矿山项目补充开展水土保持监测的技术分析

Technical analysis of soil and water conservation monitoring supplemented to mining projects

许多矿山项目由于生产周期长、建设过程复杂,补充开展水土保持监测工作尤其困难。其中,合理进行水土保持监测历史数据补充工作是提高矿山水土保持监测工作质量的关键问题。以有30多年开采历史的甘肃省某铅锌矿为研究对象,通过查阅建设资料、现状测量、咨询矿山老职工、补充1990—2019年期间的历史遥感影像数据,采用SL 773—2018《生产建设项目土壤流失测算导则》中的计算方法,完成矿山水土保持监测工作。结果表明:1)矿山尾矿库占地在逐年增大,其他区域占地面积的变化主要与建设进度相关,并在2006年实现井下开采后趋于稳定;2)矿山总挖土石方2473.03万m^(3),总填土石方205.03万m^(3),弃土石方2258.0万m^(3);3)建设期内重点土壤流失区域为运输公路区,土壤流失量为2197 t,占总流失量的42.76%;运行期重点土壤流失区域为露天采坑区,土壤流失量为6万418 t,占总流失量的85.74%;4)生产建设期内各分区平均侵蚀模数由3494 t/(km^(2)·a)逐渐降低为193 t/(km^(2)·a),水土保持措施效果显著。研究认为补充监测工作首要环节是准确调查矿山建设生产过程中的重要时间节点,重点是分析各建设时段内扰动土地面积的变化,难点是土壤流失测算。研究提出基本的水土保持监测费用基价制度、补充监测报告应按年度或者具有显著变化特征的时段进行、结合实际情况灵活运用测算方法等建议。

[Background]For many mine projects,it is particularly difficult to supplement soil and water conservation monitoring because of long production cycle and complex construction process.The key problem to improve the quality of soil and water conservation monitoring work is to supplement the historical data of soil and water conservation monitoring reasonably.[Methods]Taking a lead-zinc mine in Gansu province with a mining history of over 30 years as the research object,the monitoring work of soil and water conservation in the mine was completed by consulting construction data,measuring the current situation,consulting the mine s senior workers and supplementing the analysis of historical remote sensing image data from 1990 to 2019 and using the calculation methods in the SL773—2018 Guidelines for Measurement and Estimation of Soil Erosion in Production and Construction Projects.[Results]1)The mine tailings pond area was increasing,the change of the other area was mainly related to the construction progress,and in 2006 turn to stability after the underground mining.2)The total dug earthwork was 24.73×10^(6)m^(3),the total backfilled earthwork was 2.05×10^(6)m^(3),and the discarded earthwork was 22.58×10^(6)m^(3).3)During the construction period,the key soil loss area was transportation roads,with soil loss of 2197 t,accounting for 42.76%of the total.In the operation period,the key soil loss area was the open-pit mining area,with soil loss amount of 60418 t,accounting for 85.74%of the total.4)During the period of production and construction,the average erosion modulus of each area gradually decreased from^(3)494 t/(km^(2)·a)to 193 t/(km^(2)·a).[Conclusions]The primary part is to accurately investigate the important time nodes in the process of mine construction and production when conducting the supplementary work of soil and water conservation monitoring in mining projects,the emphasis is to analyze the change of disturbed land area in each construction period,and the difficulty is to calculate and analyze soil erosion.Based on the research findings,some suggestions are put forward,i.e.,the basic price system of water conservation monitoring fees should be introduced,the supplementary monitoring report should be carried out according to the year or the period with significant change characteristics,and the measurement guidelines flexibly should be applied in combination with actual situations.