黄土高原小流域水沙关系空间变异研究

Study on Spatial Variation of the Relationship Between Runoff and Sediment of Small Watershed on Loess Plateau

小流域水沙关系空间变异规律是建立黄土高原流域土壤侵蚀预报模型和评价水土保持效益的基础。以黄土丘陵沟壑区典型流域岔巴沟为例,结合野外实地水沙观测资料及相关分析法,对该流域次降雨水沙关系及其空间变异性进行了定量研究。结果表明,岔巴沟流域次降雨输沙模数与洪峰流量模数及径流深具有较强的相关性,这种相关性随不同支流域呈现明显的空间变异性,如何消除这种空间变异性是建立以次降雨水沙作用关系为基础的黄土高原流域水土流失预报模型亟待解决的主要问题。

The law of the spatial variation of the relationship between the runoff and sediment is the basis of the watershed soil erosion prediction model and the evaluation of soil and water conservation on Loess Plateau.Combining with the runoff,sediment data from field observation and the correlation method,the relationship between the runoff and sediment,and its spatial variation are studied quantitatively.The results show that the modulus of sediment transport,the modulus of maximum flood discharge and the runoff depth take on great positive relativity and the spatial variation of the relativity is obvious with the different sub-watershed.How to avoid the spatial variation is the chief problem of the watershed soil loss prediction model on Loess Plateau,which is based on the relationship between the runoff and sediment of the small watershed.