The Gulf of Mexico Region is a region where coastal hazards are frequently occurring. To study the resilience of the counties along the Gulf of Mexico is of great importance to its sustainable planning and development. It also plays a huge role in coastal hazard mitigation. This study assesses the temporal changes of coastal community resilience of 132 counties along the Gulf of Mexico. The basic analytical framework to assess resilience consists of three dimensions (exposure, damage, and recovery) and two relationships (vulnerability and adaptability). Vulnerability refers to the relationship between exposure and damage, whereas the relationship between damage and recovery is termed adaptability in this study. Two important concepts were advanced in this study, which are assessing community resilience by the communitys behavior before and after disturbances, and validating the results through statistical techniques. Four socioeconomic resilient systems were derived according to their behaviors before and after natural coastal hazards: susceptible, recovering, resistant, and usurper. Seven different grouping tests using k-means cluster analysis were run on the 132 counties. 28 variables from the resilience and vulnerability literature and the human development literature were examined and explored to serve as input to discriminant analysis. Factor analysis was used to find the most important variables that affected the resilience capacity. The results show that when using population growth as a recovery indicator, the classification gains the best discriminant scores (84.8% accuracy for 2000s data, and 81.8% for the 1990s data) using the 28 variables. In general, community resilience did not change much from 1990 to 2000. A total of nine counties changed their resilience capacity during the decade. Of those, four were found to have an increase in resilience, while the remaining five had a decrease in resilience.

Coastal wetlands, long recognized to be among the most productive ecosystems on the planet, are being lost at a disturbingly high rate in coastal Louisiana due to both eustatic sea-level rise and land subsidence. A number of approaches have been proposed for reducing wetland loss and restoring deteriorated wetlands, among which the addition of sediment to increase marsh surface elevation is promising. However, little is known about how the added sediment affects the biogeochemistry of marsh sediment. The objective of this study was to determine the effects of sediment slurry addition on sulfur, iron, and manganese biogeochemistry in a subsiding Spartina patens dominated marsh in coastal Louisiana. The study site was located inside the Paul J. Rainey Wildlife Sanctuary in Vermillion Parish, Louisiana where low, medium, or high levels of sediment slurry were added to each study plot in July of 2008. Sediment and porewater samples were collected from the control (i.e. no sediment addition), low, medium, and high sediment treatment plots approximately on a seasonal basis from February 2009 to June 2011. Laboratory incubation of sediment using the radioisotope 35S technique showed that there was no significant difference (p=0.2201) among the treatments in the rate of sulfate reduction 3 years after sediment slurry addition. However, significant increases (p=0.0007) in average concentrations of sulfate in sediment and decreases (p<0.0001) in sulfide in porewater with sediment addition over the 3 years measurements indicate that there likely was a decrease in sulfate reduction rate with increasing sediment addition during the preceding 3 years. Concentrations of sediment and porewater iron and manganese significantly increased when sediment addition increased, which was primarily attributed to the high levels of these two elements in the added sediment. The increased iron and manganese concentrations could, in part, explain the lower level of sulfide observed in the sediment-treated plots over the 3 year study. Additionally, average pH and redox increased significantly with sediment addition (p<0.0001 and p=0.0084, respectively). More samplings are needed to better understand the long-term impacts of sediment slurry addition on the rate of sulfate reduction in marsh sediment.

