短語詞組短語rill gully soil erosion 溯源侵蝕gully head erosion 溝頭侵蝕protection of gully head erosion 溝頭防護(hù)hillslope -gully slope erosion system 坡溝系統(tǒng)hill slope -gully side erosion system 坡面harm of gully erosion 侵蝕危害gully and valley erosion 溝谷侵蝕gully erosion development process 溝蝕演變collapse gully erosion 崩崗侵蝕 返回 gully erosion