岩溶区与红壤区不同地类产流产沙特征分析

Analysis on Characteristics of Runoff and Sediment Yield in Different Underlying Surfaces in the Karst and Red Soil Region

研究岩溶区和红壤区不同植物措施对坡面产流产沙的影响,揭示两区次降雨累积产流产沙变化规律,为区域坡面水土流失综合防治提供科学依据。基于西南岩溶区兴西湖小流域和南方红壤区山心小流域2015—2016年度观测数据,采用双累积曲线方法分析次降雨条件下不同雨强林地、草地、裸地的产流产沙变化规律,并基于多元线性回归分析方法研究降雨量对径流泥沙的定量影响。结果为:(1)岩溶区小流域裸地累积径流深分别是林地和草地处理的4. 1、2. 5倍,累积土壤流失量大小为:林地<草地<裸地;(2)红壤区小流域各级雨强径流量和土壤流失量均表现为:草地<林地<裸地,总径流深林地、裸地分别是草地小区的811%、3 229%,草地小区产沙量近乎为0;(3)岩溶区小流域累积产流量低于红壤区小流域,红壤区单位径流携沙能力是岩溶区的7. 22倍。岩溶区和红壤区林地、草地小区均具备较强的径流调蓄和保土减蚀功能,岩溶区林地措施最优而红壤区覆盖度较高的草地措施效果最好。

Effects of different plant measures on slope runoff and sediment yield were studied in the karst region and red soil region.Regular patterns of cumulative runoff and sediment yield under secondary rainfall in two regions were revealed,in order to provide a scientific basis of comprehensive management of slope soil and water loss in regions.Based on the observation data for 2015-2016 of Xingxihu small watershed in karst region and Shanxin small watershed in red soil region,double cumulative curve method were used to analyze the changes of runoff and sediment yield in different rainfall intensities in forest land,grassland and bare land.And multiple linear regression analysis was used to study the quantitative effect of rainfall on runoff and sediment.①The cumulative runoff depth of bare land in karst region was 4.1 times of that in forest land and 2.5 times of that in grassland.The cumulative amount of soil loss was:forest land<grassland<bare land.②In small watershed of red soil region,the regularity of runoff and soil loss at rainfall intensity levels was:grassland<forest land<bare land.The total runoff deep in forest land was 811%of grassland area,and which in bare land was 3229%of grassland area.It was noteworthy that the amount of sediment produced in the grassland area was almost zero.③The cumulative runoff of small watershed in karst region was lower than that in Red Soil Region,and the unit runoff carrying capacity in red soil region was 7.22 times of karst region.The functions of runoff regulation and soil conservation and erosion reduction were strong of forest land and grassland in the Karst and Red Soil Region.Forestland measure was the best measure in Karst Region,while the grassland with higher coverage in red soil region had the best effect.