Murphy Sheila F, Blake Johanna M, Ebel Brian A, Martin Deborah A
U.S. Geological Survey, Water Resources Mission Area, 3215 Marine Street, Boulder, Colorado 80303, United States.
U.S. Geological Survey, New Mexico Water Science Center, 6700 Edith Blvd. NE, Albuquerque, New Mexico 87113, United States.
Environ Sci Technol. 2025 Jan 14;59(1):35-44. doi: 10.1021/acs.est.4c09489. Epub 2024 Dec 19.
Mining and wildfires are both landscape disturbances that pose elevated and substantial hazards to water supplies and ecosystems due to increased erosion and transport of sediment, metals, and debris to downstream waters. The risk to water supplies may be amplified when these disturbances occur in the same watershed. This work describes mechanisms by which the intersection of mining and wildfire may lead to elevated metal concentrations in downstream waters: (1) conveyance of metal-rich ash and soil to surface waters, (2) increased dissolution and transport of dissolved metals due to direct contact of precipitation with mine waste, (3) increased erosion and transport of metal-rich sediment from mining waste, (4) remobilization of previously deposited metal-contaminated floodplain sediment by higher postfire flood flows, and (5) increased metal transport from underground mine workings. Predicted increases in wildfire size, frequency, and burn severity, together with the ongoing need for metal resources, indicate that improved mapping, monitoring, modeling, and mitigation techniques are needed to manage the geochemical hazard of the intersection of wildfire and mining and implications for water availability.
采矿和野火都是对景观的干扰，由于侵蚀加剧以及沉积物、金属和碎屑向下游水体的输送增加，对供水和生态系统构成严重且重大的危害。当这些干扰发生在同一流域时，供水面临的风险可能会加剧。这项研究描述了采矿与野火相互作用可能导致下游水体中金属浓度升高的机制：（1）富含金属的灰烬和土壤进入地表水；（2）降水与矿山废弃物直接接触，导致溶解态金属的溶解和迁移增加；（3）采矿废弃物中富含金属的沉积物侵蚀和迁移增加；（4）火灾后较高的洪水流量使先前沉积的受金属污染的河漫滩沉积物重新活化；（5）地下矿井作业中金属迁移增加。预计野火规模、频率和燃烧强度的增加，以及对金属资源持续不断的需求，表明需要改进测绘、监测、建模和缓解技术，以管理野火与采矿相互作用产生的地球化学危害及其对水资源可用性的影响。
