TY - JOUR

T1 - Temporal dynamics between cattle in-stream presence and suspended solids in a headwater catchment

AU - Terry, Julie

AU - Benskin, Clare

AU - Eastoe, Emma

AU - Haygarth, Philip

PY - 2014/1/31

Y1 - 2014/1/31

N2 - Cattle in-stream activity is potentially an important contributor to water pollution from agriculture. Here we present research on the physical movements of cattle within a stream on suspended solid concentrations (SSC). This study used camera surveillance to monitor the in-stream activity of dairy cattle in an unfenced reach over a four-month period. Results were compared against high-resolution SSC data. Over the days that cattle grazed the field, 57.9% of the instances when SSC crossed the 25 mg l1 Freshwater Fish Directive guideline threshold can be attributed to cattle presence in the stream. Flow was the main driver of total sediments transported over the study period, and no relationship was found between SSC and the absolute number of cattle feet in the water. Hysteresis analysis indicated a ‘first-flush’ of local sediments rapidly mobilised during the non-cattle related SSC events, a result of cattle proximity to channel margins. Results demonstrate a temporal lag between cattle in-stream presence and a critical amount of their contribution to sediment load, and that monitoring only instantaneously with cattle activity may lead to underestimation of their pollution impact.

AB - Cattle in-stream activity is potentially an important contributor to water pollution from agriculture. Here we present research on the physical movements of cattle within a stream on suspended solid concentrations (SSC). This study used camera surveillance to monitor the in-stream activity of dairy cattle in an unfenced reach over a four-month period. Results were compared against high-resolution SSC data. Over the days that cattle grazed the field, 57.9% of the instances when SSC crossed the 25 mg l1 Freshwater Fish Directive guideline threshold can be attributed to cattle presence in the stream. Flow was the main driver of total sediments transported over the study period, and no relationship was found between SSC and the absolute number of cattle feet in the water. Hysteresis analysis indicated a ‘first-flush’ of local sediments rapidly mobilised during the non-cattle related SSC events, a result of cattle proximity to channel margins. Results demonstrate a temporal lag between cattle in-stream presence and a critical amount of their contribution to sediment load, and that monitoring only instantaneously with cattle activity may lead to underestimation of their pollution impact.

KW - Diffuse pollution

KW - cattle

KW - suspended solids

KW - in-stream activity

KW - hysteresis

U2 - 10.1039/c3em00686g

DO - 10.1039/c3em00686g

M3 - Journal article

VL - 16

SP - 1570

EP - 1577

JO - Environmental Science: Processes and Impacts

JF - Environmental Science: Processes and Impacts

SN - 2050-7887

IS - 7

ER -