岩层倾向对喀斯特槽谷区地表/地下产流过程的影响

喀斯特槽谷区在降雨过程中极易发生水土流失,这使得该区生态环境被破坏。以喀斯特槽谷区为研究对象,通过室内模拟其典型顺/逆层坡面特征及地下孔裂隙发育程度,利用人工降雨试验研究不同雨强条件下地表地下产流特征,从而揭示喀斯特槽谷区地表地下产流机制。结果表明:(1)喀斯特槽谷区地表地下产流受雨强影响,小雨强(30 mm/h)条件下地下产流量大于地表产流量,中雨强(60 mm/h)条件下地表产流量增大且裸坡条件下地表产流量大于地下产流量,大雨强(90 mm/h)条件下裸坡与顺层坡的地表产流量均大于地下产流量。(2)地下孔裂隙发育程度对地表地下产流量的分配比例产生影响,地下孔裂隙度越大则地下产流量越多,且2%～3%的地下孔裂隙度时地表地下产流量分配比例发生转变。(3)不同岩层倾向条件下,地表产流量及其分配比例最高为裸坡,最低为逆层坡,地下产流量及其分配比例最高为逆层坡,最低为裸坡。(4)不同岩层倾角条件下,顺层坡地表产流量最高为30°,最低为90°,地下产流量则相反;逆层坡地表产流量最高为90°,最低为60°,地下产流量最高为60°,最低为90°。研究结果可为喀斯特槽谷区地表及地下产流机制的进一步认识提供科学依据。

Influence of Strata Tendency on the Surface / Underground Runoff Production Process in Typical Karst Valley

Karst valley area is prone to soil and water loss during rainfall, which destroy the ecological environment of the area. This study taken the karst valley area as the research object, through indoor simulation of its typical bedding/inverse layer slope characteristics and the development degree of underground hole crack and using artificial rainfall test, the characteristics of the surface underground runoff production under different rainfall conditions were studied, thereby revealing the production mechanism of surface and underground runoff in karst valley. The results showed that: (1) The surface underground runoff yield and discharge in the karst valley area was affected by rain intensity, and the underground runoff yield and discharge was greater than the surface runoff under light rain (30 mm/h), and the surface runoff yield and discharge increased under moderate rain (60 mm/h), meanwhile it was greater than underground runoff under the condition of large and bare slope. Under the condition of heavy rain (90 mm/h), the surface runoff yield and discharge were both greater than the underground runoff on bare slope and bedding slope. (2) The development degree of underground pore fissures impacted the distribution ratio of surface underground runoff yield and discharge. The larger the degree of underground pore fissure was, the greater the underground runoff yield and discharge would be, and the distribution proportion of surface underground runoff yield and discharge would change when the underground hole fissure degree was 2%~3%. (3) Under different strata tendencies, the surface runoff yield and discharge and its distribution ratio were the highest on bare slopes, and the lowest on reverse slopes, while the underground runoff yield and discharge and its distribution ratio were the highest on reverse slopes, and the lowest on bare slopes. (4) Under different strata inclination angles, the surface runoff yield and discharge was the maximum on the bedding layer of 30°, and the lowest on the bedding layer of 90°, while the underground runoff yield and discharge was opposite. For the reverse slope, the surface runoff yield and discharge was the maximum on the slope of 90°, and the minimum on the slope of 60°, the underground runoff yield and discharge was the highest on the slope of 60°, and the lowest on the slope of 90°. The results could provide scientific basis for further understanding of the production mechanism of surface and underground runoff in the karst valley area.