Timing of hurricane emergency actions

Emergency actions to prepare for hurricanes often require more time than is available from official public warnings. This means that the preparedness official must decide not onlywhat to do butwhen to do it. The action decision system, described here, developed for use in the State of Florida, reformats the hurricane track forecast, a 72-h projection, prepared at the National Hurricane Center in Miami, to specify the probability of a strike at each of 12 vulnerable coastal communities, and then normalizes the value in terms of a composite of probabilities computed for historic hurricanes that struck the respective communities. The normalization, a ratio of the two probability values, current and historic, expressed as a percentage is defined as the level of risk. When this level reaches or exceeds 100% the risk level is defined as critical and the system recommends that emergency actions to prepare begin immediately.The system is founded upon individual hurricane climatologies and decision procedures that are tailored for use at each community. The action recommendations generated by the risk analyses with a 93% level of confidence relieve the preparedness official of the need to make meteorological decisions in timing evacuations and other critical measures, even when these must begin before official hurricane warnings are received.The work that provided the basis for this publication was supported by funding under a Cooperative Agreement with the Federal Emergency Management Agency. The substance and findings of the work are dedicated to the public. The authors are solely responsible for the accuracy of the statements and interpretations contained in the publication. Such interpretations do not necessarily reflect the views of the government.     

WATERSHED PLANNING FOR ACID MINE DRAINAGE ABATEMENT1

Acid drainage from abandoned mines is a widespread problem in old mining regions. Agencies seeking to abate it face the prospect of dealing with hundreds of potential abatement projects, stretching decades into the future. A systematic regional analysis is necessary to establish locations, objectives, priorities, and phasing of such projects. The U.S. Bureau of Mines developed a novel procedure for abatement planning in the 420 square mile Blacklick Creek Watershed in Pennsylvania. The plan sought to direct abatement projects toward pollution sources where degradation was worst and adverse effects greatest. It established abatement priorities by comparing the “supply” of sources to be reclaimed (the degrees of old mines' water quality degradation) with the “demand” for abatement to be done (the natural and cultural values represented by the region's demography, land use and other non-mining characteristics). Matrices were used to define the relationships among mining and non-mining factors; maps were developed to show the geographic distribution of the conclusions. The locations, priorities, and phasing of abatement objectives shown on the maps should provide guidance for any abatement effort, no matter what type of technology is applied to achieve the objectives. Over the many years in which abatement projects are to be performed in the Watershed, the plan can be used to define, coordinate, and establish priorities for the projects in a manner that can result in maximum abatement benefits from the application of limited funds.     

WATER CONSERVATION METHODS IN URBAN LANDSCAPE IRRIGATION: AN EXPLORATORY OVERVIEW1

ABSTRACT: The increasing use of irrigation for urban landscapes is causing new demands for efficient watering systems. Conservation techniques for irrigated agricultural fields cannot be applied to urban landscapes without amendment. This paper attempts to review methods of urban landscape water conservation in the context of the diversity and complexity of urban landscapes and the demands upon them for quality of the urban environment. A development's initial site layout and planting design fundamentally determine how much irrigation water will be required; the complexity and creativity inherent in urban design open a number of specific possibilities for reducing water demand. Irrigation hardware is then designed to deliver the required volume of water to the specified landscape efficiently by implementing a number of physical and operational principles. Maintenance of the finished development involves monitoring results and making adjustments as the plantings grow and develop. The potential for conserving urban irrigation water is large. Effective conservation need not compromise other qualities of the urban environment such as aesthetics, screening, or shade. Urban design can address both the kinds of landscapes people need, and minimal consumption of irrigation water.     

SUSPENDED SEDIMENT AND TURBIDITY FOLLOWING ROAD CONSTRUCTION AND LOGGING IN WESTERN MONTANA1

ABSTRACT: Forest management activities in a second order drainage basin increased suspended sediment yields 7.7 fold in the first year following road construction, and two-fold following logging in the second year. Sediment supply limitations resulted in poor correlations between sediment concentrations with discharge. Sediment transport was strongly hysteretic, with the highest sediment concentrations occurring on the rising limbs of snowmelt hydrographs and individual peaks. In addition to discharge, hydrograph characteristics such as limb, dQ/dt, and the product of dQ/dt and limb aided in explaining variability of observed sediment concentrations. Sediment-turbidity relationships were strongly discharge dependent, reflecting the changing composition of the suspended load with stream power and sediment supplies.     

