|
Wetland | Wire |
|
|
Wetland | Wire |
|
|
Battering at the hands of hurricanes has become routine for eastern North
Carolina, but this year's catastrophic flooding may likely permanently alter this regions
future Two weeks after pesky Hurricane Dennis walloped the coast, Hurricane Floyd swept through with 110-mph winds and dumped more than 20 inches of rain on parts of eastern North Carolina. Damage estimates have been set as high as $6 billion. Thousands of people are homeless. Hundreds of thousands of farm animals–hogs, turkeys, chickens and cows–perished in the floods, threatening the health of residents. Already the economic and human toil is enormous, but it will be years before the long-term ecological effects will be realized. The flood, labeled a 500-year storm, has left the region in shambles. |
|
Duke University Wetland Center Director Curtis J. Richardson recently sat down with Jim Rattray, the Nicholas School's Director of Communications, to discuss the implications of these floods.
Why was the flooding so severe?
The massive flooding was caused by the fact that we had back-to-back hurricanes and record rainfall. We had over 20 inches of rainfall in one month, about half the rainfall we would see in a year. That's a massive amount of water.
Was this just Mother Nature's wrath or did humans influence it?
The land use patterns in the coastal plain and the Piedmont could have influenced the magnitude of the impact. North Carolina ranks first in the country in land development in the last two decades. We have altered over 1 million acres of land, which is more than any state in the United States. We've converted forests and wetlands to other uses. We've developed extensive amounts of land so the runoff is much faster.
How has this development affected wetlands?
We have drained two-thirds of the freshwater wetlands at the coast. There are some canals and ditches primarily for agricultural and forestry and to some degree urban use. This means that the first hurricane, Dennis, filled up the storage capacity of the wetlands. Secondly, having the canals in place, we have exacerbated the rate with which water can leave the system. There is some storage in a wetland, but once you put those canals in, it is greatly reduced.
Is this new or old development?
When you look at cities like Tarboro, Goldsboro and Wilson, the floods did not affect most of the older portions of town. Some say it was a 500-year flood. Others say it's really the fact that most of these villages and cities have been built in the last 20 years and new developments have gone up right in the floodplain. At East Carolina University in Greenville, new apartments were built right along the Tar River or right along the edge of some creeks.
What about building restrictions?
There are restrictions not to build on a 100-year floodplain, but they have built pretty close to it. When you couple this with the magnitude of the rain–22-plus inches–and the redirected drainage, there's just no way these rivers could handle this kind of flooding.
There must be huge economic costs as well.
Yes, and the volume of building in this area has raised the economic cost. It will be billions of dollars. Many newer and higher-cost housing projects have been built in the lower part of the landscape and down into the floodplain. The human tragedy is enormous. and it's the farming industry as well, especially the hog farms, which have built dozens of farm holding areas in the floodplains for hogs and their waste.
What is this floodwater doing to the wetlands?
When these rivers get overtopped, you get flooding with massive amounts of high-nutrient-laden, high-nitrogen, high phosphorus, high-BOD (biological oxygen demand) water that is released out into these streams. You have tremendous problems related to bacterial increases, fecal coliform increases and oxygen depletion.
What kind of long-term impact does this have?
The implications are severe for the state. We suspect the oxygen levels in the estuaries will probably be greatly reduced near shore for several months as a result of the loss of all this hog waste material. and then you will see severe problems with fish nurseries. The fishing industries are very concerned about the potential impact. They were getting ready for a very large shrimp season and a very large fishing season. And that doesn't even count the fish kills we may face as a result of all this extra waste going into the system.
If there were less development, would the wetlands have been able to handle this rainfall?
When you get this magnitude of rainfall–40 percent of your annual rainfall in one month–the wetlands themselves would not have been able to eliminate this problem. But they would have been able to somewhat reduce the degree and magnitude of the flooding.
Are any of the Wetland Center's research projects addressing these issues?
We have a big project near Fayetteville where we're looking at the locations in terms of water quality and water flow to see what effect these restored wetlands have on the landscape. We also have a second project, which will soon be funded, looking at the long-term historical changes in water quality in the Cape Fear River system. We have a number of projects that are trying to address not only the changes but also what the impact of restored wetlands is on this problem.
Are there new research tools that can help in this process?
Most definitely. LANSAT photography and low-angle radar can be used to predict the water depths. We can map the percentage of the area that was covered–almost literally day-by-day–put that into a GIS framework and suggest under certain conditions where we can expect the flooding to recur. I think there are some very powerful tools that can be used to redline some areas that probably shouldn't be rebuilt on.
