Transport of agrichemicals to ground and surface water in a small central Indiana watershed
Transport of agrichemicals to ground and surface water in a small central Indiana watershed
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DOI：
10.2134/jeq1998.00472425002700040024x
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发表时间：
1998-07-01
影响因子：
2.4
通讯作者：
Moore, RC
中科院分区：
文献类型：
--
作者：
Fenelon, JM;Moore, RC
调查了糖溪流域水中农用化学品的存在、分布、浓度和途径，糖溪流域是美国中西部典型的排水不良的农业流域。1992年5月至1996年8月，从糖溪、两条排水沟和一条通往糖溪的地下水流动路径沿线的11口井采集了水样，分析了N和农药化合物，硝酸盐是主要的N物种，农药在糖溪泛滥平原的冲积含水单元中普遍存在。在密闭分层漂移含水层中，氨是主要的氮素形态，农药很少。瓦片排水沟通过将土壤孔隙水和含有高浓度硝酸盐(NO3)和农药的浅层地下水输送到糖溪中，直接影响到糖溪的水质。当瓦片排水沟流动时(通常是12月至7月)，小溪中NO3浓度的升高(2-10 mg/L NO3N)与排放到小溪的瓦片排水沟中的NO3浓度(2-23 mg/L NO3N)相关。同样，随着阿特拉津和阿特拉津代谢物的浓度，瓷砖排水流出物的季节性趋势与糖溪的季节性趋势相似。当瓦片排水沟干涸时，小溪中的NO3浓度很低，这表明向小溪排放的地下水大多是陈旧的或反硝化的水。在低流量时，小溪中微量的杀虫剂水平可能是冲积含水层渗漏的结果。
The occurrence, distribution, concentrations, and pathways of agrichemicals in water were investigated in the Sugar Creek watershed, a poorly drained agricultural watershed typical of many watersheds in the midwestern USA, Water samples from Sugar Creek, two the drains, and 11 wells along a groundwater flowpath to Sugar Creek were collected between May 1992 and August 1996 and analyzed for N and pesticide compounds, Nitrate was the principal N species and pesticides were common in alluvial water-bearing units in the Sugar Creek floodplain. In the confined stratified drift aquifers, ammonia was the principal N species and pesticides were rare. Tile drains directly affected the water quality in Sugar Creek by transporting soil pore water and shallow groundwater containing high concentrations of nitrate (NO3) and pesticides to the creek. When tile drains were flowing (typically December through July), elevated NO3 concentrations (2-10 mg/L NO3N) in the creek correlated with high NO3 concentrations (2-23 mg/L NO3N) in tile drains discharging to the creek. Likewise, with concentrations of atrazine and atrazine metabolites, seasonal trends in the tile-drain effluent were similar to seasonal trends in Sugar Creek. When tile drains went dry, NO3 concentrations in the creek were low, indicating most groundwater discharge to the creek consisted of old or denitrified water. Trace levels of pesticides in the creek at low flow probably were the result of seepage from alluvial water-bearing units.