Water pollution from diffuse sources is one of the most important problems in groundwater protection activities. In this frame a good knowledge of the water flow in the unsatured zone is necessary to assess the risk of groundwater quality impoverishment. Mathematical modelling often represents a reliable and simple tool able to support in understanding all the physical phenomena and handling any possible managerial solution. Models application requires a number of hydrogeological information concerning all the parameters which are considered in flow and transport equations. These parameters often need to be determined by experimental tests. Consequently, a strong limitation in using mathematical models is due to the not unusual lack of these parameters. This paper reports the results of an experimentation, carried out with the purpose of defining the necessary parameters to set up and run a model to simulate the water flow in the unsatured zone. Incoming and outgoing flows were measured, almost weekly, for six months, in three lysimeters filled with a specific type of soil, cropped with loietto and irrigated with drinkable water. Using these measured data a daily water balance was performed and, later, verified using the soil moisture values measured, monthly, along the vertical profile of each lysimeter. The water balance validation produced a time series of daily incoming and outgoing flows used as boundary conditions for the model simulations. Measured values of the water content, along the vertical profile of each lysimeter, were also used for the model calibration. Satinsat, a computer program for simulating saturated/unsaturated two-dimensional flow and transport in groundwater system was used. Results in form of daily water balances, water content vs hydraulic conductivity and soil depth are reported, which confirmed that Satinsat well represents the hydrodynamics of the considered system.
SIMULATION OF INSATURED FLOW IN SOIL USING EXPERIMENTAL DATA
CAPUTO MC;DE GIROLAMO AM;PASSARELLA G
2004
Abstract
Water pollution from diffuse sources is one of the most important problems in groundwater protection activities. In this frame a good knowledge of the water flow in the unsatured zone is necessary to assess the risk of groundwater quality impoverishment. Mathematical modelling often represents a reliable and simple tool able to support in understanding all the physical phenomena and handling any possible managerial solution. Models application requires a number of hydrogeological information concerning all the parameters which are considered in flow and transport equations. These parameters often need to be determined by experimental tests. Consequently, a strong limitation in using mathematical models is due to the not unusual lack of these parameters. This paper reports the results of an experimentation, carried out with the purpose of defining the necessary parameters to set up and run a model to simulate the water flow in the unsatured zone. Incoming and outgoing flows were measured, almost weekly, for six months, in three lysimeters filled with a specific type of soil, cropped with loietto and irrigated with drinkable water. Using these measured data a daily water balance was performed and, later, verified using the soil moisture values measured, monthly, along the vertical profile of each lysimeter. The water balance validation produced a time series of daily incoming and outgoing flows used as boundary conditions for the model simulations. Measured values of the water content, along the vertical profile of each lysimeter, were also used for the model calibration. Satinsat, a computer program for simulating saturated/unsaturated two-dimensional flow and transport in groundwater system was used. Results in form of daily water balances, water content vs hydraulic conductivity and soil depth are reported, which confirmed that Satinsat well represents the hydrodynamics of the considered system.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
