What is the flood : What is the Flood What are the causes of flood ? today’s episode, the main topic is what is the flood? About the cause and effect of flood. Let’s take a look at what is the flood are and the causes and consequences of floods.
What is the flood :
Flood is one of the water related disasters. In this case, floods are caused by both natural and human causes. Basically, the tendency of a part of the land to remain under water for a long time is called flood. In other words, when excess water released from rivers or river dams inundates the lower catchment area with water, the condition is termed as flood. About 12.5 percent of India’s geographical area is flood prone.
Examples : West Bengal, Bihar, Assam, Uttar Pradesh, Punjab, Haryana, Rajasthan, Gujarat and Andhra Pradesh. Floods are high in these states of India.
Causes of floods :
Among the causes of floods, natural causes and human causes are discussed below.
Natural causes of floods :
1. Prolonged over-rainfall : Prolonged over-rainfall in an area increases the amount of water and reduces the water-holding capacity of the river, resulting in inundation of the area and taking the form of floods, so there is a positive correlation between over-viewing and flooding.
2. Shape of river course : Straight river course has less resistance to flow of water thus less prone to flooding. Similarly, there are more obstacles in the flow of water in the course of the spiral river, as a result of which the problem of water retention in the river course increases the tendency of flooding.
3. Melting of Himalayan ice : As temperatures rise in summer, the ice stored in the Himalayan mountains melts, resulting in excess water causing flooding in valley areas.
4. Shape of River Basin : If the shape of the river basin is long, the rivers have to cross a long distance which reduces the incidence of floods and conversely small river basins are more prone to flooding due to short course of the river.
5. Divergence of river slope : Excess water accumulates in areas with low slope and causes floods but if the river slope is high then the water is removed quickly, which reduces the incidence of floods.
Human causes of floods :
1. Tree felling : Trees prevent soil erosion as well as control rainfall. Necessary human logging increases soil erosion and reduces the water holding capacity of eroded soil in riverbeds, increasing floods. So floods are positively correlated with deforestation.
2. Change in river basins : Human settlement, urbanization, industrialization, expansion of agriculture in river basins lead to changes in land use which increase the chances of flooding.
3. Alteration of the river course : Artificial alteration of the river course for the purpose of meeting human needs such as construction of river dams, hydroelectric power generation increases the possibility of flooding.
4. Size of river basin : Sometimes increasing the size of river basin increases the water carrying capacity of the river, while decreasing the size of the river basin increases the incidence of floods.
So it can be said that due to natural and human causes, flood is a disaster that greatly affects the environment and human life.
Consequences of Flooding :
The effects of flood can be divided into two main categories namely – good and bad.
Bad effects of flood :
The evils of creating floods were shot
1. Impact on Natural Environment:
a. Flooding results in water pollution.
b. Flooding disrupts the balance of the environment.
c. Floods cause soil pollution and reduce soil fertility.
d. Floods are likely to disrupt the geological balance.
2. Impact on Ecosystem :
a. Small trees, paddy, vegetables, crops are heavily damaged by strong flood currents.
b. Floods disrupt food chains. As a result, the diet of herbivorous animals occurs.
c. Many animals and birds lost their lives in the flood waters.
3. Effects on Humans :
a. Due to the impact of floods, there is a huge loss of agricultural activities.
b. Due to the effect of floods, many people lost their lives and property was damaged.
c. The effect of flood causes outbreak of various water borne diseases like cholera, typhoid etc.
d. Due to flood disruption of houses, transport, communication system and various types of services, people’s lives are disrupted.
Benefits of Flooding :
Along with the disadvantages of creating floods, some advantages can also be observed, they are-
1. Floods deposit new sediments on land.
2. Flooding reduces salinity in soil by leaching process.
3. Water stored in low lying areas helps in irrigation and fisheries.
Read More : What is Drought ?