Rainfall is a key climate parameter that affects most operations that affect human life, especially in the tropics. Therefore, understanding the various factors that affect the distribution and intensity of this rainfall is important for effective planning among the different stakeholders in the weather and climate sectors. This study aimed at understanding how intra seasonal rainfall characteristics, especially Consecutive Dry Days (CDD) and Consecutive Wet Days (CWD), in the two major rainfall seasons will change under two future climate scenarios of RCP4.5 and RCP8.5 in Uganda, covering two future periods of 2021-2050 and 2051-2080. The results indicate a high likelihood of reduced consecutive rainfall days, especially over the Northeastern regions of the country, for both 2021-2050 and 2051-2080. However, the trends in the entire country for the two major rainfall seasons, March to May and September to November, are not significant. Nonetheless, the distribution of these days is important for most agricultural activities during different stages of crop growth. The consecutive dry days show a fairly increasing trend in the eastern part of the country, particularly in the second season of September to November. An increase in consecutive dry days implies more frequent dry spells in the midst of the growing season, potentially affecting some crops during critical growth stages.
References
[1]
Aguilar, E., Barry, A. A., Brunet, M., Ekang, L., Fernandes, A., Massoukina, M., Mbah, J., Mhanda, A., do Nascimento, D. J., Peterson, T. C., Thamba Umba, O., Tomou, M., & Zhang, X. (2009). Changes in Temperature and Precipitation Extremes in Western Central Africa, Guinea Conakry, and Zimbabwe, 1955-2006. Journal of Geophysical Research, 114, D02115. https://doi.org/10.1029/2008JD011010
[2]
Alexander, L. V., Zhang, X., Peterson, T. C., Caesar, J., Gleason, B., Tank, A. M. G. K. et al. (2006). Global Observed Changes in Daily Climate Extremes of Temperature and Precipitation. Journal of Geophysical Research, 111, D05109. https://doi.org/10.1029/2005JD006290
[3]
Breinl, K., Di Baldassarre, G., Mazzoleni, M., Lun, D., & Vico, G. (2020). Extreme Dry and Wet Spells Face Changes in Their Duration and Timing Environmental Research Letters Extreme Dry and Wet Spells Face Changes in Their Duration and Timing. Environmental Research Letters, 15, Article 074040. https://doi.org/10.1088/1748-9326/ab7d05
[4]
Chemura, A., Schauberger, B., & Gornott, C. (2020). Impacts of Climate Change on Agro-Climatic Suitability of Major Food Crops in Ghana. PLOS ONE, 15, e0229881. https://doi.org/10.1371/journal.pone.0229881
[5]
Gitau, W., Ogallo, L., Camberlin, P., & Okoola, R. (2013). Spatial Coherence and Potential Predictability Assessment of Intra-Seasonal Statistics of Wet and Dry Spells over Equatorial Eastern Africa. International Journal of Climatology, 33, 2690-2705. https://doi.org/10.1002/joc.3620
[6]
Gudoshava, M., Misiani, H. O., Segele, Z. T., Jain, S., Ouma, J. O., Otieno, G., Anyah, R., Indasi, V. S., Endris, H. S., Osima, S., Lennard, C., Zaroug, M., Mwangi, E., Nimusiima, A., Kondowe, A., Ogwang, B., Artan, G., & Atheru, Z. (2020). Projected Effects of 1.5˚C and 2˚C Global Warming Levels on the Intra-Seasonal Rainfall Characteristics over the Greater Horn of Africa. Environmental Research Letters, 15, Article 34037. https://doi.org/10.1088/1748-9326/ab6b33
[7]
Haile, G. G., Tang, Q., Hosseini-Moghari, S. M., Liu, X., Gebremicael, T. G., Leng, G., Kebede, A., Xu, X., & Yun, X. (2020). Projected Impacts of Climate Change on Drought Patterns over East Africa. Earth’s Future, 8, e2020EF001502. https://doi.org/10.1029/2020EF001502
[8]
Huntingford, C., Jones, R. G., Prudhomme, C., Lamb, R., Gash, J. H. C., & Jones, D. A. (2003). Regional Climate-Model Predictions of Extreme Rainfall for a Changing Climate. Quarterly Journal of the Royal Meteorological Society, 129, 1607-1621. https://doi.org/10.1256/qj.02.97
[9]
IPCC (2021). Summary for Policymakers. In V. Masson-Delmotte, P. Zhai, A. Pirani, S. L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J. B. R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, & B. Zhou (Eds.), Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (pp. 3-32). Cambridge University Press.
[10]
Krishnamurthy, V. (2011). Extreme Events and Trends in the Indian Summer Monsoon. (pp. 153-168). American Geophysical Union.
