Previous Year Question
In which of the following rivers, the upper course containing fresh water but saline water flowing at the lower part?
Barak river
Luni river
Ghaggar river
None of the above
Correct Answer: B
Detailed Solution
The Luni River is one of the important inland/desert river systems of Rajasthan. It originates on the western slopes of the Aravalli Range near Ajmer at an elevation of about 550 metres.
It flows generally in a south-westerly direction across Rajasthan and ultimately disappears in the marshy region of the Rann of Kutch in Gujarat. According to the Government of Rajasthan, the river flows for about 495 km before reaching the Rann of Kutch region.
The most important fact for this question is that the water of the Luni remains fresh up to Balotra and becomes progressively saline in its lower course. The official Luni River Basin description of the Government of Rajasthan explicitly records this characteristic.
In the lower desert region, high evaporation, low rainfall and salts present in the soil and geological formations contribute to the increasing salinity of the river water. Because of this characteristic, its name is also commonly associated with the Sanskrit word ‘Lavana’, meaning salt.
Its important tributaries include the Sukri, Mithri, Bandi, Khari, Jawai, Guhiya and Sagi, while the Jojari is an important right-bank tributary.