Looking east at Burdick Expressway as the Souris River rises in Minot, North Dakota. Photo taken by USGS personnel during a FEMA Flood Inundation Mapping Project.

Throughout the last century in the United States, on average, floods have caused more lives lost and more economic damage than any other natural hazard. According to forecasts, severe flooding in 2012 will likely be far less widespread than last year. However, scientists cannot predict weather and water patterns with 100 percent accuracy, and there is always the potential for severe flooding somewhere in the country.

When it comes to flooding, preparation is key for saving lives and protecting property. USGS scientists and hydrologic technicians are specially trained and standing by. As soon as water starts to rise, they are measuring water levels, river velocities, and high water marks. All of this information is crucial for National Weather Service flood forecasts, for decisions by the U.S. Army Corps of Engineers to operate spillways and levees, and for the planning of Federal, State, and local emergency managers, first responders, and many other groups.

In preparation for flood events, the USGS continues to invest in and update equipment like the acoustic Doppler current profiler, which measures water velocity, as well as rapidly deployable streamgages, which measure river heights in areas that do not have a permanent gage or where a gage has been damaged by fast-moving water.

Perhaps most importantly, the USGS is constantly refining, innovating, and updating its ability to deliver river information to emergency managers, first responders, and other Federal agencies before, during, and after a flood. The USGS offers an increasing number of resources to help these organizations, as well as you and your family, better prepare for flood hazards.

Flood Inundation Mapping

When the water starts to rise, how do you know if you’re going to get wet?

Right now, if you want to see areas where river levels are higher than normal, you can go to USGS WaterWatch and view a map of the thousands of real-time streamgages that constantly monitor the Nation’s rivers and streams. But how do you put that number in context? If the current stage is forecasted to go above flood stage, does that mean water will be barely spilling over the banks? Or does it mean that your house might be underwater? At what stage is the river going to spill over onto a roadway and affect traffic? Are you and your family in danger?

River stage measurements can be confusing, and they are not always a great indicator of the actual scope and impacts of the flooding. To reduce this ambiguity, the USGS and the National Weather Service are working together to create visual products, called flood inundation map libraries, that show you estimates of where the water will be — what roads, yards, and buildings will be affected — when a river or stream reaches a certain stage.

For example, in Findlay, Ohio, the flood inundation map shows that when the stream stage is around 11 feet, only the roads closest to the river are underwater, but the rest of the town is out of danger. However, when you use the tool to map out a flood stage of 18 feet, streets as far as 15 blocks away from the river’s banks are underwater, as are a few parks, a cemetery, and almost the entire Findlay Country Club.

A powerful new tool for flood response and mitigation are digital geospatial flood-inundation maps that show flood water extent and depth on the land surface. Because floods are the leading cause of natural-disaster losses, the U.S. Geological Survey (USGS) is actively involved in the development of flood inundation mapping across the Nation pursuant to its major science strategy goal of reducing the vulnerability of the people and areas most at risk from natural hazards. Flood inundation maps have been created for cities on the map indicated by a black triangle (Iowa City, IA, Marshall, MI, Ottawa, OH, Findlay, OH, Peach Creek, near Atlanta, GA, Albany, GA, Trenton, NJ St. John River, near Fort Kent, ME, and Scituate, MA).

In Iowa City, Iowa, the flood inundation map shows that when the stream stage is at 17 feet, the river is barely out of the channel, and most of the town is out of danger. But when you map out a flood stage of 25 feet, parks and local areas designed to hold floodwaters are submerged. At 30 feet, several neighborhoods and much of the University of Iowa are flooded. On this map, you can click anywhere in the flooded area to see the estimated water depth for any location at any stage. Damage estimation models, which are based on FEMA’s Hazus tool, are also available for each flood stage on the map. All of these features allow emergency managers to see what areas and how many people need to be evacuated, and to estimate the cost of potential flood damages.

This new tool is especially useful to emergency managers responsible for keeping people safe on the roads. In fact, over half of all flood-related deaths are the result of people driving their cars onto submerged roadways. These new, interactive flood maps allow emergency managers to see what roads will be submerged at a forecasted flood level, so that the roads can be closed long before waters start to rise.

Flood inundation maps have already been produced for nine areas in the United States. The USGS plans to produce over 40 more of these maps within the next year, including for Terra Haute, Ind., Sweetwater Creek, Ga., and Hattiesburg, Miss. The USGS hopes to eventually have flood inundation map libraries available for many other areas across the country.

You can see what areas have already been mapped by using the tool.

WaterAlert

Smartphones let you know when the river is rising

If you’re on the USGS site and reading this, chances are you probably have a favorite outdoor spot, a favorite river, and perhaps a favorite streamgage that you check on a regular basis. Did you know that you can get automatic notifications from that streamgage sent straight to you as an email or text message? The USGS provides a service called WaterAlert that can text or email you when water levels at a streamgage of interest exceed certain thresholds.

This means that you can keep tabs on a river without having to repeatedly check the USGS website. And if waters start to suddenly rise, you will be alerted, allowing you to put necessary precautions in place to keep yourself, your family, and your property safe.

USGS scientists take streamflow and water quality measurements downstream of the Bonnet Carre Spillway near Norco, La. The Army Corps of Engineers uses USGS streamflow data to help them manage flood control structures.

Sign up for WaterAlert by selecting a State, checking the “surface water” box, and clicking on your streamgage of choice. You can also subscribe to WaterAlert from the flood inundation interactive map. If you live in a community covered by a flood inundation library, use the flood inundation map to discover what flood stage puts you at risk, then click the link in the “Services and Data tab” to sign up to receive a text or email when the water approaches, reaches, or exceeds that stage!

