Periodic Assessment of Trend and Climatic Variability in the LCB
Keywords:
Rainfall, Precipitation, Mann Kendal, Trend, Sen’s Slope, Evapotranspiration, RunoffAbstract
Periodic assessment of trend and climatic variability is important for better planning and water resource management in the LCB catchment. This study assessed the impact of climatic variables on the LCB (LCB) using rainfall data derived from TAMSAT, run off and evapotranspiration data derived from climate engine over a period of twenty years (2001-2020). Non-parametric Mann Kendall (MK) and Spearman rho tests were applied to detect the presence of rainfall trends and trend magnitude was calculated using Sen’s Slope Estimator (SSE). With an average annual rainfall of 523.62mm, trend analysis showed an annual positive trend for precipitation at 5% significance level. Analysis of seasonal rainfall using both tests revealed an increasing trend during the dry season. However, the late dry season experienced a slight increasing trend and for wet seasons. There was 2.7% runoff and 4.6% evapotranspiration which are the lowest for the time series.
References
J.P. Carmouze. “La régulation hydrogéochimique du Lac Tchad”. Travaux et documents n °58 de l 'ORSTOM~ Armitage SJ, Bristow CS, Drake NA. 112(28: West African Monsoon Dynamics Inferred from Abrupt Fluctuations of Lake Mega-Chad, pp. 8543-8548.2015
S.E. Nicholson. “Land Surface-Atmosphere Interaction: Physical Processes and Surface Changes and their Impacts.” Progress in Physical Geography, vol.12, pp. 36-65. 1988.
S. E. Nicholson. “Land Surface Processes and Sahel Climate.” Reviews of Geophysics, vol. 38.pp. 117-139. 2000.
A. Beauvilain. “Les aleas et les Variations Climatiques au Chad: Leurs Consequence sur Evolution des Milieux Naturels et le Developpment du Monde Rural (premiers resultants du projet CAMPUS), Revue Scientifique du Tchad, vol. 4, Numero Special 1996.:
C. Caminade and L. Terray, “Twentieth Century Sahel Rainfall Variability as Simulated by the ARPEGE AGCM, and future changes,” Climate Dynamics, vol. 35, 1, pp. 75–94, Jul 2010.
P. Maharana, A.Y Abdel-Lathif, and K.C. Pattnayak. “Observed Climate Variability over Chad using Multiple Observational and Reanalysis datasets.” Global and Planetary Change, vol.162, 252-265.2018
H. Rodhe, and X. Virji. “Trends and Periodicities in East African Rainfall Data”. Monthly Weather Review, vol. 104, pp. 307– 315. 1976
M.T. Coe and J.A. Foley. “Human and Natural Impacts on the Water Resources of the LCB.” Journal of Geophysical Research Atmospheres, vol.106, pp.3349-3356.2001.
S.M Hagos and K. H. Cook. “Ocean Warming and Late-Twentieth-Century Sahel Drought and Recovery.” Journal of Climate 21: pp.3797–3814. 2008
M. Hoerling, J. Hurrell, J. Eischeid, and A. Phillips... “Detection and Attribution of Twentieth Century Northern and Southern African Rainfall Change.” Journal of Climate vol.19: pp.3989–4008, 2006.
K.Y. Li, M. T. Coe and N. Ramankutty. “An Investigation of Hydrological Variability in West Africa Using Land Surface Models.” Journal of Climate, vo. 18: pp.3173–3188. 2005
A. Giannini, M. Biasutti, M. Held, A.Sobel. “A Global Perspective on African Climate.” Climate Change. vol. 90.pp.359 – 383, 2008
C.E Ndehedehe. “Spatio-Temporal Variability of Droughts and Terrestrial Water Storage over LCB using Independent Component Analysis.” Journal of Hydrology, vol. 540, pp. 106–128, 2016.
C. Okonkwo, B. Demoz, S. Gebremariam. “Characteristics Of Lake Chad Level Variability and Links To ENSO, Precipitation, and River Discharge.” The Scientific World Journal, vol.2014, pp.1-13,2014.
