Impacts of projected changes and variability in climatic data on major food crops yields in Rwanda

Document Type: Research Paper

Authors

1 Department of Geography, Environmental Management and Energy Studies, University of Johannesburg, Auckland Park, South Africa.

2 School of Geography, Archaeology and Environmental Studies, University of Witwatersrand, Johannesburg, South Africa.

3 South African Medical Research Council, Biostatistics unit, Durban, South Africa.

Abstract

This paper investigated the response of major food crop yields namely beans,
cassava, Irish potatoes, maize and sweet potatoes to ongoing changes in climate in
Rwanda. The projected daily precipitation and temperature data for the period
2000-2050 used in this study were generated by stochastic weather generator
(LARS-WG) from daily raw data for the period 1961 -2000. These data were
collected from Rwandan Meteorological Center based in Kigali, while the
agricultural records for the period 2000-2010 used to project yields of major food
crops for 2011-2050 were obtained from the National Institute of Statistics of
Rwanda and the Ministry of Agriculture and Animal Resources. A number of
statistical techniques were applied in projecting the major food crops yields and
attempting to quantify their magnitude trends in response to projected precipitation
and temperature data. The climate and soil suitability analysis revealed that the
central plateau and south-west regions of the country will be the most suitable
regions for cultivation of major food crops except Irish potatoes which can be
grown in the north-western highlands. The central plateau region is the only region
that is expected to experience an increase in yields for most of the major food crops
under investigation. The south-west region will have increased beans, cassava and
sweet potatoes yields in season A (September-January). The eastern lowlands are
expected to register a decreasing trend in most of crops yields in season A,
corresponding to the anticipated decline in mean rainfalls and number of rainy
days. The envisaged yields increase in season B (February-June) for beans, maize and Irish potatoes will be in response to a rise in mean rainfall and number of rainy
days. Heavy rainfall in the north-western region is likely to have a negative impact
on crop yields. The rain might cause waterlogging, flooding events and landslides
which may damage and destroy the crops.




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