The entire catchment area of the Ghizar River is bleak and desolate. The slopes are devoid of a vegetative cover. The topography has been sculpted by the action of glacial amphitheaters, lakes, moraines and waterfalls.

Many small tributaries join the Ghizar River at various places along its course. These rise from the glaciers on either side of the Ghizar valley. The River descends along a steep gradient in its upper and middle courses, while its speed is reduced near the confluence with the Gilgit River and the valley becomes wider. It is strewn with boulders of varying shapes and sizes that have been brought down by the river from the high mountains. Virtually no human settlements occur along this river.

Hunza River
The River Hunza rises as the Khunjerab from a glacier north of the Karakoram range in the northwestern part of the state of Jammu and Kashmir. It flows southeast and cuts across the Karakoram range through a spectacular gorge. Downstream, the Hunza River follows a southwesterly direction in its middle course. Then it cuts across an offshoot of the Karakoram range and changes course to the southeast in its lower course before merging with the Gilgit a little upstream of Bunji where the latter river empties itself into the Indus.

Hunza is joined at different points by feeder streams like Chapursain, Ghujerab and Shimshal.

Shimshal river
This is a major tributary of the Hunza River. It rises from a glacier lying at the northern base of the Kanjut Sar massif in the area to the north of the Karakoram range in the extreme northwestern part of Jammu and Kashmir. Two main streams of this river originate in different depressions of an offshoot of the Karakoram range. They merge where the two valleys meet and flow as the main stream of the Shimshal towards west to join with the Hunza River upstream of Baltit.

The valley of the Shimshal River is U-shaped. Thick glacial deposits cover the valley bottom across which the channel of the Shimshal meanders. Small snow-fed tributaries join the river at various places.

There is an increase in the discharge of this river in late summer when the glacier melts at a faster pace. Flash floods may occur in mid-afternoon during this season when the water level rises abruptly.

The entire catchment area of the Shimshal River is devoid of a vegetative cover. Human habitation is restricted to the banks of the Hunza River.