Category: O level Geography

Soil is an important component of most ecosystems. Biotic components depend on the soil for survival. Without soils most ecosystems would be different, without vegetation and other organisms. This topic looks at the components of soil, its formation processes and characteristics.

Landform development is associated with hazards. Processes leading to development of landforms lead to disasters. Disaster risk management is the process of reducing the risks caused by disasters. It is achieved through disaster risk reduction.

There has been a misnomer that Aeolian action is more important than water in arid and semi-arid   areas. This was so because people thought deserts were completely arid. However, water is available in various forms and comes from various sources.

Arid areas or deserts are areas receiving average annual rainfall less than 250mm while as semi- arid areas receive between 250 and 500mm. Arid means dry.

The term river regime refers to the variations of river discharge throughout the year. River discharge is the amount of water passing through a given point at a given time. Sometimes this discharge is high but sometimes it is low.

River capture is the process whereby a stronger river flowing parallel to the smaller river captures the headwaters of the minor stream thereby drawing the water into its own channel.

Rivers do work. The work of the rivers is to erode, transport and deposit materials. Transportation and erosion by rivers is achieved in various ways.

To understand river processes and landforms it is important to start by looking at the course of the river. The course of the river is the stretch of the river from its source through the middle course to the mouth. This is also called the river's long profile.