基于GIS技术的降雨对微地形地表糙度的影响

Effect of rainfall on surface roughness of micro topography based on GIS technology

从微观上研究降雨过程中各个地表糙度的变化特征和规律,以杨凌坡耕地表层土为供试土壤,采用人工模拟降雨、GIS技术和激光扫描测量方法,通过室内试验与计算机模拟,研究了人工锄耕措施下雨强为60 mm/h,坡度分别为5°和10°的地表糙度变化特征,并进行了水文分析。结果表明:地表粗糙度溅蚀阶段的变化最为明显,随坡度的增大而增加;地形指数在细沟出现时变化最明显,其余阶段相对稳定;形状系数在溅蚀阶段达到最高值,随后逐渐减小,在细沟出现后,稳定在相对较低值。文中结果丰富了坡面径流理论,以期为研究区农业生产实践提供指导。

The paper studied the change characteristics and regularity each surface roughness in the process of rainfall from microcosmic. Taking slope surface soil in yangling as the test soil, it used the artificial simulation rainfall and GIS technology and laser scanning measuring method, indoor experiment and computer simulation to study the variation characteristics of surface roughness when slope is 10 and 5 degree respectively, rain intensity is 60 mm/h under the measures of artificial hoeing and carry out hydrological analysis. The results show that the change of surface roughness at splash erosion phase is the most obvious and increases with the increase of slope; the change of topographic index is the most obvious in the presence of groove, the remaining phase is relatively stable; shape factor in splash erosion stage attains peak, then gradually decreases. After rill appears, the value is stable at relative low. The results enrich the theory of slope runoff can provide guide for agricultural production practice in the study area.