Thar Desert

The Thar Desert, often called the Great Indian Desert, is a dry region in the northwestern part of the Indian subcontinent, spanning both India and Pakistan. It ranks among Asia’s largest subtropical deserts by area. Roughly two-thirds of this desert lies within India, while the rest is in Pakistan. Within India, it makes up about six percent of the country’s total land area, with most of it located in the state of Rajasthan, and parts extending into Gujarat, Haryana, and Punjab. On the Pakistani side, it stretches into the provinces of Sindh and Punjab. The desert is bordered by the Indo-Gangetic Plain to the north, west, and northeast, the Rann of Kutch to the south, and the Aravalli Range to the east.

The desert’s formation traces back to the Last Glacial Maximum, when an ice sheet covered the Tibetan Plateau. This ice sheet reflected more solar radiation into space, cooling the atmosphere above. Without the thermal low pressure that normally comes from heating, the monsoon over the Indian subcontinent failed to develop. This lack of monsoon led to dust deposition and the region’s desertification. Later, the uplift of the Aravalli Range altered the area’s hydrography. The Ghaggar-Hakra River system, which once fed the region, dried up, and the land grew increasingly arid. Over time, wind-blown sediments and sand from alluvial plains and the coast accumulated here.

The landscape is mostly sandy plains, broken by low, eroded hills. The climate is tropical desert, with extremely hot summers and cooler winters. Most rainfall comes from the southwest monsoon, averaging less than a certain amount annually, and it varies greatly from year to year, often bringing long droughts. Water sources are scarce; the inland Luni River is the only major river system. Rainwater is commonly stored in natural and man-made reservoirs for use during dry periods.

Natural vegetation includes trees, thorny scrubs, and scattered grasslands. The desert hosts a variety of animals and birds. It is one of the most densely populated deserts globally, home to the Thar people. The population lives in small villages, with many people leading nomadic lives. The local economy relies on limited agriculture, livestock herding, and ecotourism.

Geographically, the Thar Desert occupies the northwestern part of the Indian subcontinent, crossing the India-Pakistan border, and is the easternmost extension of the Sahara-Arabian desert belt. It covers a certain area, with a portion in India and the rest in Pakistan. The desert constitutes about six percent of India’s land area, mostly in Rajasthan, with parts in Gujarat, Haryana, and Punjab. To the west, it extends into Pakistan’s Sindh and Punjab provinces. Its northeastern edge lies between the Aravalli Hills, which separate it from the Central highlands and the Indo-Gangetic Plain to the east. The desert reaches from the alluvial plains of the Indus River in the west and northwest to the Great Rann of Kutch in the south.

Regarding its origin, during the Mesozoic era, the area was a low-lying peneplain covered by shallow waters. Erosion later created three layers of planation surfaces in the post-Mesozoic and early Pleistocene periods. When the Himalayas rose in the mid-Miocene, the monsoon system emerged. During the Last Glacial Maximum, the Tibetan Plateau’s ice sheet reflected more solar radiation than higher-latitude ice, cooling the atmosphere further. Without the thermal low pressure from heating, the monsoon over India failed. This caused extensive rainfall over the Sahara and more dust deposition toward the Arabian Sea, while also shifting biotic life zones—for example, Javan rusa deer migrated into India. The Aravalli Range rose rapidly and reached significant height in the early Holocene. Between 10,000 and 8,000 years ago, a channel of the Ghaggar-Hakra River (linked to the paleo Sarasvati) once flowed into the Nara River, a delta channel of the Indus, after merging with the Sutlej, but then changed course. The Aravallis’ uplift altered the hydrography, increasing water flow into the Yamuna River while cutting off the Ghaggar-Hakra’s headwaters. This left the Ghaggar-Hakra as a system of monsoon-fed rivers that no longer reached the sea, ending instead in the Thar Desert. Starting around 4,500 to 5,000 years ago, as monsoons feeding the river system weakened further—since the Aravallis blocked monsoon winds from the east—the region became increasingly arid. The Indus Valley Civilisation had thrived here, with many settlements along the river. When monsoons diminished even more, the Hakra became an intermittent river, and the urban Harappan civilisation declined.