Question

Give reasons:
a.The Ob, Yenisey and Lena rivers often form swamps and marshes.​

Answer 1

Answer:

The three great Siberian rivers, Ob River, Yenisei River and Lena River all flow into the Arctic Ocean, the problem was to find parts or branches of these rivers that flow approximately east-west and find short portages between them.Thus they form swamps and marshes.

Answer 2

Explanation:

In the span of three weeks, spring crept over the Siberian landscape surrounding the northern half of the Lena River. Many of the rivers in Earth’s temperate zones run high in the spring when melting snow and spring rain flood river basins. On the Lena River, however, spring flooding is almost inevitable for another reason: ice. Like other north-flowing rivers, the upper reaches of the Lena melt before their downstream counterparts. Because the northern mouth of the river remains frozen while the southern body of the river flows freely, water naturally builds behind the ice, forming a temporary reservoir that drains as the ice dwindles. This series of images, taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite, captured the spring flooding in May 2007.

The images were made with