Scenic vistas in most U.S. parklands are diminished by haze that reduces contrast, washes out colors, and renders distant landscape features indistinct or invisible. Protecting Visibility in National Parks and Wilderness Areas describes the current understanding of the nature and extent of haze in various regions of the United States. The book addresses the scientific and legal framework of efforts to protect and improve visibility, as well as methods for assessing the relative importance of anthropogenic emission sources that contribute to haze in national parks and for considering various alternative source control measures. The volume provides guidance on how to make progress toward the national goal of correcting and preventing visibility impairment due to human activities affecting large national parks and wilderness areas.The programa#39;s requirement that major new sources locating in clean air areas install the best available control technology has been particularly important. ... time and place; but visibility impairment depends on the total magnitude of fine particulate matter between an object and an observer. ... The other visibility protection program under the Clean Air Act requires states to establish measures to achieveanbsp;...
|Title||:||Protecting Visibility in National Parks and Wilderness Areas|
|Publisher||:||National Academies - 1993-01-01|