研究论文
单保庆,尹澄清,于静,白颖.降雨-径流过程中土壤表层磷迁移过程的模拟研究[J].环境科学学报,2001,21(1):7-12
降雨-径流过程中土壤表层磷迁移过程的模拟研究
- Study on phosphorus transport in the surface layer of soil with rainfall simulation method
- 基金项目:国家自然科学基金资助项目(49771067)
- 单保庆
- 中国科学院生态环境研究中心环境水化学国家重点实验室,北京 100085
- 尹澄清
- 中国科学院生态环境研究中心环境水化学国家重点实验室,北京 100085
- 摘要:以人工降雨的方法,对巢湖边旱作表层土壤在降雨后所产生的磷迁移过程进行了研究.结果表明:在两种雨强值(70mm和35mm)90min内模拟的降雨过程中,供试的土壤产生两种径流模式:表面径流和土壤内部壤中流.降雨强度大,表面径流和壤中流始流时间早,水流量和浓度相应高,累积输出也多.相同雨强下,农田作物的覆盖作用能促进壤中流,减缓表面流,但对始流时间的影响不大.4种模拟土壤类型的表面径流累积输出的大小顺序为:BN70(降雨量70mm,盖度为0)>BC70(降雨量70mm,盖度为80%)>BN35(降雨量35mm,盖度为0)>BC35(降雨量35mm,盖度为80%),壤中流的量序为:YC70>YN70>YC35>YN35.裸露土壤的总磷浓度曲线呈波浪状递减,作物覆盖土壤则呈均匀缓慢的递减趋势.土壤物理结构和作物特征对溶解性总磷的变化趋势起主导作用.在中到大雨条件下,壤中累积输出的径流量都低于表面流,差幅决定于土壤表层界面特征.表面径流中的磷迁移量是壤中流的3-4倍.
- Abstract:The phosphorus transport in the crop soil within Liuchahe watershed was studied with rainfall simulation method. The results showed that, under two simulated rainfall intensities (precipitation 70mm and 35mm, within 90minutes), there were two runoff forms: surface runoff and subsurface runoff. The water flow volume and phosphorus concentration in both runoffs increased with the rainfall intensity improved; during the same rainfall event, the coverage of crop increased the process of subsurface runoff and impeded the surface runoff. The TP concentration change of soil with no crop coverage exported declinedly in a wavy way, but it showed an equable decline when crop existed. The crop coverage and soil porosity influenced the concentration variation of the dissolved phosphorus (DP), especially in the subsurface runoff. The water volume of surface runoff was less than the subsurface runoff in both events, and the export difference of phosphorus between two runoff types during the same rainfall event was 3 to 4 times.
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