Links:

Flood Inundation Interactive Mapper: http://wim.usgs.gov/FIMI/FloodInundationMapper.html

Additional information about Flood Inundation Mapping: http://water.usgs.gov/osw/flood_inundation/

WaterAlert: http://water.usgs.gov/wateralert/

Main USGS Flood Site: http://water.usgs.gov/floods

News Release: Smart Phones Know When Rivers Rise…with USGS WaterAlert: http://www.usgs.gov/newsroom/article.asp?ID=2919

News Release: Instant Information about Water Conditions: Ask the River to Text You a WaterAlert: http://www.usgs.gov/newsroom/article.asp?ID=2464

As the climate changes, the conditions behind the unprecedented erosion of the 2009-2010 winter could become more common. Erosion assessments are helping coastal decison makers prepare for the potential damage of future storms. (Photo Credit: Jeff Hansen, USGS.)

• As a 5.8-magnitude earthquake near Mineral, Virginia, sent a jolt through 22 eastern States in August, many were surprised and frightened.

• As roads, homes, and farmlands were swamped by flooding from melting snowpack and spring rains, and as more property, roads, and even century-old covered bridges were washed away by flooding brought on by hurricanes this summer, many were caught off guard by the record-breaking water levels.

• As severe drought conditions in Texas caused die-offs of fish and wildlife and helped fuel widespread wildfires that forced residents to quickly gather family and escape to shelters, many were not prepared for the damages to their natural resources and homes.

• As climate change alters the ranges of species (such as moose and beaver), the reliability of vegetation (such as salmonberries), and the predictability of weather in the Arctic, residents have become concerned about their safety, their sources of food, and their livelihoods.

Unexpected hazardous events and changes to the world around us can be devastating.

But USGS science can help remove the element of surprise.

• Thanks to building codes based on USGS science, the damage to structures during the earthquake was greatly reduced.
• Thanks to streamflow data and flood statistics that support the National Weather Service’s flood warning systems, communities had real-time flooding information as well as time to prepare before the floods hit.
• Thanks to wildfire mapping to guide emergency response decisions, residents had time to evacuate areas threatened by fires.
• Thanks to climate change modeling and impact studies, decision makers are developing a better understanding of how a changing climate is impacting our societies and natural resources.

Answering the Questions Posed by Our Ever-Changing Earth

October 9 – 15, 2011, is Earth Science Week, themed “Our Ever-Changing Earth,” and October 12 is International Day for Natural Disaster Reduction.

These awareness events provide an opportunity for everyone to learn how science is helping to answer questions that arise in the face of our vulnerabilities to both natural hazards and changes to the earth.

Is your area prone to earthquakes?  

Even though East Coast earthquakes may seem rare to the current generation, they are not a new or an unknown occurrence.

Church steeples still lean in Charleston, South Carolina, after an intense earthquake shook the city in 1886. And seismic studies have shown that earthquakes in eastern States are felt over much broader areas and can cause damage many miles from their epicenter.

You can learn about the earthquake hazards in your area by accessing seismic hazard maps and data from the USGS Earthquake Hazards Program.

How can we anticipate and prepare for likely flooding?

USGS scientists monitor real-time streamflow and water quality for thousands of streams across the Nation. With the USGS WaterAlert service, you can receive data electronically from streamgage stations when certain thresholds are exceeded.

The information collected by these gages not only allows individuals and communities to have real-time warnings of flooding, but by providing a long-term record, this information also helps communities to plan for likely future flooding.

As the climate and the landscape changes, the historical record is not always a good indicator of what will happen in the future.

To help prepare for potential flooding, USGS scientists can combine an understanding of how water behaves on the landscape with detailed topographic maps of specific areas to provide cities with flood inundation maps that show which areas would likely flood given specific water levels.

What is causing the ocean and soils to become more acidic?

Increased acidity of the ocean and soils has been linked to damaged ocean food webs and to poor crop sustainability. A recent study on acidification found that it is human activities, such as the mining and burning of coal, the mining and smelting of metal ores, and the use of nitrogen fertilizer, that are making our air, water, and soils more acidic.

To help policymakers address the problem, researchers also created world maps that are helping to alert policymakers about possible future trends and areas to watch for developing hotspots.

How is climate change affecting people in the Arctic?

To help understand socioeconomic issues of climate change, the USGS interviewed those with traditional and personal environmental knowledge: Yup’ik hunters and elders in two Alaskan villages.

The villagers described the changes they have seen and expressed concerns ranging from safety, such as unpredictable weather patterns and dangerous ice conditions, to changes in plants and animals as well as decreased availability of firewood.

Are our coastal homes at risk to future storms?

The El Niño conditions of the winter of 2009 – 2010 eroded beaches at some sites in California and the Pacific Northwest. But how bad was the damage and what can residents expect in the future?

USGS erosion studies on the West Coast  revealed that the conditions produced by El Niño, with above average wave energy and ocean water levels, contributed to unprecedented beach erosion in some areas. As the climate changes, El Niño conditions are likely to be more frequent, and these assessments are helping coastal experts to better predict how future climatic patterns will affect the Pacific Coast. With this information, land managers and decision makers can mitigate for possible damage to western coastlines

Our Ever-Changing Earth

Earth is ever changing, but through earth and natural science studies, the USGS is helping the Nation to understand our vulnerabilities, to anticipate the impacts, and to mitigate the risks.

Learn more about Earth Science Week events in your area.

Interactive Flood Tool

The USGS and the National Weather Service have developed a new flood inundation map tool that enables management officials and residents to see where the potential threat of flooding is the highest along the Flint River near Albany, Georgia.

For more information http://www.usgs.gov/newsroom/article.asp?ID=2620

Flooded road at Minnesota River near Jordan, MN.

The “Flood and high flow” map shows the location of streamgages where the water level is currently above or near flood stage. Find out what rivers and creeks near you are doing.

For more information