On-stream floodplain storage: Experimental research

In order to achieve a reduction of flood wave peak discharge in a stream plain zone, it is often possible to take advantage of structural active measures consisting of flood plain storage which can be on-stream or off-stream, whose task is the temporary storage of water flood volumes with the consequent outflow of a discharge that is compatible with the hydraulic characteristic of a stream. For preliminary sizing of these measures, the hypothesis of uniform storage is made, and it is also possible to show it in the technical literature. In order to verify the reliability of the simplified hypothesis of uniform storage, in the Laboratory of the Department of Hydraulic and Environmental Engineering G. Ippolito of the University of Naples Federico II, the experimental prototype of on-stream floodplain storage has been installed and the tests have been carried out, by using a suitable electrical level probe in the inflow and outflow hydrograph reconstruction. The tests, managed by both varying the dimension of the free bottom outlet of the floodplain storage and its surface, have confirmed the reliability of the uniform storage hypothesis. Tests in the presence of obstacles, made of synthetic grass, on the bottom of the floodplain zone, are in progress to simulate the presence of vegetation, and therefore the possible influence of hydraulic resistances on the reliability still of the uniform storage hypothesis.