permaculture

["Lawrence F. London, Jr." <lfl@intrex.net>]

paul wheaton wrote:


> So there are no trickles of water anywhere the get routed from terrace
> to terrace?

I have not seen any documentation as to how they regulate overflow from all 
the terraces
but it either flows over the edges or through gates at the ends, plies of 
dirt removed
to release water downhill.

> It seems like a warm day would evaporate nearly all of that water.

Its a humid climate and there is a lot of water in containment plus regular 
rainfall
of varying intensity will replenish that which evaporated.

> Plus, when there is too much water (hard rain) ....  it seems like
> there could be problems with blowouts - especially the lower terraces.

They have been there for thousands of years. I expect they may be made of 
dense clay.

> > > What do they do each year to maintain those?
> >
> > Rice growing is a religious affair for Vietnamese. The people in farming 
> > communities, villages and outlying regions
> > do all the work partly by hand, draft animals and motor-driven tillage 
> > machines. Sometimes harvest is done, on
> > large flat areas, with small ride-on rice harvesters.
>
>
> I'm imagining that they must walk on the edges of the terraces and
> check for leaks regularly.  Then plug the leaks with ....  clay they
> pack in?  If they tried to plug leaks with muck from inside the
> terrace, the muck wouldn't last long.
>
> I'm curious how much maintenance is required to keep those terraces in shape.

I think I will Google that. Probably low maintenance due to their age and 
refinement of their farming system.

> > > As permaculture folks, I suspect that we would want to say "not enough 
> > > trees", but ....
> > > where might one plant trees so that the tree roots don't compromise a berm 
> > > and let all
> > > the water out?
> >
> > Forest gardens.

> I don't see that sort of thing in the pics.  ???

I have pix of that and will post links, not forest gardens but harvesting the lush undergrowth for livestock feed; no 
need to plant forage crops in the forests.

> The lip on the terrace seems to be pretty thin.  So it wouldn't take

It is probably tapered from narrow at the top to wide at the base, just like 
a reservoir dam.

> much to compromise it.  A small push slightly downhill of the terrace
> could send a root up to the water of the terrace and then the water
> could start to follow the root.  As the water starts to travel along
> the root, it erodes a pathway, causing a drain hole in the terrace.
>
> And if you don't have some kind of growies on that lip, rain water
> might erode it ....

Paths are located on much of the terrace rims. Overflow is probably regulated by some mechanism at the ends of the 
terraces. This will be an interesting research project.

LL
--
Lawrence F. London, Jr.
Venaura Farm
lfl@intrex.net
http://market-farming.com
http://market-farming.com/venaurafarm
http://venaurafarm.blogspot.com/
http://www.ibiblio.org/ecolandtech