Phosphorus Losses from an Irrigated Watershed in the Northwestern United States: Case Study of the Upper Snake Rock Watershed
Phosphorus Losses from an Irrigated Watershed in the Northwestern United States: Case Study of the Upper Snake Rock Watershed
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DOI：
10.2134/jeq2014.04.0166
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发表时间：
2015-03-01
影响因子：
2.4
通讯作者：
Koehn, Anita C.
中科院分区：
文献类型：
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作者：
Bjorneberg, David L.;Leytem, April B.;Koehn, Anita C.
使用地表水进行灌溉的流域通常将一部分水返回水体。这种灌溉回流通常包括降低接受水体质量的沉积物和营养物。2005年至2008年在82，000公顷的上蛇岩（USR）流域进行的研究表明，平均而言，从蛇河引水每年向灌溉区提供547千克总悬浮固体（TSS），1.1千克总磷（TP）和0.50千克溶解磷（DP）。来自USR流域的灌溉回流贡献了414 kg ha（-1）TSS、0.71 kg ha（-1）TP和0.32 kg ha（-1）DP返回斯内克河。流入流域的TP明显多于返回蛇河的TP，而TSS和DP的流入和回流负荷之间没有显着差异。回流中的平均TSS和TP浓度分别为71和0.12毫克L-1，超过了TMDL限制的52毫克L-1 TSS和0.075毫克L-1 TP设置为这一段蛇河。监测流入和流出的五个水质池塘建造，以减少泥沙和磷的损失，从流域显示，TSS浓度降低了36至75%，但DP浓度仅降低了7至16%。这项研究表明，继续实施保护措施，应导致从USR流域的灌溉回流满足总的最大日负荷限制蛇河。
Watersheds using surface water for irrigation often return a portion of the water to a water body. This irrigation return flow often includes sediment and nutrients that reduce the quality of the receiving water body. Research in the 82,000-ha Upper Snake Rock (USR) watershed from 2005 to 2008 showed that, on average, water diverted from the Snake River annually supplied 547 kg ha(-1) of total suspended solids (TSS), 1.1 kg ha(-1) of total P (TP), and 0.50 kg ha(-1) of dissolved P (DP) to the irrigation tract. Irrigation return flow from the USR watershed contributed 414 kg ha(-1) of TSS, 0.71 kg ha(-1) of TP, and 0.32 kg ha(-1) of DP back to the Snake River. Significantly more TP flowed into the watershed than returned to the Snake River, whereas there was no significant difference between inflow and return flow loads for TSS and DP. Average TSS and TP concentrations in return flow were 71 and 0.12 mg L-1, respectively, which exceeded the TMDL limits of 52 mg L-1 TSS and 0.075 mg L-1 TP set for this section of the Snake River. Monitoring inflow and outflow for five water quality ponds constructed to reduce sediment and P losses from the watershed showed that TSS concentrations were reduced 36 to 75%, but DP concentrations were reduced only 7 to 16%. This research showed that continued implementation of conservation practices should result in irrigation return flow from the USR watershed meeting the total maximum daily load limits for the Snake River.