the core idea of this thing is that it's a backpack to collect and filtration rainwater, while being worn. in a system like this, where the bag has to carry a filtration system, the backpack and the filtration process is usually separate; part of the idea was to bridge the two, so that the typical backpack-transit vs. contents-of-backpack+stasis dynamic is modified: filtration while in both transit and stasis.
as for the site: the mata atlantica rainforest, in the southeast of brazil, is a dense rainforest near heavily industrialized cities such as cubatao or sao paolo. the area around cubatao, especially, was polluted in the 80s and 90s to such a degree that it was nicknamed the 'valley of death'. as a result, the area was the focus of one of brazil's most well-funded rehabilitation programs; it's also a focus of many climatology/biology studies, as there's a unique overlapping confluence of dense tropical rainforest and urban industrial pollution in the area. rainwater, therefore, is relatively clean, as opposed to the groundwater with a history of pollution. which is why this backpack makes sense.
the folded/pleated tarp/manifold on the backpack is always collecting rainwater, regardless of movement or not, and can stretch out to increase its area to collect enough water for a family of four. there were certain requirements for the tarp/manifold that I had, such as that it had to collect the rainwater into a central area and thus needed to converge to a point; the tarp also had to curve into a c-shape so that water could be collected at any orientation, whether the backpack was lying down, or worn on the back.
I had fun playing out with different variants of pleating patterns both with grasshopper and tomohiro tachi's rigid origami simulator; in the end I reduced it to a question of implementing both latitudinal shifts and longitudinal converging pleats that created the pleat-pattern that I wanted.
I'm not completely satisfied; I could have gotten deeper, and developed it further, but I'm not unsatisfied, either. it's just that I didn't progress as much as I wanted to since the wednesday before the pinup on monday.