淮河上游流域土地利用变化对次暴雨产沙影响研究

Research on the impacts of land use change on single storm sediment yield characteristics of the upper Huaihe Basin

土地利用变化既改变水文循环过程也改变产沙过程。本文以淮河上游大坡岭以上流域为研究区,基于1990s和2000s的土地利用资料和两个年代各10场暴雨对应的水文与气象资料,以0.5 h为时间步长,应用改进的水沙模型模拟流域暴雨产沙,分析土地利用变化对次暴雨-泥沙负荷关系的影响;基于两个年代获得的模型参数,模拟1990s十场暴雨的产沙过程,分析相同暴雨条件下土地利用模式变化对产沙的影响。结果表明:模拟结果满足精度要求;土地利用变化改变了降雨-泥沙负荷关系,1990s到2000s的土地利用变化减轻了流域水土流失,导致次暴雨产沙量、沙峰及侵蚀模数均减少。研究成果可为淮河流域水土治理提供科学依据,丰富并创新湿润半湿润地区水土流失模拟理论与方法。

The change of land use alters not only hydrological cycle but also sediment yield process. The paper took the basin above Dapoling hydrological station in the upper reaches of Huaihe river as the study area. Based on data of landuse,and data of corresponding hydrology and meteorology in each 10 rainstorm in 1990s and 2000s, it modified the water - sediment model to simulate the sediment delivery process of Dapoling station with 0.5 hour as time scale and analyzed the impact of land use change on the relationship between rainfall and sediment load. Based on the parameters gotten in 1990s and 2000s,the paper simulated, sediment delivery process of 10 storms＇so as to analyze the impact of land use change on sediment yield. The results indicated that the simulated results meet precision demand. The land use pattern changed the relationship between rainfall and sediment load. The change of land use from 1990s to 2000s mitigated the soil erosion of watershed, and resulted in the decrease of sediment load, peak and Erosion modulus. The results can provide the scientific reference for the water and soil conservation of Huaihe basin, rich and innovate the theory and method of water and soil loss simulation in humid and semi - humid region.