Groundwater-surface water exchange affects nitrogen and phosphorus exports from tideless rivers to a ria coast in the sea of Japan
Groundwater-surface water exchange affects nitrogen and phosphorus exports from tideless rivers to a ria coast in the sea of Japan
复制标题
地下水与地表水交换影响从无潮河流到日本海里亚海岸的氮和磷输出
DOI：
10.1016/j.jhydrol.2022.128045
复制
发表时间：
2022
影响因子：
6.4
通讯作者：
Ryo Sugimoto
中科院分区：
文献类型：
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作者：
Toshimi Nakajima;Ryo Sugimoto
沿着河流连续体下游地区的地下水排放被认为是水和养分的重要来源。然而，地下水排放对地表水和营养物从无潮河流向沿海海洋的净输出通量的影响尚未得到彻底评估。我们进行了实地调查，在下游地区的六个无潮河流与不同的流域特性沿着日本海若狭湾的ria海岸在夏季。建立了水、盐和222 Rn的质量平衡模型，以确定地下水通量和氮、磷的相关通量。该模型显示，地下水排放量为0.08 - 3.89 m d-1，占输出通量的1.3-14.8%。河流之间的这种变异性与每条河流的河床坡度相关，表明当地地形坡度是控制无潮河流地下水-地表水交换的重要因素。地下水排放占向近海输出的氮的0.8-16.7%和磷的0.9-27.4%。我们得出的结论是，驱动的水文和地理特性的流域下游地区的无潮河流的地下水流入是不可忽视的营养动态和生物生产在沿海海域。
Groundwater discharge in downstream regions along the river continuum is considered a significant source of water and nutrients. However, the influence of groundwater discharge on the net export flux of surface water and nutrients from tideless rivers to coastal seas has not been thoroughly assessed. We conducted field surveys in the downstream region of six tideless rivers with different watershed properties along the ria coast of Wakasa Bay in the Sea of Japan during the summer. Mass balance models of water, salt, and222Rn were constructed to determine groundwater fluxes and associated fluxes of nitrogen and phosphorus. The model revealed that groundwater discharge ranged from 0.08 to 3.89 m d−1, accounting for 1.3–14.8% of the export flux. This variability among the rivers correlated with the riverbed slope in each river, indicating that the local topographic gradient was a significant factor controlling groundwater-surface water exchange in tideless rivers. Groundwater discharge accounted for 0.8–16.7% of the nitrogen export and 0.9–27.4% of the phosphorus export to coastal seas. We concluded that the groundwater inflow driven by the hydrological and geographic properties of the watershed in the downstream region of tideless rivers was nonnegligible for nutrient dynamics and biological production in the coastal seas.