According to climate condition , soil condition and afforesting tree species and water requirement rule of forest and grass , the paper analysed and calculated the slope length for collecting stream of three site preparation methods which were reverse - slope terrace , level trench and scale - hole , and the slope length for collecting stream of deferent gradients and planting bandwidths were acquired 摘要根据宁南山区的气候、土壤、造林树种等，按照林草植被建设的水分需求规律，对不同水上流失区的反坡梯田、水平沟、鱼鳞坑3种整地方式的集流坡面长度进行分析与推算，计算出了不同坡度、植树带宽度下的集流坡长。
