Description

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Context

A study by IIT Gandhinagar & NASA Research reveals a 38% annual greening increase in Thar Desert due to abnormal monsoon rainfall, extensive groundwater use & rapid agricultural expansion between 2000 & 2023.

Key Highlights

Theme	Details
Unprecedented Greening	Thar Desert experienced a 38% annual rise in greening over last two decades highest among 14 global deserts.
Main Drivers	Increase in monsoon precipitation & extensive groundwater extraction were primary causes.
Climate Data Insights	Precipitation rose by 64% between 2001 & 2023 with an increase rate of 4.4 mm/year. CHIRPS dataset used for rainfall tracking.
Groundwater vs Rainfall Contribution	Annually Groundwater 55%, Precipitation 45%. During monsoon Rainfall 66%, Non monsoon Groundwater 67%.
Geographic Spread	The desert spans 200,000 sq. km across Rajasthan, Gujarat, Punjab, Haryana & parts of southeast Pakistan.
Agricultural Expansion	Crop area grew by 74%, gross irrigated area by 95% (1980–2015) driven by monsoon aligned Kharif season & irrigated Rabi crops.
Irrigation Infrastructure	Expansion linked to Indira Gandhi Canal & increased power supply for pump irrigation.
Water Stress Risk	Groundwater levels showed significant decline especially in north-central Thar due to imbalance in extraction vs recharge.
Urbanisation Surge	Urban area expansion ranged from 50% to 800% (1985 to 2020) in several regions with increasing population density (highest among all deserts).
Ecological & Climatic Concerns	Rising moist/dry heat extremes could affect labour productivity, energy demand & water sustainability despite increased rainfall.
Global Comparison	Among 14 major deserts studied only Thar, Arabian, Negev, Eastern Gobi saw significant rise in rainfall & vegetation; Namib showed decline.
Technological Approach	Used satellite datasets like MODIS (vegetation) & GRACE (groundwater) along with CGWB well data for validation.
Historical Context	Fossil discoveries suggest Thar may have once been a tropical forest. Changing patterns now show opposing effects of climate change.
Future Outlook	Models project 20 to 50% increase in annual rainfall but heat stress & groundwater depletion may undermine long term sustainability.

Thar Desert

Aspect	Details
Name	Thar Desert (Great Indian Desert)
Etymology	Derived from thul term for sand ridges in region
Geographical Type	Subtropical arid desert
Global Ranking	9th largest subtropical desert in world
Location	Northwestern Indian subcontinent
Countries Covered	India (~85%), Pakistan (~15%)
Indian States Covered	Rajasthan (majority), Gujarat (north), Punjab & Haryana (south portions)
Pakistani Regions Covered	Punjab & Sindh provinces
Total Area	~200,000 sq. km
Boundaries	Northwest Sutlej River East Aravalli Hills South Rann of Kutch (salt marsh) West Indus River Valley
Topography	Sand dunes (10% of ecoregion) Craggy rock formations Compacted salt lake beds
Notable Feature	No natural oases, unlike many other large deserts
River System	Luni River only river that flows through desert
Climate Type	Extreme arid/semi-arid
Summer Temperature	Can exceed 50°C
Winter Temperature	Can fall to near 0°C (freezing point)
Annual Rainfall	Between 100–500 mm mostly during monsoon season (June to September)
Winds	Frequent & strong dust storms especially in summer
Vegetation Type	Sparse; xerophilous plants adapted to dry & saline soils
Flora Examples	Acacia, Prosopis juliflora, Capparis, grasses
Population Density	83 persons per sq. km highest population density for any desert in world
Livelihoods	Agriculture (irrigated), animal husbandry, handicrafts, tourism, mining
Mineral Wealth	Coal reserves (among largest in India) Gypsum, Limestone, Salt, Bauxite, Silica, Kaolin etc.
Environmental Concerns	Desertification, groundwater depletion, land degradation, climate vulnerability
Human Interventions	Indira Gandhi Canal, desert afforestation, renewable energy installations (solar parks, wind farms)

