Evaluation of drought indices using the 40-percentile threshold for the north-central regions of Namibia.
Loading...
Date
2012
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Namibia
Abstract
Drought is not uncommon to the Southern African climate and it has become a matter
of serious concern in Namibia. For that reason, almost all parts of Namibia have become
vulnerable to drought occurrence. Whilst recognising agriculture as a pertinent component
of the Namibian economy, it is imperative to underscore the importance of drought
early warning products for short- and long-term decision making in various sectors of
the country’s economy. Following the 1991/92 drought, which ravaged more than 80% of
Southern Africa, Namibia now realise the value of meteorological information in weathersensitive
decisions. This severe drought has been described as the worst in living memory.
Five stations (Ombalantu, Oshakati, Rundu, Katima Mulilo and Tsumkwe) in the northern
part of Namibia were assessed. The researcher used the rainfall decile method to assess
drought conditions by evaluating whether the widely used 40-percentile threshold is
appropriate for triggering a drought warning in Namibia. Results showed that the threshold
might have been set too high to be of use in warning farmers of coming droughts. In order
to determine the percentile that would be best serve as trigger for drought warnings,
there is need for further examination at 30, 25 and 20 percentile mark thresholds. Based on
the 40-percentile threshold, much of the drought and a decrease in rainfall accumulation
in Ombalantu and Oshakati in the Omusati and Oshana regions respectively, occurred
towards the end of the 20th century.
Description
Keywords
Drought, Namibia, Warning, Meteorological information, Evaluation, North-central
Citation
Angombe,T. 2012. Evaluation of drought indices using the 40-percentile threshold for the north-central regions of Namibia: Journal for Studies in Humanities and Social Sciences 1(2/9):247-260.