Abstract: The dam-break of tailings reservoir not only threatens the downstream life and property safety,but also seriously destroys the local ecological environment. To quantitatively assess the ecological environment losses caused by the tailings dam-break,based on the simulation of the evolution process of the dam-break tailings flow,a assessment method for ecological environment losses induced by tailings dam-break based on ecosystem service value is proposed. An iron tailings reservoir in Jiangxi Province is taken as a typical case to simulate the evolution process of discharged tailings flow due to dam-break. The distribution and risk degree zoning of the downstream affected area of the tailings reservoir are obtained. Based on these,the short-term ecological environment losses induced by the tailings dam-break are evaluated from the perspective of ecosystem service value. The results indicate that the evolution process of the dam-break tailings flow can be effectively simulated using Bingham rheological model,and the disaster situation in the downstream area of tailings reservoir can be obtained. The ecosystem affected by dam-break in the downstream area of tailings reservoir mainly includes forest ecosystem and farmland ecosystem,among which the forest ecosystem suffers the largest proportion of losses. The proposed method can provide a theoretical reference for ecological environment losses assessment caused by overtopping dam-break in similar tailings reservoir projects.

Key words: tailings reservoir,dam-break,tailings flow evolution process,short-term ecological environment loss,ecosystem service value