Analysis of Rainfall Trends and Its Relationship with SST Signals in the Lake Tana Basin, Ethiopia
The impacts of climate change and climate variability on human life have led the scientific community to monitor the behavior of weather and climate variables at different spatial and temporal scales. This paper explores seasonal and annual trends of rainfall in the Lake Tana basin (LTB) and their t...
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| Format: | Article |
| Language: | English |
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Wiley
2018-01-01
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| Series: | Advances in Meteorology |
| Online Access: | http://dx.doi.org/10.1155/2018/5869010 |
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| author | Tesfay Mekonnen Weldegerima Tadesse Terefe Zeleke Belay Simane Birhanu Benjamin Frederick Zaitchik Zewdu Alamineh Fetene |
| author_facet | Tesfay Mekonnen Weldegerima Tadesse Terefe Zeleke Belay Simane Birhanu Benjamin Frederick Zaitchik Zewdu Alamineh Fetene |
| author_sort | Tesfay Mekonnen Weldegerima |
| collection | DOAJ |
| description | The impacts of climate change and climate variability on human life have led the scientific community to monitor the behavior of weather and climate variables at different spatial and temporal scales. This paper explores seasonal and annual trends of rainfall in the Lake Tana basin (LTB) and their teleconnections with global sea surface temperatures (SSTs) over the period between 1979 and 2015. The nonparametric Mann–Kendall test and Sen’s slope estimate are applied to the rainfall data collected from the National Meteorology Agency (NMA) of Ethiopia for detecting and estimating rainfall trends. Additionally, Pearson’s correlation coefficient method is used to determine the effect of SST variations on rainfall. The assessment of rainfall trends indicates that the amount of annual rainfall in the Lake Tana basin is increasing, but the rate of increase is not statistically significant. Seasonal analysis reveals that the smallest amount of rainfall occurs in the Bega season, and this season is getting drier with time. However, the analysis indicates that the other two seasons (Belg and Kiremt) are becoming wetter. The rainfall in Kiremt is increasing significantly (significant at the p=0.05 level) in Debre Tabor station with a rate of 10.20 mm/year. Besides, 78.1% of the total annual rainfall in the basin occurs during this rainy (Kiremt) season, whereas Bega and Belg contribute some 9.4% and 12.5%, respectively. Furthermore, the correlation analysis of rainfall and SSTs indicates that rainfall of the LTB is highly affected by the variations of SSTs. |
| format | Article |
| id | doaj-art-3307d8b7e7e84bb2810cf2c32bea52cb |
| institution | Kabale University |
| issn | 1687-9309 1687-9317 |
| language | English |
| publishDate | 2018-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advances in Meteorology |
| spelling | doaj-art-3307d8b7e7e84bb2810cf2c32bea52cb2025-02-03T01:02:14ZengWileyAdvances in Meteorology1687-93091687-93172018-01-01201810.1155/2018/58690105869010Analysis of Rainfall Trends and Its Relationship with SST Signals in the Lake Tana Basin, EthiopiaTesfay Mekonnen Weldegerima0Tadesse Terefe Zeleke1Belay Simane Birhanu2Benjamin Frederick Zaitchik3Zewdu Alamineh Fetene4Atmospheric Physics, Bahir Dar University, P.O. Box 79, Bahir Dar, EthiopiaInstitute of Geophysics, Space Science and Astronomy (IGSSA), Addis Ababa University, Addis Ababa, EthiopiaCollege of Development Studies, Addis Ababa University, Addis Ababa, EthiopiaDepartment of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21218, USAAtmospheric Physics, Bahir Dar University, P.O. Box 79, Bahir Dar, EthiopiaThe impacts of climate change and climate variability on human life have led the scientific community to monitor the behavior of weather and climate variables at different spatial and temporal scales. This paper explores seasonal and annual trends of rainfall in the Lake Tana basin (LTB) and their teleconnections with global sea surface temperatures (SSTs) over the period between 1979 and 2015. The nonparametric Mann–Kendall test and Sen’s slope estimate are applied to the rainfall data collected from the National Meteorology Agency (NMA) of Ethiopia for detecting and estimating rainfall trends. Additionally, Pearson’s correlation coefficient method is used to determine the effect of SST variations on rainfall. The assessment of rainfall trends indicates that the amount of annual rainfall in the Lake Tana basin is increasing, but the rate of increase is not statistically significant. Seasonal analysis reveals that the smallest amount of rainfall occurs in the Bega season, and this season is getting drier with time. However, the analysis indicates that the other two seasons (Belg and Kiremt) are becoming wetter. The rainfall in Kiremt is increasing significantly (significant at the p=0.05 level) in Debre Tabor station with a rate of 10.20 mm/year. Besides, 78.1% of the total annual rainfall in the basin occurs during this rainy (Kiremt) season, whereas Bega and Belg contribute some 9.4% and 12.5%, respectively. Furthermore, the correlation analysis of rainfall and SSTs indicates that rainfall of the LTB is highly affected by the variations of SSTs.http://dx.doi.org/10.1155/2018/5869010 |
| spellingShingle | Tesfay Mekonnen Weldegerima Tadesse Terefe Zeleke Belay Simane Birhanu Benjamin Frederick Zaitchik Zewdu Alamineh Fetene Analysis of Rainfall Trends and Its Relationship with SST Signals in the Lake Tana Basin, Ethiopia Advances in Meteorology |
| title | Analysis of Rainfall Trends and Its Relationship with SST Signals in the Lake Tana Basin, Ethiopia |
| title_full | Analysis of Rainfall Trends and Its Relationship with SST Signals in the Lake Tana Basin, Ethiopia |
| title_fullStr | Analysis of Rainfall Trends and Its Relationship with SST Signals in the Lake Tana Basin, Ethiopia |
| title_full_unstemmed | Analysis of Rainfall Trends and Its Relationship with SST Signals in the Lake Tana Basin, Ethiopia |
| title_short | Analysis of Rainfall Trends and Its Relationship with SST Signals in the Lake Tana Basin, Ethiopia |
| title_sort | analysis of rainfall trends and its relationship with sst signals in the lake tana basin ethiopia |
| url | http://dx.doi.org/10.1155/2018/5869010 |
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