Addressing Legacies of Conflict: Remote Sensing Tools for Assessment and Mitigation of ERW and Agent Orange in Lao PDR
Dean, Andy1; Boivin, Thomas2; Pierce, Barry1; Tsui, Olivier1; Malivarn, Sivannakone3
1Hatfield Consultants, CANADA; 2Hatfield Consultants Mekong, LAO PEOPLE S DEMOCRATIC REPUBLIC; 3Ministry of Natural Resources and Environment, LAO PEOPLE S DEMOCRATIC REPUBLIC
Full title: Understanding and addressing legacies of conflict - remote sensing tools for the assessment and mitigation of explosive remnants of war and Agent Orange dioxin hotspots in Lao PDR.
Abstract: A challenge to development and poverty alleviation in many countries is the legacy of past conflicts. Lao PDR, a land-linked country in Southeast Asia, is classified by the United Nations as a Least Developed Country. Despite recent economic growth, development is constrained by contamination of large areas of the country with explosive remnants of war (ERW) as well potential contamination from Agent Orange dioxin as a result of military activities undertaken along the Ho Chi Minh Trail during the United States-Viet Nam War (1962-1975). Land use security issues particularly affect growth in natural resources sectors, including hydropower, mining, irrigation and agriculture.
In response to this situation and the requirements of government, international organizations and resource development companies, the Development of Innovative EO Applications for Clearance of Remnants of War and for Reduction of Land (EO-CLEAR) project was established to design remote sensing products and services that address these land security issues in Lao PDR. While this regional conflict is unique, the products and services are broadly applicable to contaminated sites and ERW clearance in other regions.
Maps incorporating historical and current EO products were developed to support ERW clearance planning and technical survey. Historical EO images included declassified American Corona reconnaissance satellite images from the 1960s and early 1970s. Corona images were ortho-corrected and processed to create basic land cover information as well as to detect evidence of bomb strikes. These information layers were combined with contemporary imagery, declassified American bombing records, and actual ERW clearance records to develop a model to determine areas with the greatest ERW hazard. A series of ERW clearance support maps were produced and assessed with UNDP and ERW Laos as well as a mineral mining company - the maps help improve clearance efficiency, particularly planning activities.
Residual contamination of areas with Agent Orange is a concern because of US military activities under Operation Ranch Hand during the US-Viet Nam War. In Viet Nam, the most highly contaminated areas are found at former US military installations, but the situation in Lao PDR is less well understood. A systematic screening approach was established to identify potential Agent Orange / dioxin contamination "hot spots" in Lao PDR. The long-list of contaminated sites was identified based on historical records obtained from the US National Archives and other sources, including remote sensing data. The sites were screened for potential human health risk based on a model that made use of historical and current EO images; for example, the rating of risk included information on current human land use in proximity to the site and evidence of historical military activity in Corona images. The screening approach successfully identified sites of greatest concern and a detailed risk assessment is underway at a potentially contaminated site is underway. While the regional Agent Orange dioxin contamination issue is unique, the actions required are broadly applicable to contaminated site screening and assessment and risk characterisation.