Late-winter rain and melting snow combined to trigger floods and landslides in the mountain valleys of Afghanistan’s rugged southwestern interior in mid-March 2007. By March 20, more than 50 people had died and hundreds were displaced or stranded throughout the country, said the United Nations Office for the Coordination of Humanitarian Affairs Integrated Regional Information Network (IRIN). The floods had pushed the Helmand River over its banks by March 22, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured the top image. A little more than a week earlier, when the lower image was taken, the dark blue water flowing through the river was barely visible. But on March 22, the river had widened. The reservoir behind Kajaki Dam was also swollen, and its bright blue color was a sign that mud carried by run-off permeated the water. By contrast, the reservoir was dark blue and black, the color water typically takes in this type of image, the previous week.
These images were made with a combination of infrared and visible light to highlight the presence of water on the ground. The surrounding desert is tan and pink, and clouds are pale blue and white. Irrigated crop land around the rivers and plant-covered land in the mountains are bright green. Similar images and photo-like, true-color images of Afghanistan are available from the MODIS Rapid Response System on a daily basis.