南方崩岗侵蚀机理及治理浅见

崩岗是南方红壤丘陵区生态安全、粮食安全、防洪安全和人居安全的主要威胁。降雨入渗会引起土体的湿胀干缩,增大土体的崩解特性,减小土体的抗剪强度、凝聚力,加重土体,扩大裂隙面,从而使大量土体崩塌,崩岗的最大后退速率可达11. 7 m/a。崩岗综合治理措施布局可概括为"上截、中削、下堵、内外绿化"。如果排水沟或削坡等工程措施不能有效地阻止大量雨水下渗,在一定程度上反而会增强崩岗的发展。通过调查发现,种植生态林可以有效阻止崩岗的发展。因此,建议调整崩岗治理的思路,大力提倡生态修复来进行崩岗治理,在一定程度上也可节省人力、财力。

Mechanism of hillock collapsing erosion in Southern China and its control suggestions

Hillock collapse is a major threat to the security of local ecology, food, flood control and human settlement in south China. Rainfall infiltration would cause soil swelling and shrinkage, increase soil collapse potential, reduce soil shear strength and cohesion, increase soil mass weight and enlarge the soil crack, thus resulting in numerous soil collapse with the maximum collapse rate up to 11.7 m / a. Currently comprehensive control measures for hillock collapsing erosion can be summarized as: building drainage ditch or planting hedgerow on hillock, cutting gully slope, building check dam at hillock foot, afforesting all over the hillock. However, if the above structure measures can not effectively resist massive precipitation into soil, the hillock collapse will aggregated instead. The investigation discovered that ecological forest can prevent the development of hillock collapsing very effectively. Consequently, the traditional structural hillock collapse control should be transformed to ecological restoring, which can reduce manual labor and save money to a certain.