CE5504 – Surface Water Quality Modeling CE5504 Surface Water Quality Modeling General Lecture 2. Model Development
Empirical Models CE5504 – Surface Water Quality Modeling Secchi disk and chlorophyll (Chapra 1997, Figure 29.6)
Empirical Models CE5504 – Surface Water Quality Modeling Vollenwieder plot (Chapra 1997, Figure 29.1)
(Chapra 1997, Figure 29.4) Linked Empirical-Mechanistic Models CE5504 – Surface Water Quality Modeling
Mechanistic Mass Balance Models CE5504 – Surface Water Quality Modeling (Chapra 1997, Figure 1.5)
(Chapra 1997, Figure 18.8) Temporal Resolution CE5504 – Surface Water Quality Modeling
Spatial Resolution CE5504 – Surface Water Quality Modeling (Chapra 1997, Figure 16.1)
Time and Space Scale of Water Quality Problems CE5504 – Surface Water Quality Modeling (Chapra 1997, Figure 18.9)
Kinetic Resolution CE5504 – Surface Water Quality Modeling Total Phosphorus Available Particulate Phosphorus Refractory Particulate Phosphorus Dissolved Organic Phosphorus Soluble Reactive Phosphorus
Things should be made as simple as possible -- but no simpler. Albert Einstein image source: The Guiding Principle
unlimited cost cost cost + $ desired reliability Model Complexity Model Reliability Defensible, Credible, Cost-Effective
Model Complexity Screening Management Research Striking a Balance
(Streeter-Phelps) Problems: untreated and primary effluent Pollutants: BOD Systems: streams and estuaries (1D) Kinetics: linear, feed forward Solutions: analytical Modeling: Historical Development CE5504 – Surface Water Quality Modeling (Chapra 1997)
(Computerization) Problems: primary and secondary effluent Pollutants: BOD Systems: streams and estuaries (1D/2D) Kinetics: linear, feed forward Solutions: analytical and numerical Modeling: Historical Development CE5504 – Surface Water Quality Modeling (Chapra 1997)
(Biology) Problems: eutrophication Pollutants: nutrients Systems: streams, lakes and estuaries (1D/2D/3D) Kinetics: nonlinear, feedback Solutions: numerical Modeling: Historical Development CE5504 – Surface Water Quality Modeling (Chapra 1997)
(Toxics) Problems: toxics Pollutants: organics, metals Systems: sediment-water interactions food chain interations, streams, lakes and estuaries Kinetics: linear, feed forward Solutions: analytical Modeling: Historical Development CE5504 – Surface Water Quality Modeling (Chapra 1997)
present (Ecosytems) Problems: ecosystem change, climate, invasives Pollutants: natural components – carbon, nutrients, organisms Systems: primary production, food web interactions Kinetics: nonlinear, feedback Solutions: numerical Modeling: Historical Development CE5504 – Surface Water Quality Modeling (Chapra 1997) Benthic Invertebrates Phytoplankton Whitefish