ForWarn detects early effects of Colorado flooding

In early September of 2013, unusually heavy rain resulted in catastrophic flooding across Colorado’s Front Range and downstream along the South Platte River. Rainfall exceeded 20 inches northwest of Denver, which is close to the average rainfall for that area during an entire year. Flash floods led to massive evacuations, a severe loss of public and private property, and loss of human life. Oil and gas lines and tanks were damaged, causing the release of thousands of gallons of pollutants into the South Platte River. Along the River, high waters scoured vegetation, affecting both natural areas and low-lying agricultural lands.

As shown on the accompanied maps, ForWarn's Early Detect product captured the extent and severity of flood damage from the Front Range downstream to the state line, 200 miles to the east. In this particular disturbance detection map, changes in the Normalized Difference Vegetation Index (NDVI) relative to the same time in 2012 are shown for agricultural, urban, forest and grass lands.