Study on the spatial distribution regularities of coal gangue accumulation in the coal mining area of northern Germany—taking coal gangue accumulation area of Ibbenbueren for instance

摘要

Mines in northern Germany are mostly open-pit mining,which causes many coal gangue hills.German people treat the gangue hills as reclamation object so that they can be developed into woodland suitable for people to relax.For directly describing the effect of coal gangue to the physical-chemical properties of the soil in the accumulation area of coal gangue accumulation,as well as to support the former theoretical foundations,which are about the study on using coal gangue as substrates to reclaim the subsidence in coal mining area,this paper has taken the accumulation area of coal gangue in the north of Germany for instance.It has been known after sampling in different layers and fields as well as analysis of the soil samples that after the effect of some natural factors such as weathering for a long time and some human factors such as new coal gangue piling up steadily,some physical-chemical properties of the surface soil in accumulation areas of coal gangue has changed.For example,the surface soil in Ibbenbueren has the bulk density,the average value of which is more than 1 g/cm3.The average value of saturated hydraulic conductivity in the area is lower than 1 cm/sec.And some negative situations appeared,which are pH exception (pH ＜ 4 or pH ＞ 8),the poor nutrient contents (the content of available potassium,available phosphorus and total nitrogen are all lower than the standard values,which are 5 g · m2 · a-1,1.3-1.7 g· m2· a-1 and 5-6.5 g· m2· a-1).The results of those experiments show that it is less effective on the plants in life recreation area such as woodland after reclamation though the physical-chemical properties of the soil in coal gangue accumulation area renders the negative trend in the growth of crops with the years increase.Appropriately increasing manual intervention could improve the nutrients level of the soil in coal gangue accumulation area,which will be more conducive to the growth of the forest vegetation.