Saturday, February 12, 2011

Stone terraces, Part 3

Working in the farm in Pangasinan, north of Manila, is one of my favorite hobbies. We have many trees there. Forest species include mahogany, molave, acacia auri, acacia mangium, narra, eucalyptus deglupta, benguet pine or agoho, karael, etc. Most of the trees we planted nearly 2 decades ago, the others just grew as part of natural vegetation in the area.

I go there every 3 or 4 weeks. Building stone terraces on hilly areas where the soil is prone to erosion and landslide during heavy rains is among my favorite activites. There are many stones in the creek nearby, our caretaker or some locals hired on extra, 1-day work, would gather those stones.

We built this terrace sometime in April or May 2010. But I started taking photos only last June 20. This area used to be a gully, rainwater easily passes through this natural canal. Until I decided to simply block this natural water path -- to trap the eroded topsoil and various organic matter from upstream.

This is the view at the back of the terraces. Various organic materials like dried leaves and branches, newly-cut branches. Small stones are placed at the back of the bigger stones to stabilize the former.

Top view. These were also taken last June 20, 2010. A row of stones per layer, the smaller stones at the back stabilize the bigger stones in the front.

A month after, here's a newer view. The "stairs" of stones on the right side have been there for at least 4 years now. Seemed that we built a really strong terrace that can withstand even a strong flash flood.

Another back view as of July 25, 2010. Fresh deposit of fallen leaves and branches are just dumped at the back. My goal is to fill up and flatten the gully with lots of eroded topsoil from upstream and the hilly slopes brought down by the rains and flash flood.

And here's how small water run off is trapped at the back of the strong terraces. Should the flash flood be strong, water should be able to penetrate in lots of pores as the stone terraces are not cemented.

By end-2010 up to today, this is how high the terraces has become, it should be at least 5 feet tall, with 4 layers of big stones in the front. See how our caretaker, Nong Endring Paragas, will soon be dwarfed by the height of these terraces in the next few months.

Another top view of the terraces. Four layers now. And more organic matter are deposited at the back each week.

Resting after carrying and moving those big and small stones. I hope to see this area a huge and high wall of big stones in the future, when it was just a gully and natural water path just several months ago!

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