Assessing Marsh response from sea-level rise applying local site conditions: Humboldt Bay Wetlands

The broad goal of our research was to use site-specific data to develop local and regionally applicable models that inform management of tidal wetlands within Humboldt Bay. Our overarching question was: how vulnerable are Humboldt Bay tidal marshes to different rates of SLR. This question was addressed with three broad objectives: (1) Assess past patterns in sedimentation to inform current SLR projections. This was accomplished by radioisotope dating of stratigraphic cores. (2) Measure baseline conditions in the tidal marshes. We characterized physical and biological properties at all study sites including topography, accretion rates, emergent vegetation, water level, salinity, and water temperature. These results are summarized in the main document, (3) Model tidal marsh elevation and habitat change under three SLR scenarios. We evaluated the degree of marsh habitat change under low, mid, and high SLR scenarios with the WARMER model (Swanson et al., 2014) for all study sites

Assessing coastal manager science needs and disseminating science results for planning

To facilitate communication and outreach of sea-level tidal marsh modeling results, we convened managers, biologists, Tribes, and other important decision makers and partners and hosted in-person workshops with stakeholders in six Pacific coast estuaries. Our objectives were: (1) disseminate site-specific baseline data and modeling results, reveal coast-wide trends, and identify data gaps; (2) identify how local climate science results may be incorporated into habitat conservation, planning, and adaptation strategies; and (3) develop an understanding of coastal climate change science needs to inform the California and North Pacific Landscape Conservation Cooperatives

Engineer Intelligence Study No. 191, Terrain Analysis, Alaska Slope Region, Alaska, 1959

The summary on Page 5 is paraphrased as follows. This digital document is a generalized description of the Arctic Slope region -- an area covering approximately 70,000 square miles. Access to the region and the feasibility of various access routes are discussed. Location and extent of natural fuel supplies are given. Factors controlling outdoor work feasibility are summarized graphically on Page 19. A terrain analysis of each of the three major physiographic provinces of the region. Those provinces are the Arctic Coastal Plain, Arctic Foothills, and Brooks Range provinces. Geographic factors which affected cross-country movement, construction, and water supply within those provinces are evaluated. This document contains detailed Landforms and Physiographic Provinces..., Bedrock Geography..., and Surficial Deposits... maps. The distribution list names a number of Corps of Engineers intelligence organizations and the engineering officers of army formations which might be interested in operations in Alaska. The digital document contains a bibliography. High-resolution scans of the large maps (150 to 350 MB) are attached (below) as related files

Tracking Multidecadal Lake Water Dynamics with Landsat Imagery and Topography/Bathymetry

An edited version of this paper was published by AGU. Copyright 2019 American Geophysical Union.Water resource management is of critical importance due to its close relationship with nearly every industry, field, and lifeform on this planet. The success of future water management will rely upon having detailed data of current and historic water dynamics. This research leverages Google Earth Engine and uses Landsat 5 imagery in conjunction with bathymetry and Shuttle Radar Topography Mission digital elevation model data to analyze long‐term lake dynamics (water surface elevation, surface area, volume, volume change, and frequency) for Lake McConaughy in Nebraska, USA. Water surface elevation was estimated by extracting elevation values from underlying bathymetry and digital elevations models using 5,994 different combinations of water indices, water boundaries, and statistics for 100 time periods spanning 1985–2009. Surface elevation calculations were as accurate as 0.768 m root mean square error (CI95% [0.657, 0.885]). Water volume change calculations found a maximum change of 1.568 km3 and a minimum total volume of only 23.97% of the maximum reservoir volume. Seasonal and long‐term trends were identified, which have major affects regarding regional agriculture, local recreation, and lake water quality. This research fills an existing gap in optical remote sensing‐based monitoring of lakes and reservoirs, is more robust and outperforms other commonly used monitoring techniques, increases the number of water bodies available for long‐term studies, introduces a scalable framework deployable within Google Earth Engine, and enables data collection of both gauged and ungauged water bodies, which will substantially increase our knowledge and understanding of these critical ecosystems

A comparison between London and Baghdad surface urban heat islands and possible engineering mitigation solutions

