降雨等级与种植模式对大别山变质岩区坡面产流产沙的影响

Impact of Rainfall Levels and Planting Patterns on Runoff and Sediment Yield on Slopes in Metamorphic Rock Area in Dabie Mountains

[目的]研究降雨等级、种植模式及其交互作用对变质岩地区坡面产流产沙的影响程度,为大别山区水土保持、土地管理策略和植被配置提供参考。[方法]在大别山区罗山县潘新镇开展了3种种植模式的径流小区土壤侵蚀监测试验(单种油茶、单种茶树和油茶/茶树间隔式混种),采用水土流失监测仪、翻斗式自记雨量计等仪器设备,实时跟踪监测了各径流小区2023年的产流产流及降雨情况,利用方差分析和相关性分析等方法探究降雨因子和种植模式对产流产沙的影响。[结果]不考虑降雨等级时,单种茶树小区的产流量最高,混种小区的产流量显著低于单种小区,但各小区的产沙量无显著差异(p>0.05);小雨和中雨等级下,各小区的产流量无显著差异,混种小区的产沙量低于其他小区,尤其在中雨等级下表现明显;大雨和暴雨等级下,混种小区的产流量显著低于单种小区(p<0.05),但各小区的产沙量无显著区别;产流量、产沙量与总降雨量、每小时降雨量均存在显著关联,且产流量还受最大60 min雨强的影响。[结论]相比于单种油茶或茶树,混种模式能显著降低大别山变质岩区的坡面产流量,且中/小雨等级下的坡面产沙量也能得到有效抑制。未来大别山区水土保持、土地管理策略制定和植被配置时应予以重视。

[Objective]The effects of rainfall levels,planting patterns and their interactions on slope sediment yield and loss in metamorphic rock areas were studied to provide references for soil and water conservation,land management strategies and vegetation allocation in Dabie Mountains area.[Methods]Experimental investigations on soil erosion in runoff plots with three distinct planting patterns(monoculture of Camellia oleifera,monoculture of Camellia sinensis,and mixed planting of C.oleifera and C.sinensis at intervals)were carried out in Panxin Town,Luoshan County,Dabie Mountains.Instruments such as soil erosion monitors and tipping bucket rain gauges were used to monitor real-time runoff and rainfall in the year 2023.Variance analysis and correlation analysis were conducted to investigate the impact of rainfall variables and planting configurations on runoff and sediment yield.[Results]The monoculture of C.sinensis plot exhibited the highest runoff,and the mixed planting plot demonstrated significantly lower runoff compared to the monoculture plots,but no significant variance in sediment yield among the plots(p>0.05)without considering rainfall levels.Under light and moderate rainfall,there was no significant distinction in runoff among the plots;however,the sediment yield in the mixed planting plot was notably lower than that in the other plots,particularly under moderate rainfall conditions.During periods of intense and prolonged rainfall,the runoff in the mixed planting plot exhibited a statistically significant decrease compared to the monoculture plots(p<0.05).However,there was no significant variance in sediment yield among the plots.Both runoff and sediment yield showed a significant correlation with total rainfall and hourly rainfall,but runoff was additionally influenced by the maximum 60-minute rainfall intensity.[Conclusion]Compared to the monoculture practices of C.oleifera or C.sinensis,the mixed planting pattern demonstrated a notable decrease in runoff on slopes within the metamorphic rock regions of the Dabie Mountains.Furthermore,sediment yield under light to moderate rainfall conditions was effectively mitigated.Attention should be paid to soil and water conservation,land management strategy formulation,and vegetation allocation in Dabie Mountains area in the future.