Alimini Project
Hydrodynamics study of "Alimini Grande" basin (Puglia) carried out in 2007 for the Project: "Feasibility study for the fresh water spill of the Carpignano Salentino water treatment plant in the "Zuddeo" channel, tributary of the lake "Alimini Grande" (Lecce, Apulia, Italy)"
The study carried out on the Lake Alimini Grande (Lecce, Apulia, Italy) had as its object mainly hydrodynamic analysis of the effects of a Zuddeo channel flow increase, due to the fresh water input from a new water treatment plant. The aim of the project was the evaluation of the impact on the basin circulation, due to the different discharge regimes of the Zuddeo channel, through the application of the SHYFEM numerical model.
In the first phase of the study, using a numerical grid with low spatial resolution, differences were found in the residual velocity of the order of mm/s between the natural scenario and the one with the new flow of the Zuddeo channel, (700000 m3/year from the treatment plant). These discrepancies can be considered negligible compared with the hydrodynamics of the basin, under all conditions examined.
Regarding the analysis of the basin salinity, a new numerical grid, with high resolution, has been created. This grid allowed for significantly improving the flows estimation at the inlet.
The hydrodynamic results obtained with the new grid have showed a lightly higher mean residence time (4-5 days more than natural regime), however, the new fresh water input is not significant for the hydrodynamics of the system.
The simulations carried out to calculate the salinity have qualitative features due to lack of data measured evaporation in the '98 - '99, but the results obtained with the model have showed a good agreement with the salinity trend of the system.
The effect of increased flow of Zuddeo channel is a decrease in the mean salinity values of 2 psu that can reach 3 psu especially in the area of Traugnano marsh.
In Collaboration with: Università del Salento, Università La Salpienza di Roma, CIRPS.
