20.1.13

Spatially-explicit agent-based model of jaguar movement - Overview of model

So my first week back at work after maternity leave has been spent getting re-acquainted with my model and preparing to write the next chapter for my thesis. I've found several articles which use ABMs to look at the response of populations to some form of landscape change, and whilst these are different to mine in key aspects, they nonetheless provide me a good overview of how others have gone about doing similar work.

Some papers to mention:

  • Parry et al (2007) Aphid population response to agricultural ;landscape change: A spatially-explicit, individual-based model. Ecological Modelling 199 451-463
  • Wang & Grimm (2007) Home range dynamics and population regulation: An individual-based model of the common shrew Sorex araneus. Ecological Modelling 205 397-409
  • Pitt et al (2003) An individual-based model of canid populations: modelling territoriality and social structure. Ecological Modelling 166 109-121
Grimm has been quite prolific in producing individual-based models in ecology and a great paper by Grimm (and plenty of others) outlines a standard procedure for describing these type of models, so I'll be sticking to this and following the seven elements they outline:
  1. Purpose,
  2. State Variables and Scales,
  3. Process and Overview and Scheduling,
  4. Design Concepts,
  5. Initialisation,
  6. Input, and
  7. Submodels.
Parry et al (2007) start from the protocol but provide information flow diagrams that make it easy to follow the model steps and simplify model procedures, so I've incorporated three flow diagrams into the Grimm protocol, as you can see below:

 Fig 1. Overview of model process

 Fig 2. Overview of agent process


Fig 3. Overview of movement process of agents


Fig 3 is undoubtedly quite complicated and probably subject to some change, but the current version of my model follows these steps quite literally. And I have to say it was quite difficult getting a fairly simplified(!) version of the movement process. A flow diagram is definitely the best way of presenting this information in my thesis chapter and hopefully will ease attempts at future publications as I'm following Ecological Modelling formats.