The first detailed study on the Physiography of Rajasthan was done by V.C. Mishra and he wrote a book called “Geography of Rajasthan”.
This book was published in 1968. done in. On the basis of relief, the geographical areas of Rajasthan are divided into four parts. Which are the following –
- North-West desert region.
- Central Aravalli ranges.
- Eastern plains.
- South-Eastern plateau region.
North West Desert Region: –
The 61.11%. area of Rajasthan is the part is the north-western desert.
This region is 640 km long from north-west to south-east and 300 km wide from east to west.
About 40% of the state’s population resides in the North West desert region.
Rainfall occurs between 20cm to 50cm.
The north-western part of Rajasthan, the sandy area from the Aravalli ranges to the international border is called desert area.
The name of this desert is ‘Thar Desert’. which is covering over 2,33,100 km2 of area in two countries, India and Pakistan.
About of which 1,75,000 km2 area is in Rajasthan.
The amount of rainfall in this desert area varies from 0-50 cm and it comes in arid and semi-arid climate.
61.11% area of the total area of the state is covered in the desert.
This Area is Considered as the eastern part of Africa’s Paleo arctic desert.
Highest biodiversity is found here compared to other deserts of the world. That’s why Dr. Ishwar Prakash called it the rough area.
The soil here is sandy-loamy and the Crops grown in this area are millet, moth, wheat, cotton, moong, mustard.
North-West desert region of Rajasthan is spread over 12 districts of the state.
Jaisalmer, Barmer, Bikaner, Ganganagar, Jodhpur, Hanumangarh, Nagaur, Jalore, Churu, Sikar, Jhunjhunu, western part of Pali.
The vegetation here is thorny, pine and small leaves. For example, Kairu, Bair, Khejdi, Cactus, Thohar.
On the basic of Rainfall, the desert area is divided into two parts.
- Arid desert (0-25 cm of rain)
- Semi-arid desert (25-50 cm of rain)
Aravalli in Rajasthan acts as a rain divider because it acts as rain shadow region.
50cm rainfall line separate desert from Aravalli
The 25 cm rainfall line separates eastern desert and western desert.
Arid desert Region (0-25 cm of rain)
This is an area with minimum rainfall, it receives 0-25 cm of rainfall and have some Thorny Vegetation.
Mostly the area here is completely devoid of vegetation.
In covers area of Jaisalmer, Bikaner, Barmer, Nagaur ,half of Churu and Western Jodhpur.
Major crops here have the highest area of millet and moth(dal).
We can divide this area into two parts
- Desert area with Dunes (Marusthali).
- Dune free tract.
The Marusthali area contains sand-Dunes. dunes covers 58.50% (about 60%) of this area.
There are mainly two types of sand Dunes –
- longitudinal Dunes: – These are sand dunes formed parallel to the winds. Their height is 10-60 meters.
- Transverse Dunes: – They have a height of 10-40 meters. These are sand-Dunes formed at right angles or opposite to the winds. They are responsible for desertification.
- Barchan – This is a type of transverse dune. Its height can be up to 10-20 meters. It is destructive due to being the most dynamic. It is called ‘Dharian’ in the local language. Their shape is crescent.
- Linear sand in Rajasthan -Stupa,
- Most sand-dunes are found in Shekhawati region
- longitudinal sand dunes are found in Jaisalmer-Barmer and Transverse sand stupas are found in Shekhawati region.
Dune Free tract : – (41.5%)
The part of the desert area where there is no sand dunes.
This area is rugged Hilly desert kind of area.
The Pokaran region of Jaisalmer which comes in the hilly region.
The Chappan hills of Barmer (Malani mountain region) and the granite hills of Jalore, come in the Dune free area.
Haldeshwar in the Malani hill region. The hill peak, which is known as mini-mount of Marwar.
Semi-arid desert Region
The amount of rainfall in this desert area is 25-50 cm.
This area is mainly divided into four parts.
Ghaggar River originates from Shivalik hills from a place called ‘Kalka’ in Himachal Pradesh.
This river enters Rajasthan from Tibbi thehsil of Hanumangarh district. it flows in Hanumangarh and Sriganganagar districts and flows upto Fort Abbas of Pakistan.
This river was called Mrit river, Sotar nadi, Nar nadi, Saraswati in ancient times and Dwasdvati in Vedic period.
The flow area of Ghaggar river is called ‘Nali/Paat’ in Rajasthan and ‘Hakra‘ in Pakistan.
