Soil Erosion

Why in news?

• Recently, a study ‘Geospatial modelling and mapping of soil erosion in India’ classified soil erosion on a pan-India basis for the first time.

About Soil Erosion:

• The destruction of the soil cover is described as soil erosion.
• It involves the breakdown, detachment, transport, and redistribution of soil particles by forces of water, wind, or gravity.
• Agents: Wind and water are powerful agents of soil erosion because of their ability to remove soil and transport it.
• Wind erosion is significant in arid and semi-arid regions.
• Erosion by running water is more significant in regions with heavy rainfall and steep slopes.
• Sheet erosion takes place on level lands after a heavy shower, and removes the finer and more fertile topsoil.
• Gully erosion is common on steep slopes.
• Gullies deepen with rainfall, cut the agricultural lands into small fragments and make them unfit for cultivation.
• According to Indian Council of Agricultural Research (ICAR), the extent of soil erosion, defined as soil loss more than 10 tonnes per hectare per year, in cultivable land of the country was 92.4 million hectares.

The Extent of the Problem:

• The study came up with six classifications for soil erosion — ranging from ‘minor’ to ‘catastrophic’ — in terms of soil eroded in tonnes over a hectare over a year.
• It reveals that nearly 30% of India’s landmass is experiencing minor soil erosion, while a critical 3% faces catastrophic topsoil loss.
• A region would be classified as ‘catastrophic’ if it reports over 100 tonnes of soil lost to erosion over a hectare during a year’s time.

The Worst-Affected Region:

• Brahmaputra Valley in Assam: It is the biggest hotspot for soil erosion in India.
• Data shows that the northeastern state of Assam lost close to 300 square kilometres or 31% of its surface soil to catastrophic erosion. It has severe implications for the state’s agriculture and the livelihoods of its people.
• Lower reaches of the Himalayas: These regions are characterised by moraine or loose soil and highly unstable slopes. It spans from the Kashmir Valley to the southern regions of Himachal Pradesh and Uttarakhand and extends across the border into Nepal and parts of Odisha.
• Odisha, which differs markedly from the Himalayas and the Brahmaputra valley in terms of topography and biodiversity, is also another hotspot for ‘catastrophic’ erosion.
• This region stands as one of the most prominent erosion hotspots in the country, exacerbated by its susceptibility to seismic activity or earthquakes.

The Impact of Soil Erosion:

• Soil erosion of this magnitude has far-reaching consequences. According to the Food and Agriculture Organization (FAO) of the United Nations, it could take up to 1,000 years to produce 2 to 3 centimetres of topsoil.
• It means that the land lost to erosion will take centuries to regain its fertility.
• The loss of soil not only affects the fertility of the land but also leads to a decrease in the water-holding capacity of the soil, affecting the overall ecosystem.
• The increasing soil erosion is detrimental to the region’s globally important biodiversity.

The Need for Action:

• The findings of this study underscore the urgent need for action. India needs a comprehensive strategy to combat soil erosion, which includes both preventive measures and efforts to restore eroded lands.
• Without such measures, the country’s agricultural productivity could be severely impacted, threatening food security and rural livelihoods.

Conclusion:

• The study provides valuable insights into the extent and severity of soil erosion in India. It underscores the urgent need for strategies to prevent soil erosion and restore degraded lands.
• As the country strives to achieve its sustainable development goals, addressing soil erosion must be a top priority.

ISRO’s ‘Zero Orbital Debris’ Milestone

Why in news?

• The Indian Space Research Organisation (ISRO) has said its PSLV-C58/XPoSat mission has practically left zero debris in earth’s orbit.

What is Space debris?

• Space debris are defined as all non-functional, man-made objects, including fragments and elements thereof, in Earth orbit or re-entering into Earth’s atmosphere.
• Kessler Syndrome: It is a theoretical scenario in which a cascade of collisions between artificial objects in low Earth orbit leads to a rapidly increasing amount of space debris, making the use of near-Earth space impossible for an extended period of time.

International agreements on space debris

• The Space Liability Convention of 1972: It defines responsibility in case a space object causes harm.
• The treaty says that “a launching State shall be absolutely liable to pay compensation for damage caused by its space objects on the surface of the earth or to aircraft, and liable for damage due to its faults in space.
• Absence of law: However, there is no law against space junk crashing back to earth.

About the mission

• The PSLV-C58 Mission was accomplished in January 2024.
• After completing the primary mission of injecting all satellites into their desired orbits, the terminal stage of PSLV was transformed into a 3-axis stabilized platform, the PSLV Orbital Experimental Module-3 (POEM-3).
• The stage was deorbited from 650 km to 350 km, which facilitated its early re-entry.

Significance

• The POEM, serves as a very cost-effective platform for carrying out short-duration space-borne experiments.
• This novel opportunity has been effectively utilized by numerous startups, universities, and NGEs for carrying out experiments in space, including electric thrusters, satellite dispensers, and star-tracking.

Project NETRA

• Project NETRA (Network for space object Tracking and Analysis), was initiated by ISRO.
• It is an early warning system that would help detect space hazards to Indian satellites.
• The project is expected to give India its own capability in space situational awareness (SSA), something that other space powers already have.
• The SSA is used to predict threats from debris to Indian satellites.