Observed Changes in the Frequency, Intensity, and Spatial Patterns of Nine Natural Hazards in the United States from 2000 to 2019.

There is increasing evidence from across the globe that climate change results in changes in the frequency, location, and impact of natural hazards. Much of this evidence is conceptual, inferential, or simply assumed. To provide objective support to confirm these hypotheses, we constructed county-level time-series datasets (2000-2019) for nine natural hazards for the entire United States. Hazards considered for this study included hurricanes, tropical storms, landslides, wildfires, earthquakes, drought, inland flooding, coastal flooding, and tornadoes. Geospatial analysis techniques were used to calculate the percentage (range: 0-100) of land area in each county exposed to each natural hazard for all the years that hazard data were available. The best available data were acquired from publicly accessible sources. Cumulative distribution functions were calculated for each hazard in five-year intervals to test for statistically significant changes in distribution patterns across the five-year time periods using the Kolmogorov-Smirnov test. There were significant changes in hurricanes, tropical storms, and drought over the two decades; changes in tornadoes, landslides, and wildfires were not significant in terms of frequency, likely due to the site-specific nature of their occurrences. The intensity and spatial distribution and an emerging hot spot and spatial trend analyses and an emerging hot spot and spatial trend analyses were also completed (except for flooding events and earthquakes due to insufficient data). All datasets provide empirical support for earlier inferences concerning the connections between the hazards and climate change. Analyses showed apparent changes in the frequency and intensity of hurricanes, tropical storms, and drought-related to climate change factors. Internal and coastal flooding also demonstrated these connections, although the length of the dataset did not permit significant testing but shows significant hot spots and trending locations. Tornadoes, landslides, and wildfires showed significant hot spots and trending locations, but the specific locational nature of the data did not show significant changes in frequency. Earthquakes showed no significant changes over the time period.

The role of social and intergenerational equity in making changes in human well-being sustainable.

A sustainable world is one in which human needs are met equitably and without sacrificing the ability of future generations to meet their needs. Human well-being is described by four primary elements-basic human needs, economic needs, environmental needs, and subjective well-being. These elements can interact in a myriad of ways to influence overall well-being. What makes changes in human well-being sustainable for a population or a nation? Two major interactional concepts can push changes in human well-being toward a sustainable state in space and time-social equity and intergenerational equity. The concept of social equity distributes well-being over space, ensuring the fair treatment of all members of society promoting spatial sustainability of a well-being decision. The concept of intergenerational equity distributes well-being through time, ensuring the well-being of present and future generations of a population or nation, promoting temporal sustainability of a well-being decision. The roles of social and intergenerational equity in terms of their influence on human well-being are examined with a focus on more sustainable decision-making.

A review of the elements of human well-being with an emphasis on the contribution of ecosystem services.

Natural ecosystems perform fundamental life-support services upon which human civilization depends. However, many people believe that nature provides these services for free and therefore, they are of little or no value. While we do not pay for them, we pay significantly for their loss in terms of wastewater treatment facilities, moratoriums on greenhouse gases, increased illnesses, reduced soil fertility and losses in those images of nature that contribute to our basic happiness. Little is understood about the well-being benefits of the natural environment and its ecosystem services. The interwoven relationship of ecosystems and human well-being is insufficiently acknowledged in the wider philosophical, social, and economic well-being literature. In this article, we discuss an approach to examine human well-being and the interactions of its four primary elements-basic human needs, economic needs, environmental needs, and subjective well-being-and ecosystem services.

The ecological condition of south Florida estuaries.

An assessment of the ecological condition of south Florida estuaries based on regional probabilistic monitoring was conducted during the summer of 1995. Samples and data were collected on water and sediment quality, benthos, and fish tissue contaminants. Elevated concentrations of metals and pesticides were measured in both sediments and fish tissue with some exceedances of guidance values. Bottom dissolved oxygen levels over 23-37% of the area were below state criteria. Eighty-eight percent of surface waters had greater than 10% penetration of ambient light to a depth of 1.0 m. Nine percent of the area studied in South Florida exhibited degraded biology and impaired use based on a calculated index of ecological condition. Using the probability-based monitoring design, useful information of this type can be provided to resource managers regarding estuarine condition on a regional scale.

Ecological condition of the estuaries of the Atlantic and Gulf Coasts of the United States.

Monitoring the estuaries of the Atlantic and Gulf of Mexico coastlines of the United States from Cape Cod, Massachusetts, to Brownsville, Texas, was performed annually from 1990 through 1997 to assess ecological conditions on a regional basis for four biogeographic provinces. These province estimates--Virginian, Carolinian, West Indian, and Louisianian Provinces--are combined to provide an assessment of 87% of the estuarine area of the United States and 96% of the area of the Atlantic and Gulf coasts. Combining information over the six years of monitoring showed 34 +/- 4% of the Atlantic and Gulf estuarine sediments displayed poorer than expected biological conditions, based on benthic and finfish community conditions, and 21 +/- 4% of the area was characterized by low water clarity, the presence of marine debris/noxious odors, or elevated fish tissue contaminants.

Distribution of total mercury and methyl mercury in water, sediment, and fish from south Florida estuaries.