The flow area of this river comes in the semi-arid desert region of Rajasthan.
due to better irrigation facilities, it is a fertile part of Rajasthan. also, ghaggar is the only international river of the state.
The only river of the state, which enters from the north direction.
Shekhawati region is also known as ‘Bangar region’.
It covers the area of Churu, Jhunjhunu, Sikar and the northern part of Nagaur.
Most of the Barkhan (semi-circular) type of sand dunes are found here.
Due to the high concentration of lime in the land of this region, raw wells are dug here. Which are called ‘Johad or Nada‘ in the local language. The deepest place or the base of Johad is called ‘Chombhi’.
It is a semi-arid plain formed by the river Luni, is known as Luni Basin.
Luni River flows in Pali, Jalore, Sirohi, Jodhpur, Nagaur, Barmer.
The most extensive plains in the Luni basin are flat. The ancient tremor is the plain which covers 41.51% of the entire basin.
The tributaries of the Luni river are Jojri, Bandi, Guhia, Jawai, Khari etc.
The Luni and its tributaries lie in the south-eastern part of Jodhpur district, in Pali, Jalore, Sirohi districts.
The eastern boundary of the Luni river basin is called the Kalabhara Dungar.
The water of the Luni is sweet due to the mountainous drainage system up to Balotra and further saline due to the salt particles.
Major artificial lakes of the Luni basin are Fatehsagar, Jaswantsagar, Anantsagar, Sardarsamand, Hemwas, Naya Gaon and Sarada etc.
Nagaur Upland Area:-
It is an elevated part between Luni Basin and Shekhawati region.
Nagaur Highland is 300 to 500 meters above sea level.
There are some Slaine water lakes like Sambhar, Didwana, Nawa and Kuchaman in the eastern part of this region.
The source of salt in this region is the micaceous rocks from which salt comes to the surface through dredging.
And its excessive floride in water its consumption leads to curvature in the bones of the person.
This area is known as Kubbarpatti / Bankpatti. The highest amount of fluoride in Rajasthan is in the water of Asarwa village of Makrana.
Features of North-West Desert Region
Jaisalmer is the place with the least rainfall of Rajasthan.
The wettest place of West Rajasthan is Raniwada (Jalore).
Land surrounded by low-banks between two sand dunes, in which rain water gets collected and forms a temporary lake, it is called ‘Playa Lake’.
Most of the playa lakes in Rajasthan are in Jaisalmer district.
Major playa lakes:-
Jaisalmer – Kanond, Baramsar, Bhakri
Barmer – Thob
Jodhpur – Bap
Shekhawati – Parihar run area (Sikar)
Khadin is found in Jaisalmer, which is a type of traditional water conservation. After the water dries up in Khadin, the fertile layer beneth is called Mahro.
Bejhar-agriculture (wheat barley lime) and Raika agriculture (mustard taramira) is done here. Rebari and Dewasi society is called Raika in western Rajasthan.
Batandu ka kua(बाटाडुँ का कुआ): – It is known as the ‘jalmahal’ of the desert. It was built by Rawal Guman Singh / Gulab Singh.
Chandan Nalkup(चन्दन नलकूप): – It is known as Thar ka ghada(थार का घड़ा). It provides sweet water for 24/7.
Kolayat:- It is known as the beautiful garden of the desert.
Gajner Lake: – It is called the beautiful-mirror (सुन्दर-दर्पण ) of the desert.
Pivana(पीवणा): – It is a species of snake found in this region. It is mostly found in Jaisalmer.
Lathi Series: – It is a geological water belt. on which, the grasses like Savan, Anjan, Dhaman, Mural and Tadgam grow.
Sonu / Sanu area: – This area is located in Jaisalmer district. Steel grade limestone is found here.
National Desert Park: – founded in 1981 AD is the largest sanctuary of the state in terms of area. 3162 km2. It is spread in Jaisalmer and Barmer districts.
Aankal Village (Jaisalmer): – Ankal Wood Fossil Park / Wood Fossil Park is located in this village. Where wood fossils of millions of years ago have been found.
Cactus Garden: – Kuldhara is located in Jaisalmer.
Baropal Village: – This village is located in Hanumangarh district which is affected by the problem of marshy land (सेम) due to Indira Gandhi Canal.
Explanation: Actually, there is a problem of over drained land in many areas of Hanumangar Ganganagar and Bikaner. Here, due to the leakage of water from the canals, the surrounding land became swampy and due to this agriculture could not be done there. An area of thousands of km of Rajasthan is affected by the problem.
March of the desert: – The NW desert is considered to be expanding toward the SE side this is knowns as the march of the desert.