As runoff patterns shift with a changing climate, it is critical to effectively communicate current and future flood risks, yet existing flood hazard maps are insufficient. Modifying, extending, or ...updating flood inundation extents is difficult, especially over large scales, because traditional floodplain mapping approaches are data and resource intensive. Low-complexity floodplain mapping techniques are promising alternatives, but their simplistic representation of process falls short of capturing inundation patterns in all situations or settings. To address these needs and deficiencies, we formalize and extend the functionality of the Height Above Nearest Drainage (i.e., HAND) floodplain mapping approach into the probHAND model by incorporating an uncertainty analysis. With publicly available datasets, the probHAND model can produce probabilistic floodplain maps for large areas relatively rapidly. We describe the modeling approach and then provide an example application in the Lake Champlain Basin, Vermont, USA. Uncertainties translate to on-the-ground changes to inundated areas, or floodplain widths, in the study area by an average of 40%. We found that the spatial extent of probable inundation captured the distribution of observed and modeled flood extents well, suggesting that low-complexity models may be sufficient for representing inundation extents in support of flood risk and conservation mapping applications, especially when uncertainties in parameter inputs and process simplifications are accounted for. To improve the accuracy of flood hazard datasets, we recommend investing limited resources in accurate topographic datasets and improved flood frequency analyses. Such investments will have the greatest impact on decreasing model output variability, therefore increasing the certainty of flood inundation extents.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
On August 28, 2011, after pounding the Caribbean and the U.S. Eastern seaboard for more than a week, Hurricane Irene finally made landfall in New Jersey. As the storm headed into New England, it was ...quickly downgraded to a tropical storm. And by Sunday afternoon, national news outlets were giving postmortems on the damage. Except for some flooding in low-lying areas, New York City-Irene's biggest target-had escaped its worst-case scenario. Story over. But the story wasn't over. As Irene's eye drifted north, its bands of heavy rains twisted westward over Vermont's Green Mountains. The mountains forced these bands upward, wringing the rain out of them like water from a sponge. Streams and rivers were transformed into torrents of brown water and debris, gouging mountainsides, reshaping valleys, washing out roads, pulling apart bridges, and carrying away homes, livestock, and automobiles. For weeks, mountain towns were isolated, with no way in or out, and thousands of people were left homeless. In the immediate aftermath of the disaster, it fell on the shoulders of ordinary Vermonters to help victims and rebuild the state. Deluge is the complete story of the floods, the rescue, and the recovery, as seen through the eyes of the people who lived through them: Wilmington's Lisa Sullivan, whose bookstore was flooded, and town clerk Susie Haughwout, who saved the town records; Tracy Payne, who lost her home in Jamaica-everything in it, and the land on which it sat; Geo Honigford in South Royalton, who lost his crops, but put his own mess on hold to help others in the town; the men who put U.S. Route 4 back together at breakneck speed; and the entire village of Pittsfield, completely isolated after the storm, and its inspirational story of real community.
The Early Cretaceous New England-Quebec igneous province is a classic example of postrift magmatism along the eastern North American passive margin. Although a suite of 40Ar/39Ar ages has been ...available for the Monteregian Hills lobe in the Quebec portion of the New England-Quebec igneous province for many years, only a single high accuracy radiometric age has been published for the Burlington lobe and none for the Taconic lobe in the New England portion of the province. As a result, the timing of and driving mechanisms behind the magmatism have remained unresolved, and a hotspot origin for the entire province persists in the literature. We have dated four dikes and one pluton in the Burlington and Taconic lobes using 40Ar/39Ar and U–Pb geochronology to improve understanding of the age of magmatism in the New England portion of the province. In the Burlington lobe, 40Ar/39Ar plateau ages include a 137.55 ± 1.80 Ma biotite age and a 136.9 ± 4.2 Ma amphibole age for a lamprophyre dike from Charlotte, Vermont, and a 133.6 ± 2.2 Ma biotite age for a lamprophyre dike from Colchester, Vermont. In the Taconic lobe, ages include an 40Ar/39Ar plateau amphibole age of 107.09 ± 1.32 Ma for a lamprophyre dike from Castleton, Vermont, a 122 Ma minimum 40Ar/39Ar biotite age for a lamprophyre dike from Poultney, Vermont, and a 103.13 ± 0.53 Ma LA-ICP-MS U–Pb zircon age from the quartz syenite of the Cuttingsville complex. These results show that magmatism spanned at least 35 Ma, from ∼138 to 103 Ma, which is broadly consistent with the span of magmatism suggested by workers in the 1970s and 1980s based on K–Ar and Rb–Sr ages. This extended span of magmatism for the Burlington and Taconic lobes is in contrast to the brief 1 to 2 Ma episode of magmatism at ∼124 Ma inferred for the Monteregian Hills lobe. The New England-Quebec igneous province has traditionally been attributed to passage of the Great Meteor hotspot. However, given the close proximity of the Burlington and Taconic lobes, the magmatism in these lobes should span only a few Ma if the product of a hotspot. The age data are also difficult to reconcile with a more complex expression of hotspot magmatism in continental lithosphere related to either plume head magmatism or long-distance migration of plume material. Instead, the extended duration of Early Cretaceous New England-Quebec igneous province magmatism in New England may represent an expression of edge-driven convection, a process known to occur along passive margins and inferred to be operating beneath the eastern North American margin today.