Over the past century, the growth in petrochemical manufacturing within Louisianas Upper Industrial Corridor brought economic development, but also introduced toxic emissions and environmental exposure risks to residents of the area. For the citizens living in close proximity to multiple facilities there is the added risk of chemical exposure from environmentally hazardous accidents. This study seeks to gain insights into patterns of risk-reducing behaviors of residents in East Baton Rouge Parish so that better educational outreach programs can be developed. This research addresses the following questions: To what extent are residents of Baton Rouge taking steps to reduce environmental exposure risks? What factors may influence adoption of exposure-reducing behavior? For this study, adaptive behaviors are: the adoption of a household emergency plan, more frequent checking of daily air quality ratings, and changing plans for outdoor activities on bad air quality days. Interviews with 68 residents were conducted to learn about their environmental knowledge and risk perceptions, and the extent to which they have adopted these three risk-reducing behaviors. Factors that may influence such adaptive behaviors include income, education, and proximity to regulated facilities, length of residence in the community, risk knowledge levels, and membership in local environmental groups, among other factors. The research also explores differences between interviewees living in zip codes with Toxic Release Inventory reporting facilities and those living in zip codes that do not contain the facilities. The statistical analyses indicated that demographics, such as age or education levels, and membership in local environmental groups may not play a major role in implementing these adaptive behaviors. Rather, the analysis indicates that residents who have adopted household environmental emergency plans are more informed and have a higher degree of confidence in their own knowledge of hazards and options to reduce exposure risks. Also they tended to know about and adopt other exposure-reducing behaviors. Information gained through this analysis suggests that exposure-reducing behaviors tend to be linked, and that educational outreach programs may need to focus first on effective ways to simply inform residents of risk levels and exposure-reducing strategies in order to increase their awareness and confidence in their abilities to make themselves safer.

When hurricanes Katrina and Rita hit in 2005, widespread devastation was felt in over half of the parishes in the state. More than 200,000 homes were damaged and more than 1500 people lost their lives. During this transitionary period, communities were vulnerable and looked for rebuilding leadership. As part of a post-catastrophe resilience movement, the Louisiana Recovery Authority formulated a 50-year regional plan for recovering south Louisiana called Louisiana Speaks. This planning process opened up an opportunity to reach those communities that otherwise may not have considered planning or how it could help them prepare for future events. This places Louisiana in a unique position to study how these events may have affected planning and resilience objectives in parishes throughout the state. In this thesis the following questions are examined: 1.Has there been any change in the number of plans adopted following the active hurricane seasons of 2005 and 2008? 2.What factors are associated with levels of planning in Louisiana at the parish scale since 2005? 3.Has there been more attention to resilience in planning since 2005? These questions were examined by sending out a survey to all parish planning departments or parish administration. The responses, combined with demographic data such as parish density, population change, education level, and median income, showed that there are more comprehensive plans adopted per year now than there were prior to 2005. The research also showed that more rural parishes are adopting comprehensive planning as a way to preserve their rural character against future growth. Parishes are also moving towards resilience planning, as a way to combine land use planning with tools to protect their parish from future natural disasters. This research shows that framing comprehensive planning as resilience planning may have more impact in Louisiana than it would have prior to 2005.

The city of Pittsburgh, Pennsylvania has a rich history of industrial activity, particularly steel manufacturing. This, combined with other urban waste, leaves a legacy of environmental pollution across the landscape. This study compares trace metal concentration data from a Pittsburgh tree to local and national industrial production records and local climatic data. Trace metal concentrations (lead, copper, cadmium, zinc, and nickel) in the annual growth rings of a red oak tree (Quercus rubra) from Schenley Park in Pittsburgh were measured. This metal record was used to explore the consequences of pollution over the 126 year life of this tree (1881-2006). Trace metals and wet deposition sulfate concentrations are related (r2 range of 0.0631 and 0.3458) as are national steel production and regional wet deposition sulfate concentrations (r2 = 0.7670). However, these relationships break down in the 1990s as trace metal concentrations in the tree rings continue to increase and pollution inputs decrease. One potential explanation is the increasing dominance of vehicular traffic in urban systems. Nitrate emissions from vehicles could increase soil acidity and metal bioavailability, facilitating metal uptake by plants. This suggests that Pittsburgh pollution legacy issues should be a continued concern as increased trace metal availability will impact both urban ecosystems and human populations.

