Modelling

Question 1

8 Types of Models

Answer 1

DDD SS M, + SV:
•	Descriptive
•	Dynamic
•	Deterministic
•	Static
•	Stochastic
•	Mechanistic

• Speculative
• Verifiable

Question 2

3 Major types of Models

Answer 2

SOS
Statistical
Optimisation
Simulation

Question 3

Limitations of crop-soil models (Literature-Africa)

Answer 3

1. inabilities to accurately simulate soil infertility

2. failure to represent losses associated with pests, disease, and weeds

Question 4

Limitations of crop models (Lit. - Reidsma)

Answer 4

o Designed to assess potential yields rather than actual yield, hence the influence of sub-optimal management is neglected
o The impact of extreme events including pests and diseases cannot be simulated adequately
o They don’t address crop quality
o Only few adaptation options can be simulated

Question 5

Steps in formulating dynamic simulation model

Answer 5

1. Define system boundaries
2. Define components
3. Define Interactions
4. Quantify External Drivers + Parameters
5. Material/Information Flows