Abstract
Focus on potentially increased frequency of extreme hydro-climatological events under climate change is intensified by Ghana’s reliance on rainfed agriculture, and the question whether precipitation climatology has returned to conditions prevailing before the regional drought of the 1970s and 80s. This study examines long-term (44–51 years), complete, daily rainfall records from nineteen stations nationally to determine magnitude and frequency of totals in excess of the historical 90th percentile at each station. Results are divided into three sub-populations corresponding to pre-drought, drought, and post-drought periods. Four research questions are addressed; (1) Is there evidence of significant interdecadal scale variability in these variables, (2) are there significant differences in characteristics between periods, (3) are there any distinctive regional patterns in changes, and (4) can findings be extended to various definitions of what constitutes extreme rainfalls? The Mann–Whitney U test determines significant breaks that define the overarching temporal framework of the research. The hypergeometric distribution determines the statistical significance of changes in magnitude and frequency. Exponential, generalized Pareto and Poisson distributions are fit to the magnitude and frequency of post-drought data. Recovery is broadly defined as no difference between pre-drought and post-drought data. Some locations in mid-Ghana have recovered, while coastal areas have not recovered in frequency or magnitude. Outliers correspond to Axim in the southwest and Navrongo in the north. The anomalies at Kete Krachi, located on Lake Volta, may result from its local climatological setting. Contributions of the research include the first comprehensive, national review of the characteristics of magnitude and frequency of large rainfall totals. The outstanding question of whether “climate” has returned to pre-1970 levels has been explicitly addressed in the context of the important facet of precipitation climatology. Results provide some insight into one of the frequently expressed thoughts that climate change/variability may be most sensitively expressed through changes in the frequency of processes/extreme events. Finally, it suggests a potential tool that may be used to estimate risks of extremely rare events, based on the most recent (Period 3), which is a reasonably stationary dataset.
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References
Acero FJ, García JA, Gallego MC (2011) Peaks-over-threshold study of trends in extreme rainfall over the iberian peninsula. J Clim 24(4):1089–1105. https://doi.org/10.1175/2010JCLI3627.1
Akinsanola AA, Zhou W (2019) Projections of West African summer monsoon rainfall extremes from two CORDEX models. Clim Dyn 52(3):2017–2028. https://doi.org/10.1007/s00382-018-4238-8
Asante F, Amuakwa-Mensah F (2014) Climate change and variability in Ghana: stocktaking. Climate 3(1):78–99. https://doi.org/10.3390/cli3010078
Asare-Nuamah P, Botchway E (2019) Understanding climate variability and change: analysis of temperature and rainfall across agroecological zones in Ghana. Heliyon 5(10):e02654. https://doi.org/10.1016/j.heliyon.2019.e02654
Atiah WA, Amekudzi LK, Akum RA, Quansah E, Antwi-Agyei P, Danuor SK (2021) Climate variability and impacts on maize (Zea mays) yield in Ghana, West Africa. Quart J R Meteorol Soc. https://doi.org/10.1002/QJ.4199
