Wildfires are doing severe damage in a number of western U.S. states. Extremely dry conditions, stiff winds, unusually warm weather, and trees killed by pine bark beetle outbreaks have created a situation in which major fires thrive. 52 active fires in a number of states have destroyed over 900,000 acres. Since the beginning of 2012, 27,000 fires have destroyed 1.9 million acres.
Image of the Week
Images found during the week that show change from our past that correlate to current events.
On July 23, the Landsat system will celebrate 40 years of continuous observations of the land forms of the planet. Over 7 million separate scenes have been collected by the six satellites in the series. The data from the satellites provide a permanent, objective record of land conditions and are routinely used to measure and monitor changes brought on by natural and anthropogenic events and actions.
The Philippine capital of Manila, situated on the eastern shore of Manila Bay, is the most densely populated city in the world, with over 1.6 million inhabitants in an area covering 38.5 square kilometers; the greater metro area covers 638 square kilometers, with a population of over 11 million. The impacts of the growing population create serious infrastructure and environmental problems in the areas of land, water, air, sewerage, drainage, waste, and traffic. The Pasig River, which cuts through the urban area, is one of the most polluted rivers in the world.
Landsat satellite data, archived by the U.S. Geological Survey, have proven useful for studying land surface changes over time. Images of the Mount St. Helens region in southwestern Washington illustrate the conditions before, shortly after, and decades after the eruptions of the Mount St. Helens volcano in 1980. That eruption was the most economically destructive eruption in United States history.
The 1974 image shows the snow on the southern slopes and the heavy forests surrounding the volcano.
Landsat satellite data are proving useful for monitoring and measuring the effects of wildfires across the western United States in 2012. Images acquired before, during, and after fires give state and regional authorities objective scientific data on the rate of burning, the land cover affected, and extent of the damage inflicted.
Large areas of the western United States have been affected by the drought of 2012. For example, Landsat images, acquired and processed by the U.S. Geological Survey, provide a record of the effects of the drought on the Cheyenne Bottoms Wildlife Wetlands area in central Kansas.
Fires continue to destroy residences, grassland cover, and forests in the western United States. Landsat images, acquired and processed by the U.S. Geological Survey, illustrate the damage caused by fires in the Nevada/Oregon border region.
The June 26, 2012, image shows the area before a series of fires developed.
The 2012 drought, which has affected much of the cropland in the Midwest and the western United States, has also had a major effect on the level of the Mississippi River. The diminishing flow of the river has delayed barge traffic and movement of cargoes to ports at the lower mouth of the river.
40% of the conterminous United States drains into the Mississippi River. The drought, which has diminished the flow from feeder streams, has led to a 30–50 foot drop in the river level. A drop of one foot lessens the amount of cargo that can be carried downstream by 200 tons.
Landsat satellite data, acquired and processed by the U.S. Geological Survey, illustrate the effects of Hurricane Isaac on land between Lake Maurepas and Lake Pontchartrain northwest of New Orleans, Louisiana.
The hurricane made landfall in the region on August 28, 2012, and moved very slowly north. While levees in the New Orleans area prevented massive flooding in that city, strong winds, rain, and storm surges caused massive flooding in the region between the lakes.
Day County, located in the northeastern corner of South Dakota, sits within the Coteau des Prairies – a plateau created from deposits derived from repeated glaciation. Many small lakes occur in this region due to a perched water table. In the past 20 years, lake waters have been swallowing up land, roads, and homes in the region. The area around the town of Waubay, which is noted on these Landsat images acquired in 1991 and 2011, is particularly affected.