Concentrations of total mercury and methyl mercury were determined in sediment and fish collected from estuarine waters of Florida to understand their distribution and partitioning. Total mercury concentrations in sediments ranged from 1 to 219 ng/g dry wt. Methyl mercury accounted for, on average, 0.77% of total mercury in sediment. Methyl mercury concentrations were not correlated with total mercury or organic carbon content in sediments. The concentrations of total mercury in fish muscle were between 0.03 and 2.22 (mean: 0.31) micrograms/g, wet wt, with methyl mercury contributing 83% of total mercury. Methyl mercury concentrations in fish muscle were directly proportional to total mercury concentrations. The relationship of total and methyl mercury concentrations in fish to those of sediments from corresponding locations was fish-species dependent, in addition to several abiotic factors. Among fish species analyzed, hardhead catfish, gafftopsail catfish, and sand seatrout contained the highest concentrations of mercury. Filtered water samples from canals and creeks that discharge into the Florida Bay showed mercury concentrations of 3-7.4 ng/L, with methyl mercury accounting for < 0.03-52% of the total mercury. Consumption of fish containing 0.31 microgram mercury/g wet wt, the mean concentration found in this study, at rates greater than 70 g/day, was estimated to be hazardous to human health.

An assessment of water quality and primary productivity in Perdido Bay, a Northern Gulf of Mexico Estuary.

Perdido Bay is a shallow estuarine system of approximately 130 km(2) with three major freshwater inputs. On a seasonal basis the productivity and chlorophyll a concentration of phytoplankton in Perdido Bay are controlled by temperature. One input, Eleven Mile Creek, is influenced by a paper mill discharge. Eleven Mile Creek exhibits high levels of light attenuation, high concentrations of dissolved nutrients, and low rates of carbon fixation that are significantly different from the other inputs or areas of Perdido Bay and productivity in Eleven Mile Creek is light limited. Upper Perdido Bay had slightly elevated concentrations of dissolved nutrients which correlate with significantly higher rates of carbon fixation and phytoplankton biomass. Nutrients and color from Eleven Mile Creck are diluted by the Perdido River inflow, restricting nutrient and light limitations to the area at the mouth of Eleven Mile Creek.

Evaluation of sampling strategies to characterize dissolved oxygen conditions in northern Gulf of Mexico estuaries.

Dissolved oxygen was continuously monitored in eight sites of northern Gulf of Mexico estuaries in August, 1990. Monte Carlo analyses on subsamples of the data were used to evaluate several commonly used monitoring strategies. Monitoring strategies which involve single point sampling of dissolved oxygen may often misclassify an estuary as having good water quality. In the case of shallow, often well-mixed estuaries that experience diurnal cycles, such monitoring often does not occur at night, during the time of lowest dissolved oxygen concentration. Our objective was to determine the minimum sampling effort required to correctly classify a site in terms of the observed frequency of hypoxia. Tests concluded that the most successful classification strategy used the minimum dissolved oxygen concentration from a continuously sampled 24-hour period.

Evaluation of transport and storage of 60Co, 134Cs, 137Cs and 65Zn by river sediments in the lower Susquehanna River.

The Peach Bottom Atomic Power Station (PBAPS) has contributed measurable quantities of radioactivity to Conowingo Reservoir, an impoundment of the lower Susquehanna River. As part of an ongoing radiological assessment program, concentrations of plant-related radionuclides in sediments have been monitored in spring and fall since 1980. Mass balance estimates derived from grab samples of surface sediments (< 10 cm) indicate that less than 20% of reactor released (60)Co, (65)Zn, (134)Cs and (137)Cs is present in these sediments. Significant seasonal variations in radionuclide trapping efficiency by the reservoir are not apparent. Deep core samples (c. 200 cm) confirm that some, but not all, of this surface sediment radionuclide inventory remains within the reservoir-trapped in discrete locations by subsequent sediment accumulation. The remaining radionuclide mass, in dissolved or particle-associated form, appears to be transported downstream, through Conowingo Dam, to upper Chesapeake Bay. The detection of PBAPS-derived radionuclides in the sediments of upper Chesapeake Bay, primarily the Susquehanna Flats, confirms the transport of these radionuclides from the lower Susquehanna River.

Radiosilver (Ag-110m) concentrations in Chesapeake Bay oysters maintained near a nuclear power plant: A statistical analysis.

An ongoing biomonitoring program using oysters (Crassostrea virginica) was implemented in 1978 to monitor radionuclide releases from the Calvert Cliffs Nuclear Power Plant located on Chesapeake Bay. The program involves quarterly removal and replenishment of oysters located in a tray about 0.2 km from the effluent discharge. Radiosilver (Ag-110m) concentrations in tray oysters (pCi/kg ww) were analyzed using ANCOVA-like models with plant releases of Ag-110m in the present and immediately preceding quarters and season of exposure as explanatory variables. Hypothesis testing based on the estimated models and comparison among model predictions under hypothetical release scenarios showed that season of exposure was important in influencing Ag-110m concentrations, with exposure during the Fall and Summer seasons resulting in significantly higher Ag-110m concentrations in tray oysters than exposure during the Winter and Spring seasons. From a management perspective of minimizing Ag-110m concentrations in oysters located near the plant, Winter and Spring are the preferred seasons for plant releases.