Atiah WA, Tsidu GM, Amekudzi LK, Yorke C (2020) Trends and interannual variability of extreme rainfall indices over Ghana, West Africa. Theor Appl Climatol. https://doi.org/10.1007/s00704-020-03114-6
Badr HS, Dezfuli AK, Zaitchik BF, Peters-Lidard CD (2016) Regionalizing Africa: Patterns of precipitation variability in observations and global climate models. J Clim 29(24):9027–9043. https://doi.org/10.1175/JCLI-D-16-0182.1
Beguería S, Vicente-Serrano SM (2006) Mapping the hazard of extreme rainfall by peaks over threshold extreme value analysis and spatial regression techniques. J Appl Meteorol Climatol. https://doi.org/10.1175/JAM2324.1
Biasutti M (2019) Rainfall trends in the African Sahel: Characteristics, processes, and causes. Wires Clim Change 10(4):e591. https://doi.org/10.1002/wcc.591
Bras RL, Rodríguez-Iturbe I (1985) Random functions and hydrology. Addison-Wesley
Burszta-Adamiak E, Stańczyk J, Łomotowski J (2019) Hydrological performance of green roofs in the context of the meteorological factors during the 5-year monitoring period. Water Environ J 33(1):144–154. https://doi.org/10.1111/wej.12385
Calzadilla A, Rehdanz K, Betts R, Falloon P, Wiltshire A, Tol RSJ (2013) Climate change impacts on global agriculture. Clim Change. https://doi.org/10.1007/s10584-013-0822-4
Chakravarty IM, Laha RG, Roy J (1967) Handbook of methods of applied statistics. Wiley. https://books.google.com/books?id=IdI-AAAAIAAJ
Coles S (2001) An introduction to statistical modeling of extreme values. Springer, London. https://doi.org/10.1007/978-1-4471-3675-0
Connolly-Boutin L, Smit B (2016) Climate change, food security, and livelihoods in sub-Saharan Africa. Reg Environ Change 16(2):385–399. https://doi.org/10.1007/s10113-015-0761-x
Contractor S, Donat MG, Alexander LV, Ziese M, Meyer-Christoffer A, Schneider U, Rustemeier E, Becker A, Durre I, Vose RS (2020) Rainfall estimates on a gridded network (REGEN) – a global land-based gridded dataset of daily precipitation from 1950 to 2016. Hydrol Earth Syst Sci 24(2):919–943. https://doi.org/10.5194/hess-24-919-2020
Derbile EK, File DJM (2016) Community risk assessment of rainfall variability under rain-fed agriculture: the potential role of local knowledge in Ghana. Ghana J Dev Stud 13(2):66. https://doi.org/10.4314/gjds.v13i2.4
Derbile EK, File DJM, Dongzagla A (2016) The double tragedy of agriculture vulnerability to climate variability in Africa: how vulnerable is smallholder agriculture to rainfall variability in Ghana? Jàmbá J Dis Risk Stud. https://doi.org/10.4102/jamba.v8i3.249
Diallo I, Giorgi F, Deme A, Tall M, Mariotti L, Gaye AT (2016) Projected changes of summer monsoon extremes and hydroclimatic regimes over West Africa for the twenty-first century. Clim Dyn 47(12):3931–3954. https://doi.org/10.1007/s00382-016-3052-4
Diongue-Niang A, Pinto I, Dosio A, Engelbrecht F, Barimalala R (2021) Regional fact sheet – Africa (contribution of working group I; six assessment report of the intergovernmental panel on climate change). Cambridge University Press. https://www.ipcc.ch/report/ar6/wg1/downloads/factsheets/IPCC_AR6_WGI_Regional_Fact_Sheet_Africa.pdf
Dosio A, Jury MW, Almazroui M, Ashfaq M, Diallo I, Engelbrecht FA, Klutse NAB, Lennard C, Pinto I, Sylla MB, Tamoffo AT (2021) Projected future daily characteristics of African precipitation based on global (CMIP5, CMIP6) and regional (CORDEX, CORDEX-CORE) climate models. Clim Dyn 57(11):3135–3158. https://doi.org/10.1007/s00382-021-05859-w
