System Dynamics Conf. – IV – Day 2

I saw six presentations today, three of which were interesting enough to write about:

• Simulating Pollution from Urban Stormwater in Project Twin Streams Catchment, Auckland, New Zealand by Ines Winz, Gary Brierley
  • As far as I’m aware, the author of this paper was the only other person from NZ at the conference, though I haven’t yet had a chance to talk to her. She presented a model of the impacts of stormwater runoff in terms of erosion and pollution, in that storm water commonly picks pollutants from the land as it runs towards the sea. She sought to use the model to examine and predict the efficacy of different approaches to mitigating the impact of runoff. I picked up one new concept; that of imperviousness – ground coverings and land features that prevent water from being absorbed by the earth, instead diverting it into stormwater drains that generally lead to streams and rivers. Generally, designs that reduce imperviousness are a good thing. Found an interesting primer on the topic here
• An Operational Framework for Seeing and Simulating Feedbacks in Land Change Science by Burak Guneralp, Michael Reilly, Karen Seto
  • I didn’t get a lot out of the content of this talk, but I liked the modelling technique of integrating multiple system dynamics models together through a spatial model. For example, imagine you’re seeking to model local behaviour in subregions across a large area, where local results have some impact on their neighbours. Using this technique, you’d run models for each subregion in parallel, with each taking inputs and passing outputs to neighbouring subregion models, global models, or perhaps some sort of multi-subregion aggregating models. In essence, you end up with a system dynamics cellular automata, which the geek in me finds particularly awesome.
• Modeling Insurgencies and Counterinsurgencies by Edward Anderson
  • Apparently models of insurgencies and counter-insurgencies were a big topic this year – one presenter commented that the papers being presented this year represent the bulk of the work in this area over the last ten years. This paper pulled out and modelled insurgencies and counter-insurgency tactics based on the US Army FM 3-24. It focused a lot on population dynamics, including popular support, recruiting, intelligence, and a number of other factors. Of course, given the complexity and uncertainty of contemporary insurgencies, it’s very hard to validate the models, and the authors were up front about that – to cope, they used data from the Irish war of 1919-21, which was simpler (involving only one insurgent faction) and, being historic, was accessible for both sides, though still nonetheless quite sparse. One really interesting summary point from the model: counter-insurgency actions are the only way to defeat an insurgency, but their introduction will always worsen things in the short term and, furthermore, removing them too early may well be worse than not introducing them at all. All up, this was a really interesting paper; Richard – you should look at this.

In the afternoon, I snuck away to visit the Albuquerque Aquarium and Botanical Gardens. There were stingrays, sharks, and a great big tubular tank full of beautiful moon jellyfish lit by the refracted light of various informative displays. On entering the gardens proper, I began to wonder if I’d stepped through a looking glass somewhere on the way as huge fake vegetables, ants, and garden implements surrounded me in a truly surreal setting. The four metre high pumpkin, complete with fake rotting interior was particularly strange. Other parts of the garden were more traditional, with glass houses, a rose garden, and, of course, a great big desert garden. For bonus points, there were lots of hummingbirds and dragonflies. Photos of all this when I get back to Seattle.

After a quick trip back to my hostel to change into something a bit more formal than shorts and t-shirt, I returned to the conference hotel for the conference banquet. The food was great, and the scotch was cheap. After the obligatory speeches, there was traditional Navajo dancing, a little more scotch, and an hour reclining in a chair on the portico outside the conference hotel watching the clouds drift by, chatting, and enjoying the warm night air. Divine.