Suitability analysis of coffee growing area in the Context of climate change in Nyaruguru District, Rwanda

Abstract

Coffee is a top export commodity and an important source of revenue for Rwandan economy contributing to about 33 % of gross domestic product of the country. Unfortunately, the changing climate and climate variability poses a great threat to the growing sector. Rwanda in general and rural areas specifically are threatened by the changing climate due to poverty and high population. With about three quarters of the Rwandan population relying on agriculture, suitability analysis for coffee has to be conducted to inform decision makers, development partners and famers on possible alternatives for adaptation mostly in rural areas. In this study, Suitability analysis of coffee growing area in the context of climate change in Nyaruguru District, Rwanda, a combination of GIS and spatial statistics methodology were used. We used a geographic information system (GIS) for a weighted overlay analysis to produce Arabica Coffee suitability map. The Elevationally Detrended Ordinary Kriging and the Inverse Distance Interpolation technics were used together with Multiple-criteria decision analysis to produce suitability maps. Hence, the results show that the projected temperature and precipitation for over 30 years from 2016 will increase between 1.3°C and 2.25°C considering both RCP4.5 and RCP8.5 scenarios. Thus, this increase will lead the temperature beyond optimum Arabica coffee growing condition of 22°C in the large part of the district area in next 30 years. The 2016 suitability map shows that 77.6% of Nyaruguru is suitable and 4% is highly suitable while about 17.9% of Nyaruguru district which is unsuitable is part of Nyungwe National Park where precipitation is the limiting factor. The results suggest that progressive coffee extension to more suitable areas and smart agriculture practices such as contour farming should be taken into consideration by the government and development partners, and smallholder famers respectively to avoid the loss of yield and good quality in coming years.