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The Scientific World Journal
Volume 2014, Article ID 145893, 13 pages
http://dx.doi.org/10.1155/2014/145893
Research Article

Characteristics of Lake Chad Level Variability and Links to ENSO, Precipitation, and River Discharge

Beltsville Center for Climate System Observation (BCCSO), Atmospheric Science Program, Howard University, Washington, DC 20059, USA

Received 29 May 2014; Revised 15 September 2014; Accepted 28 September 2014; Published 27 November 2014

Academic Editor: Catherine Ottle

Copyright © 2014 Churchill Okonkwo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This study used trend, correlation, and wavelet analysis to characterize Lake Chad (LC) level fluctuations, river discharge, El Niño Southern Oscillation (ENSO), and precipitation regimes and their interrelationships. Linear correlation results indicate a negative association between ENSO and LC level, river discharge and precipitation. Trend analysis shows increasing precipitation in the Lake Chad Basin (LCB) but decreasing LC level. The mode of interannual variability in LC level, rainfall, and ENSO analyzed using wavelet analysis is dominated by 3-4-year periods. Results show that variability in ENSO could explain only 31% and 13% of variations in LC level at Kindjeria and precipitation in the northern LCB, respectively. The wavelet transform coherency (WTC) between LC level of the southern pool at Kalom and ENSO is statistically significant at the 95% confidence level and phase-locked, implying a cause-and-effect association. These strong coherencies coincide with the La Niña years with the exception of 1997-1998 El Niño events. The WTC shows strong covariance between increasing precipitation and LC level in the northern pool at a 2- to 4-year band and 3- to 4-year band localized from 1996 to 2010. Implications for water resource planning and management are discussed.