Comparison with Global Deserts & Indian Arid Zones

Aspect	Thar Desert	Sahara Desert	Gobi Desert	Atacama Desert	Great Victoria Desert	Indian Arid Zones (Other than Thar)
Location	Northwestern India & SE Pakistan	North Africa	Mongolia & China	Northern Chile	Australia (SA & WA)	Rajasthan (west), Gujarat (Kutch), parts of Punjab & Haryana
Area	~200,000 sq. km	~9.2 million sq. km	~1.3 million sq. km	~105,000 sq. km	~348,750 sq. km	~60,000 sq. km (excluding Thar)
Climate Type	Hot semi-arid to arid	Hyper-arid	Cold desert	Hyper-arid	Hot desert	Arid to semi-arid
Rainfall	100–300 mm annually	<100 mm/year	194 mm/year	~15 mm/year	200 to 250 mm/year	150 to 500 mm/year
Temperature Extremes	Summer: >50°C, Winter: ~5°C	Up to 58°C	–40°C to 45°C	0 to 30°C	15 to 40°C	5°C to 50°C
Soil Type	Sandy, saline, loamy	Sandy, rocky	Rocky, compact	Saline, stony	Red desert sands	Sandy, loamy, alluvial
Vegetation Cover	Scrubland, Prosopis, Acacia	Sparse shrubs, date palms in oases	Grasslands, shrubs	Cacti, saltbush	Spinifex grass	Prosopis, millets, dry shrubs
Population Density	Most densely populated desert (83/km²)	Sparse, mostly nomadic	Sparse settlements	Very low	Extremely low	Low to moderate
Cultural Importance	Dense habitation, agriculture, heritage towns (Jaisalmer, Bikaner)	Nomadic tribes, historical trade	Mongol influence, trade routes	Pre-Columbian cultures	Aboriginal heritage	Local tribes (Rabari, Ahir), pastoral systems
Major Livelihoods	Agriculture, livestock, mining, tourism	Pastoralism, oasis farming	Livestock, mining	Mining (copper, lithium)	Mining, indigenous economies	Rain-fed farming, animal husbandry
Water Sources	Groundwater, Indira Gandhi Canal	Oases, groundwater	Rivers (seasonal), wells	Fog harvesting, rivers (occasional)	Rain tanks, ephemeral rivers	Groundwater, canals, seasonal rivers
Biodiversity	Desert fox, blackbuck, chinkara, peacocks	Fennec fox, addax	Bactrian camel, snow leopard	Lichens, beetles	Marsupials, reptiles	Indian fox, wild cats, reptiles
Current Issues	Groundwater depletion, urbanisation, desertification	Desertification, conflict zones	Climate variability	Mining impact, aridity	Climate change	Salinity, land degradation, water scarcity
Recent Trends	Greening (↑38%) due to climate & agriculture expansion	Encroachment from Sahel	Desertification reversal efforts	NASA fog collection projects	Mining vs conservation debates	Some greening, but also water stress in Kutch

Indian Arid Zones (as per National Bureau of Soil Survey & Land Use Planning)

Zone	Region Covered	Annual Rainfall (mm)	Dominant Soil	Farming Systems
Arid Western Plains	Western Rajasthan (Barmer, Jaisalmer)	<250 mm	Sandy, saline	Bajra, gram, livestock
Arid Saurashtra & Kutch	Western Gujarat	250–400 mm	Black & sandy loam	Cotton, groundnut, cattle
Semi-arid Transitional Zone	Eastern Rajasthan, Haryana fringes	400–600 mm	Sandy loam	Millets, pulses
Cold Arid Zone	Ladakh, Spiti	<150 mm	Gravelly, glacial soils	Barley, potato, yak herding

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Sources:

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PRACTICE QUESTION

Q. Thar Desert presents a unique paradox of being most densely populated desert in world yet highly ecologically fragile. Discuss climatic, geographical & human factors contributing to this paradox.