DOI: 10.5194/hess-19-3349-2015
Scopus记录号: 2-s2.0-84938634486
论文题名: Investigating suspended sediment dynamics in contrasting agricultural catchments using ex situ turbidity-based suspended sediment monitoring
作者: Sherriff S ; C ; , Rowan J ; S ; , Melland A ; R ; , Jordan P ; , Fenton O ; , Huallacháin D ; O
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2015
卷: 19, 期: 8 起始页码: 3349
结束页码: 3363
语种: 英语
Scopus关键词: Agriculture
; Catchments
; Dynamics
; Erosion
; Land use
; Risk analysis
; Runoff
; Sediments
; Soils
; Storms
; Turbidity
; Water quality
; Agricultural activities
; Agricultural catchments
; Experimental catchments
; High temporal resolution
; High-resolution monitoring
; Interannual variability
; Landscape characteristic
; Suspended sediment concentrations
; Suspended sediments
; agricultural catchment
; annual variation
; bare soil
; data set
; drainage network
; environmental monitoring
; fluvial deposit
; flux measurement
; grassland
; landscape structure
; precipitation (climatology)
; resolution
; risk factor
; river water
; sediment transport
; soil erosion
; suspended sediment
; turbidity
; water quality
; Ireland
英文摘要: Soil erosion and suspended sediment (SS) pose risks to chemical and ecological water quality. Agricultural activities may accelerate erosional fluxes from bare, poached or compacted soils, and enhance connectivity through modified channels and artificial drainage networks. Storm-event fluxes dominate SS transport in agricultural catchments; therefore, high temporal-resolution monitoring approaches are required, but can be expensive and technically challenging. Here, the performance of in situ turbidity sensors, conventionally installed submerged at the river bankside, is compared with installations where river water is delivered to sensors ex situ, i.e. within instrument kiosks on the riverbank, at two experimental catchments (Grassland B and Arable B). The in situ and ex situ installations gave comparable results when calibrated against storm-period, depth-integrated SS data, with total loads at Grassland B estimated at 12 800 and 15 400 t, and 22 600 and 24 900 t at Arable B, respectively. The absence of spurious turbidity readings relating to bankside debris around the in situ sensor and its greater security make the ex situ sensor more robust. The ex situ approach was then used to characterise SS dynamics and fluxes in five intensively managed agricultural catchments in Ireland which feature a range of landscape characteristics and land use pressures. Average annual suspended sediment concentration (SSC) was below the Freshwater Fish Directive (78/659/EEC) guideline of 25 mg Lg'1, and the continuous hourly record demonstrated that exceedance occurred less than 12 % of the observation year. Soil drainage class and proportion of arable land were key controls determining flux rates, but all catchments reported a high degree of inter-annual variability associated with variable precipitation patterns compared to the long-term average. Poorly drained soils had greater sensitivity to runoff and soil erosion, particularly in catchments with periods of bare soils. Well drained soils were less sensitive to erosion even on arable land; however, under extreme rainfall conditions, all bare soils remain a high sediment loss risk. Analysis of storm-period and seasonal dynamics (over the long term) using high-resolution monitoring would be beneficial to further explore the impact of landscape, climate and land use characteristics on SS export. © Author(s) 2015. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/78457
Appears in Collections: 气候变化事实与影响
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作者单位: Johnstown Castle Research Centre, Teagasc, Wexford, Ireland; School of the Environment, University of Dundee, Dundee, United Kingdom; National Centre for Engineering in Agriculture, University of Southern Queensland, Toowoomba, Australia; School of Environmental Sciences, Ulster University, Coleraine, Co. Derry, United Kingdom; Agricultural Catchments Programme, Johnstown Castle Research Centre, Teagasc, Wexford, Ireland
Recommended Citation:
Sherriff S,C,, Rowan J,et al. Investigating suspended sediment dynamics in contrasting agricultural catchments using ex situ turbidity-based suspended sediment monitoring[J]. Hydrology and Earth System Sciences,2015-01-01,19(8)