【摘要】 在宁夏固原六盘山叠叠沟小流域坡面径流小区(长0.9 m、宽0.5 m)内进行了10种枯落物覆盖量(0.0、0.5、1.0、3.0、5.0、7.0、10.0、15.0、20.0、25.0 t.hm-2)、5个入口流量(10、20、30、40、60 mL.s-1)的地表径流试验。结果表明:当枯落物覆盖量从0.0 t.hm-2增加到25.0 t.hm-2时,地表径流流速与无枯落物覆盖相比减小了57.50%~72.27%;地表径流流速随入口流量增加而明显加大,尤其是无枯落物覆盖时增加最快;在坡度为14°的条件下,枯落物覆盖对地表径流流速的阻延值△V(cm.s-1)与单宽流量q(mL.s-1.cm-1)、枯落物覆盖量G(t.hm-2)的关系为:△V=3.617 7q0.507 5G0.431 5(R2=0.910 2);枯落物覆盖量增加使地表曼宁阻力系数n值加大,在枯落物覆盖量小于10.0 t.hm-2时,n值随枯落物量增加而急剧加大;当枯落物覆盖量在10.0~25.0 t.hm-2范围内增加时,n值的加大趋势逐渐变缓;n值与枯落物覆盖量之间呈较好的二项式关系。更多还原

【Abstract】 For studying the effect of ground covering by Larix principis-rupprechtii litter on reducing the velocity of surface runoff,the experiment was conducted with 0.9 m×0.5 m plots on slopes in Diediegou small watershed of Liupan Mountain in Guyuan,Ningxia.The treatments of 10 litter coverage(0.0,0.5,1.0,3.0,5.0,7.0,10.0,15.0,20.0 and 25.0 t·hm^-2) and 5 input flux(10,20,30,40 and 60 mL·s^-1) were used.The results showed that compared with the treatment with no litter coverage,the surface runoff velocity was reduced by 57.50%⁷2.27% when the litter coverage varies from 0.0 to 25.0 t·hm^-2.The surface runoff velocity had an evident increase with increasing input flux,especially the fastest increase in the case of without litter coverage.On the slope of 14°,the relation among the reduced runoff velocity(△V,cm·s^-1),the flow of unit width(q,mL·s^-1·cm^-1),and litter coverage(G,t·hm^-2) was: △V=3.617 7q^{0.507 5}G^{0.431 5}（R²=0.910 2）.The Manning resistant coefficient（n） increased with litter coverage.When the litter coverage was less than 10.0 t·hm^-2,the value of n evidently increased with the litter coverage;while the litter coverage caries in the range of 10.0 to 25.0 t·hm²,the value of n increased more and more slower.And there was a satisfied binomial relationship between n and litter coverage.更多还原