Trend analysis of major hydroclimatic variables in the Langat River basin, Malaysia
Trend analyses of monthly, seasonal and annual rainfall, air temperature, and streamflow were performed using Mann‐Kendall test within the Langat River basin to identify gradual trends and abrupt shifts for 1980 − 2010. Annual rainfall showed an increasing trend in upstream flow, a combination of de...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Department of Geography, National University of Singapore and John Wiley & Sons Australia
2018
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| Online Access: | http://psasir.upm.edu.my/id/eprint/64060/1/Trend%20analysis%20of%20major%20hydroclimatic%20variables%20in%20the%20Langat%20River%20basin%2C%20Malaysia.pdf |
| _version_ | 1796977822665801728 |
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| author | Ebrahimian, Mahboubeh Nuruddin, Ahmad Ainuddin Mohd Soom, Mohd Amin Mohd Sood, Alias Liew, Ju Neng Galavi, Hadi |
| author_facet | Ebrahimian, Mahboubeh Nuruddin, Ahmad Ainuddin Mohd Soom, Mohd Amin Mohd Sood, Alias Liew, Ju Neng Galavi, Hadi |
| author_sort | Ebrahimian, Mahboubeh |
| collection | UPM |
| description | Trend analyses of monthly, seasonal and annual rainfall, air temperature, and streamflow were performed using Mann‐Kendall test within the Langat River basin to identify gradual trends and abrupt shifts for 1980 − 2010. Annual rainfall showed an increasing trend in upstream flow, a combination of decreasing and increasing trends in middle stream flow, and a decreasing trend in downstream flow. Monthly rainfall in most months displayed an insignificant increasing trend upstream. Stations with significant increasing trends showed larger trends in summer than those of other seasons. However, they were similar to the trends observed in annual rainfall. Annual minimum air temperature showed a significant decreasing trend upstream and significant increasing trends in the middle stream and downstream areas. Annual maximum air temperature portrayed increasing trends in both upstream and middle stream areas, and a decreasing trend for the downstream area. Both monthly and seasonal maximum air temperatures exhibited an increasing trend midstream, whereas they demonstrated trends of both decreasing and/or increasing temperatures at upstream and downstream areas. Annual streamflow in upper, middle and lower catchment areas exhibited significant increasing trend at the rates of 0.036, 0.023 and 0.001 × 103 m3/y at α = 0.01, respectively. Seasonal streamflow in the upstream, midstream and downstream areas displayed an increasing trend for spring (0.55, 0.33 and 0.013 m3/y respectively) and summer (0.51, 0.37, 0.018 m3/y respectively). The greatest magnitude of increased streamflow occurred in the spring (0.54 m3/y). Significant increasing trends of monthly streamflow were noticed in January and August, but insignificant trends were found in May, September and November at all stations. Annual streamflow records at the outlet of the basin were positively correlated with the annual rainfall variable. This study concludes that the climate of the Langat River basin has been getting wetter and warmer during 1980‐2010. |
| first_indexed | 2024-03-06T09:45:42Z |
| format | Article |
| id | upm.eprints-64060 |
| institution | Universiti Putra Malaysia |
| language | English |
| last_indexed | 2024-03-06T09:45:42Z |
| publishDate | 2018 |
| publisher | Department of Geography, National University of Singapore and John Wiley & Sons Australia |
| record_format | dspace |
| spelling | upm.eprints-640602018-06-08T01:00:44Z http://psasir.upm.edu.my/id/eprint/64060/ Trend analysis of major hydroclimatic variables in the Langat River basin, Malaysia Ebrahimian, Mahboubeh Nuruddin, Ahmad Ainuddin Mohd Soom, Mohd Amin Mohd Sood, Alias Liew, Ju Neng Galavi, Hadi Trend analyses of monthly, seasonal and annual rainfall, air temperature, and streamflow were performed using Mann‐Kendall test within the Langat River basin to identify gradual trends and abrupt shifts for 1980 − 2010. Annual rainfall showed an increasing trend in upstream flow, a combination of decreasing and increasing trends in middle stream flow, and a decreasing trend in downstream flow. Monthly rainfall in most months displayed an insignificant increasing trend upstream. Stations with significant increasing trends showed larger trends in summer than those of other seasons. However, they were similar to the trends observed in annual rainfall. Annual minimum air temperature showed a significant decreasing trend upstream and significant increasing trends in the middle stream and downstream areas. Annual maximum air temperature portrayed increasing trends in both upstream and middle stream areas, and a decreasing trend for the downstream area. Both monthly and seasonal maximum air temperatures exhibited an increasing trend midstream, whereas they demonstrated trends of both decreasing and/or increasing temperatures at upstream and downstream areas. Annual streamflow in upper, middle and lower catchment areas exhibited significant increasing trend at the rates of 0.036, 0.023 and 0.001 × 103 m3/y at α = 0.01, respectively. Seasonal streamflow in the upstream, midstream and downstream areas displayed an increasing trend for spring (0.55, 0.33 and 0.013 m3/y respectively) and summer (0.51, 0.37, 0.018 m3/y respectively). The greatest magnitude of increased streamflow occurred in the spring (0.54 m3/y). Significant increasing trends of monthly streamflow were noticed in January and August, but insignificant trends were found in May, September and November at all stations. Annual streamflow records at the outlet of the basin were positively correlated with the annual rainfall variable. This study concludes that the climate of the Langat River basin has been getting wetter and warmer during 1980‐2010. Department of Geography, National University of Singapore and John Wiley & Sons Australia 2018 Article PeerReviewed text en http://psasir.upm.edu.my/id/eprint/64060/1/Trend%20analysis%20of%20major%20hydroclimatic%20variables%20in%20the%20Langat%20River%20basin%2C%20Malaysia.pdf Ebrahimian, Mahboubeh and Nuruddin, Ahmad Ainuddin and Mohd Soom, Mohd Amin and Mohd Sood, Alias and Liew, Ju Neng and Galavi, Hadi (2018) Trend analysis of major hydroclimatic variables in the Langat River basin, Malaysia. Singapore Journal of Tropical Geography, 39 (2). pp. 192-214. ISSN 0129-7619; ESSN: 1467-9493 https://onlinelibrary.wiley.com/doi/abs/10.1111/sjtg.12234?af=R 10.1111/sjtg.12234 |
| spellingShingle | Ebrahimian, Mahboubeh Nuruddin, Ahmad Ainuddin Mohd Soom, Mohd Amin Mohd Sood, Alias Liew, Ju Neng Galavi, Hadi Trend analysis of major hydroclimatic variables in the Langat River basin, Malaysia |
| title | Trend analysis of major hydroclimatic variables in the Langat River basin, Malaysia |
| title_full | Trend analysis of major hydroclimatic variables in the Langat River basin, Malaysia |
| title_fullStr | Trend analysis of major hydroclimatic variables in the Langat River basin, Malaysia |
| title_full_unstemmed | Trend analysis of major hydroclimatic variables in the Langat River basin, Malaysia |
| title_short | Trend analysis of major hydroclimatic variables in the Langat River basin, Malaysia |
| title_sort | trend analysis of major hydroclimatic variables in the langat river basin malaysia |
| url | http://psasir.upm.edu.my/id/eprint/64060/1/Trend%20analysis%20of%20major%20hydroclimatic%20variables%20in%20the%20Langat%20River%20basin%2C%20Malaysia.pdf |
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