The summer monsoon (June through September), or southwest seasonal rains, contribute 78% of India’s annual rainfall. It is the greatest climatic water resource of India. The country’s agriculture and food production depend on these rains. Rainfed farming areas in India account for about 70% of the total arable land in the country, with nearly 100 million ha depending on the monsoon rains. The rains also contribute to power generation and industrial production

Kothawale, D. R.

Munot, A. A.

Parathasarathy, B.

English

Parthasarathy, B

Munot, AA

Kothawale, DR

Ministry of Earth Sciences, Government of India

Droughts over homogeneous regions of India : 1871-1990

DigitalCommons@University of Nebraska

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Drought Network News (1994-2001) Drought -- National Drought Mitigation Center June 1994 Droughts over Homogeneous Regions of India: 1871–-1990 B. Parathasarathy Indian Institute of Tropical Meteorology, Pune, India A. A. Munot Indian Institute of Tropical Meteorology, Pune, India D. R. Kothawale Indian Institute of Tropical Meteorology, Pune, India Follow this and additional works at: https://digitalcommons.unl.edu/droughtnetnews  Part of the Climate Commons Parathasarathy, B.; Munot, A. A.; and Kothawale, D. R., "Droughts over Homogeneous Regions of India: 1871–-1990" (1994). Drought Network News (1994-2001). 67. https://digitalcommons.unl.edu/droughtnetnews/67 This Article is brought to you for free and open access by the Drought -- National Drought Mitigation Center at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Drought Network News (1994-2001) by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Droughts over Homogeneous Regions of India: 18711990*The summer monsoon (June through September), or southwest seasonalrains, contribute 78% of India’s annual rainfall. It is the greatest climaticwater resource of India. The country’s agriculture and food productiondepend on these rains. Rainfed farming areas in India account for about 70%of the total arable land in the country, with nearly 100 million ha dependingon the monsoon rains. The rains also contribute to power generation andindustrial production.It is well known that the summer Indian monsoon phenomenon is theresult of a series of physical processes over the Asian region and adjoiningseas during the pre-monsoon months, March–May. The fluctuations in thequantity of monsoon rainfall over different parts of the country have animportant bearing on agriculture and living conditions. Many recent studiesaimed at the understanding or prediction of monsoon rainfall behavior overIndia have considered the country as one unit—All-India. The Indianmonsoon rainfall over different regions is known to have considerable spatialvariability, which imposes certain limitations on the All-India averagerainfall used at present. Monsoon rainfall also shows conspicuous episodicvariations in its association with different circulation parameters. Parthasarathyet al. have divided the country into 5 homogeneous macroregions (Figure 1)B. Parthasarathy, A. A. Munot, and D. R. KothawaleIndian Institute of Tropical MeteorologyPune, IndiaTable 