TIME-LINE OBSERVATION OF EMVIRONMENTAL IMPACTS SCRACHED BY HERBICIDE SPLAY DURING VIETNAM WAR

摘要

Introduction: Every value of coordinate, date, type of agent and sprayed quantity of whole spraying mission were recorded in HERBS Tape (HBT). HBT was leased by the web site of The National Agricultural Library in Beltsville, Maryland in 2003 as one of the collections of 'Alvin L. Young Collection on Agent Orange'. Materials and Methods: Values and alphabet abbreviations of 5,350 times of missions were punched manually in geographic information system (GIS), then total volume of sprayed herbicide is calculated 58,180 kilo liters. Universal Transverse Mercator coordinates for each spraying mission in HBT was converted into World Geodetic 84 (WGS84) to overlay satellite images and Global Positioning System (GPS) data. Reliability of HBT was examined by GPS and hearing investigations of two veterans of Vietnam War in July 2007. Path of the spaying mission was overlaid with satellite images that have been taken from 1972. Results and Discussion: It reveals that heavily and frequently sprayed area lost surface vegetation and subsequent topsoil erosion occurred in mountainous and Cambodian and Laos's border areas. These areas have been exposing rocks and bear soils until today.