8599 This work is published under Attribution-NonCommercial-ShareAlike 4.0 International License International Journal of Informative & Futuristic Research ISSN: 2347-1697 Volume 4 Issue 12 August 2017 www.ijifr.com Abstract In India dominantly tropical monsoon climate prevails. Among the climatic elements temperature and rainfall are the most significant one. Rainfall is main source of water in India. From precipitation, India receives 4000 BCM (Billion Cubic Metres) water. Out of the total precipitation, about 75 per cent is received in months from June to September in the form of rainfall. Rainfall is required not only for water security but also for food security of the country. Monsoon rainfall is highly uncertain and irregular. The spatio-temporal variability of rainfall plays havoc with agriculture which shatters the very foundation of economy in a predominantly agricultural country like India. Indian rainfall is basically torrential in nature. It is generalized that it pours in India and rarely rains. Another important aspect of Indian rainfall is that it is largely controlled by relief.The objectives of the present paper are – (i) to describe the characteristics of Indian rainfall; (ii) to provide causative explanation of the spatial distribution of precipitation; (iii) to highlight the seasonal distribution of precipitation; (iv) to explain the variability of rainfall and (v) to describe the trend of rainfall in India from 1901 to 2013. I. INTRODUCTION In India dominantly tropical monsoon climate prevails. Among the climatic elements temperature and precipitation are the most significant one. Precipitation provides water security along with food security. Except for the Himalayan region, in all parts rain is the dominant form of precipitation. Monsoon rainfall is highly uncertain and irregular. The spatio-temporal variability of rainfall plays havoc with agriculture which shatters the very foundation of economy in a predominantly agricultural country like India. Indian rainfall Characteristics, Distribution and Trends of Precipitation in India Paper ID IJIFR/V4/ E12/ 034 Page No. 8599- 8614 Subject Area Geography Key Words Precipitation, Spatial, Seasonal, Irregular and Orographic Dr. Jitender Saroha Associate Professor, Dr. Bhim Rao Ambedkar College, University of Delhi, Delhi
16
Embed
Characteristics, Distribution and Trends of Precipitation in India · 2017-09-08 · precipitation in north India is associated with western disturbances or temperate cyclones. Tropical
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
8599 This work is published under Attribution-NonCommercial-ShareAlike 4.0 International License
International Journal of Informative & Futuristic Research ISSN: 2347-1697
Volume 4 Issue 12 August 2017 www.ijifr.com
Abstract
In India dominantly tropical monsoon climate prevails. Among the climatic elements temperature and rainfall are the most significant one. Rainfall is main source of water in India. From precipitation, India receives 4000 BCM (Billion Cubic Metres) water. Out of the total precipitation, about 75 per cent is received in months from June to September in the form of rainfall. Rainfall is required not only for water security but also for food security of the country. Monsoon rainfall is highly uncertain and irregular. The spatio-temporal variability of rainfall plays havoc with agriculture which shatters the very foundation of economy in a predominantly agricultural country like India. Indian rainfall is basically torrential in nature. It is generalized that it pours in India and rarely rains. Another important aspect of Indian rainfall is that it is largely controlled by relief.The objectives of the present paper are – (i) to describe the characteristics of Indian rainfall; (ii) to provide causative explanation of the spatial distribution of precipitation; (iii) to highlight the seasonal distribution of precipitation; (iv) to explain the variability of rainfall and (v) to describe the trend of rainfall in India from 1901 to 2013.
I. INTRODUCTION
In India dominantly tropical monsoon climate prevails. Among the climatic elements
temperature and precipitation are the most significant one. Precipitation provides water
security along with food security. Except for the Himalayan region, in all parts rain is the
dominant form of precipitation. Monsoon rainfall is highly uncertain and irregular. The
spatio-temporal variability of rainfall plays havoc with agriculture which shatters the very
foundation of economy in a predominantly agricultural country like India. Indian rainfall
Characteristics, Distribution and Trends
of Precipitation in India
Paper ID IJIFR/V4/ E12/ 034 Page No. 8599- 8614 Subject Area Geography
Key Words Precipitation, Spatial, Seasonal, Irregular and Orographic
Dr. Jitender Saroha
Associate Professor,
Dr. Bhim Rao Ambedkar College,
University of Delhi, Delhi
8600
ISSN: 2347-1697
International Journal of Informative & Futuristic Research (IJIFR)
Volume - 4, Issue -12, August 2017
Continuous 48th Edition, Page No. : 8599- 8614
Dr. Jitender Saroha :: Characteristics, Distribution and Trends of Precipitation in India
is basically torrential in nature. It is generalized that it pours in India and rarely rains.
Another important aspect of Indian rainfall is that it is largely controlled by relief. In the
absence of Himalayas the whole of India would have been a vast desert.
In India precipitation is dominantly of orographic form. However, the winter
precipitation in north India is associated with western disturbances or temperate cyclones.
Tropical depressions contribute to summer monsoon rain also. The frequency and
intensity of the tropical depressions developing over the Bay of Bengal and entering into
the Ganga Plain determine the amount of rainfall in summer season also. Convectional
rainfall is confined to the interior regions like parts of the peninsular plateau and
Rajasthan. The pre-monsoon rains along the eastern coast and in Ganga Valley are also
partly convectional.