H. Niel, C. Leduc, C. Dieulin. “Caractérisation De La Variabilité Spatiale Et Temporelle des Précipitations Annuelles Sur Le Bassin Du Lac Tchad au Cours Du 20ème Siècle/Spatial and Temporal Variability of Annual Rainfall in the LCB During the 20th Century.” Hydrological Sciences Journal, vol. 50(2). pp. 243. 2005
E. Nkiaka, N.R. Nawaz and J.C. Lovett. “Analysis of Rainfall Variability in the Logone Catchment, LCB.” International Journal of Climatology, vol. 37 (9). pp. 3553-3564.2017
R. Mahmood, S. Jia and W. Zhu. “Analysis of Climate Variability, Trends, and Prediction in the Most Active Parts of the LCB.” Africa. Science Rep vol. 9, 6317, 2019.
T. Lebel, A. Diedhiou, H. Laurent. “Seasonal Cycle and Interannual Variability of the Sahelian Rainfall at Hydrological Scales.” Journal of Geophysical Research. vol 108(D8, 8389. 2003
S. Armitage, C.S. Bristow N.A. Drake. “West African Monsoon Dynamics Inferred from Abrupt Fluctuations of Lake Mega-Chad.” Proceedings of the National Academy of Sciences of the USA, vol.112 (28), pp.8543-8548, 2015
M.K Jury. “Ethiopian Decadal Climate Variability.” Theoretical and Applied Climatology. vol.101, pp 29–40, 2010.
H. Paeth, A. Hense. “SST Versus Climate Change Signals in West African Rainfall: 20th Century Variations and Future Projections.” Climate Change, vol .65:pp. 179–208, 2004.
N. Zeng J.D Neelin, K.M Lau, C.J. Tucker. “Enhancements Of Interdecadal Climate Variability in The Sahel by Vegetation Interaction.” Science, vol.286, pp. 1537–1540, 1999.
D. Labat. “Cross Wavelet Analyses of Annual Continental Freshwater Discharge and Selected Climate Indices.” Journal of Hydrology, vol. 385, no. 1–4, pp. 269–278.2010.
F. Mercier, A., Cazenave and C. Maheu, “Interannual Lake Level Fluctuations in Africa from Topex/Poseidon: Connections with Ocean–Atmosphere Interactions Over the Indian Ocean.” Global and Planetary Change, vol.32, pp. 141–163. 2002.
Xia Jun and A.B Bantin, “The Impact of Hydro Climatic Variability on Ater Resiurces of Lake Chad Hydro Graphic Basin.” Hydrology current Research, vol. 8: 282, pp.5-10. 2017.
A.Tarhule and P.J Lamb. “Climate Research and Seasonal Forecasting for West Africans: Perceptions, Dissemination, and Use.” Bulletin of the American Meteorological Society, vol.84, pp. 1741–1759. 2003.
M. Leblanc, J. Lemoalle, J.C Bader, S. Tweed and L Mofor. “Thermal Remote Sensing of Water Under Flooded Vegetation: New Observations of Inundation Patterns for the “Small” Lake Chad”. Journal of Hydrology, vol.404, pp. 87–98, 2011.
D. Lauwaet, N.P.M van Lipzig, K. Van Weverberg, K. De Ridder, and C. Goyens. “The Precipitation Response to The Desiccation of Lake Chad”. Quarterly Journal of Royal Meteorological Society, vol 138, pp. 707–719, 2011.
T.B. Ketchemen. “Etude hydrogéologique du Grand Yaéré (Extrême Nord du Cameroun). Synthèse hydrogéologique et étude de la recharge par les isotopes de l’environnement. Thèse de Doctorat 3ème cycle, Université Cheikh Anta Diop Dakar, Sénégal .1992
J. Lemoalle, J.C. Bader, M. Leblanc, and A. Sedick, “Recent Changes in Lake Chad: Observations, Simulations and Management Options (1973–2011).” Global and Planetary Change, vol. 80–81, pp. 247–254.2012.
S.E. Nicholson. “The Nature of Rainfall Fluctuations in Sub-Tropical West Africa, Mon.We. Rev, 108,473-487.-1985: Sub-Saharan Rainfall 1981-1984,” Journal of Climate, vol .24, pp. 1388-1391, 1980.
H. B. Mann, “Nonparametric tests against trend,” Econometrica, vol. 13, pp. 245–259, 1945.
M. G. Kendall. “Rank Correlation Methods.” 4th edition. Charles Griffin, London, UK (1975) [34] Charles Ichoku , “Dynamics of the water resources within the Lake Chad Basin”, NASA Goddard Space Flight Center References.Presented at the International Conference on Lake Chad Basin, Abuja, Nigeria, 26–28 February 2018
Downloads
Published
How to Cite
Issue
Section
License
Authors who submit papers with this journal agree to the following terms.
