四川盆地西部漂洗土壤区水体铁元素的分布特征

铁是水质监测的重要指标。为了弄清四川盆地西部漂洗土壤区不同水环境中铁的形态和含量、浅层潜水的季节动态及其形成原因,为该区土、水资源合理利用提供一定参考,于不同时期在四川省名山县漂洗土壤区采集潜水、池塘水、稻田和茶园沟渠地表水、土壤孔隙水及相应的土壤样品,分析了其铁的形态和含量及相应的理化性质。结果表明,从潜水和土壤孔隙水来看,潜水总铁和亚铁含量（分别为0.30、0.08mg·L^-1）均为最低,稻田孔隙水总铁和亚铁含量（分别为2.92、1.13mg·L^-1）均为最高,茶园孔隙水总铁和亚铁含量（3a生以下茶园分别为1.25、0.92mg·L^-1,6a生以上茶园分别为2.66、0.65mg·L^-1）居中;就稻田和茶园的土壤孔隙水与沟渠地表水比较而言,孔隙水总铁和亚铁含量总体上高于沟渠地表水相应的总铁和亚铁含量;潜水总铁和亚铁含量分别变动在0~0.86mg·L^-1和0~0.36mg·L^-1之间,其季节动态在不同区域间存在一定差异,与其所处地形部位及地表径流条件、离居民房屋和畜禽圈舍远近、土壤pH、有机质和铁元素的形态和含量、土地利用方式及作物种植年限、天气状况及水井自身氧化还原电位等条件有关。

Distribution of Iron in Water in Bleached Soil Region of the West Sichuan Basin, China

Iron is the important index of water quality monitoring. To study the iron form and content in different water body and the seasonal dynamic of groundwater in bleached soil area in the west of Sichuan Basin, surface and ground water samples from well, pool, paddy field and tea garden, and soil samples from paddy field and tea garden were collected in Mingshan County, Sichuan Province at different time, then the form and content of iron, and other basic chemical properties in water and soil were analyzed. The results showed that the content of total and ferrous iron in groundwater（0.30 mg·L^-1 and 0.08 mg·L^-1, respectively） was the lowest, and that in porewater from paddy field（2.92 mg·L^-1 and 1.13 mg·L^-1, respectively） was the highest. The content of total and ferrous iron in porewater from paddy field was higher than that from tea garden（1.25 mg·L^-1 and 0.92 mg·L^-1 from less than 3 years tea garden, 2.66 mg·L^-1 and 0.65 mg·L^-1 from more than 6 years tea garden）. The content of total and ferrous iron in porewater was higher than that in surface water. The content of total iron varied from 0 to 0.86 mg·L^-1, and the ferrous iron content varied from 0 to 0.36 mg·L^-1, and seasonal dynamic of iron in groundwater in different area was different. These were related to topography position, surface runoff condition, distance to house of human and animal, soil pH, form and content of organic matter and iron in soil, type and time of land use, weather status and micro-environment of well itself.