论文部分内容阅读
植被对坡面水蚀具有重要影响,其减水、减沙效益广受关注。以广东省五华县源坑水小流域2011—2014年的径流小区次降雨水沙观测数据为基础,分别在次降雨、月、年及不同降雨区间讨论植物类型差异、月际植被盖度变化、年际植物生长及不同次降雨量对坡面产流、产沙的影响。研究结果表明:(1)在次降雨尺度,植物小区平均减沙效益、减水效益分别为24.77%、12.95%,其减沙效益大于减水效益;(2)在各降雨区间,相较于裸土小区,桉树、松树和糖蜜草小区分别在次降雨量为20~30 mm、20~40 mm和20~50 mm的降雨区间具有较为显著的减沙效益。松树和糖蜜草在次降雨量为10~50 mm的降雨区间均具有显著的减水效益。但在次降雨量>50mm的降雨区间植物的减沙、减水效益均不显著。(3)在月尺度上,各径流小区产流、产沙量均无显著差异。但由于月际植被盖度的变化,不同月份植物减沙效益数值顺序存在一定变化,但植物减水效益数值顺序较为稳定均呈现为糖蜜草>松树>桉树。(4)在年尺度上,桉树,松树和糖蜜草的减沙、减水效益区间分别为7.00%~38.66%、2.98%~8.76%,7.74%~37.30%、6.67%~19.67%和8.35%~45.33%、10.00%~23.36%。各径流小区年均次降雨产流、产沙数值顺序均呈现裸土小区>桉树小区>松树小区>糖蜜草小区。各植物小区的减水效益与减沙效益相一致,表明相较于植物通过改变水沙关系减沙而言,植物主要是通过减水来减沙。
Vegetation has an important impact on water erosion on the slope, and its water reduction and sand reduction benefits have drawn much attention. Based on the data of rainfall and sediment in runoff plots in Yuankengshui small watershed of Wuhua County, Guangdong Province from 2011 to 2014, the differences of plant types, monthly vegetation cover changes , Annual plant growth and different rainfall on the runoff and sediment yield. The results show that: (1) In the sub-rainfall scale, the average sediment reduction benefit and water reduction benefit of plant community are 24.77% and 12.95%, respectively, and the benefits of sediment reduction are greater than those of water-reducing benefit; (2) The bare soil plot, eucalyptus, pine and molasses grass plot have significant sediment reduction benefits in the rains with secondary rainfall of 20-30 mm, 20-40 mm and 20-50 mm, respectively. Pine trees and molasses grass had significant water-reducing benefits in the rainfall range of 10-50 mm. However, the sediment reduction and water-reducing effects were not significant in rainfall periods> 50mm rainfall. (3) On the monthly scale, there was no significant difference in runoff and sediment yield among all runoff plots. However, due to the variation of monthly vegetation cover, there is a certain change in the numerical order of soil sediment reduction benefits in different months, but the numerical order of the water reducing benefits of the plants is relatively stable, showing as follows: molasses> pine> eucalyptus. (4) On the annual scale, the benefit ranges of reducing and reducing water of eucalyptus, pine and molasses grass are 7.00% ~ 38.66%, 2.98% ~ 8.76%, 7.74% ~ 37.30%, 6.67% ~ 19.67% and 8.35% ~ 45.33%, 10.00% ~ 23.36%. Annual runoff yield and runoff in each runoff plot showed that bare soil plot> eucalyptus plot> pine plot> molasses plot. The water-reducing benefits of all plant communities are consistent with those of reducing sediment yield, indicating that compared with plants, sediment reduction is mainly achieved by reducing water and sediment.