Laser-induced breakdown spectroscopy (LIBS) has been applied for the quantitative analysis of various samples, but it is controversial for chemically-complex soils. In order to study the effect of delay time, gate width, and repetition rate on the LIBS signal in soil, the emission line at 396.84 nanometer was selected. The results indicated that repetition rate, delay time, and gate width significantly affected the LIBS signal, delay time was more important than gate width in controlling the LIBS signal. The optimum instrumental parameters for soil analysis were obtained when repetition rate, delay time, and gate width equaled 10 hertz, 1 microsecond, and 10 microsecond, respectively. In order to compare the analytical ability of univariate and multivariate approaches in analyzing the LIBS spectral data and to quantitatively determine copper and zinc concentrations in soils, 12 samples with different copper and zinc concentrations were analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES) and LIBS, respectively. The univariate and the partial least square (PLS) regression were coupled with LIBS to build the calibration models and to predict copper and zinc concentrations. The background-subtracted signal intensity at 324.75 nanometer (copper) and 334.59 nanometer (zinc) were used for the univariate analysis, and the full spectral range 200-600 nanometer and the reduced spectral ranges 250-450 nanometer and 300-350 nanometer were used for the PLS analysis. Copper and zinc concentrations predicted by LIBS were compared with those measured by ICP-OES. The results demonstrated that (1) the PLS regression was powerful in analyzing the LIBS spectral data, and compared to the univariate regression, it improved the normalized root mean square error of calibration (NRMSEC) about 15% and the normalized root mean square error of prediction (NRMSEP) about 10% respectively; (2) The PLS regression using the reduced spectral range (300-350 nanometer) containing copper and zinc peaks produced the best results among all the spectral ranges, which indicated that use of the suitable spectral range in the PLS regression improved the LIBS analytical ability; (3) The implementation of multivariate approaches in analyzing the LIBS spectral data made the quantitative analytical ability of LIBS promising and comparable to that of ICP-OES.

The value of air quality improvement following the 1990 Clean Air Act Amendments is estimated at the county level in the lower 48 United States. This study applies a hedonic model to assess the economic benefits of air quality improvement using an instrumental variable approach that combines geographically weighted and spatial autoregression methods to account for spatial heterogeneity and spatial autocorrelation. Positive amenity values of improved air quality are found in five major clusters of areas across Eastern Kentucky and most of Georgia around Southern Appalachian area, the State of Illinois, on the border of Oklahoma and Kansas, on the border of Kansas and Nebraska, and Eastern Texas. The reason for the clusters of significant positive amenity values may be due to the combination of intense air pollution, consumers’ awareness of diminishing air quality, and higher marginal benefit of reductions of TSPs in communities with relatively low pollution levels. Surprisingly, negative amenity values of improved air quality are found in the three distinctive clusters of east Virginia, west and central Texas, and southeast Montana. This unexpected result may be explained by worsening air quality with intensive economic growth, greater appreciation in housing prices in those regions, and/or missing variables reflecting regionally specialized economic growth.

Groundwater-surface water interactions can substantially influence the quality of surficial water bodies and are thus important when investigating ecological health of and climate change impacts on an area. However, data collection can be hindered when the location is remote and/or legally protected. This paper presents a methodology to implement minimallyinvasive field techniques at a remote and protected location that allows preliminary identification of the relationship between groundwater and surface water. Great Smoky Mountains National Park was selected as the study area as it is subjected to some of the highest rates of acid deposition in the country. Ecological damage is evident in several areas, including Ramsay Prong, a typical fourth-order stream located on the Tennessee side of the park. Ramsay Prong is evaluated on the basis of discharge, water quality, geochemistry, and stable isotopes at six points along the channel. It should be noted that increasing drought conditions occurred in the basin over the course of this study, providing an opportunity to evaluate the situation of low baseflow. Results indicate that storage capacity in the headwaters is insufficient to supply typical baseflow volume during extended dry periods, whereas sufficient alluvium exists at the bottom of the catchment to capture and recharge the basin water supply. A shallow fracture network likely provides long flowpaths for water to travel toward the basin bottom. Furthermore, baseflow is supplied by interflow as well as shallow groundwater storage; the portion of baseflow comprised by interflow increases with increasing antecedent precipitation. Diffuse groundwater recharge occurs mainly in the headwaters where steep slopes dominate the topography, while focused recharge occurs in bedrock depressions within the reaches and at the end of the channel. These observations, coupled with geochemical and isotopic data, indicate that neutralization of acidic inputs is best accomplished in the lower elevations of the basin. It is recommended that future studies investigate the ecological impacts of reduced precipitation in terms of acid neutralization capabilities along Ramsay Prong.

