Oklahoma State University, Biosystems and Agricultural Engineering, 245 Agricultural Hall, Stillwater, OK, USA.
Oklahoma State University, Department of Plant and Soil Sciences, 268 Agricultural Hall, Stillwater, OK, USA.
J Environ Manage. 2016 Oct 1;181:602-614. doi: 10.1016/j.jenvman.2016.06.071. Epub 2016 Aug 5.
Sediment and phosphorus (P) are two primary pollutants of surface waters. Many studies have investigated loadings from upland sources or even streambed sediment, but in many cases, limited to no data exist to determine sediment and P loading from streambanks on a watershed scale. The objectives of this paper are to review the current knowledge base on streambank erosion and failure mechanisms, streambank P concentrations, and streambanks as P loading sources and then also to identify future research needs on this topic. In many watersheds, long-term loading of soil and associated P to stream systems has created a source of eroded soil and P that may interact with streambank sediment and be deposited in floodplains downstream. In many cases streambanks were formed from previously eroded and deposited alluvial material and so the resulting soils possess unique physical and chemical properties from adjacent upland soils. Streambank sediment and P loading rates depend explicitly on the rate of streambank migration and the concentration of P stored within bank materials. From the survey of literature, previous studies report streambank total P concentrations that consistently exceeded 250 mg kg(-1) soil. Only a few studies also reported water soluble or extractable P concentrations. More research should be devoted to understanding the dynamic processes between different P pools (total P versus bioavailable P), and sorption or desorption processes under varying hydraulic and stream chemistry conditions. Furthermore, the literature reported that streambank erosion and failure and gully erosion were reported to account for 7-92% of the suspended sediment load within a channel and 6-93% of total P. However, significant uncertainty can occur in such estimates due to reach-scale variability in streambank migration rates and future estimates should consider the use of uncertainty analysis approaches. Research is also needed on the transport rates of dissolved and sediment-bound P through the entire stream system of a watershed to identify critical upland and/or near-stream conservation practices. Extensive monitoring of the impact of restoration/rehabilitation efforts on reducing sediment and P loading are limited. From an application standpoint, streambank P contributions to streams should be more explicitly accounted for in developing total maximum daily loads in watersheds.
泥沙和磷（P）是地表水中的两种主要污染物。许多研究已经调查了来自高地源甚至河床泥沙的负荷，但在许多情况下，流域尺度上确定来自河岸边坡的泥沙和 P 负荷的数据有限或不存在。本文的目的是回顾当前关于河岸侵蚀和破坏机制、河岸 P 浓度以及河岸作为 P 负荷源的知识库，然后确定该主题的未来研究需求。在许多流域中，土壤和相关 P 向溪流系统的长期负荷已经产生了一个侵蚀土壤和 P 的来源，这些土壤和 P 可能与河岸泥沙相互作用，并在下游洪泛区沉积。在许多情况下，河岸是由先前侵蚀和沉积的冲积材料形成的，因此形成的土壤具有与相邻高地土壤不同的物理和化学特性。河岸泥沙和 P 负荷速率明确取决于河岸迁移的速率和储存在岸材料中的 P 浓度。从文献调查来看，以前的研究报告表明，河岸总 P 浓度始终超过 250mgkg(-1)土壤。只有少数研究还报告了水溶性或可提取 P 浓度。应投入更多研究来了解不同 P 库（总 P 与生物可利用 P）之间的动态过程，以及在不同水力和溪流化学条件下的吸附或解吸过程。此外，文献报告称，河岸侵蚀和破坏以及沟壑侵蚀占河道中悬浮泥沙负荷的 7-92%，占总 P 的 6-93%。然而，由于河岸迁移率在流域尺度上存在变化，因此这种估计会存在很大的不确定性，未来的估计应考虑使用不确定性分析方法。还需要研究通过流域整个溪流系统运输溶解态和固着态 P 的速率，以确定关键的高地和/或近岸保护措施。对减少泥沙和 P 负荷的恢复/修复工作的影响进行广泛监测的工作有限。从应用的角度来看，在流域中制定最大日负荷总量时，应更明确地考虑河岸 P 对溪流的贡献。
