我国东北黑土区侵蚀沟道的普查方法与成果

Survey methods and results of erosion gullies in black soil areas of northeastern China

东北黑土区侵蚀沟道普查是第一次全国水利普查中水土保持情况普查的重要组成部分,也是我国对该区侵蚀沟道开展的首次全面调查。本文全面介绍了本次普查的对象、范围、内容、技术方法、质量控制和成果,对进一步规范和完善侵蚀沟道调查方法、分级分类标准以及开展东北黑土区侵蚀沟道治理意义重大。东北黑土区侵蚀沟道普查以2.5 m分辨率遥感影像和1∶5万数字线划图为主要信息源,采取人机交互的方式辨识50 km2小流域内长度在100 m和5 000 m之间的侵蚀沟道,提取沟道面积、长度、纵比和起讫经纬度等指标。在沟道提取、数据填报和成果审核汇总等阶段,县级、省级和流域等各级普查机构通过野外核查、室内检查和数据比对等严格的质量控制方法,对侵蚀沟道的遥感解译与识别、沟道勾绘精度、图形数据接边进行审核,保证普查结果的全面性和准确性。经调查东北黑土区共有侵蚀沟道29万5 663条。

Survey of erosion gullies in black soil areas of northeastern China is the main part of the project Soil and Water Conservation Census of China Census for Water, which is the first comprehensive survey of erosion gullies in this region. This paper introduces the objects, scope, indexes, technical methods, quality control methods and results of the survey, which is of important significance for improving and standardizing erosion gully survey methods, classification criteria and governance in the region. Based on remote sensing images with a resolution of 2.5 m and digital line graphs of 1 ： 50 000 scale, the survey adopted the human-computer interaction method to identify soil erosion channels of 100 -5 000 m in length in the 50 km2 watershed, and then extracted indicators of these channels like area, length, aspect ration, latitude and longitude of the start and end. The census agencies at county, provincial and basin levels adopted strict quality control methods such as field verification, interior inspection and data comparison to verify the remote sensing interpretation and recognition, channel drawing precision and graphical data edging of soil erosion channels, so as to guarantee the completeness and accuracy of the survey results at the stage of channel extraction, data reporting and results verification and summary. It is found that there are totally 295 663 soil erosion channels in the black soil areas in northeastern China.