The Apache Longbow–Hellfire Missile Test at Yuma Proving Ground: Ecological Risk Assessment for Helicopter Overflight

ABSTRACT

A multi-stressor risk assessment was conducted at Yuma Proving Ground, Arizona, as a demonstration of the Military Ecological Risk Assessment Framework. The focus of the assessment was a testing program at Cibola Range, which involved an Apache Longbow helicopter firing Hellfire missiles at moving targets, that is, M60-A1 tanks. This article focuses on the wildlife risk assessment for the helicopter overflight. The primary stressors were sound and the view of the aircraft. Exposure to desert mule deer (Odocoileus hemionus crooki) was quantified using Air Force sound contour programs NOISEMAP and MR_NMAP, which gave very different results. Slant distance from helicopters to deer was also used as a measure of exposure that integrated risk from sound and view of the aircraft. Exposure-response models for the characterization of effects consisted of behavioral thresholds in sound exposure level or maximum sound level units or slant distance. Available sound thresholds were limited for desert mule deer, but a distribution of slant-distance thresholds was available for ungulates. The risk characterization used a weight-of-evidence approach and concluded that risk to mule deer behavior from the Apache overflight is uncertain, but that no risk to mule deer abundance and reproduction is expected.

Key Words:

• ecological risk assessment
• aircraft overflight
• mule deer
• noise
• noise contour
• sound

ACKNOWLEDGMENTS

This research was funded by a contract from the U.S. Department of Defense Strategic Environmental Research and Development Program (SERDP) project CS-1054, A Risk Assessment Framework for Natural Resources on Military Training and Testing Lands, to Oak Ridge National Laboratory, which is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. We thank Bob Holst and John Hall for serving as project sponsors and Winifred Hodge Rose and Keturah Reinbold of the U.S. Army Corps of Engineers Construction Engineering Research Laboratory (CERL) for serving as project Co-Principal Investigators. We also acknowledge the contributions of the following people for data, guidance, manuals, programming advice, text reviews, activity descriptions, and other assistance: Valerie Morrill, Chuck Botdorf, and Junior Kerns from the Yuma Proving Ground Environmental Sciences Division; Sergio Obregon, David McIntyre, and Bruce Goff from Jason & Associates, Yuma Proving Ground Office; Rick Douglas and Bert Evans from Yuma Proving Ground Aviation and Airdrop Systems; Dick Gebhart and Kim Majerus from CERL; Todd Kuiken, Paul Hanson, and Robert Washington-Allen from Oak Ridge National Laboratory; Bob McKinley from Wright-Patterson Air Force Base; Bob Lester and Nancy Mabie from the U.S. Air Force Center for Environmental Excellence; Kevin Bradley from Wyle Labs; Catherine Stewart from the U.S. Army Center for Health Promotion and Preventive Medicine; Mara Weisenberg from the USFWS San Andres NWR; and Paul R. Krausman from the University of Arizona.

This article has been authored by a contractor of the U.S. Government under contract DE-AC05-00OR22725. Accordingly, the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U.S. Government purposes.

William W. Hargrove is currently affiliated with the USDA Forest Service, Eastern Forest Environmental Threat Assessment Center, Asheville, NC, USA.

Notes

¹The U.S. Army is considering changing its noise regulation AR 100-1 to rely on peak sound levels rather than DNLs as predictors of human community annoyance. These peak sound levels would also be useful for estimating wildlife effects (C. Stewart, USACHPPM, personal communication, February 2006).

¹A waypoint represents an intermediate destination along the flight path. These are YPG designations that appear on figures.

¹Core area and influence area, combined.

²Low confidence in MR_NMAP L_max (based on response of horses) compared to other L_max values (based on response of mule deer).

¹An effect is presumed to be negative if fewer than 20% of the mule deer are affected.

²Population-level effects may occur (±) if behavioral effects are significant, but would be predicted to occur (+) only if effects were large scale.