风沙区采煤塌陷对沙质地貌及植被生境的影响

Influence of Coal Mining Subsidence on Sandy Geomorphology and Vegetation Habitat in Sandy Area

为了探究风沙区采煤塌陷引起的“二次荒漠化”问题与治理对策,通过野外分区调查及统计分析,对塌陷区塌陷边缘、塌陷中部及塌陷盆地引发的塌陷裂缝变化、植被位移及倾斜、干沙层及风蚀/风积情况进行了详细的研究。结果表明:塌陷边缘形成的裂缝宽度、密度最小,塌陷中部次之,塌陷盆地最大,而裂缝错落和地表破损变化则反之;塌陷区植被平均位移长度达60 cm以上,倾斜率变化为5.67~28.63,主干根部风蚀/风积最大深度达-30.52 cm/+25.41 cm,以塌陷边缘最为严重;植被的位移长度和倾角变化与塌陷裂隙高度和地表破碎呈正线性相关;塌陷边缘干沙层平均厚度达14 cm以上,比对照增大了4~6 cm,而塌陷中部和塌陷盆地变化在11 cm左右,比非塌陷增加了1~4 cm;塌陷边缘风蚀率高达83.34%,塌陷中部次之52.06%,而塌陷盆地风积率为51.84%。塌陷边缘对沙质地表和植被生境影响最为强烈,为生态修复的重点区域,建议采煤塌陷后及时进行分区治理,避免“二次”荒漠化现象的发生。

In order to explore the‘secondary desertification’problems and countermeasures caused by coal mining subsidence in the arid and semi-arid sandy area,through field partition quadrat survey,using statistical methods,detailed research on the subsidence collapse edge,the central subsidence and subsidence basin led to the collapse of central crack width and strewn at random,the vegetation of displacement and tilt,dry sand and wind erosion/wind laid situation has carried out.The results show that the width and density of cracks are the smallest in the margin of collapse,the second in the middle of collapse,and the largest in the basin of collapse,whereas the changes of fracture staggering and surface damage are the opposite;the average displacement length of vegetation in the subsidence area is more than 60 cm,and the change of tilt rate is between 5.67 and 28.63;the average depth of main wind erosion/wind laid is up to-30.52 cm/+25.41 cm,which is the most serious in the collapse margin;the displacement length and change of tilt rate of vegetation are in positive linear correlation with the height of collapse fracture and the fragmentation of surface;the average thickness of the dry sand layer at the collapse edge was more than 14 cm,which increased by 4~6 cm compared with the control,while the changes in the central subsidence and the subsidence basin were about 11 cm,which increased by 1~4 cm compared with the non-collapse;the wind erosion rate of the collapse edge is as high as 83.34%,followed by 52.06%in the central subsidence,and is 51.84%in subsidence basin.The comprehensive analysis shows that the collapse edge has the strongest impact on sandy land surface and vegetation habitat,and is the key area for ecological restoration.It is suggested to carry out zonal control in time after coal mining collapse and take appropriate measures to avoid the occurrence of‘secondary desertification’in the subsidence area.