1. Introduction to ModelMaker
Soils & Environmental Exposure Assessment
Introduction to ModelMaker
Sabine Beulke, CSL, York, UK
FOCUS Work Group on Degradation Kinetics
Estimating Persistence and Degradation Kinetics
from Environmental Fate Studies in EU Registration
Brussels, January 2005
PSD, 6-7 March 2003

2. Curve fitting with ModelMaker

3. Model construction

4. Model components Compartment Flow Variable
Part of the system with defined boundaries which can store the quantity of interest (e.g. a pesticide)
Represents the movement of the quantity from one compartment to another
Parent in soil
Metabolite in soil
Parent  Metabolite
Change of quantity in compartment with time
dCompartment / dt = + Flows in - Flows out
Variable
Quantity which is a function of other model components or a function of an independent variable (e.g. time)
DT50 as a function of other model parameters

5. Initial conditions and parameters
For each compartment, the starting point (quantity present at the beginning of the simulation) must be defined
Parent: 100% applied radioactivity
Metabolite: zero
Parameters are constants which do not change
during the simulation
kparent degradation rate constant for the parent in soil
M initial amount of the parent compound
ffM formation fraction

6. ModelMaker toolbar run model optimise model create graph create table
add and define
parameters
compartment
flow
variable