南方红壤农作区数字流域建立和应用

数字流域是用数字化专题图形、图像、表格和相应的模型对流域各要素的数字表达,数字流域可为数字化流域管理与评价提供支持。以1∶5万地形图和高分辨率(2.5m)遥感影像为基础,利用数字地形分析、遥感解译和野外调查的方法,建立了南方红壤农作区典型治理区的数字流域,并对土壤侵蚀强度等级进行了划分。研究结果表明:(1)所建立的包含Hc-DEM、地形因子、土地利用、植被盖度和水土保持措施的数字流域能够反映研究区治理前后土地利用和水土保持措施的变化;(2)侵蚀强度等级以中到强度为主,治理前后轻度侵蚀增加比较明显、中度和强度侵蚀减少。该研究可为水土保持效益评价和流域管理提供支持。

Establishment and Application of Digital Watershed in the Red Earth Areas,Southern China

Digital Watershed is a digital representation of watershed with digital thematic maps,remote sensing images,tables and corresponding models,which provides supports in the accurate management and evaluation of watershed.Through digital terrain analysis,remote sense interpretation and field investigation,the digital watershed in the red earth area of southern China is established,and soil erosion intensity is evaluated in terms of different grades in this study based on the topographical maps of 1∶50 000 and remote sensing images of 2.5 m.The results showed that:(1) integrating Hc-DEM,terrain factor,land use,vegetation cover and soil conservation,the established digital watershed could present the different patterns in land use and soil conservation between pre-and post-periods of soil conservation;(2) erosion intensity was mainly associated with moderate and strong erosion levels throughout the entire study period,while in the post—period,slight erosion increased dramatically and moderate as well as strong erosion presented the opposite trend.This study could be helpful for soil and water conservation benefit evaluation and watershed management.