1. Statistical details of homogeneous regions of India, 1871–1990.Region No. of % Area Mean % of Standard CVSub- of India JJAS Annual Deviation %divisions Rainfall Amount (mm)(mm)Northwest 6 22.0 490.0 89.9 132.4 27.0West Central 8 33.4 933.2 86.3 126.0 13.5Central Northeast 5 19.9 1002.4 83.3 112.7 11.2Northeast 4 9.3 1419.2 68.7 121.3 8.6Peninsular 6 15.4 659.4 57.0 98.3 14.9Table 2. Drought years over different regions of India, 1871–1990.Northeast India(includes subdivisions3, 4, 5, 6)Northwest India(includes subdivisions13, 14, 17, 18, 21, 22)West Central India(includes subdivisions19, 20, 23, 24, 25, 26, 28, 32)Peninsular India(includes subdivisions27, 29, 30, 31, 33, 34)Area not considered(includes subdivisions1, 2, 12, 15, 16, 35)Central Northeast India(includes subdivisions7, 8, 9, 10, 11)Figure 1. Homogeneous regions of India.Figure 1. Homogeneous regions of India.by analyzing the 29 subdivisional monsoon rainfall series (prepared on thebasis of 306 fixed well-distributed rain gages in the plain regions of India,each one properly weighted) for 1871–1990, with similar rainfall character-istics and association with 12 regional/global circulation parameters. Thestatistical details of this analysis are presented in Table 1.It is difficult to define drought (dry) conditions precisely over a region,but in general terms, it can be regarded as the condition in which water isinsufficient to meet the requirements of plants, animals, and humans of thatregion. Therefore, a monsoon rainfall year over a region is classified as drywhen Ri ≤ R - S and wet when Ri ≥ R + S, where Ri is the monsoon rainfallof the ith year, R the mean, and S the standard deviation of the series. Thisclassification is considered rational for the tropical regions with high spatialand temporal variability of rainfall, where the crop growth and waterrequirement and management are tuned to the local conditions of the region.Table 2 shows the drought years over different regions of India on adecadal basis. Table 2 shows that during the periods 1899–1925 and 1962–87, many below-normal rainfall years with drought conditions were ob-served.Decade All- North- Central Central North- PeninsularIndia West NE east1871-80 1873 1877 1877 1873 1873 18731877 1877 18761878 18801881-90 — — — — 1884 188118841891-1900 1899 1899 1899 — 1891 18911892 1899189619001901-10 1901 1901 1902 1901 — 19051904 1904 1904 19031905 1905 1905 19071911-20 1911 1911 1911 1918 1914 19111918 1915 1913 19131920 1918 1918 191819201921-30 1928 1925 — 1928 1925 19301931-40 — 1938 — 1932 — 193419391941-50 1941 1948 1941 — — 19521951-60 1951 1951 1951 1951 1957 —1954 19581959 19591961-70 1965 1965 1965 1965 1961 —1966 1968 1966 1966 19621968 1968 1968 19671971-80 1972 1972 1972 1972 1972 19721974 1974 1974 1974 1975 19761979 1979 1979 19801981-90 1982 1982 1984 1987 1981 19871985 1985 1985 1982 19901986 1986 1987 19861987 1987Total 22 21 20 19 20 18This article appeared in the June 1994 issue of Drought Network News.* This article was originally printed with a second figure that could not be satisfactorily reproduced here. For a complete copy of the article, please contactthe National Drought Mitigation Center.

