Small reservoir effects on headwater water quality in the rural-urban fringe, Georgia Piedmont, USA
Small reservoir effects on headwater water quality in the rural-urban fringe, Georgia Piedmont, USA
复制标题
DOI：
10.1016/j.ejrh.2016.08.005
复制
发表时间：
2016-12-01
影响因子：
4.7
通讯作者：
Rasmussen, Todd C.
中科院分区：
文献类型：
--
作者：
Ignatius, Amber R.;Rasmussen, Todd C.
小型水库是影响源头河流物理、化学和生物特征的普遍景观特征。过去一个世纪，美国境内修建了数以万计的小型水库，通常面积不到一公顷。虽然遥感和地理测绘技术有助于识别和量化这些特征，但它们对水质的局部影响尚不确定。我们报告了对佐治亚州皮埃蒙特奥科尼和布罗德河流域内的九个小型水库（0.15-2.17 公顷）进行的为期一年的物理化学研究。研究地点是沿着城乡梯度选择的，具有不同数量的农业、森林和发达土地覆盖。每月对站点的排放和流入/流出水质参数（温度、电导率、pH、溶解氧、浊度、碱度、总磷、总氮、硝酸盐、铵）进行采样。虽然流域内发达土地覆盖的比例与水库比电导率值呈正相关，但农业和林地覆盖与水库碱度、总氮、硝酸盐和比电导率呈正相关（分别为正相关和负相关）。全年所有土地利用的大部分流出温度都高于流入温度，尤其是在夏季。流出物的硝酸盐浓度较低，但铵浓度较高。流出结构的类型也有影响；顶部泄水坝的溶解氧和 pH 值高于底部泄水坝。大坝以下 250 m 处的水质影响仍然明显，但有所减弱。 (C) 2016 年作者。由 Elsevier B.V. 出版
Small reservoirs are prevalent landscape features that affect the physical, chemical, and biological characteristics of headwater streams. Tens of thousands of small reservoirs, often less than a hectare in size, were constructed over the past century within the United States. While remote-sensing and geographic-mapping technologies assist in identifying and quantifying these features, their localized influence on water quality is uncertain. We report a year-long physicochemical study of nine small reservoirs (0.15-2.17 ha) within the Oconee and Broad River Watersheds in the Georgia Piedmont. Study sites were selected along an urban-rural gradient with differing amounts of agricultural, forested, and developed land covers. Sites were sampled monthly for discharge and inflow/outflow water quality parameters (temperature, specific conductance, pH, dissolved oxygen, turbidity, alkalinity, total phosphorus, total nitrogen, nitrate, ammonium). While the proportion of developed land cover within watersheds had positive correlations with reservoir specific conductivity values, agricultural and forested land covers showed correlations (positive and negative, respectively) with reservoir alkalinity, total nitrogen, nitrate, and specific conductivity. The majority of outflow temperatures were warmer than inflows for all land uses throughout the year, especially in the summer. Outflows had lower nitrate concentrations, but higher ammonium. The type of outflow structure was also influential; top-release dams showed higher dissolved oxygen and pH than bottom-release dams. Water quality effects were still evident 250 m below the dam, albeit reduced. (C) 2016 The Authors. Published by Elsevier B.V.