金川河水位变化对河岸带表土层土壤理化性质的影响

Influence of Water Level of Jinchuan River Change on Soil Physical and Chemical Properties in Topsoil Layer of River Bank Zone

以金川河为例，沿河岸带纵向在3个取样点采取18个土壤样本，研究高低水位条件下河岸带不同深度表土层的土壤理化性质，探讨了水位变化对河岸带表土层土壤理化性质及氮磷元素形态分布的影响规律。结果表明，在同一水位条件下，随着土层深度的增加。土壤含水率、容重均有所增加，孔隙率有所减小，pH值变化幅度不大（维持在中性），Eh、全氮、氨氮、全磷、有效磷浓度均有所减少，而硝氮浓度有所增加；20～40cm土层的土壤理化特性受河流水位变化的影响显著，而长期浸泡在河水下的河岸带土壤以及河水高水位以上河岸带土壤的理化性质受水位变化的影响不明显；土壤氮素和磷素各形态在高低水位条件下垂向变化规律基本一致。

Taking Jinchuan River for an example, 18 sediment samples at 3 sampling sites along the longitudinal di- rection of river bank zone are collected, and the influence law of water level changes on the soil physical and chemical properties and the species distribution of nitrogen and phosphorus in the topsoil of the river bank zone are discussed. The results show that under the condition of the same level, with the increase of soil depth, soil moisture content and bulk density increase, but the porosity decreases, and the pH value changes slightly and it remains neutral; Eh and the concen- tration of total nitrogen, ammonia nitrogen, total phosphorus, available phosphorus decrease; the concentration of Ni trate increases; as the water level change area of this test, physical and chemical characteristics of 20 40 cm soil layer is significantly affected by the river water level changes; river bank zone soil under long-term soaking in the water and the zone above the high water level, which physical and chemical properties affected by water level change are not obvious; in the high and low water level conditions, the vertical variation law of the nitrogen, phosphorous with various forms is basi- cally the same.