位山灌区农业活动对地下水水质的影响

为了研究位山引黄灌区农业活动对地下水的污染情况,采取点面结合方式对灌区地下水水质状况进行调查,分析地下水中氮、磷的质量浓度,并根据地下水评价标准进行单指标的水质评价。结果表明,位山灌区的地下水水质有30%左右劣于Ⅲ类水质标准,呈现逐年恶化趋势。由于灌区地势平缓,土壤水分以垂向运动为主,灌区地下水中氮素质量浓度受农田灌溉及施肥等农业活动的影响比较显著,近年来地下水中氮素质量浓度有所增加。指出通过灌溉渗漏和排水进入地下水的农业施肥可能是该区域的地下水中氮素逐年累积的主要原因。

Impacts of agricultural activities on ground water quality in Weishan irrigation district

In order to investigate the groundwater pollution status caused by agricultural activities in the Weishan irrigation district along the Yellow River, a water quality survey was carried out using the point-area combined method.The nitrogen and phosphorus concentration of the groundwater samples were measured and analyzed,and the water quality was assessed according the Quality Standards for Ground Water using the single-index method.The results showed that nearly 30% of the groundwater quality was worse than the level Ⅲ water standard,and the groundwater showed an obvious trend of deterioration year by year.Because of the plain geomorphology,the soil water mainly moved vertically.The nitrogen concentration in the groundwater was affected by irrigation and fertilization remarkably,and increased in recent years.Nitrogen leaching through irrigation and vertical drainage might be the major reason for the nitrogen accumulation in groundwater.