Desertification

Desertification is an important topic in World Geography, focusing on land degradation in arid and semi-arid regions and its environmental and socio-economic impacts. It covers the major causes of desertification, global efforts such as the United Nations Convention to Combat Desertification (UNCCD), and the issue of land degradation and desertification in India. Understanding these aspects helps in analyzing sustainable land management and environmental conservation strategies.

Definition – Desertification is the process by which the land in arid, semi-arid and dry sub-humid regions loses its productivity, water holding capacity and vegetation cover due to natural and anthropogenic factors. As a result the land turns barren and develops desert-like conditions.

Desertification a global problem

Desertification is a historical phenomenon. The world’s largest deserts have formed over long periods due to interactions of natural processes.
In the central highland plateau of Madagascar, slash-and-burn agriculture practices by indigenous peoples have caused desertification of up to 10% of the country.
Palaeodeserts are former deserts or sand seas that have become inactive due to climate change and the development of vegetation cover. Some existing deserts, such as Sahara, are expanding beyond their current boundaries.
In Western Asia, several deserts were formed during the late Cretaceous period due to the high population of prehistoric tribes and sub-tribes.
Sahel is another example of desertification.
The primary causes of desertification in the Sahel include slash-and-burn agriculture, where wind removes unprotected topsoil, leading to soil erosion.
Central Asian countries such as Kazakhstan, Kyrgyzstan, Mongolia, Tajikistan, Turkmenistan, and Uzbekistan are also affected by desertification.
In Kazakhstan, more than half of the arable land has been abandoned since the 1980s.

Major causes of desertification

Industrial waste – Large-scale discharge of industrial waste from cotton textile industry in Amu Darya and Syr Darya. Industrial and textile waste led to water pollution and large-scale desertification in Aral Sea region of Central Asia.
Soil erosion by wind – Sand dunes and other sand formations of Thar are affected. Deep ploughing by tractors, cultivation on sandy hill slopes, leaving land fallow for long periods and other traditional agricultural systems lead to the spread of sand and accelerate the process of desertification of land.
Environmental issues are left behind due to population pressure and economic reasons.
Increasing waterlogging and salinity and alkalinity in the ground – Irrigation from saline groundwater in the alluvial plains has led to the problem of salinity and alkalinity. In Kutch and Saurashtra, salty sea water has filled the water sources. The problem of waterlogging and salinity-alkalinity is also increasing rapidly in the Indira Gandhi Canal area.
Deforestation – Due to the increasing pressure on land due to the exponentially increasing population, the vegetation is decreasing, the forests are shrinking and desertification is increasing.
Water erosion – Large areas of the upper regions of Saurashtra and Kutch are affected. Due to erosion, many changes occur in the land surface and soil erosion increases.

Control measures

Sand dune stabilization – CAZRI technique, windbreak shrubs and suitable vegetation (Israeli Babul, Fog, Sevan, Mopane, Ghamn, Tumba).
Protector belt plantation – Preventing soil erosion by planting trees in 3-5 rows in the direction of the wind.
Sowing seeds from airplanes – Ensuring 70–80% germination by putting seed tablets mixed with cow dung-soil in inaccessible and dry areas.
Silvopasture System: Planting trees and grasses together to increase the yield of both fuel and fodder.
Efficient water use- Sprinkler system to save water and increase the yield of grasses (e.g. Lasiurus scindicus).
Mine land rehabilitation – Restoring greenery to closed mines by planting species like Prosopis juliflora and Acacia tortilis.

United Nations Convention to Combat Desertification (UNCCD)

The UNCCD is one of the three Rio Conventions under the United Nations.
It is the only legally binding international agreement that addresses both environmental and developmental issues.
June 17 is observed annually as “World Day to Combat Desertification and Drought” to raise awareness about global efforts to combat desertification.

The Bonn Challenge

The Bonn Challenge is a global initiative aimed at restoring degraded forests and improving ecological balance.
It was launched in 2011 in Bonn, Germany.
Goals of the Bonn Challenge:
- Restore 150 million hectares of degraded and deforested land by 2020.
- Restore 350 million hectares by 2030.
At the Paris Climate Summit in 2015, India voluntarily committed to the Bonn Challenge.
Initially, in 2015, India set restoration targets under two phases:
- 13 million hectares by 2020.
- 8 million hectares by 2030.
Later, India increased its target to restore a total of 26 million hectares by 2030.

India’s efforts

To prevent desertification, the Government of India has launched several programs and schemes, including afforestation efforts.
Key initiatives include:
- Green India Mission (GIM)
- Nagar Van Yojana (Urban Forest Scheme)
- Compensatory Afforestation Fund Management and Planning Authority (CAMPA)
- Mahatma Gandhi National Rural Employment Guarantee Scheme (MGNREGS), which focuses on land restoration.
India has also launched a National Action Plan to combat desertification and forest degradation through afforestation efforts.
However, despite these efforts, India faces a major challenge, as 32% of land has undergone soil degradation, and 25% of land has been affected by desertification.

Land degradation and desertification in India

97.85 million hectares of India (29.77% of the total geographical area of the country) faced land degradation during 2018-19.
During the period 2011-13 and 2003-05, 96.40 million hectares (29.32%) and 94.53 million hectares (28.76%) of land was degraded respectively.
Total increase in land degraded area between 2011-13 to 2018-19 – 1.45 million hectares (0.44% of total geographical area).
Causes of land degradation/desertification in India-
1. Water erosion [11.01%]
2. Vegetation loss [9.15%]
3. Wind erosion [5.46%]
Land degradation in dry regions (arid, semi-arid and dry-sub-humid) is called desertification.
- A total of 83.69 million hectares of area was affected by desertification in 2018-19.
- Increase in desertified area between 2011-13 and 2018-19 – 1.05 million hectares.
- Wind erosion is the main cause of desertification in dry areas.
- Water erosion and vegetation loss are the main causes in semi-arid and dry-sub-humid areas.
About 23.79% of the area affected by desertification/land degradation in relation to the total geographical area of the country was from Rajasthan, Maharashtra, Gujarat, Karnataka, Ladakh, Jharkhand, Odisha, Madhya Pradesh and Telangana.
In terms of their total geographical area (TGA), Jharkhand, Rajasthan, Delhi, Gujarat and Goa have more than 50% of their area facing desertification/land degradation.

In the context of Rajasthan

In Rajasthan, 62.06% (21.23 m.ha) of the total geographical area of the state was facing desertification/land degradation in 2018-19.
During the period 2011-13 and 2003-05, this area was 62.90% and 63.19% respectively.
A reduction of 0.84% was observed in desertification/land degradation between 2011-13 and 2018-19.
The main cause of desertification/land degradation in the state
- Wind erosion [43.37%]
- Vegetation loss [7.64%]
- Water erosion [6.21%].
Between 2011-13 and 2018-19, there was a decrease in the area affected by wind erosion/deposition and an increase in the area affected by human activities. Whereas, between 2003-05 and 2011-13, there was a decrease in the area affected by wind erosion/deposition and an increase in the forest area affected by vegetation loss.