Droughts over Homogeneous Regions of India: 1871–-1990

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University of Nebraska - Lincoln 
DigitalCommons@University of Nebraska - Lincoln 
Drought Network News (1994-2001) Drought -- National Drought Mitigation Center 
June 1994 
Droughts over Homogeneous Regions of India: 1871–-1990 
B. Parathasarathy 
Indian Institute of Tropical Meteorology, Pune, India 
A. A. Munot 
Indian Institute of Tropical Meteorology, Pune, India 
D. R. Kothawale 
Indian Institute of Tropical Meteorology, Pune, India 
Follow this and additional works at: https://digitalcommons.unl.edu/droughtnetnews 
 Part of the Climate Commons 
Parathasarathy, B.; Munot, A. A.; and Kothawale, D. R., "Droughts over Homogeneous Regions of India: 
1871–-1990" (1994). Drought Network News (1994-2001). 67. 
https://digitalcommons.unl.edu/droughtnetnews/67 
This Article is brought to you for free and open access by the Drought -- National Drought Mitigation Center at 
DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Drought Network News 
(1994-2001) by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. 
Droughts over Homogeneous Regions of India: 18711990*
The summer monsoon (June through September), or southwest seasonal
rains, contribute 78% of India’s annual rainfall. It is the greatest climatic
water resource of India. The country’s agriculture and food production
depend on these rains. Rainfed farming areas in India account for about 70%
of the total arable land in the country, with nearly 100 million ha depending
on the monsoon rains. The rains also contribute to power generation and
industrial production.
It is well known that the summer Indian monsoon phenomenon is the
result of a series of physical processes over the Asian region and adjoining
seas during the pre-monsoon months, March–May. The fluctuations in the
quantity of monsoon rainfall over different parts of the country have an
important bearing on agriculture and living conditions. Many recent studies
aimed at the understanding or prediction of monsoon rainfall behavior over
India have considered the country as one unit—All-India. The Indian
monsoon rainfall over different regions is known to have considerable spatial
variability, which imposes certain limitations on the All-India average
rainfall used at present. Monsoon rainfall also shows conspicuous episodic
variations in its association with different circulation parameters. Parthasarathy
et al. have divided the country into 5 homogeneous macroregions (Figure 1)
B. Parthasarathy, A. A. Munot, and D. R. Kothawale
Indian Institute of Tropical Meteorology
Pune, India
Table 1. Statistical details of homogeneous regions of India, 1871–1990.
Region No. of % Area Mean % of Standard CV
Sub- of India JJAS Annual Deviation %
divisions Rainfall Amount (mm)
(mm)
Northwest 6 22.0 490.0 89.9 132.4 27.0
West Central 8 33.4 933.2 86.3 126.0 13.5
Central Northeast 5 19.9 1002.4 83.3 112.7 11.2
Northeast 4 9.3 1419.2 68.7 121.3 8.6
Peninsular 6 15.4 659.4 57.0 98.3 14.9
Table 2. Drought years over different regions of India, 1871–1990.
Northeast India
(includes subdivisions
3, 4, 5, 6)
Northwest India
(includes subdivisions
13, 14, 17, 18, 21, 22)
West Central India
(includes subdivisions
19, 20, 23, 24, 25, 26, 28, 32)
Peninsular India
(includes subdivisions
27, 29, 30, 31, 33, 34)
Area not considered
(includes subdivisions
1, 2, 12, 15, 16, 35)
Central Northeast India
(includes subdivisions
7, 8, 9, 10, 11)
Figure 1. Homogeneous regions of India.
Figure 1. Homogeneous regions of India.
by analyzing the 29 subdivisional monsoon rainfall series (prepared on the
basis of 306 fixed well-distributed rain gages in the plain regions of India,
each one properly weighted) for 1871–1990, with similar rainfall character-
istics and association with 12 regional/global circulation parameters. The
statistical details of this analysis are presented in Table 1.
It is difficult to define drought (dry) conditions precisely over a region,
but in general terms, it can be regarded as the condition in which water is
insufficient to meet the requirements of plants, animals, and humans of that
region. Therefore, a monsoon rainfall year over a region is classified as dry
when Ri ≤ R - S and wet when Ri ≥ R + S, where Ri is the monsoon rainfall
of the ith year, R the mean, and S the standard deviation of the series. This
classification is considered rational for the tropical regions with high spatial
and temporal variability of rainfall, where the crop growth and water
requirement and management are tuned to the local conditions of the region.
Table 2 shows the drought years over different regions of India on a
decadal basis. Table 2 shows that during the periods 1899–1925 and 1962–
87, many below-normal rainfall years with drought conditions were ob-
served.
Decade All- North- Central Central North- Peninsular
India West NE east
1871-80 1873 1877 1877 1873 1873 1873
1877 1877 1876
1878 1880
1881-90 — — — — 1884 1881
1884
1891-1900 1899 1899 1899 — 1891 1891
1892 1899
1896
1900
1901-10 1901 1901 1902 1901 — 1905
1904 1904 1904 1903
1905 1905 1905 1907
1911-20 1911 1911 1911 1918 1914 1911
1918 1915 1913 1913
1920 1918 1918 1918
1920
1921-30 1928 1925 — 1928 1925 1930
1931-40 — 1938 — 1932 — 1934
1939
1941-50 1941 1948 1941 — — 1952
1951-60 1951 1951 1951 1951 1957 —
1954 1958
1959 1959
1961-70 1965 1965 1965 1965 1961 —
1966 1968 1966 1966 1962
1968 1968 1968 1967
1971-80 1972 1972 1972 1972 1972 1972
1974 1974 1974 1974 1975 1976
1979 1979 1979 1980
1981-90 1982 1982 1984 1987 1981 1987
1985 1985 1985 1982 1990
1986 1986 1987 1986
1987 1987
Total 22 21 20 19 20 18
This article appeared in the June 1994 issue of Drought Network News.
* This article was originally printed with a second figure that could not be satisfactorily reproduced here. For a complete copy of the article, please contact
the National Drought Mitigation Center.


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Droughts over Homogeneous Regions of India: 1871–-1990

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