Rainfall and Temperature Predictions: Implications for Rice Production in the Lower River Region of The Gambia

Abstract

Climate change impacts have been the major subject of discussion for scientists from different fields of study, including the agriculture sector. This study investigates the effects and implications of future climate change on rice production in the Lower River Region of The Gambia. The study seeks the following specific objectives: i) Analyse temperature and rainfall trends over Lower River Region; ii) Determine the relationship between temperature, rainfalls and rice production in the study area; and iii) Simulate temperature, rainfalls and rice production as well as the existing relationship among those parameters in the future using seasonality. The trend was examined after an exploratory data analysis, a unit root test and a correlation analysis. The study revealed an increase in maximum temperature (Tmax) and a variation in minimum temperature (Tmin) where the increase is not constant over 1981-2015. Also, the harvested area, production and rainfall increased while yield decreased. The data was extrapolated to 2035 using a VARMA statistical forecast method. Ordinary Least Squares and robust linear regression models were applied to find out the future implications (2035 and subsequent near years) of the climate parameters on rice production using 1981 to 2015-year series. The model shows that by 2035, yields will negatively be affected by the increase in Tmax and positively by the very little variation in Tmin. But the risk is that the ratio is not balanced, the damages of Tmax will be greater than the good productions of Tmin. The Tmin will also decrease as a general trend occasioning severe conditions for rice production in the region. This reveals the effects of climate change on rice production even though the relationship between climatic and rice variables remains low, because of the numerous parameters in rice production. This calls for an urgent need to improve rice varieties that will thrive well in the anticipated new climatic conditions (high yielding, heat tolerant, saline tolerant and early maturing) and promotion of good cultural practices that save water to cope with future climate. This study suggests that more studies should include other parameters of rice production for improved predictions.