Describe the location and main features of the Indus Plain.
- The Indus River plain is a vast expanse of fertile land, covering about 200,000 square miles (518,000 square km), with a gentle slope from the Himalayan piedmont in the north to the Arabian Sea in the south.
- The average gradient of the slope is no more than 1 foot per mile (1 metre per 5 km). Except for the micro relief, the plain is featureless. It is divisible into two sections, the upper and lower Indus plains, on account of their differing physiographic features.
- The upper Indus plain is drained by the Indus together with its tributaries, the Jhelum,Chenab,Ravi,Beas andSutlej rivers, forming a developed system of interfluves, known locally as doabs,, in Punjab province (Persian panj āb, “five waters,” in reference to the five rivers). In the lower plain the Indus River has a Nilotic character; i.e., it forms a single large river with no significant tributaries.
- Flooding is a perennial problem, especially along the Indus, as a consequence of heavy rains (usually in July and August).
- The Himalayan piedmont, or the sub-Shiwalik zone, is a narrow strip of land where the rivers enter into the plain from their mountain stage, thereby giving each a somewhat steeper gradient.
- The Indus basin soils are mostly thick alluvium deposited by rivers and are of recent origin. Soils in the vicinity of river courses are the most recent and vary in texture from sand to silt loam and silty clay loams.