[11]
Kuya, K. E. (2016). Precipitation and Temperatures Extremes in East Africa in Past and Precipitation and Temperatures Extremes in East Africa in Past and Future Climate. Master’s Thesis, University of Oslo.
[12]
Lambert, D. K. (2014). Historical Impacts of Precipitation and Temperature on Farm Production in Kansas. Journal of Agricultural and Applied Economics, 4, 439-456. https://doi.org/10.1017/S1074070800029047
[13]
Liu, B., Xu, M., Henderson, M., & Qi, Y. (2005). Observed Trends of Precipitation amount, Frequency, and Intensity in China, 1960-2000. Journal of Geophysical Research, 110, D08103. https://doi.org/10.1029/2004JD004864
[14]
Ministry of Water and Environment (2022). Uganda’s Third National Communication to the United Nations Convention on Climate Change.
[15]
Nicholson, S. E. (2017). Climate and Climatic Variability of Rainfall over Eastern Africa. Reviews of Geophysics, 55, 590-635. https://doi.org/10.1002/2016RG000544
[16]
Nsubuga, F. W. N., Botai, O. J., Olwoch, J. M., Rautenbach, C. J., Bevis, Y., Adetunji, A. O. et al. (2014). The Nature of Rainfall in the Main Drainage Sub-Basins of Uganda. Hydrological Sciences Journal, 59, 278-299. https://doi.org/10.1080/02626667.2013.804188
[17]
Omondi, P. A., Awange, J. L., Forootan, E., Ogallo, L. A., Barakiza, R., Girmaw, G. B., Fesseha, I., Kululetera, V., Kilembe, C., & Mbati, M. M. (2014). Changes in Temperature and Precipitation Extremes over the Greater Horn of Africa Region from 1961 to 2010. International Journal of Climatology, 34, 1262-1277. https://doi.org/10.1002/joc.3763
[18]
Ongoma, V., Chen, H., & Omony, G. W. (2018). Variability of Extreme Weather Events over the Equatorial East Africa, a Case Study of Rainfall in Kenya and Uganda. Theoretical and Applied Climatology, 131, 295-308. https://doi.org/10.1007/s00704-016-1973-9
[19]
Osima, S., Indasi, V. S., Zaroug, M., Endris, H. S., Gudoshava, M., Misiani, H. O., Nimusiima, A., Anyah, R. O., Otieno, G., Ogwang, B. A., Jain, S., Kondowe, A. L., Mwangi, E., Lennard, C., Nikulin, G., & Dosio, A. (2018). Projected Climate over the Greater Horn of Africa under 1.5˚C and 2˚C Global Warming. Environmental Research Letters, 13, Article 065004. https://doi.org/10.1088/1748-9326/aaba1b
[20]
Philippon, N., Camberlin, P., Moron, V., & Boyard-Micheau, J. (2015). Anomalously Wet and Dry Rainy Seasons in Equatorial East Africa and Associated Differences in Intra-Seasonal Characteristics. Climate Dynamics, 45, 1819-1840. https://doi.org/10.1007/s00382-014-2436-6
[21]
Shiferaw, A. (2018). Precipitation Extremes in Dynamically Downscaled Climate Scenarios over the Greater Horn of Africa. Atmosphere, 9, Article 112. https://doi.org/10.3390/atmos9030112
[22]
Shukla, S., McNally, A., Husak, G., & Funk, C. (2014). A Seasonal Agricultural Drought Forecast System for Food-Insecure Regions of East Africa. Hydrology and Earth System Sciences, 18, 3907-3921. https://doi.org/10.5194/hess-18-3907-2014
[23]
Sippel, S., Zscheischler, J., Heimann, M., Lange, H., Mahecha, M. D., Van Oldenborgh, G. J. et al. (2017). Have Precipitation Extremes and Annual Totals Been Increasing in the World’s Dry Regions over the Last 60 Years? Hydrology and Earth System Sciences, 21, 441-458. https://doi.org/10.5194/hess-21-441-2017
[24]
Uganda Bureau of Statistics (UBOS) (2022). Uganda Bureau of Statistics Statistical Abstract 2022.
[25]
Yang, W., Seager, R., & Cane, M. A. (2014). The East African Long Rains in Observations and Models. Journal of Climate, 27, 7185-7202. https://doi.org/10.1175/JCLI-D-13-00447.1
[26]
Ye, H. (2018). Changes in Duration of Dry and Wet Spells Associated with Air Temperatures in Russia. Environmental Research Letters, 13, Article 34036. https://doi.org/10.1088/1748-9326/aaae0d
