Use of Indices on Daily Timescales to Study Changes in Extreme Precipitation Across Nepal Over 40 Years (1976–2015)
Abstract This paper presents a comprehensive picture of extreme precipitation across Nepal from 1976 to 2015 based on high‐quality daily precipitation observations from 28 precipitation stations spatially distributed across the country. We computed 11 extreme precipitation indices. The selected indi...
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| Format: | Article |
| Language: | English |
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American Geophysical Union (AGU)
2023-01-01
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| Series: | Earth and Space Science |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2020EA001509 |
| _version_ | 1811176697396985856 |
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| author | Manisha Maharjan Minoru Yoneda Rocky Talchabhadel Bhesh Raj Thapa Anil Aryal |
| author_facet | Manisha Maharjan Minoru Yoneda Rocky Talchabhadel Bhesh Raj Thapa Anil Aryal |
| author_sort | Manisha Maharjan |
| collection | DOAJ |
| description | Abstract This paper presents a comprehensive picture of extreme precipitation across Nepal from 1976 to 2015 based on high‐quality daily precipitation observations from 28 precipitation stations spatially distributed across the country. We computed 11 extreme precipitation indices. The selected indices allow the analysis of extreme events (such as flood/inundation) related to heavy precipitation and evaluate the linkage with indications of agricultural production and drought (such as consecutive dry and wet days). Using a simple daily intensity index (SDII) and the number of days with daily precipitation ≥10 mm (R10), along with the total amount of annual precipitation (PRCPTOT), we summarized the distribution of the wet periods of the year at different locations. We divided the study period into two halves (T1: 1976–1995 and T2: 1996–2015) to examine the temporal mean, trends, and their shift. We emphasized the changes in those indices between these two periods across the country. Our results show that although the amount of precipitation (in terms of PRCPTOT and SDII) did not change significantly between the two periods (i.e., T1 and T2), there exists a clearly increasing trend of extreme precipitation indices in T2 compared to T1. In addition, the consecutive dry days show the rising tendency of elongated dry spells that can adversely affect plant/crop growth in the future. Our study recommends the need for effective management of both precipitation extremes (i.e., drier and wetter), for instance, by introducing irrigation facilities and flood mitigation measures. |
| first_indexed | 2024-04-10T19:57:06Z |
| format | Article |
| id | doaj.art-5cb8e31553c84a1bb55d7347c9e12f86 |
| institution | Directory Open Access Journal |
| issn | 2333-5084 |
| language | English |
| last_indexed | 2024-04-10T19:57:06Z |
| publishDate | 2023-01-01 |
| publisher | American Geophysical Union (AGU) |
| record_format | Article |
| series | Earth and Space Science |
| spelling | doaj.art-5cb8e31553c84a1bb55d7347c9e12f862023-01-27T18:36:33ZengAmerican Geophysical Union (AGU)Earth and Space Science2333-50842023-01-01101n/an/a10.1029/2020EA001509Use of Indices on Daily Timescales to Study Changes in Extreme Precipitation Across Nepal Over 40 Years (1976–2015)Manisha Maharjan0Minoru Yoneda1Rocky Talchabhadel2Bhesh Raj Thapa3Anil Aryal4Department of Environmental Engineering Kyoto University Kyoto JapanDepartment of Environmental Engineering Kyoto University Kyoto JapanTexas A&M AgriLife Research Texas A&M University El Paso TX USASmartphones For Water‐Nepal Lalitpur NepalWater Engineering and Management Asian Institute of Technology Pathum Thani ThailandAbstract This paper presents a comprehensive picture of extreme precipitation across Nepal from 1976 to 2015 based on high‐quality daily precipitation observations from 28 precipitation stations spatially distributed across the country. We computed 11 extreme precipitation indices. The selected indices allow the analysis of extreme events (such as flood/inundation) related to heavy precipitation and evaluate the linkage with indications of agricultural production and drought (such as consecutive dry and wet days). Using a simple daily intensity index (SDII) and the number of days with daily precipitation ≥10 mm (R10), along with the total amount of annual precipitation (PRCPTOT), we summarized the distribution of the wet periods of the year at different locations. We divided the study period into two halves (T1: 1976–1995 and T2: 1996–2015) to examine the temporal mean, trends, and their shift. We emphasized the changes in those indices between these two periods across the country. Our results show that although the amount of precipitation (in terms of PRCPTOT and SDII) did not change significantly between the two periods (i.e., T1 and T2), there exists a clearly increasing trend of extreme precipitation indices in T2 compared to T1. In addition, the consecutive dry days show the rising tendency of elongated dry spells that can adversely affect plant/crop growth in the future. Our study recommends the need for effective management of both precipitation extremes (i.e., drier and wetter), for instance, by introducing irrigation facilities and flood mitigation measures.https://doi.org/10.1029/2020EA001509extreme precipitationprecipitation indicesNepaltrendspatiotemporal changenonparametric test |
| spellingShingle | Manisha Maharjan Minoru Yoneda Rocky Talchabhadel Bhesh Raj Thapa Anil Aryal Use of Indices on Daily Timescales to Study Changes in Extreme Precipitation Across Nepal Over 40 Years (1976–2015) Earth and Space Science extreme precipitation precipitation indices Nepal trend spatiotemporal change nonparametric test |
| title | Use of Indices on Daily Timescales to Study Changes in Extreme Precipitation Across Nepal Over 40 Years (1976–2015) |
| title_full | Use of Indices on Daily Timescales to Study Changes in Extreme Precipitation Across Nepal Over 40 Years (1976–2015) |
| title_fullStr | Use of Indices on Daily Timescales to Study Changes in Extreme Precipitation Across Nepal Over 40 Years (1976–2015) |
| title_full_unstemmed | Use of Indices on Daily Timescales to Study Changes in Extreme Precipitation Across Nepal Over 40 Years (1976–2015) |
| title_short | Use of Indices on Daily Timescales to Study Changes in Extreme Precipitation Across Nepal Over 40 Years (1976–2015) |
| title_sort | use of indices on daily timescales to study changes in extreme precipitation across nepal over 40 years 1976 2015 |
| topic | extreme precipitation precipitation indices Nepal trend spatiotemporal change nonparametric test |
| url | https://doi.org/10.1029/2020EA001509 |
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