Over the last 200 years Australians have been busy building cities […] as a result the health of the River itself has declined. Visit our Impacts and Problems pages for more information and tips on how you can help to improve the health of the Georges River Catchment.Impacts and Problems Reservoirs tend to retain material and often generate the first water quality warning. What is wrong with our [Australian] catchments now?
Threats in a catchment Water resources conservation o Quantity: o Quality: eutrophication Soil conservation o Erosion, o Organic matter loss o Salinisation o Landslides o Soil sealing o ….. Desertification is the loss of one or more soil properties, originating lower productivity.
Water is linking all catchment activities Integrated modelling of soil and water processes is required
Types of models Many…. They can be specific of a water compartment: o Meteorologists develop models for evapotranspiration, o Hydrogeologists develop models for groundwater o Agronomists put emphasis on the vadose zone models o Hydrologists tend to concentrate on surface fresh water (some on reservoirs) o Oceanographers tend to study estuary and coastal waters They can address a specific scale: o Local, catchment or global o Daily time step, event oriented. They can be process oriented o Salinisation o Erosion o Fertilization
Dia mundial da água, Cascais, D Overland flow Precipitation Variable in Time & Space 3D Porous Media 1D Drainage network Integrated Basin Modelling
Integrated Basin Modeling Rain Intensity Flow Production 2 Different Soils Infiltration Overland Flow
Dia mundial da água, Cascais, 2007 Integrated Basin Modeling Rain Intensity Sediment Transport 2 Catchments 1 Reservoir
Simple comprehensive Catchment models (e.g. SWAT) Diffuse Nitrogen Load Soil Texture Precipitation Land Use
Nutrient Budgets 18
Water Pathways (Hydrology) Precipitação Runoff Unsaturated Flow Saturated Flow ETa
Objective of the Modelling Lectures Describe the main processes and how they are being handled in each type of model. Provide to the student a clear idea of how to use models o clarify problems and optimize solutions, converting DPSIR into Numbers D river, P ressure, S tate, I mpact, R esponse.