This study adopts remote sensing techniques to compare the Surface urban Heat Island (SUHI) in Bagh-dad and London as they represent different climatic conditions, natural environments and levels of urbandevelopment. It tests the reported correlation of land surface temperature (LST) with land cover in theliterature under different conditions and, based on the findings, suggests engineering mitigation strate-gies for each city. The land surface was characterized using supervised classification and spectral indices,using the Landsat 8 optical bands (2–7), and the LST was retrieved from Landsat’s thermal band 10 afteremissivity calibration. Two Landsat 8 satellite images were used, acquired in July 2013 when maximumsurface temperature would be expected in both these capital cities. Image processing included radio-metric calibration and atmospheric correction and various land surface indices were then calculated.The independent validation of land cover types was performed using higher spatial resolution opticaldata, and LST patterns were validated using ASTER thermal images. Land cover types or indices and landsurface temperature display high correlations, with most having a positive relationship with LST, but veg-etation has a negative relationship. The hottest surface type also differs for the two cities. Consequently,covering the soil in Baghdad with new construction, for example, reduces the surface temperature andhence urban heat island effect, while the same action in London increases it. Thus, engineering solutionsto urban heat island issues need to take local factors into accoun

West Nile Virus Epidemics in North America Are Driven by Shifts in Mosquito Feeding Behavior

West Nile virus (WNV) has caused repeated large-scale human epidemics in North America since it was first detected in 1999 and is now the dominant vector-borne disease in this continent. Understanding the factors that determine the intensity of the spillover of this zoonotic pathogen from birds to humans (via mosquitoes) is a prerequisite for predicting and preventing human epidemics. We integrated mosquito feeding behavior with data on the population dynamics and WNV epidemiology of mosquitoes, birds, and humans. We show that Culex pipiens, the dominant enzootic (bird-to-bird) and bridge (bird-to-human) vector of WNV in urbanized areas in the northeast and north-central United States, shifted its feeding preferences from birds to humans by 7-fold during late summer and early fall, coinciding with the dispersal of its preferred host (American robins, Turdus migratorius) and the rise in human WNV infections. We also show that feeding shifts in Cx. tarsalis amplify human WNV epidemics in Colorado and California and occur during periods of robin dispersal and migration. Our results provide a direct explanation for the timing and intensity of human WNV epidemics. Shifts in feeding from competent avian hosts early in an epidemic to incompetent humans after mosquito infection prevalences are high result in synergistic effects that greatly amplify the number of human infections of this and other pathogens. Our results underscore the dramatic effects of vector behavior in driving the transmission of zoonotic pathogens to humans

Stratified slopes, numerical and empirical stability analysis

Urbanisation means that many natural slopes in and around cities are often subjected to cuts resulting in dramatic changes in the geometry of slope faces mostly by increasing slope angle which could lead to failures with catastrophic consequences. As most natural slopes are of nonhomogeneous layered nature, understanding the stability behaviour of such slopes will be of utmost importance. The current practice in analysing slopes of complicated nature, geometrically and materially, is mostly to apply simplifications sacrificing accuracy leading to use of large factors of safety, which could undermine analytical and economic feasibility of projects. In this research limit-equilibrium and finite element methods are used, respectively by OASYS Slope and PLAXIS 2D, to empirically and numerically model and analyse geometrically non-homogeneous stratified slopes with the aim of understanding the effects of non-homogeneity of geometry and materials on stability under various inclination angles of slope face. The analysis included determination of factors of safety as well as a sensitivity analysis looking into the combined effects of contributing parameters

Inter-annual variability in isotope and elemental ratios recorded in otoliths of an anadromous fish

Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Geochemical Exploration 102 (2009): 181-186, doi:10.1016/j.gexplo.2008.10.001.Isotope ratios and elemental concentrations in otoliths are often used as natural tags to reconstruct migratory movements and connectivity patterns in marine and anadromous fishes. Although differences in otolith geochemistry have been documented among geographically separated populations, inter-annual variation within locations is less frequently examined. We compared otolith isotope (δ18O and 87Sr:86Sr) and elemental ratios (Sr:Ca and Ba:Ca) from several annual cohorts of juvenile American shad (Alosa sapidissima) in three rivers. These four geochemical signatures distinguished among river-specific populations of this species at both large and small geographic scales, with δ18O and 87Sr:86Sr generating the majority of multivariate variation. We found significant variation among years for all variables in two to three rivers. However, the magnitude of variability differed among ratios, with δ18O ratios showing substantial inter-annual shifts while 87Sr:86Sr ratios were relatively stable across years. Sr:Ca and Ba:Ca ratios also varied among years. These results imply that investigators using environmentally labile signatures must quantify geochemical signatures for each cohort of interest in order to confidently identify origins of migrants.Funding was provided by National Science Foundation grants to SRT (OCE-0215905 and OCE-0134998) and grants by the American Museum of Natural History Lerner-Gray Fund for Marine Research, SEASPACE, Inc., and the WHOI Ocean Life Institute to BDW