This dataset includes measurements of the temporal and spatial concentration distributions within a porous city block, conducted on a physical model scaled at 1:50 and 1:10 in the horizontal and vertical planes, respectively. The experimental setup consists of a 5.4 m long and 3.8 m wide tilting platform, where the flow along the X-axis is driven by a longitudinal bed slope (Sx = 0.12 %) with no transverse slope. The sidewalls of the block and the platform bottom are hydraulically smooth, and all the street cross-sections are rectangular (width b = 15 cm, and height of 15 cm). The studied configuration represents a highly simplified flooded street network with two inflows and four outflows, centered on a city block featuring an interior open space and surrounded by four streets.

The experiments were performed under a steady flow regime, with a total inflow discharge, Qi1+Qi2 = 6.5 l/s, partitioned between the inflow in the Right street (Qi1 = 4.5 l/s) and the Left street (Qi2 = 2.0 l/s).

The block was studied under three cases of increasing porosity, denoted as C1, C2, and C3. The pollutant release strategy involved two types of durations: a “very long release” duration exceeding 2500 s, applied to cases C1, C2 and C3; “short release” durations of 25 s, 100 s, 250 s, 1220 s and 2110 s, applied only to case C1.

The experimental dataset includes:

very long release experiments: (i) temporal and spatial distributions of concentration for the three cases C1, C2, and C3 at one-second time steps; (ii) time-evolution of the corresponding spatial-averaged concentration for each case; short releases: (i) temporal and spatial distributions of concentration for the case C1 at one-second time steps for durations of 25 s, 100 s, 250 s and 1220 s; (ii) time-evolution of the corresponding spatial-averaged concentration in case C1 for 25 s, 100 s, 250 s, 1220 s and 2110 s.

A complementary experimental dataset providing time-averaged surface velocity fields and flow discharges for each block cases is available in: Mejía-Morales, Miguel Angel; Mignot, Emmanuel; Paquier, André; Proust, Sébastien, 2023, "Data set of a laboratory experiment on the impact of the conveyance porosity of an urban block on the flood risk assessment", https://doi.org/10.57745/UJOCJ8, Recherche Data Gouv, where cases C1, C2 and C3 are denoted as C00-04, C1_block and C00-12, respectively.