Are there any lessons to be learned here?
For sure it's not to build in the floodplain for either waste holding ponds or urbanization. We also need to look at wetland restoration. The state is very actively considering what they can do related to this flood. For example, the Clean Water Management Trust Fund has suspended all funding pending a review of coastal areas. They are considering what projects they might fund to eliminate the threat of this in the future.
A lot of people will rebuild. Should they?
Well, they certainly have a tendency to do that, especially if they can get federal or state assistance to do so. I think the state and federal governments need to very carefully reassess whether they would put money into rebuilding in those areas, especially those that are in the lower part of the floodplain. This is a problem that recurs.
This event certainly illustrates how communities are linked by watersheds.
We are absolutely closely tied by water quality and water routes. You can't just separate the coastal people from the Piedmont. The Jordan and Falls reservoirs were asked to hold water back because of the flooding downstream in the east. But the amount of water in the reservoirs from the rainfall was so large that it could only be held for an additional 48 hours. So when our neighbors "Down East" were experiencing their worst conditions, the Piedmont actually increased the problem by having to open those reservoirs and release massive amounts of water to those areas. If upstream communities hadn't done this, there would have been severe damage in Raleigh and Durham.
Some towns, like Princeville, population 1,700, were completely underwater.
It's not the first time. Princeville was completely flooded in 1913 and 1924 and totally wiped out. We're just repeating history over and over again. And every time we have more individuals in the same place causing greater and greater damage. We know the problem–and we know how to prevent it.
So what should be done now?
The state should carefully reassess where people can rebuild. They should look at the satellite photographs and do a study to quantify where the water and water depths were the greatest and look at the areas that were significantly affected. They need to try to determine whether these are realistic areas where developers should be allowed to rebuild. Stop the taxpayer from having to pay to rebuild these areas every time.
The times they are a-changin'
The song captures the spirit here at the Wetland Center, for many changes have taken place over the last few months. First, with the completion of a number of our projects, Sherri Cooper, Assistant Research Professor of Paleoecology at the Wetland Center, and Edwin Romanowicz, Assistant Research Professor of Wetland Hydrology, have both taken tenure track positions at other institutions starting this fall.
Cooper has been appointed Assistant Professor of Biology at Bryn Athyn College in Bryn Athyn, Pa. Romanowicz is now at the Center for Earth and Environmental Sciences at The State University of New York at Plattsburgh as an Assistant Professor. Both these individuals have made great contributions to our research program over the past few years and they will be sorely missed. We wish them well in their new endeavors.
At the same time, we are pleased to welcome our new visiting scholar, Yongxing Yang, Deputy Director of the Laboratory of Ecology and Environment of Wetlands at the Chinese Academy of Science's Changchun Institute of Geography. Yang is visiting the center this year to work on a number of peatland systems in the southeast. He comes to us with nearly 20 years experience and research on the wetland and mire systems of China. In fact, just prior to his arrival at Duke, he finished work on the Tibetan plateau wetlands. We are excited about this important exchange with our colleague and will keep you posted on future research projects with which he will become involved.
On another front, we have collected baseline information for the Duke Forest Wetland Restoration Project, a proposed 14-hectare wetland to be built directly on the edge of the Duke campus. This wetland restoration would provide unique teaching potential and research opportunities for both graduate and undergraduate students. We look forward in the months ahead to developing a rigorous scientific and educational program that can be used by the entire Duke community. The project is also an important endeavor for the university and the city of Durham, as the new wetland will provide stormwater retention and water quality improvements for the western portions of the city of Durham.
Finally, we can now resume fieldwork on our North Carolina wetland projects as flooding caused by Hurricanes Dennis, Floyd, and Irene subsides. Eastern North Carolina has received more than 30 inches of rainfall in the last month. Our research sites were inundated, but this pales in comparison to the human tragedies taking place in communities built on floodplains, wetland systems, and low-lying coastal areas during the past decades. Some 49 people are dead. Countless homes and businesses have been damaged or destroyed. Overflow from hog farm waste lagoons and the carcasses of drowned livestock and poultry foul the landscape, causing serious health problems. The environmental damage resulting from shortsighted development in ecologically sensitive areas will be felt for generations to come. Hopefully, future planning efforts will take into account lessons learned from this disaster.