NEW HAMPSHIRE WATER SYSTEMS: ENVIRONMENTAL AND OWNERSHIP CONSIDERATIONS1

An econometric model was developed to measure the influence of several environmentally oriented variables and an ownership variable upon the average total residential water costs for New Hampshire water systems. The implementation of leak detection programs, localized institutional rules and regulations, and hazardous waste inspection programs were statistically significant in influencing residential water costs. The existence of a water conservation program did not statistically influence these per unit costs. Water systems that were privately owned resulted in per unit costs that were higher relative to firms that were publicly owned.     

Comparison of field-observed and model-predicted plume trends at fuel-contaminated sites: implications for natural attenuation rates

Subsequent to modeling of natural attenuation processes to predict contaminant trends and plume dynamics, monitoring data were used to evaluate the effectiveness of natural attenuation at reducing contaminant concentrations in groundwater at seven fuel-contaminated sites. Predicted and observed contaminant trends at seven sites were compared in order to empirically assess the accuracy of some fundamental model input parameters and assumptions. Most of the models developed for the study sites tended to overestimate plume migration distance, source persistence, and/or the time required for the benzene, toluene, ethyl benzene, and xylenes (BTEX) plumes to attenuate. Discrepancies between observed and predicted contaminant trends and plume behavior suggested that the influence of natural attenuation process may not have been accurately simulated. The conservatism of model simulations may be attributed to underestimation of natural source weathering rates, overestimation of the mass of contaminant present in the source area, and/or use of overly conservative first-order solute decay rates.     

HEAVY METALS AND SELENIUM IN GREBE EGGS FROM AGASSIZ NATIONAL WILDLIFE REFUGE IN NORTHERN MINNESOTA

Metal levels in eggs can often be used as an indicator of exposure and of potential effects. In previous work at Agassiz National Wildlife Refuge, northwestern Minnesota, the levels of several heavy metals were shown to be significantly higher in the eggs of eared grebes (Podiceps nigricollis) compared to those in the eggs of Franklin’s gulls (Larus pipixcan), black-crowned nightherons (Nycticorax nycticorax) and double-crested cormorants (Phalacrocorax auritus, except for mercury). In the present study we test the hypothesis that there are no differences in the levels of heavy metals in eggs of three species of grebes nesting at Agassiz National Wildlife Refuge (1997, 1999). There were significant differences in levels of selenium, manganese and mercury in the eggs of the grebes collected in 1997, with pied-billed grebe (Podilymbus podiceps) having significantly higher levels of manganese and mercury, and significantly lower levels of selenium, than eared or red-necked grebes (Podiceps grisegena). In 1999, pied-billed grebes had significantly higher levels of mercury, but lower levels of selenium and tin than the other species. The only pattern that was significant and consistent among yearswas selenium; in both years pied-billed grebes had lower levels than the other species. For eared grebes, there was a decline from 1997 to 1998, and again to 1999 for arsenic, cadmium, and selenium. Levels of mercury in the eggs of grebes were not as high, however, as those found in cormorants or night-herons sampled in 1994 at Agassiz National Wildlife Refuge. There were few consistent patterns in the relationships among metals in eared grebe eggs (with the largest sample sizes). The possible reasons for the high levels of some metals in eggs of grebes are unknown, but presumably egg levels represent exposure on the wintering grounds or migratory routes. In comparison to eggs of other birds: 1) the mean levels for manganese were at the high end of the range, and the mean was an order of magnitude higher than the median for the studies examined, 2) mean levels were above the median in the eggs of other birds for lead (red-necked grebe), mercury (pied-billed grebe) and selenium (eared and red-necked grebe).