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在贵州全境建造石头梯田来减少水土流失的现象十分普遍。但此项技术本身却有其固有的风险性。石头梯田通常比土质的梯田高,填在石头挡墙中的土壤的量更大,更易导致梯田的垮塌,也会减少梯田上部的土壤,降低土壤的养分和水分含量。石头的挡墙会威胁土地的长期生产力,因为一旦石头挡墙垮塌,所有的碎石就会堆积在下部的梯田中,使耕作十分困难。这种垮塌现象会通过增加地表径流而形成冲沟,使向下的沉积物运输增加。尤其是梯田之间的人工排水道使这种风险加剧。因为这种排水道使降水很难渗人土壤中,使土壤的保水和蓄水能力下降,从而造成作物的受旱。水流通过排水道输送的速度加快,很容易造成水流的汇集,增加洪水泛滥的可能性。由于建造了排水道,即使一般的暴雨,也会因为输送速度的加快而导致洪峰升高而成灾。因此,对水土流失的工程治理方式不应该取代、而应该与好的土地管理策略相结合。尽管土地利用方式有所改变,但通过采用新技术和坚持可持续发展的原则,在此类的土地上仍可获得最高的产量。图7表1参14。
It is very common to build stone terraces throughout Guizhou to reduce soil erosion. But the technology itself has its inherent risks. The stone terraces are usually taller than the terraced terraces. The amount of soil filled in the stone retaining wall is larger and more likely to lead to the collapse of the terraces. It also reduces the soil in the upper part of the terraces and reduces soil nutrients and moisture content. The stone retaining wall threatens the long-term productivity of the land because once the stone wall collapses, all the gravel will pile up in the lower terraces, making farming difficult. This collapsing phenomenon creates gullys by increasing surface runoff, increasing the transport of sediments downwards. This risk is exacerbated, in particular, by the artificial drains between the terraces. Because this drainage channel makes it difficult for precipitation to infiltrate into the soil, reducing the ability of the soil to retain water and retain water, resulting in crop drought. Water flow through the drainage channels to speed up, it is easy to cause the collection of water flow, increase the possibility of flooding. Due to the construction of the drainage channel, even heavy rains could be disastrous because of the rising peak due to the speeding up of the conveyance. Therefore, the project management of soil and water loss should not be replaced, but should be combined with good land management strategies. Despite the changes in land use patterns, the highest yields are still achievable on such land through the adoption of new technologies and adherence to the principle of sustainable development. Figure 7 Table 1 reference 14.