Question

1.natural vegetation on lower course of ganga
2. forms of precipitation on upper , middle and lower course of ganga

Answer 1

(1) Bhagirathi is the source stream of Ganga. It emanates from Gangotri Glacier at Gaumukh at an elevation of 3, 892 m (12,770 feet). Many small streams comprise the headwaters of Ganga. The important among these are Alaknanda, Dhauliganga, Pindar, Mandakini and Bhilangana. At Devprayag, where Alaknanda joins Bhagirathi, the river acquires the name Ganga. It traverses a course of 2525 km before flowing into the Bay of Bengal. It has a large number of tributaries joining it during this journey.

          In Uttarakhand, Tehri dam has been built on Bhagirathi for hydropower generation resulting in regulated additional water discharge during the dry months. At Haridwar, Ganga opens to the Gangetic Plains, where a barrage diverts a large quantity of its waters into the Upper Ganga Canal, to provide water for irrigation. At Bijnore, another barrage diverts water into the Madhya Ganga Canal but only during monsoon months. At Narora, there is further diversion of water into the Lower Ganga Canal.

          Further down, River Ramganga joins Ganga near Kannauj, adding additional water to the river. Yamuna confluences Ganga at the Sangam in Allahabad, making a major contribution to the river flow. Beyond Allahabad, Ganga is joined by several tributaries, most of which are from the north and a few from the south. In the stretch between Allahabad in U.P. and Malda in West Bengal, Ganga, therefore, has considerable flow. The Farakka barrage in West Bengal regulates the flow of the river, diverting some of the water into a feeder canal linking Hooghly to keep it relatively silt-free.Downstream of this barrage, River Ganga splits,into two, Bhagirathi (Hooghly) on the right and Padma on the left. Bhagirathi (Hooghly) meets the Bay of Bengal about 150 km downstream of Kolkata. Padma enters Bangladesh and meets river Brahmputra and Meghna before finally joining the Bay of Bengal.
In the upper course of a river gradients are steep and river channels are narrow. Vertical erosion is greatest in the upper course of a river. As the result of this typical features include steep valley sides, interlocking spurs, rapids, gorges and waterfalls.

When a river runs over alternating layers of hard and soft rock, rapids and waterfalls may form.

Waterfalls commonly form where water rushes down steep hillsides in upland areas and quickly erodes the rocks. The height and number of waterfalls along a stream or river depends upon the type of rocks that are being eroded by the water. Some types of rocks (shale, for example) wear away more easily than others (such as sandstone or limestone).
As the river or stream wears away the weak rocks, they travel across the surface of stronger rocks. These more resistant rocks become the capstones to waterfalls. The number and thickness of these stronger rock units in a vertical sequence of rocks controls how many water falls there are and how much vertical drop there is on each waterfall.


source

The diagram above shows the formation of a waterfall. Soft rock is undercut (1). This leaves a layer of hard rock which overhangs the layer of soft rock (2). The water flows over the overhang and creates a plunge pool in the soft rock below (3). Eventually the overhang will collapse due to the erosion of the soft rock beneath it. The waterfall then retreats up stream (4). This creates a steep, gorge-like valley.

An example of a water fall is High Force in Northumberland. It is located on the River Tees, near Middleton in Teesdale, Tees Valley, England. The waterfall is 20m in height.


(2)