对我国水土流失调查评价方法若干问题的思考

Thoughts on the Methods of Soil and Water Loss Survey and Evaluation in China

历时3 a(2010—2012年)的全国第一次水利普查工作圆满结束,同步开展的我国水土保持情况普查取得了一系列的成果,为国家生态环境建设宏观决策提供了科学依据。在总结经验的同时,为了使今后的普查工作更符合我国实际、科学性,提出5点需要加强研究及改进的建议。1.建议分类调查评价,自然侵蚀区开展"潜在土壤侵蚀危险度"调查,20 a为一个调查周期,加速侵蚀区则应缩短调查周期;2.建议水蚀调查将点、面结合,将实地单元格调查、模型评价法与遥感调查结合,优势互补,完成区域土壤侵蚀强度空间格局分布图;3.将坡面侵蚀调查与侵蚀沟道调查结合,纠正侵蚀沟道发育区可能产生的侵蚀强度偏低的问题;4.建议加强水、风、冻复合侵蚀区土壤侵蚀调查与评价方法的研究;5.建议加强冻融作用对土壤侵蚀影响的研究。

The First National Water Conservancy Survey,which included soil and water conservation survey,was conducted in China during the period of 2010—2012.This national survey will provided scientific basis for macrodecision in ecological and environmental construction of China.Furthermore,to attain the successful experience for the following national survey,we offer some proposals which need to be researched intensively or improved in the future.First of all,the soil loss area in China should be divided as natural erosion area and accelerated erosion area.The method of potential soil erosion risk should be applied to natural erosion areas with a period 20 years,while the survey period should be shorted in the accelerated areas.The onsite unit survey method,model evaluation method and remote sensing method should be combined to investigate the water erosion,and thus the spatial distribution map of water erosion intensity can be proposed.Furthermore,to avoid the underestimate of soil erosion rate in the gully developmental area,both the slope soil erosion and the gully erosion need to be taken into the soil erosion survey.More studies need to be conducted in the multiple erosion areas where contain water erosion,wind erosion and freeze-thaw erosion.Finally,more studies which focus on effects of freeze-thaw on soil erosion should be conducted.