Dataset to "Fine-sediment erosion and ridge morphodynamics in coarse-grained immobile beds"

The dataset is connected to the paper "Fine-sediment erosion and ridge morphodynamics in coarse-grained immobile beds".

The dataset is subdivided in "topographic" and "PIV" data. Each dataset refers to an experiment presented in the paper.

The filenames of the topographic data specify the location where the data were collected ("upstream" or "downstream"). The topographic data contain the bed elevations measured around each sphere over a measurement area as wide as the channel and covering nine patterns of spheres (see paper for a definition of the pattern of spheres). Each topographic dataset contains four structures:

- A time vector "T" identifying the sampling times at which the bed topography was measured (unit: h)

- A space vector "x" identifying the streamwise position of the spheres with the origin of the coordinate system positioned at the beginning of the measurement areas (upstream or downstream) - unit cm

- A space vector "y" identifying the transverse position of the spheres with the coordinate system centred in the middle of the channel and positively oriented towards the left side of the flume looking in streamwise direction - unit cm

- A matrix "Z" identifying the protrusion levels of the spheres  (as defined in the paper) as a function of space and time (x times y times T) - unit cm

The PIV data were acquired during experiments 1b and 5b at the upstream location. The data are a collection of the velocity fields measured above the top of the spheres and over two pattern of spheres in the middle "m" and in the quarter plane "q" of the channel for three different time instants (t1, t2, t3) during the experiments. Each dataset contains 6 variables:

- the "sampling time" of the bursts - unit s

- the "acquisition time" of the PIV run during the experiments - unit h

- a vector "x" identifying the streamwise position of the velocity vectors for a coordinae system centred in the centre of the sphere and pointing in the longitudinal direction.

- a vector "z" identifying the vertical direction of the coordinate system with the origin at the top of the sphere and pointing upwards - unit cm

- a matrix "vx" containing 1000 fields of the streamwise velocity component - unit cm/s

- a matrix "vz" containing 1000 fields of the vertical velocity component - unit cm/s