Dunning CM, Black ECL, Allan RP (2016) The onset and cessation of seasonal rainfall over Africa. J Geophys Res Atmos 121(19):11405–11424. https://doi.org/10.1002/2016JD025428
Farnsworth A, White E, Williams CJR, Black E, Kniveton DR (2011) Understanding the large scale driving mechanisms of rainfall variability over Central Africa. In: Williams CJR, Kniveton DR (eds) African climate and climate change: physical, social and political perspectives pp 101–122. Springer Netherlands. https://doi.org/10.1007/978-90-481-3842-5_5
Giannini A, Saravanan R, Chang P (2003) Oceanic Forcing of Sahel Rainfall on Interannual to Interdecadal Time Scales. Science 302(5647):1027–1030. https://doi.org/10.1126/science.1089357
Giorgi F, Raffaele F, Coppola E (2019) The response of precipitation characteristics to global warming from climate projections. Earth Syst Dyn 10(1):73–89. https://doi.org/10.5194/esd-10-73-2019
Grimm AM, Barros VR, Doyle ME (2000) Climate variability in southern South America associated with El Nino and La Nina events. J Clim 13(1):35–58. https://doi.org/10.1175/1520-0442(2000)013%3c0035:CVISSA%3e2.0.CO;2
Gutiérrez JM, Jones RG, Narisma GT, Alves LM, Amjad M, Gorodetskaya IV, Grose M, Klutse NAB, Krakovska S, Li J, Martínez-Castro D, Mearns LO, Mernild SH, Ngo-Duc T, van den Hurk B, Yoon J-H (2021) Atlas In: Masson-Delmotte V, Zhai P, Pirani A, Connors SL, Péan C, Berger S, Caud N, Chen Y, Goldfarb L, Gomis MI, Huang M, Leitzell K, Lonnoy E, Matthews JBR, Maycock TK, Waterfield T, Yelekçi O, Yu R, Zhou B (eds) (Climate change 2021: the physical science basis contribution of working group i; sixth assessment report of the intergovernmental panel on climate Change, pp 1927–2058). Cambridge University Press https://doi.org/10.1017/9781009157896.021
Hosking JRM, Wallis JR, Wood EF (1985) Estimation of the generalized extreme-value distribution by the method of probability-weighted moments. Technometrics. https://doi.org/10.1080/00401706.1985.10488049
Incoom ABM, Adjei KA, Odai SN (2020) Rainfall variabilities and droughts in the Savannah zone of Ghana from 1960–2015. Sci Afr 10:e00571. https://doi.org/10.1016/j.sciaf.2020.e00571
IPCC (2013) Climate Change 2013: the physical science basis (full report). In: Stocker TF, Qin D, Plattner G-K, Tignor M, Allen SK, Boschung J, Nauels A, Xia Y, Bex V, Midgley PM (eds) (The physical science basis contribution of working group i; fifth assessment report of the intergovernmental panel on climate change, p 1535). Cambridge University Press https://doi.org/10.1017/CBO9781107415324.
Issahaku A-R, Campion BB, Edziyie R (2016) Rainfall and temperature changes and variability in the Upper East Region of Ghana. Earth Space Sci 3(8):284–294. https://doi.org/10.1002/2016EA000161
Kolavalli S, Diao X, Folledo R, Ngeleza G, Robinson E, Alpuerto V, Slavova M, Asante F (2012) Economic transformation in Ghana: where will the path lead? J Afr Dev 14(2):41–78. https://doi.org/10.5325/jafrideve.14.2.0041
Kyei-Baffour N, Ofori E (2007) Irrigation development and management in Ghana: prospects and challenges. J Sci Technol. https://doi.org/10.4314/just.v26i2.32996
