Understanding Soil Erosion: Types, Causes, and Control Methods
Erosion: Definition
Erosion is the physical process of soil evolution involving movement and displacement of soil materials. It is caused by water, wind, temperature changes, biological activity, and human interference.
Types of Erosion
Natural Erosion
This is normal erosion occurring due to natural forces.
Induced or Accelerated Erosion
This type of erosion is caused by the combined action of natural forces and human activities. It is often faster than natural erosion due to land mismanagement.
Agents of Erosion
The main agents of erosion are:
- Water
- Wind
- Temperature changes
- Biological activity
- Human interference
Water and wind are the most significant agents.
Acceptable Soil Loss
There is an upper limit of soil loss where high productivity can be maintained without causing long-term deterioration.
Forms of Water Erosion
Gully Erosion
Advanced erosion forming deep ditches or gullies.
Splash Erosion
Disaggregation and dispersion of soil structure by raindrop impact.
Laminar Erosion
Uniform removal of soil layers on slopes due to saturation.
Pedestal Erosion
Occurs when soil is protected from raindrop impact by stones or roots, forming isolated pedestals.
Fall or Remontant Erosion
Erosion in gully walls without human intervention, caused by streams eroding the lower side.
Degradation and Fertility Loss
Erosion leads to loss of soil nutrients and vertical movement of colloidal soil, reducing fertility.
Wind Erosion
Wind force moves soil particles, influenced by climate, soil, and vegetation.
Wind Mobilization
Wind creates whirlpools, vortexes, and crashes, causing soil movement.
Soil Movement Types
Soil moves by saltation, suspension, and rolling.
Forms Produced by Wind Erosion
Sand dunes are a typical result of wind erosion.
Wind Erosion Control
Control methods include:
- Reducing wind speed
- Altering soil properties for resistance
- Watershed management
- Windbreaks
- Tillage methods
Quantifying Soil Loss
Methods to quantify soil loss include:
- Transects: Measuring gully depth and width.
- Volandas Nails: Using nails and washers to measure soil loss thickness.
- Tapa Crowns: Using bottle caps to create pedestals and measure soil loss.