Reader Department of Geology
Aligarh Muslim University
The changes in the climate of the earth during the past few decades have become the focus of scientific and social attention. As a result climate change has become one of the hot topics and is considered a threat to the entire world, with the research undergoing in many parts of the world on the adverse impacts of the climate change on the ecosystem, forests, water resources, agriculture, livelihood etc. Climate change threat is real and will affect all economic sectors to some degree, but the agricultural sector is perhaps the most sensitive and vulnerable. The impact of climate change may be felt more severely in developing countries such as India, whose economy is largely dependent on agriculture. The 3rd assessment report of Inter-governmental Panel on Climate Change (IPCC) of 2001states that many drylands areas could become even hotter and drier over the 21st Century. Studies indicate that the last decade (1990-2000) across the globe have recorded the warmest years during the past century, the years, i.e. 1997, 1998 and 1999 recording more warmer conditions increasing in sequence. The report also points out that over the 20th century global average surface air temperatures have risen by about 0.6o C. There is already evidence of changes in physical and biological systems- melting of glaciers and polar ice caps, late freezing and early break-up of ice on rivers and lakes, pole ward shift of plants and animals and changes in the habits of migratory birds.
Climate change is likely to threaten all life forms on earth, including plants and animals. The degree of sensitivity to this given change will however vary from one species to the other, changes in temperature and precipitation patterns will affect several weather sensitive sectors such as agriculture, forestry, water resources, coastal ecosystems.
The present paper describes in detail the methodology for developing vulnerability indices and making use of Geographical Information System (GIS) to map, analyse, assess and present these indices in the form of national vulnerability profiles taking district as a spatial unit of analysis.
Current research on the climate change
In India many studies are being carried out on the climate change and its impact particularly on agriculture, since about 67% people are directly or indirectly dependent on it. A number of government aided research institutes and independent research NGOs are involved in studies related to climate change and its impacts. Crop specific responses to climate change have been studied by number of institutes and research centers under Indian Council of Agricultural Research (ICAR). Ramakrishna et al (2002) studied the impact of climate change scenarios on Indian agriculture and some evidences in the desert state of Rajasthan. Houghton et al (1999) predicted an increase in rainfall by 5 to 15% in the South Asia region due to GHG concentration. The effect of increased CO2 and temperature on Indian agriculture was carried out by Aggarwal and Sinha (1993) and predicted a shift in wheat production belt. Hundal and Kaur (1996) attempted crop weather simulation models to know the effect of temperature on the phenology and yield of important crops grown in Punjab. Ramakrishna et al (1996) have estimated a fall in productivity of pearl millet in Rajasthan by 10-15% due to increase in temperature by 2 degrees C. Sinha et al (1998a) observed that during the past 25 years, significant changes in climate are observed over different regions of country. Many parts of northern India show increase in minimum temperature by about 1 degree C in rabi cropping season.
Vulnerability concept and GIS mapping
Vulnerability may be defined as the extent to which a natural or social system is susceptible to sustaining damage from climate change. It is generally perceived to be a function of two components i.e. the effect that an event may have on humans, referred to as capacity or social vulnerability; and the risk that such an event may occur, often referred to as exposure (Adger, 1996). Vulnerability has two aspects, an external risk (shock to which an individual or community is subject) and internal risk (lack of means to cope). The net impact may be positive for resilience or negative to become vulnerable. Amongst the human activities, agriculture activities are considered to be the most sensitive to climatic conditions and to climatic variability.
Vulnerability may be of different kind, i.e. social, climate, trade and liberalisation, bio-physical etc. The mapping of vulnerability may involve the indicators selected for mapping and representing the vulnerability at a particular spatial unit. Vulnerability of a country, community or group may be assessed, mapped and represented by using modern tools such as remote sensing and GIS. The Geographical Information System (GIS) is a powerful tool to store, manage, update, manipulate and analyse spatial data related to natural resources, socio-economic parameters, industries, meteorology, environment and utilities. GIS has wide ranging capabilities for data analysing such as overlaying different themes, suitability criteria, ranking and identifying highly vulnerable hot spots. GIS can be used to prioritise areas for adaptation measures based on their relative vulnerability and ranking.