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.
Acquired on July 18 and August 1, 2009, these false-color images provide a before-and-after view of the Sitamarhi District of the Indian state of Bihar. The image from August 1 shows swollen waterways and large areas of standing water.
India’s Brahmaputra River was already flooded in early August, but those floods turned out to be small compared to the floods that hit the river in early September. The river flooded for the third time in 2007 when monsoon rain pounded northeastern India, Bhutan, and Bangladesh in September.