Rajasthan, situated at the northwestern part of India is the biggest state in the country of India and lies between 23°30′ and 30° 11′ North latitude and 69° 29′ and 78° 17′ East longitude. The state shares its north-western and western boundary with the Indo-Pakistan international border that extends about 1,070 km and touches the major districts Barmer, Bikaner, Sriganganagar and Jaisalmer. It is bounded on the west and northwest by Pakistan, on the north and northeast by Haryana &Uttar Pradesh, on the south-southeast and southwest by Madhya Pradesh and Gujarat States respectively. The huge portion of the state of Rajasthan is desiccated and houses the biggest Indian desert- the Thar desert known as the ‘Maru-kantar’. The oldest chain of fold mountains- the Aravali range splits the state into two geographical zones- desert at one side and forest belt on the other. Only 10% of the total geographical region lies under forest vegetation. The Mount abu is the only hill station of the state and houses the Guru Shikhar Peak that is the highest peak of the Aravali range with an elevation of 1,722 m. The area to the east of the hills is covered by the eastern plains and the Vindhyan plateau. Distribution Rainfall Rajasthan Geography
There is a wide variation in the mean annual rainfall over Rajasthan as the extreme western parts of Jaisalmer district receive rainfall less than 100mm in contrast to more than 900mm in the eastern parts of Jhalawar and Banswara. The districts of East Rajasthan receive more rainfall than those of West Rajasthan. The mean annual rainfall in the East and West Rajasthan is about 64.9 cm and 32.7 cm respectively.
There is a huge variation in the mean annual rainfall over the entire Rajasthan state. The extreme western parts of Jaisalmer districts receives the rainfall less than 10cm wherein the south-eastern parts of Rajasthan receives the rainfall more than 100 cm, which is 10 time more of earlier.
The southern and south-eastern districts, Jhalawar and Banswara, receive the maximum rainfall in the state, which is about 120 cm.
The southern and south-eastern districts Kota, Baran, Jhalawar, Baswara, Pratapgarh and Udaipur and Mount Abu region of the Rajasthan receive the rainfall more than 100 cm.
The districts of Eastern plains i.e. Bharatpur, Dholpur, Kota, Bundi, Sawai Madhopur, North-west Udaipur, South-east Tonk and Chittorgarh receive the 60-80 cm rainfall.
The districts of Aravalli Range i.e. Alwar, Japur, Ajmer, Pali, Jalore, Eastern parts of Nagaur and Jhunjhunu and north-west part of Tonk, Bhilwara and Sirohi receive the 40-60 cm rainfall.
The districts, Shri Ganganagar, Hanumangarh, Churu, Southern Barmer, Eastern parts of Bikaner and Jodhpur and western parts of Pali, Jalore, Sikar, Nagaur and Jhunjhunu receive the 20-40 cm rainfall.
The districts or western Rajasthan, Thar Desert, i.e. Jaisalmer, Hanumangarh, Eastern Barmer, Southern Shri Ganganagar and Western Bikaner and Jodhpur receive the rainfall less than 20cm. Distribution Rainfall Rajasthan Geography
The maximum rainfall in the state is received in the Southern or South- Eastern districts of the state. On the west of Aravalli hills Pali and Jalore districts receive maximum amount of rain of 50 cm and 43 cm in West Rajasthan.
In the North or North-Western districts Jaisalmer district receives the lowest rainfall. Bikaner, Ganganagar, Jaisalmer receive annual rainfall of 26cm, 24cm and 17cm respectively. The adjoining areas of these districts constitute the driest zone of the state.
The lowest recorded annual rainfall in the past 100 years i.e. between 1900 and 2010 was 24 mm in the western Rajasthan and whereas it was never below 120 mm in the eastern Rajasthan.