Storm events dominate riverine loads of dissolved organic carbon (DOC) and nitrate and are expected to increase in frequency and intensity in many regions due to climate change. We deployed three ...high‐frequency (15 min) in situ absorbance spectrophotometers to monitor DOC and nitrate concentration for 126 storms in three watersheds with agricultural, urban, and forested land use/land cover. We examined intrastorm hysteresis and the influences of seasonality, storm size, and dominant land use/land cover on storm DOC and nitrate loads. DOC hysteresis was generally anticlockwise at all sites, indicating distal and plentiful sources for all three streams despite varied DOC character and sources. Nitrate hysteresis was generally clockwise for urban and forested sites, but anticlockwise for the agricultural site, indicating an exhaustible, proximal source of nitrate in the urban and forested sites, and more distal and plentiful sources of nitrate in the agricultural site. The agricultural site had significantly higher storm nitrate yield per water yield and higher storm DOC yield per water yield than the urban or forested sites. Seasonal effects were important for storm nitrate yield in all three watersheds and farm management practices likely caused complex interactions with seasonality at the agricultural site. Hysteresis indices did not improve predictions of storm nitrate yields at any site. We discuss key lessons from using high‐frequency in situ optical sensors.
Key Points
An improved hysteresis index revealed remarkable variation in storm dynamics for 126 storms in watersheds with varied land use/land cover
Seasonality influenced storm nitrate loading; interactions between farm practices and seasonal dynamics were captured by sensors
Sites had generally anticlockwise storm hysteresis for DOC, though storm nitrate hysteresis direction varied by land use/land cover
This paper describes an open-source geographical information system (GIS) called Whitebox Geospatial Analysis Tools (Whitebox GAT). Whitebox GAT was designed to provide a platform for the rapid ...development and testing of experimental geospatial analysis methods, supported by its extensible design, integrated facilities for custom plug-in tool authoring, and its novel open-access design philosophy. One of the unique characteristics of Whitebox GAT is the ease with which users can inspect and modify the algorithms for individual geoprocessing tools. The open-access software model that Whitebox GAT adopts is designed to lessen the barriers that are often imposed on end-users when attempting to gain deeper understanding of how a specific function operates. While Whitebox GAT has an extensive range of GIS and remote sensing analytical capabilities, making it broadly suited for advanced scientific research applications in the Earth Sciences, this paper focusses on the software's application in the field of geomorphometry. An airborne LiDAR data set for a small headwater catchment of the Missisquoi River in northern Vermont, USA, was filtered to identify ground-points and then interpolated into a 2.0m resolution bare-Earth DEM. The DEM was processed to remove spurious off-ground objects (mainly buildings), to reduce surface roughness under heavy forest cover, and to hydrologically pre-condition the DEM. These data were then used to extract salient hydrological structures, i.e. the stream network and their associated sub-basins.
•A new open-source geographical information system is introduced.•Whitebox is a platform for developing and testing geospatial analysis techniques.•The open-access project model facilitates experimenting with existing functionality.•The paper demonstrates Whitebox GAT's capabilities for geomorphometric processing.•The hydrological structure of a small catchment is modeled using LiDAR data.
Letter to the Editor: Response to Finkelstein Re Fordyce, Tiffani Ann; Leonhard, Megan J; Mowat, Fionna ...
Journal of occupational and environmental medicine,
04/2020, Letnik:
62, Številka:
4
Journal Article
InMeanings of Maple, Michael A. Lange provides a cultural analysis of maple syrup making, known in Vermont as sugaring, to illustrate how maple syrup as both process and product is an aspect of ...cultural identity.Readers will go deep into a Vermont sugar bush and its web of plastic tubes, mainline valves, and collection tanks. They will visit sugarhouses crammed with gas evaporators and reverse-osmosis machines. And they will witness encounters between sugar makers and the tourists eager to invest Vermont with mythological fantasies of rural simplicity.So much more than a commodity study,Meanings of Mapleframes a new approach for evaluating the broader implications of iconic foodways, and it will animate conversations in food studies for years to come.
Quantitative climate reconstructions are crucial for understanding the magnitude of and mechanisms behind natural and anthropogenic climate change, yet there are few proxies that can reliably ...reconstruct terrestrial temperature. Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are bacterial membrane lipids that are increasingly used to reconstruct paleotemperature from lake sediments, but despite their potential, we have a poor understanding of (1) autochthonous vs. allochthonous sources of brGDGTs in lakes and (2) the seasonality of and environmental controls on brGDGT production within lakes. To investigate these factors, we examined water column suspended particulate matter (SPM) and settling particles from a sediment trap collected on a biweekly to monthly basis over a period of threeyears at Lower King Pond, a small kettle lake in northern Vermont, USA. We also compared the concentration and fractional abundances of brGDGTs in SPM and settling particles with those of catchment soils, river sediments, and lake surface sediments to constrain the relative importance of brGDGTs derived from the landscape versus brGDGTs produced within the lake itself. We find significant differences in concentrations and fractional abundances of brGDGTs between soil and river sediment samples from the catchment and lake sediments, indicating a mostly autochthonous source for lacustrine brGDGTs. BrGDGT concentrations, fluxes, and fractional abundances in SPM vary over the annual cycle, indicating that brGDGTs are produced throughout the year and respond to changes within the water column. The total annual flux of brGDGTs settling through the water column is comparable to the brGDGT accumulation rates in surface sediments, indicating that in this lake brGDGTs are mostly produced within the water column, not in the sediment itself. While brGDGTs are produced in all seasons within the water column, the flux to the sediments is highest during periods of spring and fall isothermal mixing, potentially biasing paleotemperature reconstructions towards mixing season temperature. Because the seasonal timing and frequency of lake mixing varies as a function of regional climate, lacustrine brGDGT calibrations should be regional in nature and comprise lakes with similar mixing regimes.
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