Lacombe G, McCartney M, Forkuor G (2012) Drying climate in Ghana over the period 1960–2005: evidence from the resampling-based Mann-Kendall test at local and regional levels. Hydrol Sci J. https://doi.org/10.1080/02626667.2012.728291
Li C, Zwiers F, Zhang X, Li G, Sun Y, Wehner M (2021) Changes in annual extremes of daily temperature and precipitation in CMIP6 models. J Clim 34(9):3441–3460. https://doi.org/10.1175/JCLI-D-19-1013.1
Logah FY, Obuobie E, Ofori D, Kankam-Yeboah K (2013) Analysis of Rainfall Variability in Ghana. Int J Latest Res Eng Comput 1(1):1–8
Mamalakis A, Randerson JT, Yu JY, Pritchard MS, Magnusdottir G, Smyth P, Levine PA, Yu S, Foufoula-Georgiou E (2021) Zonally contrasting shifts of the tropical rain belt in response to climate change. Nat Clim Chang. https://doi.org/10.1038/s41558-020-00963-x
Mauget S (2011) Time series analysis based on running Mann-Whitney Z Statistics. J Time Ser Anal 32(1):47–53. https://doi.org/10.1111/j.1467-9892.2010.00683.x
Mendes DM, Paglietti L, Jackson D, González Altozano A (2014) Ghana: irrigation market brief. FAO Investment Centre. Country Highlights (FAO) Eng No. 19. http://www.fao.org/3/a-i4158e.pdf
Niang I, Ruppel OC, Abdrabo MA, Essel A, Lennard C, Padgham J, Urquhart P (2014) Africa—Chapter 22. In: Barros VR, Field CB, Dokken DJ, Mastrandrea MD, Mach KJ, Bilir TE, Chatterjee M, Ebi KL, Estrada YO, Genova RC, Girma B, Kissel ES, Levy AN, MacCracken S, Mastrandrea PR, White LL (eds) (Climate change 2014: impacts, adaptation, and vulnerability part b: regional aspects. contribution of working group II.; Fifth Assessment Report of the Intergovernmental Panel on Climate Change, pp 1199–1265). Cambridge University Press. https://www.ipcc.ch/site/assets/uploads/2018/02/WGIIAR5-Chap22_FINAL.pdf
Nicholson S (2005) On the question of the “recovery” of the rains in the West African Sahel. J Arid Environ 63(3):615–641. https://doi.org/10.1016/j.jaridenv.2005.03.004
Nicholson SE (2009) A revised picture of the structure of the “monsoon” and land ITCZ over West Africa. Clim Dyn 32(7–8):1155–1171. https://doi.org/10.1007/s00382-008-0514-3
Nicholson SE, Grist JP (2001) A conceptual model for understanding rainfall variability in the West African Sahel on interannual and interdecadal timescales. Int J Climatol 21(14):1733–1757. https://doi.org/10.1002/joc.648
Nordin CF, Rosbjerg DM (1970) Applications of crossing theory in hydrology. Int Assoc Sci Hydrol Bull 15(1):27–43. https://doi.org/10.1080/02626667009493929
Opoku-Ankomah Y, Cordery I (1994) Atlantic sea surface temperatures and rainfall variability in Ghana. J Clim 7(4):551–558. https://doi.org/10.1175/1520-0442(1994)007%3c0551:ASSTAR%3e2.0.CO;2
Owusu K, Obour PB, Asare-Baffour S (2015) Climate Variability and climate change impacts on smallholder farmers in the Akuapem North District, Ghana. In: Leal Filho W (ed), Handbook of Climate change adaptation, pp 1791–1806. Springer Berlin Heidelberg. https://doi.org/10.1007/978-3-642-38670-1_111
Owusu K, Waylen P (2009) Trends in spatio-temporal variability in annual rainfall in Ghana (1951–2000). Weather 64(5):115–120. https://doi.org/10.1002/wea.255
Owusu K, Waylen P, Qiu Y (2008) Changing rainfall inputs in the Volta basin: Implications for water sharing in Ghana. GeoJournal. https://doi.org/10.1007/s10708-008-9156-6
Owusu K, Waylen PR (2013) Identification of historic shifts in daily rainfall regime, Wenchi, Ghana. Clim Change. https://doi.org/10.1007/s10584-013-0692-9
