Assessing Economic Changes Due to an Expanding Dairy Industry in the Texas High Plains

The dairy industry in the Texas High Plains has experienced rapid expansion in the past two decades. This study assesses the impact of the increased presence of dairies on overall water use, crop composition, and the local economy. The increase in water use related to the dairy industry from 2000 to 2015 was primarily due to an increase in demand for drinking by the cows (direct water) as well as an increased demand for silage (indirect water). However, a comparative analysis (dairy presence vs. no dairy presence) from a single year indicates minimal impacts on total water use due to dairies. During the same time period, the number, size, and employment of related local business establishments have increased economic activity in rural areas. Editor's note : This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series.     

Development of a High-Speed Ultraviolet Spectrometer for Remote Sensing of Mobile Source Nitric Oxide Emissions

ABSTRACT

The University of Denver (DU) has developed a new remote sensor for the measurement of mobile source nitric oxide (NO). This system is integrated with an existing infrared remote sensor and is capable of measuring carbon monoxide and hydrocarbons in addition to NO, at a rate of more than 1000 vehicles/hr. The detection limit on a low-emitting vehicle under typical measurement conditions is 24 parts per million NO (3σ). Measurements from this instrument correlated well in a side-by-side comparison with the previous NO remote sensor developed at DU, and we have used this study to confirm a suspected interference by aromatic hydrocarbons in the older instrument. The results of an extended field experiment using the new instrument, conducted in fall 1997, are also presented. The NO emissions of the fleet measured in this study (averaging 15.0 g NO/gal) exhibit a skewed distribution typical of mobile sources. This paper also describes the relationship between NO emissions and model year and NO emissions and vehicle acceleration, as measured by the new remote sensor.     

A steady-state approach for evaluating the impact of solute transport through composite liners on groundwater quality

New adaptations of analytical equations for predicting the impact of solute transport through composite landfill liners on groundwater quality for steady-state conditions are presented. Analytical equations are developed for evaluating average concentration and mass flow rate in an underlying aquifer resulting from diffusion of volatile organic compounds (VOCs) through intact composite liners and transport of inorganic constituents through defects in composite liners. The equations are applied to evaluate the effectiveness and equivalency of composite liners having either a 0.6 m-thick compacted soil liner or a 6.5 mm-thick geosynthetic clay liner (GCL) overlying an intermediate attenuation layer and an aquifer having horizontal flow. Example analyses for designing composite liners meeting particular performance criteria are also provided. The analytical equations are relatively simple to apply and can be used for preliminary design and analysis, to evaluate experimental results, and to possibly verify more complex numerical models for evaluating the impact of landfills on groundwater quality if consistency of the assumptions of the analytical equations and the more complex numerical models can be specified.     

Coastal construction trends in response to coastal erosion: an opportunity for adaptation

In Florida, more than half of the state’s sandy beach coastlines are designated as critical erosion areas by the Florida Department of Environmental Protection (FDEP 2008). At the same time, the economic contribution of coastal construction is being confounded by the fiscal peril facing Florida (Bird in Ann Geomorph 57:1–9, 1985, Pew Center on the States 2009, U.S BEA 2009). It is therefore an opportune time for an evaluation of coastal erosion policy response which specifically addresses coastal construction. Furthermore in Florida, an increasing coastal population requiring the provision of structural development necessitates an improved understanding of how legislative intent which avoids the cumulative impacts of development is translated through quantified policy response. This study characterizes how coastal development trends in Florida have responded to critical erosion designation. Using spatial and temporal analysis of coastal construction permitting data from 1987 to 2007, three coastal counties in northwest Florida were selected for this study. This selection was based on proximity to the designated ecologically sensitive Apalachicola National Estuarine Research Reserve (ANERR). This study has indicated that clusters of development have not been reduced or redirected by critical erosion designation in certain areas of the study counties. Therefore this study has implications for the regulatory framework governing coastal development permitting in Florida, which is of timely relevance for sea-level rise adaptation.     

Monte Carlo Simulation Techniques Applied to Air Quality Impact Assessment

Hammersly and Handscomb¹ describe Monte Carlo Methods as a branch of experimental mathematics concerned with experiments on random numbers. The purpose of this paper is to suggest methods through which this powerful technique can be applied to the problem of evaluating the return period of a concentration estimate.