The dramatic drop in elevation causes the rivers and streams to erode the land more rapidly, and the HuaTung Valley has a limited hinterland, giving it almost no ecological protection belt to speak of. The soil is thus simply sloshed down around the villages and towns in the valley at the foot of the mountains. The complete eradication of Tungmen Village two years ago and of Hungyeh Village last year are tragic testimony.
急劇的落差，使溪流沖蝕更劇烈，而花東縱谷腹地有限，幾乎沒有生態緩衝帶可言，水土直接就泛濫在山腳下的部落與谷地上的市鎮，前年的銅門村與去年紅葉村整個淹沒，都是慘烈的例證。