Thar Desert

The Thar Desert, also known as the Great Indian Desert, is a vast subtropical desert.

It is located in the north-western part of the Indian subcontinent. This arid region stretches across the international borders of India and Pakistan. About two-thirds of the desert area lies within India. Most of this land is in the state of Rajasthan. Some parts also extend into Gujarat, Haryana, and Punjab. To the west, the desert reaches into the Sindh and Punjab provinces of Pakistan.

It is one of the largest subtropical deserts in Asia by area.

The formation of this desert involved complex geological and climatic shifts. During the Last Glacial Maximum, an ice sheet covered the Tibetan Plateau. This ice sheet reflected at least four times more solar radiation into space than ice at higher latitudes. This process, known as radiative forcing, cooled the overlying atmosphere. Without the thermal low pressure caused by heating, the monsoon rains did not reach the Indian subcontinent. This lack of moisture led to the deposition of dust and desertification.

Over time, wind-blown sediments and sand from alluvial plains accumulated here.

Changes in the landscape also came from the movement of the earth. The Aravalli Range underwent upliftment, which changed the local hydrography. This movement altered how water flowed through the region. A major river system called the Ghaggar-Hakra once fed the area. This system included the Sutlej River and flowed into the Nara River. However, the rising Aravallis caused the headwaters to shift toward the Yamuna River. This deprived the Ghaggar-Hakra of its water. The river system eventually dried up, leaving the region much more arid.

The topography of the Thar Desert is varied. The eastern part near the Aravalli foothills has sandy plains and low, eroded hills. These elevations can reach about 300 meters. As you move west toward the India-Pakistan border, the altitude drops to about 150 meters. Much of the desert is covered by mobile sand dunes. These dunes are formed by the accumulation of wind-blown sand. Strong winds rise every year before the monsoon season, moving the sand constantly. The bedrock below often consists of igneous and metamorphic rocks.

The climate in the Thar is characterized by extreme temperatures. During the summer months of April to June, average maximum temperatures are high. They often exceed 45 degrees Celsius during the peak of summer. In contrast, the winter months of December to February are much cooler. Minimum temperatures can drop to 5 degrees Celsius. Most precipitation arrives via the southwest monsoon from June to September. The average annual rainfall is quite low, often less than 250 millimeters. Because rainfall varies so much, the region frequently experiences long droughts.

Water management is essential for survival in this environment. The Luni River is the only major inland river system in the desert. There are also several endorheic salt water lakes, such as Sambhar and Didwana. These lakes collect monsoon water that evaporates slowly during the dry season. To support life, people use the 650-kilometer long Indira Gandhi Canal. This canal channels water from the Indus River system for drinking and irrigation.

People also build man-made reservoirs called tobas, johads, and taankas to store rainwater.

Human history in the desert is very long and rich. The Indus Valley Civilisation flourished near the Ghaggar-Hakra River between 3300 BCE and 1300 BCE. After this civilization declined around 1900 BCE, Indo-Aryan groups migrated into the area. Many famous empires eventually controlled parts of the desert. These include the Mauryan, Kushan, and Gupta Empires.

Later, the region saw the rise of Rajput states and conflicts with the Mughal Empire. Today, the Thar is one of the most widely populated deserts in the world.

People live in small villages and rely on herding, limited agriculture, and eco-tourism.