Xi Sigma Pi

The Department of Forestry at Iowa State University provides students with countless opportunities, acknowledgments, and awards. The opportunity to gain membership into the national forestry honor society, xi sigma pi, is one such benefit

Acoustic Quality and Health in Urban Environments – The SALVE Project

Background sounds of urban regions have been a concern of architecture and construction engineering for years. In the context of health research however, sound has been restricted to the health risk factor noise, thus reduced to sound decibel levels. Accordingly, noise mitigation measures aim exclusively at the reduction of noise level below a certain threshold. Soundscapes on the other hand, comprise all acoustic events of the natural, physical and human environment, which are determined by sound level, frequency, time and space. Soundscape Ecology which includes the study of spatio-temporal heterogeneity of sounds in different landscapes, provides a suitable methodical approach to analyse the relationships between soundscapes, the built environment and human health. This paper presents SALVE (Acoustic Quality and Health in Urban Environments), a two year interdisciplinary pilot project that started in October 2018 and involves the disciplines of public health and spatial planning. The project aims at the identification of criteria for health-promoting soundscapes in cities. By making year long direct and automated auditory measurements of a robust landuse sample in the city of Bochum, located in the highly urbanized Ruhr Area of Germany, one of the largest multi-seasonal urban soundscape datasets will be generated. These data will be merged with health data from the longitudinal, population-based Heinz Nixdorf Recall (HNR) study. Spatio-statistical models will be further developed to analyse health effects of different types of soundscapes in urban neighborhoods. The project serves as a starting point for an innovative and comprehensive approach to understanding the effects of sound quality on urban public health beyond noise protection. Additionally, knowledge will be gained for the development of solution based health-promoting strategies in spatial planning

Analysing Interlinked Frequency Dynamics of the Urban Acoustic Environment

As sustainable metropolitan regions require more densely built-up areas, a comprehensive understanding of the urban acoustic environment (AE) is needed. However, comprehensive datasets of the urban AE and well-established research methods for the AE are scarce. Datasets of audio recordings tend to be large and require a lot of storage space as well as computationally expensive analyses. Thus, knowledge about the long-term urban AE is limited. In recent years, however, these limitations have been steadily overcome, allowing a more comprehensive analysis of the urban AE. In this respect, the objective of this work is to contribute to a better understanding of the time-frequency domain of the urban AE, analysing automatic audio recordings from nine urban settings over ten months. We compute median power spectra as well as normalised spectrograms for all settings. Additionally, we demonstrate the use of frequency correlation matrices (FCMs) as a novel approach to access large audio datasets. Our results show site-dependent patterns in frequency dynamics. Normalised spectrograms reveal that frequency bins with low power hold relevant information and that the AE changes considerably over a year. We demonstrate that this information can be captured by using FCMs, which also unravel communities of interlinked frequency dynamics for all settings

Hydraulic modeling of irrigation-induced furrow erosion

In the experimental Version 4.xx series, erosion science is introduced into the surface-irrigation simulation model, SRFR. The hydraulics of water flow in furrows for individual irrigation events is predicted by numerical solution of the unsteady equations of mass and momentum conservation coupled to generally applicable empirical equations describing infiltration and soil roughness and to a known furrow configuration and inflow hydrograph. Selection of appropriate field values for the infiltration and roughness coefficients yields infiltration distributions and surface flows (including runoff) in reasonable agreement with measurements. The erosion component consists in applying the simulated hydraulic flow characteristics to site-specific empirical determinations of soil erodibility, to general empirical sediment-transport relations, and to general physically based deposition theory to provide estimates of soil erosion, flux, and deposition at various points along the furrow as functions of time. Total soil loss off the field and ultimate net erosion and deposition along the furrow follow. At this initial stage of the investigations, a single representative aggregate size is assumed adequate for the analysis. Results are compared to measurements of sediment concentrations in the furrow quarter points and in the tailwater. For a given representative aggregate size, the results are heavily dependent on the choice of transport formula. The Laursen (1958), Yang (1973), and Yalin (1963) formulas are programmed for investigation, as are a variety of computational options. Preliminary comparisons suggest the superiority of the Laursen formulation, with the Yang and Yalin formulas significantly over-predicting transport