Land disturbance intensity quantification and evolution law of open-pit mining

In view of the difficulty of scientific quantitative evaluation of land disturbance intensity of open-pit mining,the fair conversion criteria and detailed calculation methods of evaluation indicators were proposed based on the standard coal and ecological footprint calculation principles and the open-pit mining disturbance effect theory.Combined with the space-time development law of open-pit mine full-life mining and drainage engineering,the variation curves of Land Excavation Intensity(LEI) and Land Occupied Intensity(LOI) were drawn,the change phases were divided and the indicator characteristics of each stage were analyzed.An empirical study was carried out by taking the open-pit mine in the Jungar mining area as an example:affected by the construction of the Harwusu open-pit mine,the average annual growth rate of LEI and LOI were 56% and 70.42% respectively from 2006 to 2010,and the Land Productivity Resilience (LPR)<1,the negative land disturbance effect is stronger.After reaching production and ecological reconstruction in 2011,the average annual growth rate of LEI and LOI was 8% and 2.8% respectively,the growth rate slowed down significantly,LPR>1 with an average annual growth rate of 17.5%.By the end of 2015,the land productivity of the mining area has nearly doubled,and the actual land area disturbed by mining tons of standard coal has decreased by 35.9% compared with before 2014.The negative land disturbance effect was gradually weakening.The research results showed that it is practical to quantify the land disturbance intensity of open-pit mining with three indicators including Land Excavation Intensity(LEI),Land Occupied Intensity(LOI) and Land Productivity Resilience(LPR),but it is incomplete to analyze the damage of open pits to the environment from the perspective and land occupation of open-pit mining and it is also necessary to fully consider the role of land reclamation and ecological reconstruction in improving and enhancing land values and environmental functions.Therefore,the mining technology decision of open-pit mine is the key to affect the intensity of land disturbance intensity,and the scientific planning and design of open-pit mining technology is the key way to reduce the disturbance effect.