Water table depth tied to droughts

Water table depth tied to droughts

Will there be another "dust bowl" in the Great Plains similar to the one that swept the region in the 1930s?

It depends on water storage underground. Groundwater depth has a significant effect on whether the Great Plains will have a drought or bountiful year.

Recent modeling results show that the depth of the water table, which results from lateral water flow at the surface and subsurface, determines the relative susceptibility of regions to changes in temperature and precipitation.

"Groundwater is critical to understand the processes of recharge and drought in a changing climate," said Reed Maxwell, an atmospheric scientist at Lawrence Livermore National Laboratory, who along with a colleague at Bonn University analyzed the models that appear in the Sept. 28 edition of the journal Nature Geoscience.

Maxwell and Stefan Kollet studied the response of a watershed in the southern Great Plains in Oklahoma using a groundwater/surface-water/land-surface model.

The southern Great Plains are an important agricultural region that has experienced severe droughts during the past century including the "dust bowl" of the 1930s. This area is characterized by little winter snowpack, rolling terrain and seasonal precipitation.

While the onset of droughts in the region may depend on sea surface temperature, the length and depth of major droughts appear to depend on soil moisture conditions and land-atmosphere interactions.

That's what the recent study takes into account. Maxwell and Kollet created three future climate simulations based on the observed meteorological conditions from 1999. All included an increase in air temperature of 2.5 degrees Celsius. One had no change in precipitation; one had an increase in precipitation by 20 percent; and one had a decrease in precipitation by 20 percent.

"These disturbances were meant to represent the variability and uncertainty in regional changes to central North America under global model simulations of future climate," Maxwell said.

The models showed that groundwater storage acts as a moderator of watershed response and climate feedbacks. In areas with a shallow water table, changes in land conditions, such as how wet or dry the soil is and how much water is available for plant function, are related to an increase in atmospheric temperatures. In areas with deep water tables, changes at the land surface are directly related to amount of precipitation and plant type.

But in the critical zone, identified here between two and five meter's depth, there is a very strong correlation between the water table depth and the land surface.

"These findings also have strong implications for drought and show a strong dependence on areas of convergent flow and water table depth," Maxwell said. "The role of lateral subsurface flow should not be ignored in climate-change simulations and drought analysis."

Note: This story has been adapted from a news release issued by the DOE/Lawrence Livermore National Laboratory

WEATHER NOTE

In Natural Disasters, America is lacking a culture of preparedness

By Retired Lt. General Russel Honoré, NNPA Guest Commentary
September 22, 2008

America needs a culture of preparedness. We are seeing that more state governments are struggling in response to recent disasters. Recent Red Cross data shows that for every dollar spent on preparedness, it saves six to nine dollars during disaster response and recovery. As many have seen, disasters cause drama, drama for state governments especially when plans don't execute or the storm trumps the states capability to deal with the disaster response.

"Blame the Federal government and FEMA", that is the get-out-of-jail-free card that the state governments have. We can do better, this America and one solution is to transform state government.

First and foremost, we have to optimize technology. We need to issue disaster assistance cards which can easily be activated and provide financial assistance to those who need it. Secondly, all state employees should be trained to register folks for relief following a disaster, which currently few states are trained to execute when needed. Officials also need to be mindful to pre-position food water and tarps in communities, as well as use local businesses to serve as a large part of the area's disaster response. Each area affected should have assistance locations and they should be well marked. They shouldn't block major roads and supplies should be given to anyone who shows up, no matter what county they are from.

Cities should utilize resources and use local businesses as an integral part of the disaster response. Businesses should be aware of response logistics and local governments should have pre-arranged contracts with local businesses to provide emergency goods and services. One idea would be to have local businesses provide hot meals at fixed prices - approximately 8 dollars each.

Officials should also think of the residents in disaster areas as resources as well. School systems in each state should integrate disaster preparedness and first aid into its curriculum and every college graduate should be first aid certified. We need to involve the members of our communities, where we can create a civilian response corps in each community. I like to call them "men of consequence" - those who volunteer their time and talent to create resilient communities. These volunteers would be prepared and trained to clear debris from roads and help shore up levees. They would be taught how to operate distribution points and help evacuate communities.

A very important point that I must make is that local officials must assure that residents in our communities have power. It is imperative that various laws are passed that will require gas stations and drug/grocery stores to have generators. When cities lose electrical power, our quality of life regresses back 80 years - people have no television, no running water or working sewer, no internet or cell phones. Facilities such as hospitals, courthouses and emergency response stations should have mandatory generators on the 2nd floor to protect the power source. As we saw during Hurricane Katrina, many City of New Orleans public buildings did have generators - but unfortunately they were in the basement or at ground level, which did not serve them in the disaster.

Lastly, officials need to improve evacuation contra flow. We need full use of interstate highways. The federal government owns the flow on the interstate but during hurricane Gustav, unfortunately, we saw city, state and county officials blocking traffic on interstate highways. This policy needs to be reviewed and the act of surrounding states rerouting traffic to protect the flow of tourist traffic to local resorts is unacceptable. Going 40 miles in 12 hours is another disaster in the making.

We need to create a culture of preparedness in America. Our forefathers knew how to take care of themselves, their families, and the communities in which they lived. As citizens, we need to be prepared to do that same - we cannot wait on the federal government to do it for us. For more information, go to www. CNN.com.

Retired Lieutenant General Russel Honoré serves as Emergency Preparedness contributor to CNN Worldwide. He focuses exclusively on disaster preparedness, response, and recovery activities, with multi-sector integration of emergency management. Then Lt. Gen. Honoré was also a recipient of the NNPA 2006 Newsmaker of the Year Award for his leadership and sensitivity during the Hurricane Katrina disaster in New Orleans. Before retiring, he commanded Joint Task Force-Katrina. In that capacity, he led the Department of Defense response to Hurricanes Katrina and Rita in Alabama, Mississippi, and Louisiana, and directed the operations of more than 22,000 Service members, 200 aircraft, and 20 ships.

MARITIME NOTE

EU assembly urges tougher maritime safety rules

The Associated Press

Wednesday, September 24, 2008

BRUSSELS, Belgium: The European Parliament has urged EU governments to back tougher rules on maritime safety.

The European Union's assembly voted Wednesday to support two proposals which are opposed by most of the 27 EU member nations.

One would give the EU a greater say in forcing governments to ensure that ships flying their flags meet international safety standards. The other proposal would set common EU standards for insurance and liability for ship operators.

Governments say such issues should be left to national authorities, not the EU.

Talks to find a compromise are expected to start Oct. 7

RS