RESTON, Va. — For the first time, U.S. Geological Survey scientists have mapped long-term average evapotranspiration rates across the continental United States – a crucial tool for water managers and planners because of the huge role evapotranspiration plays in water availability.
Why are evapotranspiration rates so important to know? It's because the amount of water available for people and ecosystems is the amount of annual precipitation – that is, snow or rain – minus the amount of annual evapotranspiration. Evapotranspiration itself is the amount of water lost to the atmosphere from the ground surface. Much of this loss is the result of the "transpiration" of water by plants, which is the plant equivalent of breathing. Just as people release water vapor when they breathe, plants do too.
"Since evapotranspiration consumes more than half of the precipitation that happens every year, knowing the evapotranspiration rates in different regions of the country is a solid leap forward in enabling water managers and policy makers to know how much water is available for use in their specific region," said Bill Werkheiser, associate director for water at the USGS. "Just as importantly," he added, "this knowledge will help them better plan for the water availability challenges that will occur as our climate changes since transpiration rates vary widely depending on factors such as temperature, humidity, precipitation, soil type, and wind."
In spite of its importance, evapotranspiration has been difficult to measure accurately on a regional or continental scale. To produce these maps, USGS scientists Ward Sanford and David Selnick examined Landsat satellite imagery for climate and land-cover data from 1971 to 2000 and streamflow data for more than 800 watersheds for the same time period. This information allowed them to generate a mathematical equation that can be used to more precisely estimate long-term evapotranspiration at any location in the continental United States.
"The map of the long-term average annual evapotranspiration rates for different areas should be immensely helpful for ensuring the long-term, sustainable use of water in different regions, especially since forecasted climate change will, in many places, change the amount of precipitation and evapotranspiration that occurs," Sanford said. "This tool, for example, allows water managers to quantify surface water runoff to reservoirs or water recharge to aquifers. It will also enable natural resource planners to understand the water needed for healthy-functioning ecosystems."
One interesting finding illustrated in the maps is that in certain regions of the United States, such as the High Plains and the Central Valley of California, evapotranspiration exceeds the amount of precipitation because water is imported from other regions. The map also shows that the Pacific Northwest has many areas with low evapotranspiration to precipitation rates because of the area’s very high rainfall and low-to-moderate temperatures. In contrast, counties in the arid Southwest have evapotranspiration rates that usually exceed 80 percent of precipitation.
The research was published this week in the Journal of the American Water Resources Association. To read the article and see the maps, click here.
DENTON, Texas - Residents and business owners in Haltom City, Texas can now enjoy a reduction in flood insurance premiums because of the city's active participation in the National Flood Insurance Program's (NFIP) Community Rating System (CRS). In addition to lower premiums, the CRS program helps to reduce the threat of damage due to flooding.Language English
DENTON, Texas – Residents, business and residential renters, and business owners in Deer Park, Texas can now enjoy a 5 to 10 percent reduction in flood insurance premiums because of the city’s active participation in the National Flood Insurance Program’s (NFIP) Community Rating System (CRS).
This means those policyholders who reside in Special Flood Hazard Areas (SFHA) will receive a 10 percent reduction on flood insurance premiums, and policyholders located outside the SFHA will enjoy a 5 percent discount.Language English
NEW YORK – Survivors with home accessibility needs because of Hurricane Sandy, especially older adults and people with disabilities, are encouraged to stay in touch with the Federal Emergency Management Agency. FEMA may be able to assist if elevators or electricity are not working properly, even if the structure did not sustain damage.Language English
TRENTON, N.J. -- Just two weeks remain for Hurricane Sandy survivors in New Jersey to register for potential recovery assistance with the Federal Emergency Management Agency. The deadline is Friday, March 1 at 10 p.m. local time by phone and at midnight for those who register online.Language English
NEW YORK – Disaster help begins with registering with the Federal Emergency Management Agency and the Feb. 27 deadline is coming up soon.
Less than two weeks remain for Hurricane Sandy survivors to register for help from FEMA. That’s the same deadline for returning the disaster loan application to the U.S. Small Business Administration.Language English
HARRISBURG, Pa. -- Philadelphia County has been added to the Public Assistance declaration for Hurricane Sandy recovery in Pennsylvania, according to officials from the Pennsylvania Emergency Management Agency (PEMA) and the Federal Emergency Management Agency (FEMA).
This announcement makes categories A-G of the federal Public Assistance program available to eligible local governments and certain private nonprofit organizations in Philadelphia County.Language English
TRENTON, N.J. -- Disaster recovery centers in New Jersey will close for Presidents Day Monday, Feb. 18. Small Business Administration disaster loan outreach and business recovery centers also will be closed.
The centers will resume normal hours Tuesday, Feb. 19.Language English
Following is a summary of key federal disaster aid programs that can be made available as needed and warranted under President Obama’s major disaster declaration issued for Mississippi.
Assistance for Affected Individuals and Families Can Include as Required:Language English
WASHINGTON -- The U.S. Department of Homeland Security's Federal Emergency Management Agency announced that federal disaster aid has been made available to the State of Mississippi and ordered federal aid to supplement state, tribal, and local recovery efforts in the area affected by severe storms, tornadoes, and flooding beginning on February 10, 2013, and continuing.
The President's action makes federal funding available to affected individuals in Forrest and Lamar counties.Language English
NEW YORK – More than 500 residents from New York City’s five boroughs and Long Island have been hired by FEMA in the aftermath of Hurricane Sandy.
Within the first weeks of the storm, FEMA deployed nearly 3,800 reservists from all over the country. These reservists came from every walk of life and professional background. For example, in External Affairs, a former TV broadcaster from Tennessee may work alongside a retired Navy public affairs officer from Missouri.Language English
TRENTON, N.J. -- The disaster recovery center at Boardwalk Hall in Atlantic City will close Thursday, Feb. 14, at 7 p.m.
State and federal officials have been paying close attention to how many applicants are visiting centers throughout the state. Over the past weeks, the number of individuals seeking help at the Atlantic City center has dropped, indicating the information needs of survivors in the area have mostly been met.Language English
TRENTON, N.J. -- Getting free advice on how to repair or rebuild your home to minimize future disaster damage is as easy as visiting your local home improvement store. Specialists from the Federal Emergency Management Agency will offer their expertise on building techniques that can help protect your home, business or other property.
This free service also offers information and publications on topics such as:Language English
NEW YORK – Hurricane Sandy survivors in New York have until 3 p.m. Saturday, Feb. 16, 2013, to visit four disaster recovery centers.
The State of New York and the Federal Emergency Management Agency closely monitor visitor traffic at all New York recovery centers. Traffic at the four centers has slowed, indicating the information needs of survivors in those areas have mostly been met. So far, there have been more than 13,000 visits to the four centers combined.Language English
NEW YORK – Following Hurricane Sandy, the Federal Emergency Management Agency has been working to reimburse local governments and some private nonprofits for some of the costs of emergency response, debris removal and for repairing or rebuilding damaged public facilities.
So far, nearly $608 million in Public Assistance (PA) grant funding from FEMA has been approved for projects in the 14 New York counties designated for PA disaster assistance.Language English