- — Curtis J. Richardson,
- Director, Duke Wetland Center
Research News
Funds sought for on-campus wetlandNearly $600,000 in state funding has been sought to transform a portion of the Duke Forest into a wetland. The wetland would filter pollutants washed away from Durham streets and serve as an educational laboratory for students at NSOE and other Duke departments. "This would be a model laboratory on wetlands, which doesn't really exist anywhere in North Carolina," said Professor Curtis J. Richardson, Director of the Duke University Wetland Center. Research in the area, located near the Washington Duke Inn & Golf Club, would look at sediment retention and water quality. The North Carolina Wetlands Restoration Program, which has committed $94,000 to the project, is the lead agency for the project. A decision is expected soon from the Clean Water Management Trust Fund. |
Wetlands contribute to the maintenance of watershed-scale water quality, biodiversity and hydrologic regimes. How effective these contributions are depends in part on the wetland types, spatial arrangement and total wetland area within the watershed.
For this reason, the North Carolina Wetland Restoration Program (NCWRP) was mandated to develop basin-wide wetland restoration plans.
Funded by a three-year, $551,000 grant from the US Department of Agriculture, in partnership with the National Science Foundation and the US Environmental Protection Agency, the Duke University Wetland Center is currently working with the NCWRP to develop procedures identifying the best restoration sites for maximal watershed-level water quality improvement.
DUWC research focuses on the development of a Decision Support system to assist NCWRP with the process while taking into account ecological, economic and political constraints.
The study will result in several products of interest to watershed managers:
Wetland Center researchers are currently collecting site-specific data from a restored wetland within Harrison Bay in Cumberland county, N.C. All of Harrison Bay was originally a Carolina Bay wetland, portions of which were converted to agricultural use.
Approximately 600 acres of agricultural land on a holding called Barra Farms were restored to wetlands in 1998. the project began with monitoring water quality in the restored areas, in adjacent agricultural fields, and in areas of Harrison Bay that were never used for agriculture.
These data will provide information to assess the changes in water quality that are attributable to wetland restoration. In addition, these data will enable comparisons between water quality in the restored wetland and water quality in areas never impacted by agriculture.
Furthermore, to determine factors that predict nutrient retention in restored wetlands, nutrient cycling will be examined in the restored areas, agricultural areas, and unimpacted areas of Harrison Bay. This information will be used to identify potential wetland restoration sites and types that maximize water quality improvements.
- Neal Flanagan, Ph.D.
| Center students spend
summer on restoration projects
Right - Dan Berlin, second-year wetland hydrology MEM student, and Greg Bruland, DUWC Ph.D. student, insert ion exchange membranes (IEMs) into soils of the restored section of Barra Farms. IEMs are used to quantify spatial and temporal variations in soil nutrient availability. |
 |
Photo by Sarah Watts/NSOE student |
Barra Farms is on the coastal plain in Cumberland County, N.C. The site is the headwaters for Harrison Creek, which feeds into the Cape Fear River.
Prior to its conversion to farmland, the area was a Carolina Bay wetland. the property, consisting of the relic bay and surrounding areas, is approximately 2,400 acres in size. It includes disturbed bay, pocosin, riparian forest and agricultural land.
The soil is predominantly Croatan muck mixed with Leon sand and Johnston loam. Much of the site has been logged, cleared, leveled, ditched, and actively drained during silvicultural and agricultural activities begun in the early 1960s.
In its prime during the 1970s and early 1980s, Barra farms was one of the largest farming operations in North Carolina. Jesse Bullard, a long-time resident of the area and former property manager at the farm, remembered a bustling concern with more than 50 tractors operating day and night. The farm even had its own small runway for an airplane that applied fertilizers and pesticides to the crops.
Production dropped off in the early 1980s, and the property was sold. For the last ten years, Barra has been farmed much less intensively.
Between October 1997 and January 1998, some 600 acres at the southern end of the site underwent restoration from agricultural land back to wetland. The restoration process consisted of two components: filling 11,000 feet of linear canals to reestablish groundwater flow through the restored wetland, and planting 192,000 individual wetland plants, including cypress (Taxodium distichum) and water tupelo (Nyssa aquatica).
From February to June 1998, the entire restored section was inundated with surface water from record El Nino rainfall. Blooms of algae and large fish and amphibian populations developed within the bank.
On June 9, 1998, as surface water receded, over 1000 coastal birds were observed feeding in the drying pools. In contrast, the summer of 1999 was extremely dry. Only a few small pools of standing water remained in the restored section over the course of the summer.
