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| Survey methods and results of erosion gullies in black soil areas of northeastern ChinaLi Zhiguang, Wang Yansong, Liu Xianchun, Liu Jianxiang |
(1.Soil and Water Conservation Monitoring Centre, Ministry of Water Resources, 100053, Beijing, China;
2.The Monitoring Center of Soil and Water Conservation，Songliao River Basin，Songliao Water Resources Commission，the Ministry of Water Resources，130021，Changchun,China) |
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Abstract 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 2.5m and digital line graphs of 1∶50000 scale, the survey adopted the human-computer interaction method to identify soil erosion channels of 100-5000m in length in the 50km2 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 295663 soil erosion channels in the black soil areas in northeastern China.
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Received: 07 April 2013
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