1995). All these systems integrate weather variables to assess fire danger, calculated as a numerical index. A variety of fire danger ratings are used around the world, including the McArthur Forest Fire Danger Index (FFDI, McArthur 1967), used in the eastern parts of Australia, the Forest Fire Behavior Tables (FFBT, Sneeuwjagt and Peet 1998), developed for use in Western Australia, the Fire Weather Index (FWI, van Wagner 1987) used in Canada, the National Fire Danger Rating System (Deeming et al. 1977) used in the USA and the Nestrov Fire Danger Index System used in the Russia. Why Himachal Pradesh: Forests are an important resource of Himachal Pradesh. The forests of the state are rich in biodiversity and play a vital role inpreserving the fragile Himalayan ecosystem while also being a primary livelihood source for the rural population and prime source of fresh water for both urban and rural population (Report of Himachal Pradesh Forest Department 2005). Forest wealth of Himachal Pradesh is estimated at over Rs. 1,00,000 crores. Most of precious coniferous forests are of such nature that these cannot be truly regenerated by human beings if these are cut once (Annual plan 2006-07).Forest fires are occurred every year. Recently, in the year 2012, Forest fires have destroyed more than 20,000 acres of forest land and caused a loss of more than Rs 2.6 crores of green property in three weeks. The fires, which first started in the Hamirpur circle, were later also reported in the forests of Shimla, Nahan and Mandi (Madhuri Gaur et al 2012).

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