Study On Soil Environment Of Typical Abandoned Lands In Laiyuan County

In recent years,with the continuous development of science and technology,the mechanical industry is also progressing.Due to the increase of mining losses,abandoned lands are increasing,and the harm to soil environment is also further promoted.Up to now,the research on mine soil environment is mainly focused on the reclamation of mine abandoned lands soil and heavy metal pollution,and the specific impact on soil and soil environment of typical abandoned lands are less studied.The studies of mine typical abandoned lands soil environment are conducive to scientifically and reasonably restore the mine damaged ecosystem,and are of great significance to ensure the mines ecological safety and human settlements safety.This paper takes the typical mine abandoned lands in Wangergou,Laiyuan County,Hebei Province as the research object.Based on the analysis of the typical nature of the Wangergou mine abandoned lands,through the comparative analysis and comprehensive evaluation of the main properties of soil environment in two typical abandoned lands,dumps and tailing pond,the degree of damage to soil and the degree of difficulty in reclamation of typical waste land were determined.The results are as follows.(1)Analyzing the typical characteristics of mine abandoned lands in WangergouAbandoned lands of Wangergou are divided into four typical waste lands that are mine stope,dumps,tailing pond and other areas.The area of mine stope accounts for 24.29% of the total mining area,which is formed by open-pit mining and has bare bedrock and no soil.Other areas,including factory buildings and roads,are accounting for 47.37% of the total mining area.Physical damage is the main factor affecting and destroying the soil environment.Dumps and tailing pond account for 28.34% of the total mining area,which has the most serious impact on and damage to the soil environment.According to statistical analysis,among the mine abandoned lands in Laiyuan County,the dumps and tailing pond are the most prominent,typical and comparable to the soil environment.(2)Revealing the physical properties difference between dumps and tailing pondUsing adjacent unbroken hillsides as contrast check,we know that the dumps are mainly gravel,while the tailing pond is mainly the physical sand.Tailing pond is closer to contrast check's texture than dumps.The bulk density of the dumps from the top to the bottom of the slope present an upward trend,but the bulk density of the tailing pond does not decrease with the increasing height because the machine compaction on the top of the slope which make the bulk density is similar to the contrast check's.The soil moisture content of dumps in shady slope is about 10% higher than that in sunny slope,and the bottom of slope is higher than that at the top of slope.The trend of saturated water content and field water content are basically the same,which is the bottom?platform?CK.The soil moisture content of tailing pond increases gradually from top to bottom of slope.The trend of saturated water content and field water content is slightly different.The saturated water content is expressed as bottom <platform<CK,CK content is about 13% higher than the bottom of the slope's,while the field water content is expressed as bottom<CK<slope,the content of slope is about 3% higher than bottom's.(3)Revealing the chemical properties difference between dumps and tailing pondThere is no obvious difference in the pH value between the top,middle and bottom of the dumps,and there is fluctuation in the top,middle and bottom of the slope of the tailing pond.The pH value of dumps are slightly higher than that of tailing pond.The organic matter content of the dumps are the highest at the bottom,but the CK content is 2.78 times bottom's.The organic matter content of tailing pond is the highest at the platform,but the CK content is 2.36 times platform's.There is no significant difference in organic matter content between dumps and tailing pond.The content of total nitrogen of dumps is expressed as sunny slope?shady slope and slope?bottom?platform.The platform content is 2.43 times middle of the slope's.The content of total nitrogen in tailing pond is not significantly different from CK and is larger than that in dumps.The content of available potassium in dumps are significantly higher than that in tailing pond,and the content of available phosphorus in tailing pond is significantly higher than that in dumps.(4)Exploring soil environment in different typical abandoned areasThrough analytic hierarchy process and synthetic index method,the soil quality of the dumps and the tailing pond are evaluated comprehensively.The comprehensive evaluation index of the soil quality of the tailing pond is 0.576 1,and the comprehensive evaluation index of the soil quality of the dumps are 0.290 6.It shows that the soil environment system of Wangergou mine tailing pond in Laiyuan county has been damaged to a certain extent,the soil ecosystem has been degraded,and the ecological restoration is slightly difficult,while the soil environment of the dumps have been severely damaged,the ecological restoration and reconstruction are difficult,and the ecological problems are serious.The results show that the soil quality of these two different types of typical abandoned lands are quite different,which shows that the soil quality of tailing pond is better than that of dumps.Tailing pond is more suitable for simple regulation,covering soil,selecting suitable grass seeds and sowing in time.The dumps are more suitable for combining fertilization with soil improvement,planting suitable grass and tree species,providing a general direction for the subsequent restoration of typical abandoned land,and playing an important role in improving the sustainable utilization of land resources.