喀斯特坡地裸露心土层产流产沙模拟研究  

Simulation Study on Bare Subsoil Runoff and Sediment Yield on Karst Slope

作　　者：严友进 戴全厚[1] 伏文兵 靳丽[1] 兰雪[1,3] 

机构地区：[1]贵州大学林学院,贵阳550025 [2]贵州晟泰工程咨询有限公司,贵阳550002 [3]贵州师范大学地理与环境科学学院,贵阳550001

出　　处：《土壤学报》2017年第3期545-557,共13页Acta Pedologica Sinica

基　　金：国家重点研发计划课题(2016YFC0502604);国家自然科学基金项目(41671275;41461057);贵州省重大专项(黔科合重大专项字[2016]3022号)资助~~

摘　　要：通过人工降雨探索表土剥离后喀斯特坡地侵蚀产沙特征及机制,为该地区开展地下水土流失研究及指导水土流失防治工作具有重要的理论和现实意义。试验采用钢槽装填土石模拟喀斯特地区表土剥离后坡地的"二元结构",通过人工模拟降雨揭示了雨强(30、50、80mm h^(-1))、坡度(10°、15°、20°、25°)和地下孔(裂)隙度(1%、2%、3%、4%、5%)对坡地土壤侵蚀的影响,并在此基础上进一步讨论了各因子对剥离表土后的坡地造成的影响。结果表明:(1)表土剥离后地下漏失的隐蔽性增强,小雨强的坡地土壤侵蚀容易被忽视,30、50 mm h^(-1)雨强条件下,仅当坡地坡度≥15°时地表出现径流,坡地侵蚀产沙以地下流失为主,地下产流量、产沙量随雨强先增大后减小。(2)喀斯特地区坡地土壤侵蚀治理不应只重视地表水土流失,更应关注垂直方向上的土壤侵蚀——地下漏失,低坡度(坡度≤15°)条件下,地表近乎无产流产沙,坡地侵蚀产沙集中在地下孔(裂)隙,而坡度为20°、25°的坡地,其地下产沙比重仍分别高达0.85~0.97、0.59~0.84。剥离表土后的坡地水土保持应从地表、地下两个方向进行,避免由地下漏失引起的岩溶塌陷。增大地下孔(裂)隙度能显著提高地下产流量和产流系数,并促进地下孔裂隙产沙量和产沙比重的增加。【Objective】The unique “dualistic structured” （land surface and underground） hydrologic system in the karst areas of Southwest China has the areas subjected to two types of soil erosion simultaneously, i.e. surface erosion and underground erosion. Relevant researches show that soil erosions on the land surface and in the underground crevices are the two pathways for and components of the soil and water loss in the karst region. In recent years, with the intensified development in the karst region of Southwest China, construction of industrial parks and urbanization has become a hot spot. Consequently large areas of forest land and/or cultivated land have or are being stripped of topsoil for construction projects, thus depriving the land of its vegetation protection and topsoil cover, and making it completely nude and exposed to rainfall erosion. Currently, though much effort has been done studying underground soil and water loss in karst area, almost nothing has been reported about characteristics of the soil erosion on slope land with topsoil stripped of, and the researches, done or being carried on, fail to illustrate either characteristics of the spatial distribution of runoff and sediment in the surface and underground of slopes or effects of affecting factors, like rainfall, slope, underground fissure porosity, etc. of slope soil erosion on characteristics and mechanisms of runoff and sediment generation on stripped slopes in the areas. Therefore, this study is oriented to illustrate and analyze distribution characteristics of runoff and sediment in the surface and underground along stripped slopes, and further to explore effects of rainfall, slope, underground fissures, pores and holes on soil erosion. 【Method】An indoor experiment was carried out using steel troughs filled up with rocks and soil to simulate the ＂dualistic structure＂ of stripped slopes the karst area. In the experiment, troughs were adjusted to slope gradient, 10°, 15°, 20° and 25°, separately, and rainfalls different

关 键 词：表土剥离 土壤侵蚀 地下漏失 喀斯特坡面 

分 类 号：S157.1[农业科学—土壤学]