Majority rainfall in India is received during the period of southwest monsoon winds. The
rainy season of India dominates from June to September. Of the country’s total rainfall,
about 75 per cent is received in this rainy season, 13 per cent in post monsoon season, 10
per cent in the pre-monsoon season and the remaining 2 per cent in the winter season
(Table 1). Only a small part of the country in the north and Tamil Nadu receive some
precipitation in winter. Rainfall by southwest monsoon dominates in India. In some areas
this dominance is more pronounced. For instance, the average annual rainfall over the
Northern Great Plains of India in this rainy season is about 92 cm which is about 87 per
cent of the total annual rainfall and rest of the months receive only 13 per cent of the total
i.e. about 14 cm rainfall.
Table 1: Seasonal Distribution of Rainfall in India
Season Annual Rainfall (per cent)
Pre-monsoon 10
Monsoon 75
Post-monsoon 13
Winter 2
Indian rainfall is largely torrential in nature. Most of the rainfall is received over a limited
number of rainy days. Cherrapunji has a record of receiving 103.6 cm rainfall in 24
hours. Here the number of rainy days is also the largest(180 days). In most places the
number of rainy days ranges between 45 and 50. Sri Ganganagar in the western part
receives 12 cm of rainfall over 10 - 12 rainy days. That is the reason people say, 'it pours,
it never rains in India'. The sudden heavy downpour results in flash floods in many areas.
The rainfall received in different parts of India varies a great deal in amount and intensity
over years. There are wide variations in the actual precipitation from the normal. Also
the monsoon is occasionally delayed leading to drought conditions in several parts of the
country. Occasionally the rains exceed the normal amount by a large margin leading to
floods in many parts. A large amount of rainfall in the northeast causes frequent floods in
that part. Parts of Odisha, Rajasthan and Gujarat are highly prone to droughts and most
areas in the Ganga Plains are prone to frequent floods.
8601
ISSN: 2347-1697
International Journal of Informative & Futuristic Research (IJIFR)
Volume - 4, Issue -12, August 2017
Continuous 48th Edition, Page No. : 8599- 8614
Dr. Jitender Saroha :: Characteristics, Distribution and Trends of Precipitation in India
Another important aspect of Indian rainfall is that it is largely controlled by
topography or relief. The impact of the Himalayas, the Western Ghats and the Meghalaya
plateau on the amount and distribution of rainfall is well known. Similarly, the position of
the Aravalis parallel to prevailing winds is responsible for arid conditions in this part of
India. The whole of India would have been a vast desert but for the size and position of
Himalayas and Western Ghats. The summer season would have been hot and dry and
winter season in northern part of India would have been mainly dry and too cold.
Therefore, it can be concluded that the rainfall over India is primarily orographic.
II. DISTRIBUTION OF RAINFALL
India receives 4000 BCM (Billion Cubic Metres) of water from precipitation. Out of the
total precipitation, the rainy months from June to September receive 3000 BCM. India as
a whole on an average receives 118 cm annual precipitation. However, the distribution of
rainfall in India is highly variable. About 11 per cent area receives over 200 cm of annual
rainfall, 21 per cent area receives 125 to 200 cm, 37 per cent area receives 75 to 125 cm,
24 per cent area gets 35 to 75 cm and 7 per cent area gets less than 35 cm average annual
rainfall (Table 2).
Table 2: Distribution of Rainfall in India
Annual Rainfall (cm) Area (per cent)
> 200 11
125 – 200 21
75 – 125 37
35 – 75 24
< 35 7
The rainfall is heavy along the western coast and in Assam, south Meghalaya, Tripura,
Nagaland and Arunachal Pradesh. All these regions receive rainfall above 200 cm. The
whole of Rajasthan, Punjab Haryana, western and southwestern parts of Uttar Pradesh,
western Madhya Pradesh and practically the entire Deccan Trap or plateau region east of
Western Ghats except for a narrow strip along Tamil Nadu coast receive a low rainfall of
less than 100 centimeters. The rest of the areas receive a rainfall ranging between 100 and
200 centimeters. The distribution of rainfall is represented in Fig.1. The distribution of rainfall is highly variable. Large parts of Meghalaya receive about
1,000 cm annual rainfall while on the other hand; districts of south-west Rajasthan hardly
receive annual rainfall of 15 cm. The average annual rainfall received at Cherrapunji is
1,102 cm.
Earlier it was considered as the place receiving highest rainfall in the world. But the
recorded data of recent years has established Mawsynram as the place receiving the
highest rainfall in the world. It is located about 16 km west of Cherrapunji in Meghalaya.
It receives the highest annual precipitation i.e. 1,221 cm in India as well as world. The
average annual rainfall at Jaisalmer rarely exceeds 12 cm. At place Tura (Garo Hills,
Meghalaya) the single day rainfall equals to the rainfall received for about 10 years at
Jaisalmer in Rajasthan.
