滇中高原不同土地利用类型产流产沙特征及影响因素——以尖山河小流域为例

Characteristics of Runoff and Sediment Yield Under Different Land Uses and Its Influencing Factors in Central Yunnan Plateau-A Case Study at Jianshan River Small Catchment

[目的]研究滇中高原山区小流域不同土地利用类型植被措施的水土保持效益,为合理种植及改善土地利用现状提供科学依据及理论指导。[方法]以玉溪市尖山河小流域为研究区,采集研究区2012-2022年的降雨数据结合径流小区径流量和产沙量数据,研究分析次生林地、人工林地、灌草丛地、农耕地、经果林地径流量和产沙量特征及影响因素。[结果]①径流量排序为:农耕地>经果林地>灌草丛地>次生林地>人工林地,产沙量排序为农耕地>人工林地>经果林地>次生林地>灌草丛地。相同降雨条件下农耕地较其他土地利用类型的抗侵蚀性差。②产沙量与径流量二者之间呈明显的正相关性(p<0.01),产沙相较于产流具有滞后性,当次生林地径流量≥0.02 mm,灌草丛地≥0.46 mm,人工林地≥0.4 mm,经果林地≥0.62 mm,农耕地≥0.09 mm时才会携带泥沙。③径流量和产沙量与植被盖度、降雨特征因子之间的相关性显著(p<0.05),与土壤理化指标中的毛管持水量、毛管孔隙度、总孔隙度之间存在显著相关性(p<0.05),与其余的理化指标相关性不显著(p≥0.05)。[结论]研究区内应科学设置植被类型布局,合理分配土地种植模式,科学布局农田整地。

[Objective]The soil and water conservation benefits of vegetation measures were analyzed under different land use types for the small catchment from the mountainous areas in the Central Yunnan Plateau to provide scientific basis and theoretical guidance for rational planting and improvement of land use status in the area.[Methods]The Jianshan River small catchment from Yuxi City of Yunnan Province was selected as the study area,and the rainfall data were collected from 2012 to 2022.The runoff and sediment yield characteristics and their influencing factors under different land use types(secondary forest,artificial forest,shrub land,cultivated land,economic fruit forest)were analyzed based on the runoff and sediment data from the runoff plots.[Results]①The order of runoff from different land uses was in the order of cultivated land>economic fruit forest>shrub land>secondary forest>artificial forest,and the order for sediment yield was cultivated land>artificial forest>economic fruit forest secondary forest>shrub land.The erosion resistance of cultivated land was worse than that of other land use types under the same rainfall conditions.②A significant positive correlation was determined between sediment yield and runoff(p<0.01).The sediment delivery lagged behind the runoff generation.Only when the runoff was≥0.02 mm for the secondary forest,≥0.46 mm for shrubland,≥0.4 mm for artificial forest,≥0.62 mm for economic fruit forest,and≥0.09 mm for cultivated land could they carry sediment.③Runoff and sediment yield were significantly correlated with vegetation coverage,rainfall,soil capillary water-holding capacity,soil capillary porosity,and total soil porosity(p<0.05).[Conclusion]This study has an important practical significance for scientifically setting up the layout of vegetation types,reasonably allocating the land planting pattern,and laying out the farmland consolidation.