Monitoring and Modelling Hydrological Processes in Greenhouse Horticulture Districts

The hydrological response of greenhouse horticulture districts has not been comprehensively investigated, neither from a monitoring nor a modelling point of view. Some land reclamation authorities are now challenged by an increasing flood risk, due to plastic covers expanding imperviousness. In the south of Italy, we are monitoring a 10.1 km2 agricultural catchment, covered by plastic greenhouses, where we apply the integrated surface-subsurface hydrological model “CATchment HYdrology” (CATHY) to obtain a mechanistic understanding of surface water and groundwater processes. We are also developing a greenhouse environmental model, based on previously published research, to estimate indoor crop transpiration given outdoor meteorological variables. The greenhouse climate model was validated on experimental data and it was able to simulate indoor air temperature and relative humidity with satisfying accuracy. Upon using the Penman-Monteith equation for calculating the reference evapotranspiration (ET0) indoor and outdoor, we determined that ET0 was lower indoor than outdoor by about 1 mm/day on average over 35 days. The CATHY model simulated the water levels at the outlet in accordance with measured values. Numerical scenario analyses corroborated an increase in streamflow during rain events and revealed a substantial reduction in groundwater recharge.