<P> The Ghaggar is another intermittent river in India, flowing during the monsoon rains . It originates in the Shivalik Hills of Himachal Pradesh and flows through Punjab and Haryana to Rajasthan; just southwest of Sirsa, Haryana and by the side of talwara jheel in Rajasthan, this seasonal river feeds two irrigation canals that extend into Rajasthan . It terminates in Hanumangarh district . </P> <P> The Rajasthan Canal system is the major irrigation scheme of the Thar Desert and is conceived to reclaim it and also to check spreading of the desert to fertile areas . It is world's largest irrigation which is being extended in an attempt to make the desert arable . It runs south - southwest in Punjab and Haryana but mainly in Rajasthan for a total of 650 kilometers and ends near Jaisalmer, in Rajasthan . After the construction of the Indira Gandhi Canal, irrigation facilities were available over an area of 6770 km2 in Jaisalmer district and 37 km2 in Barmer district . Irrigation had already been provided in an area of 3670 km2 in Jaisalmer district . The canal has transformed the barren deserts of this district into rich and lush fields . Crops of mustard, cotton, and wheat now flourish in this semi-arid western region replacing the sand there previously . </P> <P> Besides providing water for agriculture, the canal will supply drinking water to hundreds of people in far - flung areas . As the second stage of work on the canal progresses rapidly, there is hope that it will enhance the living standards of the people of the state . </P> <P> Thar Desert provides the recreational value in terms of desert festivals organized every year . Rajasthan desert festivals are celebrated with great zest and zeal . This festival is held once a year during winters . Dressed in brilliantly hued costumes, the people of the desert dance and sing haunting ballads of valor, romance and tragedy . The fair has snake charmers, puppeteers, acrobats and folk performers . Camels, of course, play a stellar role in this festival, where the rich and colorful folk culture of Rajasthan can be seen . </P>

Give reasons for the low population density in himalayas and thar desert