The Western Sandy Plains is one of the most prominent physical division of Rajasthan. It covers a large part of the state in the west and the northwest of the Aravalli axis. It is bounded on the southwest by Gujarat, on the west by international boundary between India and Pakistan and on the north by Punjab.
इस लेख को हिंदी में पढ़ें – पश्चिमी मरूस्थलीय प्रदेश
The western sandy plains are divided into two major regions and 6 sub-regions as following:
- A. Sandy Arid Plain
- A1. Marusthali
- A2. Dune free Tract
- B. Semi-Arid Basin or Rajasthan Bangar
- B1. Luni Basin
- B2. Shekhawati Region
- B3. Nagaur Upland
- B4. Ghaggar Plain
A. Sandy Arid Plain
- Area- 61% of total area of W.S.P.
- Population- 40%
- Minimum Rainfall- 50 Cm
- There are vast expanses of sand & rock outcrops mainly limestone are found in Jaisalmer, Barmer, Bikaner, Churu, Hanumangarh & Sriganganagar.
- Sandy Arid Plain further Sub-divided into two sub-regions.
- District- Bikaner, Barmer, Jaisalmer, Jodhpur, Nagaur, Churu
- Area – 120500 Sq. Km (Thar Desert)
- Height of sand dunes – 6 m to 60 m
- Length of sand dunes – 3 km to 5 km
- Towards west this sandy arid Marushthali is known as Thar Desert. Shifting sand dunes is locally terms as Dharians.
A2. Dune free Tract
- Districts- Bikaner, Jaisalmer, Phalodi & Pokhran
- Area – 65 Sq. Km.
- Limestone & Sandstone rocks exposes (to lay open) here belong to Jurassic & Eocene formations.
- It is rocky but dune free tract.
- Small hills are found within a circle of 64 Km of Jaisalmer town
- Dry beds & banks could easily be tapped for ground water
- Grid conglomerate, gneiss, schist & granite rocks are also exposed at places.
B. Semi-Arid Basin or Rajasthan Bangar
- District – Jaipur, Jodhpur, Nagaur, Pali, Jalore, Barmer
- Area – 7500 Sq. Km
- Rainfall – 20 cm
- In it lies in the eastern part & drained by the Luni in its south-eastern portion.
- Gullying has given rise to conglomerate landscape. Its eastern part is covered with superficial sand deposits.
- Towards north lies the Shekhawati tract which is semi arid transitional plain characterized by inland drainage & stream with salt lakes like Sambhar, Didwana etc.
- In the extreme north lies the Ghaggar Plain.
B1. Luni Basin
- District – Barmer, Jalore, Jodhpur, Nagaur Area – 34866 .4 Sq. Km
- Basin is drained by the Luni River & its tributaries Bandi, Sagi, etc. Covers the area from its source to Tiwara (Barmer) where Sukari river meets it.
- It is a seasonal river
- Floods occur during the rains in Luni
- Topography is marked by hills with steep slopes & extensive alluvial plains.
- This area is locally known as Naid (Rel) & is one of best alluvial plains.
B2. Shekhawati Region
- District: Churu, Sikar, Jhunjhunu & Nagaur
- Live stock, Milk production & dairy are the occupation of this region
- Aravalli hills runs through this region from south to north, cutting into almost two halves.
- Topography of the Shekhawati tracts is characterized by an undulating sandy terrain traversed by longitudinal sand dunes. There is only one seasonal river kantli
- Here the sand dunes are of transverse type
- The calcareous substratum is exposed of the tract from the sea level is 450m.
B3. Nagaur Upland
- District: Nagaur
- Average Height of this region from sea level – 300 m to 500 m
- Rainfall – 25 cm in west to 50 cm in east
- This region is full of sand hills & low depressions.
- The temperature being High, the evaporation of the saline flood-water results in the deposits of the salt & soda in these depressions.
B4. Ghaggar Plain
- Districts- Hanumangarh & Sriganganagar (75% of district).
- No existing river or stream except ancient Ghaggar and region is known as Ghaggar plain.
- It is a sandy plain interspersed with sand-dunes (6-30m high) & small sand-hills.
Featured Image Source: Geography of Rajasthan by Dr. VC Mishra, NBT New Delhi (1967)