High-frequency dissolved organic carbon and nitrate measurements reveal differences in storm hysteresis and loading in relation to land cover and seasonality

被引：170

作者：

Vaughan, M. C. H. ^{[1
]}

Bowden, W. B. ^{[1
]}

Shanley, J. B. ^{[2
]}

Vermilyea, A. ^{[3
]}

Sleeper, R. ^{[1
]}

Gold, A. J. ^{[4
]}

Pradhanang, S. M. ^{[4
]}

Inamdar, S. P. ^{[5
]}

Levia, D. F. ^{[5
]}

Andres, A. S. ^{[5
]}

Birgand, F. ^{[6
]}

Schroth, A. W. ^{[1
]}

机构：

[1] Univ Vermont, Burlington, VT 05405 USA

[2] US Geol Survey, Montpelier, VT USA

[3] Castleton Univ, Castleton, VT USA

[4] Univ Rhode Isl, Kingston, RI 02881 USA

[5] Univ Delaware, Newark, DE USA

[6] North Carolina State Univ, Raleigh, NC USA

来源：

WATER RESOURCES RESEARCH | 2017年 / 53卷 / 07期

基金：

美国国家科学基金会;

关键词：

NORTHEASTERN UNITED-STATES; BY-PRODUCT PRECURSORS; HIGH-RESOLUTION; FORMATION POTENTIALS; NITROGEN POLLUTION; FLOOD EVENTS; PHOSPHORUS; EXPORT; MATTER; WATER;

D O I：

10.1002/2017WR020491

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Storm events dominate riverine loads of dissolved organic carbon (DOC) and nitrate and are expected to increase in frequency and intensity in many regions due to climate change. We deployed three high-frequency (15 min) in situ absorbance spectrophotometers to monitor DOC and nitrate concentration for 126 storms in three watersheds with agricultural, urban, and forested land use/land cover. We examined intrastorm hysteresis and the influences of seasonality, storm size, and dominant land use/land cover on storm DOC and nitrate loads. DOC hysteresis was generally anticlockwise at all sites, indicating distal and plentiful sources for all three streams despite varied DOC character and sources. Nitrate hysteresis was generally clockwise for urban and forested sites, but anticlockwise for the agricultural site, indicating an exhaustible, proximal source of nitrate in the urban and forested sites, and more distal and plentiful sources of nitrate in the agricultural site. The agricultural site had significantly higher storm nitrate yield per water yield and higher storm DOC yield per water yield than the urban or forested sites. Seasonal effects were important for storm nitrate yield in all three watersheds and farm management practices likely caused complex interactions with seasonality at the agricultural site. Hysteresis indices did not improve predictions of storm nitrate yields at any site. We discuss key lessons from using high-frequency in situ optical sensors.

引用

页码：5345 / 5363

页数：19

共 103 条

[1] Dissolved organic carbon and nitrogen in urban and rural watersheds of south-central Texas: land use and land management influences [J].