Analyzing rainfall trend and drought occurences in Sudan Savanna of Nigeria

Monthly precipitation data that span from 1986 – 2019 (34) years were downloaded from the website of Nigeria Meteorological Agency, (NIMET), Abuja, Nigeria and were used to assess rainfall trend and drought occurrences in the Sudan Savanna of Nigeria. The non-parametric Mann – Kendall test was emplo...

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Main Authors: Ernest Benjamin Ikechukwu Ugwu, Desmond Okechukwu Ugbor, Jonas Udoka Agbo, Abigail Alfa
Format: Article
Language:English
Published: Elsevier 2023-07-01
Series:Scientific African
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2468227623001266
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author Ernest Benjamin Ikechukwu Ugwu
Desmond Okechukwu Ugbor
Jonas Udoka Agbo
Abigail Alfa
author_facet Ernest Benjamin Ikechukwu Ugwu
Desmond Okechukwu Ugbor
Jonas Udoka Agbo
Abigail Alfa
author_sort Ernest Benjamin Ikechukwu Ugwu
collection DOAJ
description Monthly precipitation data that span from 1986 – 2019 (34) years were downloaded from the website of Nigeria Meteorological Agency, (NIMET), Abuja, Nigeria and were used to assess rainfall trend and drought occurrences in the Sudan Savanna of Nigeria. The non-parametric Mann – Kendall test was employed to test for trends while Standardized Precipitation Index (SPI) was used to generate SPI values and graphs. Our findings show that rainfall is on the declining trend in Gombe (z-value = -0.5930) and Kaduna (z-value = -2.520) but on increasing trend in Sokoto (z-value = 1.9272). Kaduna alone with P-value of 0.0117 which is less than 0.05 level of significance showed monotonic declining trend. In Sokoto, even though there is an increase, it is not monotonic since the P- value of 0.0540 is greater than the significant value of 0.05. The SPI values show only two extreme droughts in Kaduna in 2004 and 2013 with SPI of -2.04 and -2.08 respectively. Some of the years experienced between moderate to severe drought in all the stations while near normal condition is predominant in all the stations. Apart from the only incidence of extreme flooding in Sokoto in 2019 with SPI of 2.755, there were a few incidences of severe wetness or moderate wetness for the other years in all the stations.
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spelling doaj.art-1e06e739849b4a5bb79d62ae4507a5882023-06-17T05:19:53ZengElsevierScientific African2468-22762023-07-0120e01670Analyzing rainfall trend and drought occurences in Sudan Savanna of NigeriaErnest Benjamin Ikechukwu Ugwu0Desmond Okechukwu Ugbor1Jonas Udoka Agbo2Abigail Alfa3Department of Physics and Astronomy, University of Nigeria, Nsukka, Nigeria; Natural Science Unit, University of Nigeria, Nsukka, Nigeria; Corresponding author at: Department of Physics and Astronomy, University of Nigeria, Nsukka, Enugu State, Nigeria.Department of Physics and Astronomy, University of Nigeria, Nsukka, NigeriaDepartment of Physics and Astronomy, University of Nigeria, Nsukka, NigeriaDepartment of Physics and Astronomy, University of Nigeria, Nsukka, NigeriaMonthly precipitation data that span from 1986 – 2019 (34) years were downloaded from the website of Nigeria Meteorological Agency, (NIMET), Abuja, Nigeria and were used to assess rainfall trend and drought occurrences in the Sudan Savanna of Nigeria. The non-parametric Mann – Kendall test was employed to test for trends while Standardized Precipitation Index (SPI) was used to generate SPI values and graphs. Our findings show that rainfall is on the declining trend in Gombe (z-value = -0.5930) and Kaduna (z-value = -2.520) but on increasing trend in Sokoto (z-value = 1.9272). Kaduna alone with P-value of 0.0117 which is less than 0.05 level of significance showed monotonic declining trend. In Sokoto, even though there is an increase, it is not monotonic since the P- value of 0.0540 is greater than the significant value of 0.05. The SPI values show only two extreme droughts in Kaduna in 2004 and 2013 with SPI of -2.04 and -2.08 respectively. Some of the years experienced between moderate to severe drought in all the stations while near normal condition is predominant in all the stations. Apart from the only incidence of extreme flooding in Sokoto in 2019 with SPI of 2.755, there were a few incidences of severe wetness or moderate wetness for the other years in all the stations.http://www.sciencedirect.com/science/article/pii/S2468227623001266DroughtFloodingRainfallStandardized precipitation indexTrend
spellingShingle Ernest Benjamin Ikechukwu Ugwu
Desmond Okechukwu Ugbor
Jonas Udoka Agbo
Abigail Alfa
Analyzing rainfall trend and drought occurences in Sudan Savanna of Nigeria
Scientific African
Drought
Flooding
Rainfall
Standardized precipitation index
Trend
title Analyzing rainfall trend and drought occurences in Sudan Savanna of Nigeria
title_full Analyzing rainfall trend and drought occurences in Sudan Savanna of Nigeria
title_fullStr Analyzing rainfall trend and drought occurences in Sudan Savanna of Nigeria
title_full_unstemmed Analyzing rainfall trend and drought occurences in Sudan Savanna of Nigeria
title_short Analyzing rainfall trend and drought occurences in Sudan Savanna of Nigeria
title_sort analyzing rainfall trend and drought occurences in sudan savanna of nigeria
topic Drought
Flooding
Rainfall
Standardized precipitation index
Trend
url http://www.sciencedirect.com/science/article/pii/S2468227623001266
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