Before we answer “how do human activities cause soil erosion”, we need to first understand what is soil erosion.
What is Soil erosion?
Soil erosion is defined as the wearing away of topsoil. Soil is naturally created when small pieces of weathered rocks and minerals mix with organic materials from decaying plants and animals. It takes many years to create soil. However, the soil that is created faces constant pressure of natural and human activities.
How human activities can accelerate soil erosion?
Human activities are one of the major reason behind soil erosion. When we say human activities, the following activities fall under this category:-
- Agriculture activities
- Deforestation
- Construction activities
- Overgrazing
- Overcropping
Let’s get to know about each one of these activities:-
1. Agriculture activities:- Irrigation is an important aspect of farmer’s life. When a farmer plows a field to sow a crop. They leave the soil bare and exposed to some natural elements like rain, wind, sun rays. These are called exogenic forces, because they have the power to cause enough damage to the soil. Wind can carry the loose soil from one place to another with force. Rain can sweep into the open bare soil and wash away the soil quickly. Sun rays can penetrate and dry up the moisture content of a soil which has tremendous impact on the soil’s fertility.
2. Deforestation:- Wood is an essential natural resource for human beings. It is used to produce paper, paper products, fabrics and many consumer goods. These products comes from tree harvesting. But tree harvesting is an underestimated word, instead complete annihilation of forest ecosystem takes place. Deforestation causes some of the worst soil erosion. The root structure of trees hold the soil in one place. The leaves and canopy of big, tall trees protects the soil from wind and rain. In the absence of trees, it can lead to heavy erosion of topsoil.
3. Construction activities:- Construction of roads and buildings, excavation, mining has resulted in huge amount of soil erosion. This makes the soil expose to natural forces of wind and rain. Construction is also synonymous to urbanization. On one hand, development of cities and mega-cities is seeing as a progressive sign of a nation, and on the other hand rapid urbanization results in soil erosion and loss of natural habitat.
4. Overgrazing:- There is direct connection between overgrazing and increase in soil erosion. Dairy farmers allow animals like cattle, goat, sheep to graze in open area for a longer duration. Because of which, overgrazing is a common phenomena. When animals graze and area for a longer duration without giving the grasses enough time to grow back. It makes the topsoil expose to the forces of wind and rain and that leads to increase in soil erosion. Overgrazing can cause damage to the quality of land.
5. Over-cropping:- Over-cropping leads to depletion of nutrient from the topsoil. It makes the land prone to desertification. In other words, a land can look like a desert which will further accelerate soil erosion. Over-cropping leads to soil exhaustion and makes the soil vulnerable to erosion.