A framework to incorporate spatiotemporal variability of rainfall extremes in summer monsoon declaration in India
The Indian summer monsoon rainfall is a lifeline for agricultural activities and the socio-economic development of more than 1 billion people. All-India averaged summer monsoon rainfall has about 10% variability from its long-term mean. A departure of all-India averaged precipitation within ±10% is...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2022-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/ac8c5c |
| _version_ | 1797747294055956480 |
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| author | Vimal Mishra Amar Deep Tiwari Rohini Kumar |
| author_facet | Vimal Mishra Amar Deep Tiwari Rohini Kumar |
| author_sort | Vimal Mishra |
| collection | DOAJ |
| description | The Indian summer monsoon rainfall is a lifeline for agricultural activities and the socio-economic development of more than 1 billion people. All-India averaged summer monsoon rainfall has about 10% variability from its long-term mean. A departure of all-India averaged precipitation within ±10% is declared a normal summer monsoon. Using the long-term (1901–2021) gridded rainfall observations, we highlight the limitations in the current approach to the declaration of the normal summer monsoon, which ignores the role of spatiotemporal variability of rainfall. Dry and wet extremes within the same monsoon season can lead to a normal monsoon. Moreover, different parts of the country face drought and wet extremes, while the summer monsoon can be declared normal. Considering the profound implications of dry and wet extremes on agricultural activities, we propose a novel framework to account for the rainfall variability in the declaration of the summer monsoon. The proposed framework accounts for the temporal variability through a combined severity coverage index, while spatial variability using a clustering approach. Based on the existing framework, we find that 84 years were declared normal in the last 121 years (1901–1921). However, 13 years (out of 84) were not normal based on the new framework due to dry and wet extremes occurring at different times and in different regions. The new framework of summer monsoon declaration can account for the occurrence of extremes and their implications for agriculture and water management. |
| first_indexed | 2024-03-12T15:49:39Z |
| format | Article |
| id | doaj.art-2a8ceef0a3974ba6b0269086620de2d9 |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:49:39Z |
| publishDate | 2022-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-2a8ceef0a3974ba6b0269086620de2d92023-08-09T15:16:10ZengIOP PublishingEnvironmental Research Letters1748-93262022-01-0117909403910.1088/1748-9326/ac8c5cA framework to incorporate spatiotemporal variability of rainfall extremes in summer monsoon declaration in IndiaVimal Mishra0https://orcid.org/0000-0002-3046-6296Amar Deep Tiwari1Rohini Kumar2https://orcid.org/0000-0002-4396-2037Civil Engineering and Earth Sciences, Civil Engineering, Indian Institute of Technology (IIT) Gandhinagar , Gujarat, India; Earth Sciences, Indian Institute of Technology (IIT) Gandhinagar , Gujarat, IndiaCivil Engineering and Earth Sciences, Civil Engineering, Indian Institute of Technology (IIT) Gandhinagar , Gujarat, IndiaUFZ-Helmholtz Centre for Environmental Research , Leipzig, GermanyThe Indian summer monsoon rainfall is a lifeline for agricultural activities and the socio-economic development of more than 1 billion people. All-India averaged summer monsoon rainfall has about 10% variability from its long-term mean. A departure of all-India averaged precipitation within ±10% is declared a normal summer monsoon. Using the long-term (1901–2021) gridded rainfall observations, we highlight the limitations in the current approach to the declaration of the normal summer monsoon, which ignores the role of spatiotemporal variability of rainfall. Dry and wet extremes within the same monsoon season can lead to a normal monsoon. Moreover, different parts of the country face drought and wet extremes, while the summer monsoon can be declared normal. Considering the profound implications of dry and wet extremes on agricultural activities, we propose a novel framework to account for the rainfall variability in the declaration of the summer monsoon. The proposed framework accounts for the temporal variability through a combined severity coverage index, while spatial variability using a clustering approach. Based on the existing framework, we find that 84 years were declared normal in the last 121 years (1901–1921). However, 13 years (out of 84) were not normal based on the new framework due to dry and wet extremes occurring at different times and in different regions. The new framework of summer monsoon declaration can account for the occurrence of extremes and their implications for agriculture and water management.https://doi.org/10.1088/1748-9326/ac8c5cdroughtwet extremesIndian monsoon |
| spellingShingle | Vimal Mishra Amar Deep Tiwari Rohini Kumar A framework to incorporate spatiotemporal variability of rainfall extremes in summer monsoon declaration in India Environmental Research Letters drought wet extremes Indian monsoon |
| title | A framework to incorporate spatiotemporal variability of rainfall extremes in summer monsoon declaration in India |
| title_full | A framework to incorporate spatiotemporal variability of rainfall extremes in summer monsoon declaration in India |
| title_fullStr | A framework to incorporate spatiotemporal variability of rainfall extremes in summer monsoon declaration in India |
| title_full_unstemmed | A framework to incorporate spatiotemporal variability of rainfall extremes in summer monsoon declaration in India |
| title_short | A framework to incorporate spatiotemporal variability of rainfall extremes in summer monsoon declaration in India |
| title_sort | framework to incorporate spatiotemporal variability of rainfall extremes in summer monsoon declaration in india |
| topic | drought wet extremes Indian monsoon |
| url | https://doi.org/10.1088/1748-9326/ac8c5c |
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