Question

Given below is the cascade of events following deforestation. Select the option which arranges them in the correct sequence.
P: erosion of topsoil
Q: river channel become shallow
R: eroded soil gets deposited on the river bed as slit
S: destruction of crops leads to starvation
T: shallow channels cannot hold excess water during rain and hence cause flood
U: floods damage agricultural crops
A. P→Q→R→S→T→U
B. P→R→Q→T→U→S
C. Q→R→P→S→T→U
D. P→T→U→Q→R→S

Answer 1

Hint: Deforestation is the process of removing trees from forests (or other places) on a big scale in order to facilitate human operations. It's a major environmental concern since it can lead to a loss of biodiversity, harm to natural ecosystems, water cycle disruptions, and soil erosion. Climate change and global warming are also exacerbated by deforestation.
The following are the key anthropogenic (human) activities that lead to deforestation:
Agriculture is divided into two categories: small-scale and large-scale agriculture.
Logging is the process of harvesting trees for use as raw materials.
Mining and urban expansion entails the clearance of forest land to make way for infrastructure.

Complete answer:
Option A: Erosion occurs at the top layer of the soil. The eroded soil is deposited on the riverbed as silt. Flooding occurs when river channels become shallow, unable to hold surplus water during rain. Floodwaters destroyed a large number of crops. There is a food scarcity as a result of the agricultural damage.
So, option A is not correct.
Option B: The permanent deterioration in the productivity of the land is referred to as land degradation. It entails several steps:
The top layer of the soil is subjected to erosion. In recent years, more than half of the world's topsoil has been lost. The eroded soil is then deposited as silt on the riverbed.
The river channels become shallow, unable to hold excess water during rain, resulting in flooding. Floodwaters wreaked havoc on a big number of crops. This agricultural damage causes a food shortage.
So, option B is correct.
Option C: The first step leading to deforestation is erosion of topsoil followed by deposition of that soil at the river bed.
So, option C is not correct.
Option D: the foremost step leading to deforestation is erosion of topsoil followed by deposition of the soil at river bed slit as a result of which there is shallowing of river channels.
So, option D is not correct.

So, option B is the correct answer.

Additional information:
Causes of global warming-
Man Made causes: deforestation, use of vehicles, CFC’s, agriculture, industrial development, etc.
Natural causes: volcanoes, water vapours, melting permafrost, forest blazes.

Note:
The phenomena of steady increases in temperature near the earth's surface is known as global warming. Over the last one or two centuries, this phenomenon has been noticed. The earth's climate pattern has been disrupted as a result of this alteration.
There are various factors that contribute to global warming, all of which have severe consequences for humans, plants, and animals. These factors could be natural or the result of human activity. It is critical to comprehend the harmful effects of global warming in order to address the challenges.