东北黑土区融雪径流对流域产沙的贡献及因素分析

目的]揭示流域融雪期径流产沙特征及对全年总产沙的贡献,阐明东北黑土区影响融雪期产沙贡献的主控因素,并进而为东北黑土区流域综合治理提供科技支撑。方法]基于东北地区203个气象站点数据以及15个流域水文站点径流泥沙资料,通过提取流域降水、地形、气候、土壤和土地利用等因子,采用多因素相关分析的方法,开展融雪期产沙贡献影响因素研究。结果]东北黑土区不同流域年均降雪量占年均降水量的比例为3.7%～23.9%,空间分布差异较大,呈东南多、西北少的分布特点。融雪期径流深占全年径流深比例为13.7%～32.5%,融雪期产沙量对全年产沙量的贡献3.8%～23.47%,融雪期产沙模数占全年产沙模数的3.1%～35.9%,且它们空间分布规律性差。年均降水量、降雪量占降水量比例、融雪期径流深占全年径流深比例3个因素与融雪期产沙贡献在0.05的水平上呈显著相关。降雪量占降水量比例对流域融雪期产沙量和产沙模数的贡献率分别为25.41%和30.22%。最大高程对流域融雪产沙量和产沙模数的贡献率分别为24.36%和20.38%。结论]东北区融雪期产沙对流域全年产沙有较大贡献,且受多重因素影响,未来应加强融雪期的侵蚀产沙观测研究。

Contribution of Snowmelt Runoff to Sediment Yield in the Black Soil Region of Northeast China and Factor Analysis

Objective]The aim of this study is to explore the contribution of catchment sediment yield to annual total as well as its main influencing factors, and then to provide scientific support. Methods] Based on precipitation data from 203 meteorological stations and runoff and sediment data from 15 hydrological stations in northeastern China, the rainfall and snowfall, topographic, climatic, and land use characteristics in the selected catchments were examined, and the annual sediment yield contributions to annual total derived from snowmelt runoff were quantified. The factors influencing catchment runoff and sediment yield during snowmelt period were further analyzed through correlation analysis and multiple regression methods. Results] Spatially, more snowfall occurred in the southeast and less in the northwest. The annual snowfall amount accounted for 3.8%～24.7% of the annual precipitation. The snowmelt runoff depth accounted for 13.7%～32.5% of the annual totals. The contributions of sediment yield(SY)derived from snowmelt to annual total were 3.8%～23.47%, and the specific sediment yields(SSYs)derived from snowmelt runoff were 3.1%～35.9% of the annual total. Their distributions were disorderly in space. The contribution of snowmelt induced SY was significantly correlated with mean annual precipitation, the ratio of snowfall amount to annual precipitation, and the ratio of snowmelt runoff depth to annual runoff depth at the 0.05 significant level. The catchment SY and SSY contributions by the ratio of annual snowfall to annual precipitation were 25.41% and 30.22%, respectively. Conclusion] Sediment yield derived from snowmelt runoff contributed a large part of catchment annual total, and was influenced by many factors. Field monitoring of snowmelt erosion and sediment yield in the black soil region ofnortheastern China should be strengthened in the future study.