Thus in its first two years, Barra Farm experienced an exceptionally wet year followed by an exceptionally dry year.
Since winter 1998, the Wetland Center has been monitoring ground water quality on a monthly basis and collecting and analyzing soil samples in order to characterize the various systems in the study site.
Barra provides an interesting framework for research because it contains natural wetland, restored wetland and cropped fields. This allows us to quantitatively assess both how successful the restoration process has been in altering the properties of the former agricultural land and how far the restored field must go to approximate the biogeochemical functioning of a natural wetland.
By comparing the outputs from the agricultural field and the restored wetland, we can gain an understanding of the benefits to local water quality derived from the restoration.
Over the next six months, we plan to begin to compile nutrient budgets for the system, install monitoring wells to assess the site hydrology and intensively sample the vegetation to characterize the communities. We hope to evaluate the direct benefit to water quality of converting agricultural land to restored wetland.
Students fine-tune skills in summer internship
 |
Left - Wetland Center intern Jim Cooper leans in for a closer inspection of a bottomland hardwood tree at the proposed constructed wetland site in the Duke Forest in Durham, N.C. |
| Photo by Sarah Watts/NSOE student |
The mosquitoes bit, just as the poison ivy itched, the yellow jackets stung and the sun beat down heavily on our shoulders in the moist Carolina air.
This daily routine was hardly a surprise because we knew what the summer held in store for us as Wetland Center interns: field work in various places throughout the state, and plenty of it.
We participated in several studies exploring many facets of wetland ecology, both on campus at a proposed constructed wetland site and off campus in Jacksonville and Fayetteville.
Our work involved three ongoing Wetland Center studies. The first–and most time consuming–was a preliminary vegetation survey of a proposed constructed wetland site in Duke Forest adjacent to the Washington Duke Inn & Golf Club.
In mid May, we established 11 transect lines perpendicular to the flow of Sandy Creek, which skirts both Duke's east and west campuses to the southeast. along each transect, sampling points were established at 10-meter intervals measured from the creek banks, extending into the surrounding upland areas.
The point-centered quarter method of tree surveying was applied at each point, providing data on species composition, density, dominance and frequency. Herbaceous sampling was also performed at each point, using the Braun-Blanquet method of areal plant cover assessment by species in the herbaceous stratum.
The proposed plan calls for a dam to be constructed across Sandy Creek, flooding some dozen acres of land adjacent to the stream channel. the resulting wetland will provide excellent research and educational opportunities, as well as water quality mitigation. Our survey provides a point of reference for future vegetative studies at the site after the wetland's completion.
Other projects took us east to North Carolina's Sandhills region. Monthly we visited Camp LeJeune in Jacksonville, which sits on the New river estuary. We assisted Neal Flanagan, a post-doc at the Wetland Center, and Ryan King, a Wetland Center Ph.D. student, in a functional assessment of highway construction and operation on wetland ecosystems.
For this project, funded by the North Carolina Department of Transportation, we collected water and periphyton samples. Additional tasks included cryocoring, which provides data on sediment accretion, and vegetation, aquatic invertebrate and fish surveys. All of these are being used to track the highway construction's effect on Edward's Creek, a tidal stream that intersects the construction site.
We also worked at Barra Farms, the site of an ongoing project funded by an EPA/NSF/USDA Partnership for Environmental Research grant. The project focuses on ecological and economic aspects of wetland restoration, and its goals are two-fold.
Curtis Richardson and Neal Flanagan are employing a watershed-level approach to determine the wetland locations, types and land uses for improved water quality benefits. Randall Kramer, an environmental economist at NSOE, is heading an effort that will assess landowner willingness to cooperate with state wetland restoration efforts on agricultural lands. Our work at the site consisted of collecting soil nutrient data and pore and surface water samples.
When we weren't in the field, we were in the lab, usually processing algal samples from the ongoing phosphorus dosing study in the Florida Everglades, funded by the Everglades Agricultural Area Environmental Protection District. This study aims to estimate a potential phosphorus threshold for various ecologically significant attributes of the Everglades.
Other lab tasks included preparing centrifuge tubes for collecting water samples, processing periphyton samples from the North Carolina Department of Transportation study and data entry and analysis.
