State PCS - Rajasthan (RAS)

• 15 Apr 2025

Thar Desert

Why in News? 

According to a new study, India's Thar Desert has recorded an annual increase of 38% in greening per year during the last two decades due to increased monsoon rainfall and agricultural expansion. 

Key Points 

• About Thar Desert: 
  • Location of the Thar Desert (The Great Indian Desert): It is an arid region of sand hills on the Indian subcontinent. It covers an area of 200,000 square kilometers in northwestern India (Rajasthan, Gujarat, Punjab and Haryana) and southeastern Pakistan (Sindh and Punjab provinces). 
  • Geography and Climate: It is bordered by the Indus River plains to the west, the Punjab Plains to the north and northeast, the Aravalli Range to the southeast , and the Rann of Kutch to the south . 
    • This desert has a subtropical desert climate , with persistent high pressure and subsidence.  
  • Soil Structure: Desert soils include desert, red desert, sierozem, red and yellow , saline, lithosols and regosols.  
    • These soils are coarse textured, well drained and calcareous , which supports specific vegetation and agriculture. 
  • Biodiversity: It supports relatively rich biodiversity, including the Blue Bull (Nilgai), Blackbuck, Great Indian Bustard (GIB) and Indian Gazella (Chinkara). 
    • One of the largest national parks in India , the Desert National Park (Rajasthan) , is located here. 
  • Mineral Resources: It has one of the world's largest lignite coal deposits in the desert . 
    • It is rich in gypsum and salt ( with saline lakes- Sambhar and Kuchaman ). 

Bisalpur Dam

Why in News? 

Intense heat and high temperatures are rapidly depleting the Bisalpur Dam water, which supplies drinking water to Jaipur, Ajmer, and Tonk in Rajasthan. If this continues, the region could soon face a severe water crisis. 

Key Points 

• About the Issue: 
  • Due to evaporation, about 15 centimetres of water has been lost in the last one month. 
  • It also affects the livelihood related to the dam. Fishermen are facing difficulty in hunting. can have an adverse effect on their economic condition. 
• About Bisalpur Dam: 
  • Bisalpur Dam is a gravity dam on the Banas River at Bisalpur in Tonk district of Rajasthan . 
    • A gravity dam is a dam made of concrete or masonry and withstands the pressure of water by its own weight. Its stability is entirely based on gravity.  
  • It was constructed in 1999 for the purpose of irrigation and drinking water supply 
  • This dam was named in honour of Bisaldev IV, the Chauhan ruler of Ajmer.