Rainfall variabilities and droughts in the Savannah zone of Ghana from 1960-2015

In the Savannah region of Ghana, water scarcity appears to be a frequent occurrence, which is expected to worsen with the anticipated reductions in the quantity of rainfall received. A better estimation of future occurrences and the subsequent preparations are hinged on a solid understanding of past...

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Main Authors: Awo Boatemaa Manson Incoom, Kwaku Amaning Adjei, Samuel Nii Odai
Format: Article
Language:English
Published: Elsevier 2020-11-01
Series:Scientific African
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2468227620303094
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author Awo Boatemaa Manson Incoom
Kwaku Amaning Adjei
Samuel Nii Odai
author_facet Awo Boatemaa Manson Incoom
Kwaku Amaning Adjei
Samuel Nii Odai
author_sort Awo Boatemaa Manson Incoom
collection DOAJ
description In the Savannah region of Ghana, water scarcity appears to be a frequent occurrence, which is expected to worsen with the anticipated reductions in the quantity of rainfall received. A better estimation of future occurrences and the subsequent preparations are hinged on a solid understanding of past climatic patterns. Given that, trends in rainfall were analysed using the non-parametric Mann-Kendal test for nine (9) climate stations in as well as the entire Savannah zone of Ghana. from 1960 to 2015. No significant trends were observed in annual rainfall for the entire study area as well as individual climate stations except Wenchi, where a negative trend (Sen's slope = -3.30, p-value = 0.01) was recorded at a 0.05 level of significance The Standardised Precipitation Index (SPI) was used to study rainfall anomalies. Droughts were observed to be a regular feature of the climate, occurring at alternating intervals with wet periods. Recovery of the wet periods from the droughts was observed to be declining post the year 2000. For most locations, 1983 recorded the most intense drought while a few others like Navrongo and Wa also saw 2015 being hardly hit by another. Aridity in the study area was found to be intensifying, with aridity index values increasing at a rate of 0.2/decade, although this was not found to be significant (p-value = 0.06) at a 0.05 level of significance. Similar to rainfall, aridity for most of the stations appeared to be increasing although these changes were not statistically significant except for Wenchi, which again recorded a significant increase (p-value of 0.02).
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spelling doaj.art-4eb3b0eaecc145faafdf51439bcb27f72022-12-21T22:48:38ZengElsevierScientific African2468-22762020-11-0110e00571Rainfall variabilities and droughts in the Savannah zone of Ghana from 1960-2015Awo Boatemaa Manson Incoom0Kwaku Amaning Adjei1Samuel Nii Odai2Regional Water and Environmental Sanitation Centre, Kumasi, Kwame Nkrumah University of Science and Technology Kumasi, Ghana; Corresponding author.Regional Water and Environmental Sanitation Centre, Kumasi, Kwame Nkrumah University of Science and Technology Kumasi, GhanaAccra Technical University AccraIn the Savannah region of Ghana, water scarcity appears to be a frequent occurrence, which is expected to worsen with the anticipated reductions in the quantity of rainfall received. A better estimation of future occurrences and the subsequent preparations are hinged on a solid understanding of past climatic patterns. Given that, trends in rainfall were analysed using the non-parametric Mann-Kendal test for nine (9) climate stations in as well as the entire Savannah zone of Ghana. from 1960 to 2015. No significant trends were observed in annual rainfall for the entire study area as well as individual climate stations except Wenchi, where a negative trend (Sen's slope = -3.30, p-value = 0.01) was recorded at a 0.05 level of significance The Standardised Precipitation Index (SPI) was used to study rainfall anomalies. Droughts were observed to be a regular feature of the climate, occurring at alternating intervals with wet periods. Recovery of the wet periods from the droughts was observed to be declining post the year 2000. For most locations, 1983 recorded the most intense drought while a few others like Navrongo and Wa also saw 2015 being hardly hit by another. Aridity in the study area was found to be intensifying, with aridity index values increasing at a rate of 0.2/decade, although this was not found to be significant (p-value = 0.06) at a 0.05 level of significance. Similar to rainfall, aridity for most of the stations appeared to be increasing although these changes were not statistically significant except for Wenchi, which again recorded a significant increase (p-value of 0.02).http://www.sciencedirect.com/science/article/pii/S2468227620303094RainfallStandardized Precipitation IndexAridity indexMann- Kendall trend testSavannah zone
spellingShingle Awo Boatemaa Manson Incoom
Kwaku Amaning Adjei
Samuel Nii Odai
Rainfall variabilities and droughts in the Savannah zone of Ghana from 1960-2015
Scientific African
Rainfall
Standardized Precipitation Index
Aridity index
Mann- Kendall trend test
Savannah zone
title Rainfall variabilities and droughts in the Savannah zone of Ghana from 1960-2015
title_full Rainfall variabilities and droughts in the Savannah zone of Ghana from 1960-2015
title_fullStr Rainfall variabilities and droughts in the Savannah zone of Ghana from 1960-2015
title_full_unstemmed Rainfall variabilities and droughts in the Savannah zone of Ghana from 1960-2015
title_short Rainfall variabilities and droughts in the Savannah zone of Ghana from 1960-2015
title_sort rainfall variabilities and droughts in the savannah zone of ghana from 1960 2015
topic Rainfall
Standardized Precipitation Index
Aridity index
Mann- Kendall trend test
Savannah zone
url http://www.sciencedirect.com/science/article/pii/S2468227620303094
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