8602
ISSN: 2347-1697
International Journal of Informative & Futuristic Research (IJIFR)
Volume - 4, Issue -12, August 2017
Continuous 48th Edition, Page No. : 8599- 8614
Dr. Jitender Saroha :: Characteristics, Distribution and Trends of Precipitation in India
Figure 1: Annual Rainfall The three major regions of high rainfall in India are – the western side i.e. the windward
side of Western Ghats – this includes the west coast from Thiruvananthapuram in the
south to Mumbai in the north. The average annual rainfall in this area is 200 – 400 cm;
(ii) seven sisters and Sikkim Himalaya region – it includes almost whole of Assam,
Arunachal Pradesh, parts of Manipur, Tripura, Nagaland, Mizoram, Sikkim and north
eastern part of West Bengal and Meghalaya. This region receives more than 200 cm
average annual precipitation. Meghalaya (abode of clouds) is the wettest part of the
8603
ISSN: 2347-1697
International Journal of Informative & Futuristic Research (IJIFR)
Volume - 4, Issue -12, August 2017
Continuous 48th Edition, Page No. : 8599- 8614
Dr. Jitender Saroha :: Characteristics, Distribution and Trends of Precipitation in India
country. Cherrapunji and Mawsynram are located on the southern slopes of the Khasi
Hills at the northern end of a funnel shaped valley running south to north; and (iii) the
islands (Andaman and Nicobar and Lakshadweep). The wind ward position of slopes and
proximity to seas are common factors for high precipitation in these three regions of high
rainfall.
The three regions of low and least rainfall in the country are - (i) Leeward side or the
rain shadow zone of the Western Ghats - it extends over the majority parts of Karnataka
and Maharashtra states. Here the average annual rainfall received is in the range of 35 to
75 cm. These areas are frequently prone to droughts; (ii) arid and semi-arid areas – it
includes the large parts of Rajashtan and Kachchh region. In this part south west
monsoon winds blow parallel to the Aravali mountain range. As this mountain range fails
to work as a barrier for moist winds arid conditions prevail. The average annual rainfall is
less than 50 cm; and (iii) the cold desert i.e. Ladakh region – it receives rainfall less than
25 cm because of its leeward position on the northern side of the Greater Himalaya. The
low rainfall areas are leeward sides or rain shadow regions of mountain ranges. For
instance, Mumbai on the west coast in wind ward slope position receives about 190 cm
rainfall but Pune located about 160 km away from Mumbai receives only 50 cm rainfall
due to its location on the leeward side or rain shadow zone position.
III. VARIABILITY OF RAINFALL
As described above rainfall is not only uneven, it is highly variable also. Variability of
rainfall is taken as a measure of reliability of rainfall. The rainfall variability and
reliability have inverse relationship. Stated simply, more variable the rainfall, less
reliable it is.
Variability of rainfall is studied in terms of co-efficient of variability (CV) which can be
Ministry of Information and Broadcasting, Govt. of India, Delhi.
[6] Ramage, C.S. (1971): Monsoon Meteorology, Academic Press, New York and London.
[7] Singh, S. and Saroha, J. (2014): Geography of India, Access Publishing, New Delhi.
[8] Tiwari, R.C. (2013): Geography of India, Pravalika Publication, Allahabad.
[9] The Times of India, 30 July 2017, P-10. IMD analysis reveals falling rainfall trend in
north India.
[10] The Hindustan Times, 27 July 2017, P-1.
[11] Guhathakurta, P. and Rajeevan, M. (2006): Trends in the Rainfall Pattern Over India,
National Climate Centre, Indian Meteorological Department, Pune.
[12] Rathore, L.S., Attri, S.D. and Jaswal, A.K. (2013): State Level Climate Change Trends in
India, Meteorological Monograph No. ESSO/IMD/EMRC/02/2013, IMD, Ministry of
Earth Sciences, Government of India.
AUTHOR DETAIL
Dr. Jitender Saroha is senior Associate Professor at Dr. B. R. Ambedkar
College (University of Delhi). He did B.A. (Hons.) in Geography from D.U. in
1991 and M.A. Geography (1993) from Delhi School of Economics, University
of Delhi. From this institute he completed M.Phil (1997) and Ph.D (2006)
research work on ‘Integrated Watershed Management in the Sikkim
Himalayas’. He has 19 years teaching experience. He has specialization in
Resource Geography, Climatology, Remote Sensing and GIS, and Disaster
Management. He has done M.Sc in Disaster Mitigation. He has participated
and presented papers in many national and international seminars and
conferences. He has completed two certificate courses in Remote Sensing and
GIS from Indian Institute of Remote Sensing (IIRS), Dehradun. He has also
worked as Joint Secretary (On Deputation) in University Grants Commission
(UGC), MHRD, GOI, New Delhi.
TO CITE THIS PAPER
Saroha, J. (2017) :: “Characteristics, Distribution and Trends of Precipitation in India” International Journal of Informative & Futuristic Research (ISSN: 2347-1697), Vol. (4)
No. (12), August 2017, pp. 8599- 8614, Paper ID: IJIFR/V4/E12/034.
Available online through- http://www.ijifr.com/searchjournal.aspx