基于5次连续模拟降雨试验对坡面沟蚀发育过程的模拟和ArcGis9.0空间分析功能,利用高精度GPS动态监测坡面沟蚀发育过程,估算沟蚀发育不同阶段的侵蚀量,分析误差产生的原因及提高精度的途径。结果表明,在高精度GPS测量生成的沟蚀发育不同阶段的5期图像上展现的侵蚀形态与实拍相片完全一一对应,完美反映了坡面侵蚀形态的空间分布及其变化。高精度GPS测量能很好地估算坡面侵蚀量,侵蚀量估算值与实测值之间的误差随沟蚀形态的发育而逐渐减少,5次测量估算的侵蚀量平均误差为7.38%。GPS测量过程中所产生的误差可以通过划分统一测量区域,适当增加测量点,特别是增加对沟壁和沟床的测量点及后期数据处理进行纠正。
Based on five continuously simulated rainfall experiments to simulate gully erosion development processes using the spatial analysis function of ArcGIS9.0, this study dynamically monitored gully erosion development processes by high-precision GPS , estimated soil loss at different development stages of gully erosion, analyzed reasons for error occurrence, and presented measures of improving estimated precision. The results showed that generating five images at different developing stages of gully erosion by GPS measurement were completely corresponding to erosion patterns captured by digital photography, perfectly reflected the spatial distribution of erosion patterns and their changes. Estimation of soil loss by GPS measurement was quite well, errors between observed data and estimated values gradually decreased with gully erosion development; average error for GPS five-time measurement was only 7.38 %. The errors produced during GPS measurement process can be corrected through dividing unified measurement area, increasing measurement points, especially increasing measurement points at gully sidewalls and gully channels, and post-event data processing.