In News:

=> Recently, the Central University of Rajasthan conducted a study on desertification of the Thar region.

About study:

The study was undertaken as part of an assessment of the environmentally sensitive areas within the framework of the UN Convention to Combat Desertification (UNCCD). The scientists associated with the project studied the climate and vegetation in Thar to understand the desertification process.

Key Findings:

=> Focused Areas: It focused on Barmer, Jaisalmer, Bikaner and Jodhpur districts covering more than 50% of the Thar desert. It found that Jodhpur had witnessed a slow speed of desertification. It also found that the vegetation cover and water bodies had increased in the area in the last 46 years and the complex sand region had decreased by 4.98%.

=> Expansion of Thar desert:  Along with the gradual destruction of the Aravalli ranges, the Thar desert is expanding fast because of the migration of people, changes in the rainfall pattern, spread of sand dunes and unscientific plantation drives.

=> Impacts: The degradation of land is posing a threat to the desert ecology, while climate change has contributed to the spread of arid regions. The loss of Aravali hills because of unchecked mining activities would result in the sandstorms travelling to NCR and Delhi. The suspended particles from the arid region are contributing to air pollution in NCR.

=> Suggestions: new plans should be evolved for the conservation of the Aravali ranges to stop the desertification towards eastern parts of the State.

What is Land degradation?

Land degradation is temporary or permanent degeneration of productivity of land due to physical, chemical or biological factors. Land degradation is caused by multiple forces, including extreme weather conditions, particularly drought. It is also caused by human activities that pollute or degrade the quality of soils and land utility.

Present status of India’s Land Degradation:

=> Some 97.85 million hectares (MHA) of India’s total geographical area (TGA) of 328.72 MHA underwent land degradation during 2018-19. Land degradation within dryland regions (arid, semi-arid and dry sub-humid regions) is termed ‘desertification’.

=> State Wise breakup: Around 23.79 per cent of the area undergoing desertification/land degradation with respect to TGA of the country was contributed by Rajasthan, Maharashtra, Gujarat, Karnataka, Ladakh, Jharkhand, Odisha, Madhya Pradesh and Telangana. However, land degradation and desertification were declining in Uttar Pradesh, Rajasthan and Telangana in 2018-2019.

Reasons for Land Degradation:

=> Loss of Fertility by Mismanagement: Due to the use of various scientific inputs like irrigation, fertilisers, pesticides etc. Unscientific cropping practices are also causing harm. This results in problems like soil erosion, loss of natural nutrients, water-logging and salinity and contamination of ground and surface water.

=> Soil Erosion: This is the process by which the topsoil is detached from land and either washed away by water, ice or sea waves or blown away by the wind.

=> Salinity/Alkalinity: This problem occurs in areas of temporary water surplus and high temperatures due to over-irrigation or high rainfall. The salt layer plays havoc with the fertility of topsoil and renders vast stretches of useful land infertile. This problem is particularly serious in areas with assured irrigation in Punjab, Haryana, Uttar Pradesh, western Maharashtra, Bihar and northern Rajasthan (the Indira Gandhi Canal command area). Such lands are known by local names, such as reh, kallar, usar, chopan etc.

=> Waterlogging: This happens when the water table gets saturated for various reasons—over-irrigation, seepage from canals, inadequate drainage etc. The land under waterlogged conditions can be used neither for agriculture nor for human settlements. This menace can be tackled by adopting scientific norms for the amount of irrigation, checking seepage from canals by proper lining and providing adequate drainage through field channels.

=> Floods and Droughts: Both these hazards have the harmful effect of limiting the use of good soil.

=> Desertification: It is also the end result of Land Degradation but it could also be the reason. The advancement of sand from the desert to the adjoining regions is called desertification. The sand covers fertile soil and affects its fertility. This problem is particularly serious in areas adjoining the Thar desert in Rajasthan.

What more needs to be done to Check Land Degradation?

=> Improved agricultural practices: Better practices need to be adopted in different regions. Tillage on higher slopes should be avoided, while contour ploughing on the slopes prone to erosion may help in maintaining the soil depth.

=> Shelterbelts: Planting shelterbelts and stubble mulching help in conserving the soils in desert regions.

=> Avoid overgrazing: The pressure of livestock on pastures in hilly, desert and plateau regions has to be reduced in order to avoid overgrazing, such as in Jammu and Kashmir, Himachal Pradesh, Rajasthan and Karnataka.

=> Prevent Ravines: The ravines and gullies should be plugged to prevent head-ward erosion.

=> Land Degradation Neutrality: A state whereby the amount and quality of land resources, necessary to support ecosystem functions and services and enhance food security, remains stable or increases within specified temporal and spatial scales and ecosystems. Regular updates and information on degraded land is essential for the Government to plan necessary measures to tackle degradation processes and to plan for reclamation programmes.