不同雨强下土壤大孔隙对坡面流水动力学参数的影响  

Influence of soil macropore on hydrodynamic parameters of overland flow with different rainfall intensities

作　　者：张小娜[1] 冯杰[2] 张超[3] 高玉芳[4] 

机构地区：[1]南京信息工程大学水文气象学院,江苏南京210044 [2]中国水利水电科学研究院水资源所,北京100044 [3]河海大学土木与交通学院,江苏南京210098 [4]南京信息工程大学应用气象学院,江苏南京210044

出　　处：《河海大学学报（自然科学版）》2012年第3期264-269,共6页Journal of Hohai University(Natural Sciences)

基　　金：国家自然科学基金(41105077);江苏省高校自然科学基础研究资助项目(11KJB170008);南京信息工程大学科研基金(S8110144001)

摘　　要：以室内试验槽为平台,利用人工模拟降雨试验,定量分析了坡度为5°时,在30mm/h,60mm/h和120mm/h降雨强度下,有大孔隙试验槽和无大孔隙试验槽坡面流的水动力学参数的异同点.结果表明,各场次降雨的两坡面流的流态均为层流,除降雨强度为30mm/h时,无大孔隙坡面的坡面流为急流外,其他场次的水流均为缓流;在同一降雨强度下,相对于无大孔隙坡面,有大孔隙坡面的坡面流流速、单宽流量、弗劳德数和雷诺数较小,径流深、径流切应力、水流运动阻力以及坡面糙率较大;随着降雨强度的增大,两坡面的径流深和单宽流量增加,坡面流流速、径流切应力和雷诺数均增大,阻力系数和曼宁糙率均呈现先增大后减小的趋势,弗劳德数则呈现先减小后增大的趋势.Through laboratory experiments perforIned in two tanks, the hydrodynamic parameters of the overland flow of the tanks with macropores and without macropores were quantitatively analyzed using simulated rainfall with rainfall intensities of 30 mm/h, 60 mm/h, and 120 mm/h, at a slope gradient of 5°. The results show that the patterns of the overland flow along the two slopes were laminar flow in all rainfall events, and the overland flow along the slope without macropores was almost tranquil flow except with the rainfall intensity of 30 mm/h, when the overland flow was torrential flow. With the same rainfall intensity, the overland flow along the slope with macropores had a lower flow velocity, unit width discharge, Froude number, and Reynolds number, and a higher runoff depth, runoff shear stress, resistance coefficient, and Manning roughness, compared with that along the slope without macmpores. For both slopes, with the increase of rainfall intensity, the runoff depth, unit width discharge, flow velocity, runoff shear stress, and Reynolds number increased, and the resistance coefficient and Manning roughness initially increased and then decreased, while the Froude number initially decreased and then increased.

关 键 词：降雨强度 土壤大孔隙 坡面流 水动力学参数 

分 类 号：S157.1[农业科学—土壤学]