Floodplain loss: Basins of Irrawaddy, Tapi, Indus, Cauvery rivers flowing through India altered most due to human activities

Subject :Geography

Section: Physical geography

Context:

A group of researchers, for the first time, has “developed the first publicly available global dataset that quantifies human alterations in 15 million square kilometers of floodplains along 520 major river basins during the recent 27 years (1992-2019)”.

About the Report:

Report title: Human alterations of the global floodplains 1992–2019
A floodplain, according to the Federal Emergency Management Agency, is “any land area susceptible to being inundated by floodwaters from any source”.
The study explained how it quantified human alteration by taking stock of three geospatial datasets for the said time period (1992-2019).
- First, they identified the global extent of floodplain, from which they identified how land use change has unfolded of the corresponding time period and finally, they used river basin boundaries to quantify the process for the rivers assed in the study.

Report findings:

Over 460,000 square kilometers of floodplain area was lost to agriculture, while another 140,000 square kilometers was redeveloped to new areas over the existing floodplain.
Continent-wise, Asia lost the biggest area of floodplains followed by South America and Africa.
In Amazon and Yangtze river basins the agricultural expansion is proportional to the reduction in the area of forests.
Highest floodplain loss in the Indian subcontinent is due to human activities.
Irrawaddy river witnessed the highest floodplain loss.
In India, Tapi river basin recorded the highest alteration with over 3 percent of the floodplain area lost due to human activities, followed by Indus (3.2 per cent) and Cauvery (2.7 per cent).