5 Aug 2022

SAGE-PEDD Theory Manual: Modeling Windblown Snow Deposition around Buildings

Abstract: Numerical modeling of snowdrifting is a useful tool for assessing the im-pact of building design on operations and facility maintenance. Here we outline the theory for the SAGE-PEDD snowdrift model that has applica-tion for determining snowdrift accumulation around buildings. This model uses the SAGE computational fluid dynamics code to determine the flow field in the computational domain. A particle entrainment, dis-persion, and deposition (PEDD) model is coupled to SAGE to simulate the movement and deposition of the snow within the computational do-main. The report also outlines areas of future development that upgrades to the SAGE-PEDD model should address.

5 Aug 2022

SAGE-PEDD User Manual

Abstract: SAGE-PEDD is a computational model for estimating snowdrift shapes around buildings. The main inputs to the model are wind speed, wind direction, building geometry and initial ground or snow-surface topography. Though developed mainly for predicting snowdrift shapes, it has the flexibility to accept other soil types, though this manual addresses snow only. This manual provides detailed information for set up, running, and viewing the output of a SAGE-PEDD simulation.

5 Aug 2022

Simulating Environmental Conditions for Southwest United States Convective Dust Storms Using the Weather Research and Forecasting Model v4.1

Abstract: Dust aerosols can pose a significant detriment to public health, transportation, and tactical operations through reductions in air quality and visibility. Thus, accurate model forecasts of dust emission and transport are essential to decision makers. While a large number of studies have advanced the understanding and predictability of dust storms, the majority of existing literature considers dust production and forcing conditions of the underlying meteorology independently of each other. Our study works towards filling this research gap by inventorying dust-event case studies forced by convective activity in the Desert Southwest United States, simulating select representative case studies using several configurations of the Weather Research and Forecasting (WRF) model, testing the sensitivity of forecasts to essential model parameters, and assessing overall forecast skill using variables essential to dust production and transport. We found our control configuration captured the initiation, evolution, and storm structure of a variety of convective features admirably well. Peak wind speeds were well represented, but we found that simulated events arrived up to 2 hours earlier or later than observed. Our results show that convective storms are highly sensitive to initialization time and initial conditions that can preemptively dry the atmosphere and suppress the growth of convective storms.

4 Aug 2022

Engineering With Nature® Principles in Action: Islands

Abstract: The Engineering With Nature® (EWN) Program supports nature-based solutions that reduce coastal-storm and flood risks while providing environmental and socioeconomic benefits. Combining the beneficial use of dredged sediments with the restoration or creation of islands increases habitat and recreation, keeps sediment in the system, and reduces coastal-storm and flood impacts. Given the potential advantages of islands, EWN seeks to support science-based investigations of island performance, impacts, and benefits through collaborative multidisciplinary efforts. Using a series of case studies led by US Army Corps of Engineers (USACE) districts and others, this technical report highlights the role of islands in providing coastal resilience benefits in terms of reducing waves and erosion as well as other environmental and socioeconomic benefits to the communities and the ecosystems they reside in.

4 Aug 2022

Supporting Bank and Near-bank Stabilization and Habitat Using Dredged Sediment: Documenting Best Practices

Abstract: In-water beneficial use of dredged sediment provides the US Army Corps of Engineers (USACE) the opportunity to increase beneficial use while controlling costs. Beneficial use projects in riverine environments include bank and near-bank placement, where sediments can protect against bank erosion and support habitat diversity. While bank and near-bank placement of navigation dredged sediment to support river-bank stabilization and habitat is currently practiced, documented examples are sparse. Documenting successful projects can support advancing the practice across USACE. In addition, documentation identifies data gaps required to develop engineering and ecosystem restoration guidance using navigation-dredged sediment. This report documents five USACE and international case studies that successfully applied these practices: Ephemeral Island Creation on the Upper Mississippi River; Gravel Island Creation on the Danube River; Gravel Bar Creation on the Tombigbee River; Wetland Habitat Restoration on the Sacramento-San Joaquin River Delta; and Island and Wetland Creation on the Lower Columbia River Estuary. Increased bank and near-bank placement can have multiple benefits, including reduced dredge volumes that would otherwise increase as banks erode, improved sustainable dredged sediment management strategies, expanded ecosystem restoration opportunities, and improved flood risk management. Data collected from site monitoring can be applied to support development of USACE engineering and ecosystem restoration guidance.

3 Aug 2022

You can go your own way: No evidence for social behavior based on kinship or familiarity in captive juvenile box turtles

Abstract: Behavioral interactions between conspecific animals can be influenced by relatedness and familiarity. To test how kinship and familiarity influenced social behavior in juvenile Eastern Box Turtles (Terrapene carolina), 16 captive-born individuals were reared under semi-natural conditions in four equally sized groups, where each group comprised pairs of siblings and non-siblings. Using separation distance between pairs of turtles in rearing enclosures as a measure of gregariousness, we found no evidence suggesting siblings more frequently interacted with one another compared to non-relatives over the first five months of life. Average pair separation distance decreased during this time but may have been due to turtles aggregating around resources like heat and moist retreat areas as colder temperatures approached. At eight months old, we again measured repeated separation distances between unique pair combinations and similarly found no support for associations being influenced by kinship. Agonistic interactions between individuals were never observed. Based on our results, group housing and rearing of juvenile box turtles did not appear to negatively impact their welfare. Unlike findings for other taxa, our results suggest strategically housing groups of juvenile T. carolina to maintain social stability may not be an important husbandry consideration when planning releases of captive-reared individuals for conservation purposes.