Q. Do you think that the pattern of Indian monsoon has changed in past decade? Discuss how it impacts various facets of our lives. (150 words)21 Dec, 2018 GS Paper 1 Geography
- Define monsoon.
- Give facts about changing pattern.
- Possible reasons of change
- Implications of changing Indian monsoon.
- Importance of Indian monsoon
- The term monsoon has been derived from the Arabic word mausim meaning ‘season’.
- It marks the seasonal reversal of easterly winds blowing from the northeast during cooler months and reverse direction to blow from the southwest during the warmer months of the year.
- Indian monsoon is the most prominent of the world’s monsoonsystems, which primarily affects India and its surrounding water bodies.
- Majority of rainfall in India is convectional in nature and falls between the months of June and September.
Changing pattern of monsoon
- Indian monsoon is considered a ‘textbook phenomenon’ clearly defined which has not changed much in the preceding century.
- The average rainfall has remained within the 10% of the long term average.
- However this process has hit an erratic front, with floods in the northwest and the northeast and rainfall deficit in southern part of the nation.
- Rainfall extremes have increased threefold over the last few years and now extend over all of central India – from Gujarat to Odisha.
- Onset of monsoon has delayed every year since 2002 and it also lasts for shorter duration, compressing the Indian monsoon.
- The interspersed breaks in the monsoon have increased resulting in larger drier periods in the monsoon itself.
- Rainfall intensity, duration, frequency and spatial distribution have significantly undergone change in the past decade or two.
Possible reasons of change
- Decreasing mean rainfall, increasing spatial variability of rainfall, and a threefold rise in rainfall extremes – are associated with a weakening monsoon wind circulation and a decrease in the number of monsoon depressions from the Bay of Bengal.
- Subcontinent has warmed significantly in the last decade and the Indian Ocean has cooled down during the same period due to anthropogenic reasons.
- The contrast in the temperature between land and sea might result in decreased moisture demand from land.
- India has experienced a reduction in low clouds, due to increase in anthropogenic aerosols such as black carbon or soot, which simultaneously absorb and heat the surrounding air, and prevent clouds from forming.
Implications of changing Indian monsoon
- Shifting monsoon patterns of the country has resulted in acute water shortage in the nation, with drying up of wells and rivers.
- Major Indian reservoirs runs 10% lower than their normal at any given point of time in the year
- There has been economic loss across agriculture and industry sectors caused by water shortage.
- Cycles of droughts and floods have become more common in many parts of India.
- Water shortage may fuel interstate tensions in India, ex- Cauvery river dispute between Karnataka and Tamil Nadu; Krishna river dispute among Andhra Pradesh, Maharashtra, Karnataka and Telangana;
- Variation in monsoon has also resulted in the incidence of vector borne diseases such as malaria, dengue.
Importance of Indian monsoon
- Indian monsoon plays vital role in India’s attempt to achieve food security.
- About 64 % Indian population depend on agriculture for their livelihood, which is based on southwest monsoon.
- Nearly 60 percent of the country’s farms lack irrigation facilities, leaving millions of farmers dependent on the rains
- Monsoon is critical to replenish 81 reservoirs necessary for power generation, irrigation and drinking.
- Monsoon regime emphasizes the unity of India with the rest of Southeast Asian region.
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