Padi M, Foli BAK, Nyadjro ES, Owusu K, Wiafe G (2021) Extreme rainfall events over Accra, Ghana, in Recent Years. Remote Sens Earth Syst Sci. https://doi.org/10.1007/S41976-021-00062-1
Paeth H, Hense A (2004) SST versus climate change signals in West African rainfall: 20th-century variations and future projections. Clim Change. https://doi.org/10.1023/B:CLIM.0000037508.88115.8a
Panitz H-J, Dosio A, Büchner M, Lüthi D, Keuler K (2014) COSMO-CLM (CCLM) climate simulations over CORDEX-Africa domain: analysis of the ERA-Interim driven simulations at 0.44° and 0.22° resolution. Clim Dyn 42(11):3015–3038. https://doi.org/10.1007/s00382-013-1834-5
Ranasinghe R, Ruane AC, Vautard R, Arnell A, Coppola E, Cruz FA, Dessai S, Islam AS, Rahimi M, Ruiz Carrascal D, Sillmann J, Sylla MB, Tebaldi C, Wang W, Zaaboul (2021). Climate change information for regional impact and for risk assessment—chapter 12. In: Masson-Delmotte V, Zhai P, Pirani A, Connors SL, Péan C, Berger S, Caud N, Chen Y, Goldfarb L, Gomis MI, Huang M, Leitzell K, Lonnoy E, Matthews JBR, Maycock TK, Waterfield T, Yelekçi O, Yu R, Zhou B (eds) (Climate change 2021: the physical science basis. contribution of working group I; sixth assessment report of the intergovernmental panel on climate change, pp 1767–1926). Cambridge University Press https://doi.org/10.1017/9781009157896.014
Reeves J, Chen J, Wang XL, Lund R, Lu QQ (2007) A Review and comparison of changepoint detection techniques for climate data. J Appl Meteorol Climatol 46(6):900–915. https://doi.org/10.1175/JAM2493.1
Rosbjerg D, Madsen H, Rasmussen PF (1992) Prediction in partial duration series with generalized pareto-distributed exceedances. Water Resour Res 28(11):3001–3010. https://doi.org/10.1029/92WR01750
Sanogo S, Fink AH, Omotosho JA, Ba A, Redl R, Ermert V (2015) Spatio-temporal characteristics of the recent rainfall recovery in West Africa. Int J Climatol 35(15):4589–4605. https://doi.org/10.1002/joc.4309
Sayemuzzaman M, Jha MK (2014) Seasonal and annual precipitation time series trend analysis in North Carolina, United States. Atmos Res. https://doi.org/10.1016/j.atmosres.2013.10.012
Seneviratne SI, Nicholls N, Easterling D, Goodess CM, Kanae S, Kossin J, Luo Y, Marengo J, McInnes K, Rahimi M, Reichstein M, Sorteberg A, Vera C, Zhang X (2012) Changes in climate extremes and their impacts on the natural physical environment. In: Field CB, Barros V, Stocker TF, Qin D, Dokken DJ, Ebi KL, Mastrandrea MD, Mach KJ, Plattner G-K, Allen SK, Tignor M, Midgley PM (eds) (Managing the risks of extreme events and disasters to advance climate change adaptation a special report of working groups I and II; Intergovernmental Panel on Climate Change, pp 109–230). Cambridge University Press. https://www.ipcc.ch/site/assets/uploads/2018/03/SREX-Chap3_FINAL-1.pdf
Seneviratne SI, Zhang X, Adnan M, Badi W, Dereczynski C, Di Luca A, Ghosh S, Iskandar I, Kossin J, Lewis S, Otto F, Pinto I, Satoh M, Vicente-Serrano SM, Wehner M, Zhou B (2021) Weather and Climate Extreme Events in a Changing Climate—Chapter 11 (Climate Change 2021: The Physical Science Basis. Contribution of Working Group I; Sixth assessment report of the intergovernmental panel on climate change) In: Masson-Delmotte V, Zhai P, Pirani A, Connors SL, Péan C, Berger S, Caud N, Chen Y, Goldfarb L, Gomis MI, Huang M, Leitzell K, Lonnoy E, Matthews JBR, Maycock TK, Waterfield T, Yelekçi O, Yu R, Zhou B (eds.) pp 1513–1766. Cambridge University Press https://doi.org/10.1017/9781009157896.013
