平原地区同样有水土流失问题。当然,从绝对量来看,土壤侵蚀模数远较山丘地区为低。但由于平原地区有平原地区的特点,它的水土流失现象也有其特殊的问题,如果再结合灌溉退水因素,情况就更复杂了。例如,平原地区河道纵断面比降小,水流输沙能力也远较山区河流为低,即使在含沙量较低的情况下,也可能造成淤积,产生严重的内涝问题,或大大增加清淤工作量。为了从根本上解决平原河流泥沙问题,就要弄清不同来源的产沙量,才能据此采取防止侵蚀、控制引水、调整水利工程规划设计或运用方式等不同的对策。因此,在特定具体情况下,平原地区设置观测站,研究水土流失现 The same problem of water and soil loss in the plain area. Of course, in absolute terms, the modulus of soil erosion is much lower than in the hills. However, due to the characteristics of plains in the plain area, its soil erosion also has its own special problems. If combined with the factors of irrigation and drainage, the situation is even more complicated. For example, river courses in the plains have a smaller vertical section ratio and a lower capacity to runoff sediment than mountainous rivers, causing siltation, serious waterlogging problems or much higher dredging even at low sediment concentrations Workload. In order to fundamentally solve the problem of sediment and sediment in plain rivers, it is necessary to understand the sediment yield of different sources so that different measures such as preventing erosion, controlling diversion of water resources and adjusting the planning, design and operation of water conservancy projects can be taken accordingly. Therefore, in specific situations, observatories should be set up in the plain areas to study the present situation of soil erosion