Rajasthan is situated in the north-western part of India. It covers 342,239 square kilometres (132,139 square miles). The capital city is Jaipur. Rajasthan lies between latitudes 23 degree 3'and 30 degree 12', north and longitudes 69 degree 30' and 78 degree 17', east. Compared to many other countries located in a similar latitudinal belt, such as in northern Arabia, Rajasthan has a less harsh climate. The State's scorching and dry summers and its parched landscape are undergoing significant changes because of the developmental effort that have led to the spread of the Indira Gandhi Nahar.
The southern part of Rajasthan is about 225 km from the Gulf of Kutch and about 400 km from the Arabian Sea. Rajasthan is bounded by Pakistan in the west and north-west; by the State of Punjab in the north; by Haryana in the north-east; by Uttar Pradesh in the east, by Madhya Pradesh in the south-east and Gujarat in the south-west India.
The main geographic feature of Rajasthan is the Aravalli Range, which runs across the state from southwest Guru Peak (Mount Abu), which is 1,722 m in height to Khetri in the northeast, for more than 850 km. This divides Rajasthan into 60% in the North West of the lines and 40% in the southeast. The northwest tract is sandy and unproductive with little water but improves gradually from desert land in the far west and northwest to comparatively fertile and habitable land towards the east of India. The area includes the Great Indian (Thar) Desert. Mount Abu is at the southwestern end of the range, separated from the main ranges by the West Banas River, although a series of broken ridges continues into Haryana in the direction of Delhi where it can be seen as outcrops in the form of the Raisina Hill and the ridges farther north of India. About three-fifths of Rajasthan lies northwest of the Aravallis, leaving two-fifths on the east and south of India.
The northwestern portion of Rajasthan is generally sandy and dry. Most of the region of Rajasthan is covered by the Thar Desert, which extends into adjoining portions of Pakistan. The Aravalli Range intercepts the moisture-giving southwest monsoon winds off the Arabian Sea, leaving the northwestern region in a rain shadow. The Thar Desert is thinly populated; the town of Bikaner of Rajasthan is the largest city in the desert. The Northwestern thorn scrub forests lie in a band around the Thar Desert, between the desert of Rajasthan and the Aravallis. This region receives less than 400 mm of rain in an average year. Summer temperatures can exceed 45°C in the summer months and drop below freezing in the winter. The Godwar, Marwar, and Shekhawati regions lie in the thorn scrub forest zone, along with the city of Jodhpur in Rajasthan. The Luni River and its tributaries are the major river system of Godwar and Marwar regions in Rajasthan, draining the western slopes of the Aravallis and emptying southwest into the great Rann of Kutch wetland in neighboring Gujarat in India. This river is saline in the lower reaches and remains potable only up to Balotara in Barmer district of Rajasthan. The Ghaggar River, which originates in Haryana, is an intermittent stream that disappears into the sands of the Thar Desert in the northern corner of the state and is seen as a remnant of the primitive Saraswati River.
The south-eastern area, higher in elevation (100 to 350 m above sea level) and more fertile, has a much diversified topography. In the south lies the hilly tract of Mewar of Rajasthan, in the southeast a large area of the districts of Kota and Bundi forms a tableland, and to the northeast of these districts is a rugged region (badlands) following the line of the Chambal River. Further north the country levels out; the flat plains of the northeastern Bharatpur district are part of the alluvial basin of the Yamuna River in India.
The Aravalli Range and the lands to the east and southeast of the range are generally more fertile and better watered. This region is home to the Kathiarbar-Gir dry deciduous forests ecoregion, with tropical dry broadleaf forests that include teak, Acacia, and other trees. The hilly Vagad region lies in southernmost Rajasthan, on the border with Gujarat. With the exception of Mount Abu, Vagad is the wettest region in Rajasthan, and the most heavily forested. North of Vagad lies the Mewar region, home to the cities of Udaipur and Chittaurgarh in Rajasthan. The Hadoti region lies to the southeast, on the border with Madhya Pradesh. North of Hadoti and Mewar is the Dhundhar region, home to the state capital of Jaipur in Rajasthan. Mewat, the easternmost region of Rajasthan, borders Haryana and Uttar Pradesh. Eastern and southeastern Rajasthan is drained by the Banas and Chambal rivers, tributaries of the Ganges.
The Aravali outlines Rajasthan's most important division. The Chambal River, which is the only large and perennial river in the State, originates from its drainage to the east of this range and flows northeast. Its principal tributary, the Banas, rises in the Aravali near Kumbhalgarh and collects all the drainage of the Mewar plateau. Further north the Banganga, after rising near Jaipur in Rajasthan, flows east-wards before disappearing. The Luni is the only significant river west of the Aravali. It rises in the Pushkar valley of Ajmer and flows 320 km west-southwest into the Rann of Kachchh. Northeast of the Luni basin, in the Shekhawati tract, is an area of internal drainage characterized by salt lakes, the largest of which is Sambhar Salt Lake.
In the vast sandy north-western plain extending over the districts of Jaisalmer, Barmer, Jalor, Sirohi, Jodhpur, Bikaner, Ganganagar, Jhunjhunu, Sikar, Pali, and Nagaur in Rajasthan’s soils are predominantly saline or alkaline. Water is scarce but is found at a depth of 30 to 61 m. The soil and sand are calcareous (chalky). Nitrates in the soil increase its fertility, and, as has been shown in the area of the Indira Gandhi Canal (formerly Rajasthan Canal), cultivation is often possible where adequate water supplies are made available.
The soils in the Ajmer district in central Rajasthan are sandy; clay content varies between 3 and 9 per cent. In the Jaipur and Alwar districts in the east, soils vary from sandy loam to loamy sand. In Kota, Bundi, and Jhalawar tract, they are in general black and deep and are well drained. In Udaipur, Chittaurgarh, Dungarpur, Banswara, and Bhilwara districts, eastern areas have mixed red and black and western areas red to yellow soils in Rajasthan.
Rajasthan is a northwesterly state of India. Rajasthan is bound on the west and northwest by Pakistan, on the north and northeast by the States of Punjab, Haryana, and Uttar Pradesh, on the east and southeast by the States of Uttar Pradesh and Madhya Pradesh, and on the southwest by the State of Gujarat. The Tropic of Cancer passes through its southern tip in the Banswara district.