Our internships exposed us to a wide array of wetland-related research and helped fine-tune our educational and professional interests. It was rewarding to take part in these studies and learn more about the environmental and political implications of each. Most helpful, though, was being able to talk regularly with the Wetland Center staff and Ph.D. students, who always provided unique advice and insights.
 |
Wetland intern prepares
for future During the summer of 1998, I was a National Network for Environmental Management Studies (NNEMS) Fellow at US EPA Region III in Philadelphia. New fellows spent their first week in Interagency Basic Wetlands Delineation Training, learning federal delineation regulations. Over the next few weeks I talked with representatives of various state agencies and with local stakeholders in the Nanticoke River Watershed, a Chesapeake Bay watershed. |
|
My goal was to design an independent project that I would work on throughout the summer and take back to Duke as my Master's project. |
| My work resulted in an index of water quality improvement
potential in the Delaware portion of the Nanticoke watershed, using GIS to investigate the
effects of land use, soil types and stream ditching. I coordinated a meeting to
present the project idea to local stake holders, then spend the remainder of the summer
planning the project and collecting necessary data. A geologist from the Delaware Geological Survey provided technical guidance. Officials from The Nature Conservancy and the largest landholder inthe watershed took me on tours of wetland sites for a better understanding of the local resources. I also participated in a Chesapeake Bay Program Wetlands Workgroup meeting in Annapolis, Md., and a regulatory Steering Committee meeting in West Virginia. A highlight of the summer was the opportunity to conduct an aerial marine survey counting visible animals (such as dolphins and turtles) and noting any algal blooms or other disturbances in the water. We flew from the New Jersey shore to the border of North Carolina and back, only about 100 meters offshore and 500 meters up–I had a perfect view of every beach along the way. I also had clear views of the Great Dismal Swamp in Virginia. The most rewarding thing I took away from the summer was a better understanding of how the federal government works toward protecting the environment. I learned of many non-regulatory programs that work with local communities, not against them. The fellowship was an excellent entrance to my professional career. –Sheryl Sussman, MEM '99 |
Student News
 |
Ph.D. Student Ryan King presented a talk entitled "Invertebrate assemblage response to experimental phosphorus dosing in the Everglades" at the 47th Annual Meeting of the North American Benthological Society in Duluth Minn., in May 1999. In June he gave the presentation "Influence of experimental P additions on invertebrate assemblages in sloughs of the northern Everglades" at the 20th Annual Meeting of Wetland Scientists in Norfolk, Va. |
| Ph.D. student Matthew F. Hanchey gave the presentation "Predicting phosphorus availability in Everglades histosols" at the 6th Symposium on Biogeochemistry of Wetlands in Fort Lauderdale, Fla., in July. He also presented, with Curtis J. Richardson, a poster entitled "Predicting phosphorus availability in Everglades histosols" at the 20th Annual Meeting of the Society of Wetland Scientists in Norfolk, Va. |  |
 |
|
Faculty Notes
Philip A.M. Bachand, Curtis J. Richardson and Panchabi Vaithiyanathan represented the Duke University Wetland Center at the Sixth Symposium on Biogeochemistry of Wetlands. The symposium, organized by the University of Florida's Wetland Biogeochemical Laboratory, was held in Fort Lauderdale, Fla. from July 11 through 14. DUWC members presented or were involved in the following symposium offerings:
Philip A.M. Bachand gave the presentation "Using alum and ferric chloride dosing to enhance phosphorus removal capabilities of treatment wetlands" at the 1999 American Society of Agricultural Engineers Annual International Meeting in Toronto from July 19 to 21.
DUWC alumna Kirsten Hofmockel, Curtis J. Richardson, and Patrick N. Halpin presented a poster entitled "Effects of hydrologic management decisions on marsh structure" at the 20th annual meeting of the Society of Wetland Scientists in Norfolk, Va. in June.
Jacqueline K. Huvane gave the presentation "Modern diatom assemblages from surface sediment and sub-aquatic vegetation samples from Florida Bay, USA" at the XV North American Diatom Symposium at the Pingree Park campus of Colorado State University in September.
Curtis J. Richardson presented a paper entitled "Utilizing ecological functional assessment (EFA) to compare natural and disturbed wetlands" at the Workshop on Nutrient Cycling and Constructed Wetlands III held in Trebon, Czech Republic, in September.
Curtis J. Richardson, Panchabi Vaithiyanathan, and Edwin A. Romanowicz gave the presentation "Everglades restoration: Hydrologic, nutrient, and fire interactions" at Wetlands Function, Assessment and Management, the 20th Annual Meeting of the Society of Wetland Scientists in Norfolk, Va., in June.
 |
|
