Typical annual sediment yields for

Typical annual sediment yields for the study area have been estimated as being

greatest for the River Dart basin (58 t km2 yr−1), and at a minimum for the River

Culm (20 t km2 yr−1) and Upper Exe (19 t km2 yr−1) basins. The mean annual

sediment yields of the remaining study basins range from 26 t km2 yr−1 (River Clyst)

to 39 t km2 yr−1 (River Creedy). The maximum suspended sediment concentration

sampled at each of the study sites during the study period follows a similar trend.

Sampled suspended sediment concentrations were at a maximum in the River Dart

at Bickleigh (2024 mg l−1) while the lowest recorded values of this parameter were

associated with the Upper Exe (241.7 mg l−1) at Pixton and the River Culm at Rewe

(406 mg l−1). Intermediate values of maximum sampled suspended sediment concen-
tration were obtained for the River Clyst at Clyst Honiton (667 mg l−1), River Creedy

at Cowley (887 mg l−1), and River Exe at Thorverton (805 mg l−1), while relatively

high values of 1040 mg l−1 and 1275 mg l−1 were recorded for the Jackmoor Brook

at Pynes Cottage and Yendacott, respectively. The APSD of suspended sediment has

also been previously shown to differ between the study sites.29,30 While the precise

values of the absolute particle size statistics reported depend on the measurement tech-
nique employed, the study period mean values of the median absolute particle size

(Ad50) measured in this study are consistent with those of the previous studies in the

Exe Basin. In particular, suspended sediment collected from the Upper Exe at Pixton

had a characteristically coarser Ad50 (7.7 μm) than all the other study sites. In addi-
tion, suspended sediment samples collected from those basins underlain primarily by

Permian strata (the Clyst, Yendacott, Jackmoor Brook, and Culm catchments) were

characterized by a considerably finer median particle size (4.2 μm, 4.3 μm, 4.6 μm,

and 5.0 μm, respectively) than those collected from the River Exe at Thorverton

(6.5 μm), and River Dart at Bickleigh (6.1 μm), which are underlain primarily by

Devonian and Carboniferous rocks, respectively.