Rainfall regime changes and trends in Botswana Kalahari Transect's late summer precipitation

Mphale, K.; Dash, S.; Adedoyin, A.; Panda, S.
April 2014
Theoretical & Applied Climatology;Apr2014, Vol. 116 Issue 1/2, p75
Academic Journal
Sixty-year-long January-March (JFM) rainfall data from four (4) stations along the Kalahari Transect were analyzed for long-term trends and abrupt changes in rainfall regimes. On average, JFM rainfall accounts for more than 50 % of annual rainfall in the region. Mann-Kendall trend test has shown an insignificant heterogeneous trend in the seasonal rainfall of −1.097, 0.029, −0.407, and −1.327 mm/year for Maun, Ghanzi, Tsabong, and Tshane, respectively. An abrupt change in rainfall regimes in these areas was investigated and was found to occur in the year 1982 for all stations. The change is related to large-scale atmospheric circulations. Analysis of large-scale atmospheric circulations before 1982 over the region has shown the formation of a tropical low pressure convective system over the Kalahari Transect. The tropical system shifted eastward after 1982 to be centered over southeastern southern Africa with a significant reduction in rainfall over the Kalahari. A direct impact of this is the livestock-induced overgrazing which has lead to excessive removal of palatable herbaceous species thereby giving woody species, such as Accacia mellifera and Grewia flava, a competitive edge for dominance in the ecosystems. Seed production of A. mellifera depends on rainfall; therefore, abrupt changes in rainfall regimes impact livelihood and eco-tourism industry. The correlation studies between rainfall anomalies and NINO3.4 indices show a reduction in the influence of El-Niño Southern Oscillation on the Kalahari Transect rainfall after 1982.


Related Articles

  • The 1997/98 Summer Rainfall Season in Southern Africa. Part II: Model Simulations and Coupled Model Forecasts. Lyon, Bradfield; Mason, Simon J. // Journal of Climate;Jul2009, Vol. 22 Issue 13, p3802 

    This is the second of a two-part investigation of rainfall in southern Africa during the strong El Niño of 1997/98. In Part I it was shown that widespread drought in southern Africa, typical of past El Niño events occurring between 1950 and 2000, generally failed to materialize during the...

  • Formation of the anomalous summer precipitation in east China in 2010 and 1998: A comparison of the impacts of two kinds of El Niño. Wang, Qin; Li, Shuanglin; Fu, Jianjian; Li, Guoping // Acta Meteorologica Sinica;Dec2012, Vol. 26 Issue 6, p665 

    In the summers of 1998 and 2010, severe floods occurred in the middle and lower reaches of the Yangtze River. Although an El Niño event took place preceding each of the summer floods, significant differences between the two summer floods and the two El Niño events were identified. The...

  • Global Monsoon, El Niño, and Their Interannual Linkage Simulated by MIROC5 and the CMIP3 CGCMs. Kim, Hyung-Jin; Takata, Kumiko; Wang, Bin; Watanabe, Masahiro; Kimoto, Masahide; Yokohata, Tokuta; Yasunari, Tetsuzo // Journal of Climate;Nov2011, Vol. 24 Issue 21, p5604 

    This study evaluates the capability of coupled global climate models (CGCMs) in simulating the prime examples of the forced response (global monsoon) and internal feedback process (El Niño). Emphases are also placed on the fidelity of the year-to-year variability of global monsoon...

  • Two Distinct Modes of Tropical Indian Ocean Precipitation in Boreal Winter and Their Impacts on Equatorial Western Pacific**. Wu, Bo; Zhou, Tianjun; Li, Tim // Journal of Climate;Feb2012, Vol. 25 Issue 3, p921 

    The observational analysis reveals two distinct precipitation modes, the zonal dipole (DP) mode and the monopole (MP) mode, in the tropical Indian Ocean (TIO) during the El Niño mature winter, even though sea surface temperature anomalies (SSTAs) have a similar basinwide warming pattern...

  • Simulation of daily rainfall scenarios with interannual and multidecadal climate cycles for South Florida. Hyun-Han Kwon; Lall, Upmanu; Obeysekera, Jayantha // Stochastic Environmental Research & Risk Assessment;Oct2009, Vol. 23 Issue 7, p879 

    Concerns about the potential effects of anthropogenic climate change have led to a closer examination of how climate varies in the long run, and how such variations may impact rainfall variations at daily to seasonal time scales. For South Florida in particular, the influences of the...

  • Mapping Drought Risk in Indonesia Related to El-Niño Hazard. Supari; Muharsyah, R.; Sopaheluwakan, A. // AIP Conference Proceedings;2016, Vol. 1730 Issue 1, p070001-1 

    This work is aimed to identify areas in the country that are at high propensity to the impact of global climate phenomenon i.e. El-Nino. An adected area is recognized when rainfall decreases up to below normal condition which frequently leads drought event. For this purpose, two packages of...

  • Extreme precipitation related to circulation types for four case studies over the Eastern Mediterranean. Tolika, K.; Anagnostopoulou, Chr.; Maheras, P.; Kutiel, H. // Advances in Geosciences;2007, Vol. 12, p87 

    The analysis of the links between the extreme precipitation and the associated atmospheric conditions through an aloft circulation type approach at the 500-hPa geopotential level, for the time period of 1958-2000, is the main motivation for the present study. Four stations in the eastern...

  • The Andes climate and weather. Garreaud, R. D. // Advances in Geosciences;2009, Vol. 22, p3 

    This paper documents the main features of the weather, climate and climate variability over Andes cordillera in South America on the basis of instrumental observations. We first provide a basic physical understanding of the mean annual cycle of the atmospheric circulation and precipitation and...

  • Effects of El Niño Modoki on winter precipitation in Korea. Kim, Do-Woo; Choi, Ki-Seon; Byun, Hi-Ryong // Climate Dynamics;Apr2012, Vol. 38 Issue 7/8, p1313 

    This study compares the impacts of El Niño Modoki and El Niño on precipitation over Korea during the boreal winters from 1954 to 2009. Precipitation in Korea tends to be equal to or greater than the normal level during an El Niño Modoki winter, whereas there is no significant change...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics