亚热带典型小流域磷收支及流失特征对比研究

发布时间：2018-08-24 07:46

【摘要】：磷素(P)在环境中的过量累积是导致农业面源污染的主要因素。论文以湖南省长沙县脱甲河农区小流域(52 km2)和涧山河森林-农区小流域(50 km2)为研究单元,基于入户调查资料和连续4 a的流域把口站水文水质定位观测数据,采用物质流分析法,对比研究了亚热带丘陵区典型小流域P的收支平衡及流失特征。结果表明,农区小流域出口地表水总磷(TP)含量变化为0.03~0.68 mg·L-1,平均含量为0.21 mg·L-1,整体达到Ⅲ类水质标准;森林-农区小流域TP含量变化范围为0.01~0.35 mg·L-1,平均为0.08 mg·L-1,整体为Ⅱ类水质,表明森林-农区小流域地表水水质明显优于农区小流域。农区小流域P的环境滞留强度(32.0 kg·hm-2·a-1)显著高于森林-农区小流域(20.6 kg·hm-2·a-1),对环境影响更大。以2013年为例,农区小流域P的主要输入项为饲料,占53.1%,森林-农区小流域则以肥料为主,占53.0%;两个流域的P输出项都以植物和畜禽产品输出为主,均占总输出量的94.0%左右。控制小流域肥料和饲料投入、增加循环利用途径以及提高P利用率是当前减轻水体富营养化的有效途径。
[Abstract]:Excessive accumulation of phosphorus (P) in the environment is the main factor leading to agricultural non-point source pollution. This paper takes the small watershed (52 km2) and the small watershed (50 km2) of Jianshan River forest agricultural area as the research units, based on the household survey data and the hydrological and water quality observation data of the river basin at Baikou station for 4 consecutive years. The characteristics of P budget balance and loss in typical small watershed in subtropical hilly region were studied by means of material flow analysis. The results showed that the content of total phosphorus (TP) in the surface water of small watershed was 0.03 ~ 0.68 mg / L ~ (-1), and the average content was 0.21 mg / L ~ (-1), which reached the standard of class 鈪，

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