We investigated, under long-term no-till in western Tennessee, the effects of rotating the low-input crops cotton and soybeans with the high-input crop corn, compared to continuous monocultures of cotton and soybeans, and of using the winter cover crops (WCCs) winter wheat and hairy vetch, compared to winter fallow, on key indicators of soil health concerning vegetative cover and labile SOM. The line-transect method was used to measure percent vegetative cover. Dry weight of surface crop residue and aboveground living plant biomass (WCCs and winter weeds) was obtained. The living plant biomass was analyzed for carbon (C) and nitrogen (N) by dry combustion to determine C/N ratios. The sand-sized POM-C fraction at 0 to 5 and 5 to 15 cm was physically fractionated and analyzed for C by dry combustion. The inclusion of corn in rotation with cotton significantly increased aboveground crop residue quantity, aboveground winter weed biomass quantity, total aboveground biomass quantity, percent vegetative cover, and POM-C at 0 to 5 cm. The inclusion of corn in rotation with soybeans significantly increased aboveground crop residue quantity and POM-C at 0 to 5 cm, but significantly decreased aboveground winter wheat biomass quantity, total aboveground biomass quantity under winter wheat, aboveground winter weed biomass C/N ratio, and POM-C at 5 to 15 cm. The use of WCCs did not significantly increase total aboveground biomass quantity under most cropping sequences, and significantly reduced aboveground crop residue quantity, aboveground winter weed biomass quantity, and percent vegetative cover. The WCCs generally did not affect POM-C at either depth, though they significantly increased POM-C at 5 to 15 cm under continuous soybeans. Compared to winter wheat, hairy vetch significantly increased aboveground winter weed biomass quantity and percent vegetative cover. Our results demonstrate that the inclusion of corn in rotation with cotton is highly effective, while inclusion of corn in rotation with soybeans and the use of WCCs are ineffective in improving soil quality by increasing vegetative cover and the labile pool of SOM under these conditions.

Agricultural runoff is a leading non-point source contributor to water quality impairment in the United States and is associated with eutrophication of surface waters. Phosphorus (P) is often the most limiting nutrient for eutrophication in freshwaters. The objectives of this study were to characterize the P forms in surface runoff from an agricultural field that has received long-term applications of liquid dairy manure and to determine the forms of soil P that occur within a sinkhole feature located within the application field. Three 21-m x 6 m bermed plots were established to collect storm water runoff from a portion of the study site which drains into the sinkhole. The runoff collected was analyzed for total P (TP), dissolved reactive phosphorus (DRP), total dissolved P (TDP), dissolved organic phosphorus (DOP), and particulate P (PP). Soils were sampled from various elevations within the sinkhole feature and were analyzed for TP, total organic P (TOP), Mehlich-3 extractable P, and the maximum P sorption capacity. The results showed a precipitous increase in TP of surface runoff after manure application, from 2.2 g ha-1 to 21.9 g ha-1. The majority of P leaving the field as runoff prior to manure application was associated with the PP fraction (63% of TP). Surface runoff from two rainfall events occurring after diary manure was applied consisted predominately of DRP (67% of TP). Dissolved reactive P in runoff ranged from 0.02 to 0.2 mg L-1 before manure application and 7.1 to 17.1 mg L-1 after application. It has been reported that DRP concentrations in the low ìg/L range can negatively stimulate aquatic vegetation growth in P-limited waters, which indicates the runoff leaving the study site has the potential to impair water quality. A statistically significant difference existed for soil TP concentrations at different elevations within the sinkhole feature, ranging from 3116 mg kg-1 in the base to 914 mg kg-1 in the higher elevations of the sinkhole. A slight increase in TOP concentrations from the base (407 mg kg-1) to the higher elevations of the sinkhole (513 mg kg-1) occurred. The measured maximum P sorption capacity of soils within the sinkhole feature showed that these soils can potentially sorb between 284-379 mg kg-1 of P indicating that the soils are not P saturated and are capable of fixing additional P from runoff.