Climate and Weather
Rwanda is a very hilly country, with steep slopes ravaged by massive and devastating soil erosion which is exacerbated by overstripping of land, deforestation, and inadequate use of land improvement techniques. The relief of the country can be divided into three distinct types stretching from west to east. To the west is the Congo-Nile watershed that rises over Lake Kivu. To the north is a chain of volcanoes, and to the east are the lowlands. The central part of the country has an altitude of between 1,500 m and 2,000 m, with stretched hills and more or less rounded hilltops separated by large valleys. This type of relief covers almost half of the country and has earned Rwanda the nickname of the “Land of a Thousand Hills”.
With more or less constant temperatures throughout the year (16 - 170C in the high altitudes, 180C - 210C in the central plateau and 200C - 240C in the eastern and western lowlands), Rwanda has an equatorial-continental temperate type of climate classified as AW3, according to the Köppen classification. The country has four seasons which are determined by the variability of rainfall. However, the rainfall is quite irregular and gives rise to prolonged drought periods, especially in the regions of Bugesera, Mayaga and Umutara, causing serious setbacks to agricultural activities that are totally dependent on rainfall.
Rwanda’s soils are naturally fragile. They are a result of the physical and chemical alteration of schistose, quartzite, gneiss, granite, and volcanic rocks which form the surface geology of the country.
The soil map of Rwanda, which was published in 1992, shows six types of soils:
1) Soils derived from schistose, sandstone and quartzite which cover almost 50% of the national territory
2) Soils derived from granite and gneiss which make up about 20% of the national territory
3) Soils originating from intrusive basic rocks that hardly cover 10% of the national territory
4) Soils originating from recent volcanic materials that cover 10% of the national territory
5) Soils originating from ancient volcanic materials that cover 4% of the national territory
6) Alluvial and colluvial soils which are typical of Rwanda’s swamps occupy 6% of the national territory
The map of soil capacity, which is complementary to the soil map, shows that more than half of Rwanda’s soils are unsuitable for crops that are particularly demanding. The very good soils occupy a very small space and are found mostly in densely populated areas.