Geography & History Notes | KCSE, NECTA, ZIMSEC & GCSE

  Soil is thin upper layer of the earth with unconsolidated materials where plant and animals derive their living. Soil catena refers to the sequence of different soils down a slope. the soil are usually derived from the same or similar parent materials but they vary with relief and drainage. The following are main factors influencing the development of soil catena.   Relief . This is the influence of topography on the surface soil. Slope influence drainage which in turn influence moisture content of the soil. Soil on the upper slopes are likely to be different from those of the valley floor. The upper slopes are generally steeper than the lower ones. They are therefore well drained. On the very steep slopes, the soils are thin because of high rate of erosion. On gentle slopes  the soil is thick because the rates of erosion and weathering are balanced. On the valley floors the soils may be peat or alluvial due to deposition.   Drainage . There is close rel...

  Soil catena is the successive arrangement or sequence of arrangement of differing soil types along the slope from the hill top (summit) to the valley bottom. This sequence varies with relief and drainage though it may be derived from the same parent material e.g. the soils at the valley bottom are likely to be different from those of the hill top.   The factors influencing the development of soil catena: Relief  which is the physical appearance (morphology) of the landscape affects or influences the development of soil catena in such a way that differences in relief affect the nature or soil type due to the fact that they influence erosion, deposition and human activities. Hill tops have lateritic capping with the resultant thin/ skeletal soils. The very steep slope/free face hardly has any soil i.e. has bare rock. The waxing slope/ convex slope is characterised by coarse, stony, creep soils due to erosion. The waning slope is fairly deep with clay loam so...