Sidibe M, Dieppois B, Mahé G, Paturel JE, Amoussou E, Anifowose B, Lawler D (2018) Trend and variability in a new, reconstructed streamflow dataset for West and Central Africa, and climatic interactions, 1950–2005. J Hydrol. https://doi.org/10.1016/j.jhydrol.2018.04.024
Suárez-Moreno R, Rodríguez-Fonseca B, Barroso JA, Fink AH (2018) Interdecadal changes in the leading ocean forcing of Sahelian Rainfall interannual variability: atmospheric dynamics and role of multidecadal SST background. J Clim 31(17):6687–6710. https://doi.org/10.1175/JCLI-D-17-0367.1
Sylla MB, Gaye AT, Jenkins GS (2012) On the fine-scale topography regulating changes in atmospheric hydrological cycle and extreme rainfall over West Africa in a regional climate model projections. Int J Geophys. https://doi.org/10.1155/2012/981649
Sylla MB, Giorgi F, Coppola E, Mariotti L (2013) Uncertainties in daily rainfall over Africa: Assessment of gridded observation products and evaluation of a regional climate model simulation. Int J Climatol 33(7):1805–1817. https://doi.org/10.1002/joc.3551
Sylla MB, Giorgi F, Pal JS, Gibba P, Kebe I, Nikiema M (2015) Projected changes in the annual cycle of high-intensity precipitation events over west africa for the late twenty-first century. J Clim 28(16):6475–6488. https://doi.org/10.1175/JCLI-D-14-00854.1
Trisos CH, Adelekan IO, Totin E, Ayanlade A, Efitre R, Gemeda A, Kalaba K, Lennard C, Masao C, Mgaya Y, Ngaruiya G, Olago D, Simpson NP, Zakieldeen S (2022) Africa—Chapter 9 (Climate Change 2022: Impacts, Adaptation and Vulnerability Contribution of Working Group II. In: Pörtner H-O, Roberts DC, Tignor M, Poloczanska ES, Mintenbeck K, Alegría A, Craig M, Langsdorf S, Löschke S, Möller V, Okem A, Rama B (eds) Sixth Assessment Report of the Intergovernmental Panel on Climate Change, pp 1285–1455. Cambridge University Press https://doi.org/10.1017/9781009325844.011
van Horn J, Richardson J, Waylen P (2015) Analysis of historical streamflow trends of the Santa Fe river, Florida, 1932–2012. Southeastern Geogr. https://doi.org/10.1353/sgo.2015.0022
Vizy EK, Cook KH (2012) Mid-twenty-first-century changes in extreme events over northern and Tropical Africa. J Clim 25(17):5748–5767. https://doi.org/10.1175/JCLI-D-11-00693.1
Wang Q, Fan X, Qin Z, Wang M (2012) Change trends of temperature and precipitation in the Loess Plateau Region of China, 1961–2010. Global Planet Change 92–93:138–147. https://doi.org/10.1016/j.gloplacha.2012.05.010
Waylen P, Laporte MS (1999) Flooding and the El Niño-Southern oscillation phenomenon along the Pacific coast of Costa Rica. Hydrol Process 13(16):2623–2638. https://doi.org/10.1002/(SICI)1099-1085(199911)13:16%3c2623::AID-HYP941%3e3.0.CO;2-H
Yorke CKA, Omotosho JB (2010) Rainfall Variability In Ghana During 1961–2005. J Ghana Sci Assoc. https://doi.org/10.4314/jgsa.v12i1.56813
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Capps Herron, H., Waylen, P. & Owusu, K. Spatial and temporal variability in the characteristics of extreme daily rainfalls in Ghana. Nat Hazards 117, 655–680 (2023). https://doi.org/10.1007/s11069-023-05876-4
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DOI: https://doi.org/10.1007/s11069-023-05876-4