不同空间尺度上侵蚀产沙模型研究

Study of Soil Erosion Modeling in Different Spatial Scales

土壤侵蚀模型在空间尺度上可以划分为坡面、小流域和区域3个不同层次。在坡面尺度上,主要考虑坡面侵蚀的垂直分带性及其相互影响;小流域尺度上,不但考虑坡面侵蚀的特点,还要考虑坡面来水来沙对沟道侵蚀产沙的影响、重力侵蚀及泥沙输移情况;在区域尺度上则主要考虑小流域各自的侵蚀产沙特点及其相互影响。因侵蚀的空间尺度不同,在建立土壤侵蚀模型时,要考虑由于空间变化所引起的侵蚀因子对侵蚀产沙响应的不同。通过分析国内外常用的不同尺度上的侵蚀产沙模型及其最新发展情况,提出模型建立中存在的问题,可以为以后建立土壤侵蚀产沙模型提供借鉴。

According to the spatial scale,almost all of the soil erosion models can be classified as field-scale models,catchment-scale models and region-scale models.Each type of erosion models has its distinctive characteristics.As to the field scale,the analysis of the clear vertical zones and the interaction between them is very important.In addition to the analysis of soil erosion on hill slopes,effects of runoff and sediment from hill slope on erosion and sediment at the followed gully zone and the erosion caused by gravity are complex and pivotal in the catchment scale.The sediment delivery has a significant importance to the erosion modeling.Establishing region scale erosion model,the relationship and the interaction of the subordinate drainages together with the style of the runoff yield and runoff concentration should be taken into account.In different scale,the influence of the main factors on runoff and sediment yield and the composition of the main factors is not the same.Commenting on the fitness and the existing problems of the popular erosion models home and abroad in these three scales will provide some useful suggestions for soil erosion modeling in the future.