Field trip to Pingtung County
Trip Start
Apr 26, 2008
1
16
20
Trip End
May 09, 2008
Pingtung,
Pingtung,
Taiwan
Monday, May 5, 2008
In a little more than an hour we arrive at the seaside town of Linpien in Pingtung County. Our first stop is at a now abandoned house that looks like it was built for the 7 dwarfs. The door is short and the window sills are sitting on the ground. Dr Wu explains that this area is sitting on a very large alluvial fan. Aquaculture is the areas most popular way to make a living and years of over pumping the ground water to control the salinity and temperature of the fish ponds has caused enough ground water depletion to compact the alluvial sediments. Land surface has dropped by around 10 feet in 50 years.
Sandstone formations like the badlands
Over time, the subsidence has caused this house (and others like it) to flood during the rainy season, so the homeowners continued to fill in the front yard with excess dirt and raised the floor inside the house. Eventually the inside of the house became unusable and the house was abandoned.Standing on the front porch of the small house and looking forward I see what looks like a levee (or sea wall) that stands about 20 feet above ground level. We drove a bit further down the street, got out, and walked up the steps onto the sea wall.
The coast bordering the China Sea is about 150 feet away from me and the first thing I realize that the beach sand is black. Also, there is an inordinate amount of trash on the beach. The Taiwanese do not swim in the ocean on the west side of Taiwan because years of industrial and municipal dumping have polluted the waters, a fact that is now plainly obvious.
What I have noticed is that the homes below the sea wall are at least 10 feet below the level of the sea, and it's probably more than 15 feet. I have been to New Orleans and I don't remember the topographic relief being this stark, but I was younger then and I don't think I grasped the implication of what I was looking at. There is no way this area could not flood severely during typhoon season. I cannot imagine the devastation it must bring the towns people each year.
From the coast we moved inland toward the foothills of central Pingtung County. We are going to meet Dr Ting, a professor of hydrogeology from National Pingtung University of Science and Technology.
another badlands like formation
But first, we make a quick stop to view a local spring. During the wet season the water table rises so dramatically that they use the water to fill a large public swimming pool. Right now the water level looks to be about 20 feet below us. Next, we stop for lunch. Lunch goes about the same it always does. We sit, Dr Wu orders 8 to 10 dishes of food, and we eat whatever he is in the mood for. Today it is fish and vegetables in many different combinations and sauces with a few surprises thrown in. The only dish I have eaten before is boiled cold shrimp, including head and tails of course. One new dish, is pig intestines, which were surprisingly tasty. As usual, I don't leave hungry.
After lunch we continue on the study site where we will be meeting Dr. Ting. This must be an agricultural center for Taiwan, because for the first time we pass farms growing row after row of soy beans, pineapples, beetle nuts, corn, and coconuts. There were many other plants that I didn't recognize. In the middle of a set of fields we stopped at a fenced area that includes a maze of blue pipes and large electrical panel.
Dr Ting arrived and we learned that this is a pilot study site to stave off land subsidence as well as supply irrigation to the farms bordering the site. The pipes are really a complex system for aquifer withdrawal and injection. Water is withdrawn from a deeper aquifer and can be injected back into the shallow aquifer to help with subsidence, or withdrawn water can be diverted to irrigation ditches if needed.
downtown Llinbian
There are several nests of monitoring wells to track the subsurface movement of water.We get back in the car and move on to the Linpien River. The river is very wide (over 2000 ft across at least) and it is obvious by the size of the boulders littering the river bed that flow rates can be very high during the rainy season. It is unimaginable to me what this river would look like when it is flowing, and how you would make a discharge measurement on it. There are several dump trucks traversing the nearly dry river bed, and Dr Wu explained that companies mine the gravel in the river bed to be used for construction. The mining has turned what little water there flowing in the river into a grey sediment laden stream. I hope there aren't any fish trying to survive in the water.
We stop on the right bank of the river next to what looks like a large concrete gaging station, very similar (but more ornately decorated) to our "mushroom" houses in NC, only larger. Looking out into the river we see an exposed concrete slab that extends about 750 ft perpindicular to the river bank out into the river. Dr Ting tells us that what we are looking at is an underground river weir, originally built by the Japanese in the 1920s, to provide irrigation for sugar cane in the dry season. When it was constructed, it was covered by 4 to 5 meters of river gravel, but recent gravel mining has exposed the concrete top of the weir. There is a second weir that parallels the right river bank but it collects ground water that would be discharging into the river.
viewing the land subsidence problem
Underground, the ground water weir T's into the river weir and the waters combine into one subsurface tunnel that supplies drinking and irrigation water to the village near by. Dr Ting asked if we would like to enter the gaging station and climb into the subsurface tunnel. His graduate student has just emerged from below and announces that the water is about 2.5 ft high and flow is about 1.5 m3/s (somewhere around 12 cfs). Ted is all ready to go, while Melinda and Shuying opt to stay up top. I peered into the gage house and saw a small sub floor that leads to a series of rebar rungs set into the poured concret wall. Ted had already removed his shoes and began climbing down the ladder after Dr Ting's graduate student. Not wanting to miss out, I decide to go too. I roll up my pant legs to mid thighs, remove my shoes, and empty my pocket contents just in case. I also gave my wedding ring to Shuying to hold since I have lost it once before and Paul will be most unhappy if I lose it again.
So before I give the description of what I did next, I just have to acknowledge that my dad was a health and safety manager for different industries in the US, and I know what we did violated about 7 different OSHA laws in the US, most of which involve confined space entry. I shudder to think of the things that could have happened, but didn't. OSHA-like laws in Taiwan are non-existent and I am amazed that I don't see more people with catastrophic injuries from mechanical devices that are not properly protected.
Ted, Melinda, and Shuying on the frot porch
Dad, I'm fine, don't worry. Nothing happened.I enter the gage house and encounter my first problem, there is a 4 ft drop down from the floor of the gage house to the sub floor near the ladder rungs that go below and there isn't enough room for me to jump without falling. There is a valve stem and wheel sticking up near the center of the house and nothing else to grab on to or step on. Since there was no one to help me, I used the valve body as a step stool, which was not all that comfortable on my bare feet. Once on the sub floor, it was an easy transfer to the ladder rungs, and I began my descent to the water 50 feet below. The ladder rungs were very competent and hardly corroded with rust, which surprised me. The climb down did not take long, and soon I was standing in thigh deep water next to Ted and Dr Ting's student at the bottom of the shaft.
The water was flowing with more of a current than I expected and the temperature was pleasant, about 75F. I had a brief mental image of what fun this would be to have an innertube and go from one end to the other. I was standing in a small tunnel that I expected would be rather cramped, but it wasn't. To my left (in the direction towards the river) was a sliding gate that could be lowered from the ceiling and I assume was connected to the valve stem I saw above. Using a flashlight to look down the tunnel (towards the river) I could see that the tunnel was quite sizable, about 5 1/2 ft tall and 5 ft wide. Looking the other direction (in the direction of flow away from the river) the tunnel began to decrease in size, but it looked to only go down to about 4 ft x 3ft.
Dr Ting, Alan, and Patrick soon joined us, and Dr Ting suggested that we walk upstream through the flow to look at the weir itself.
me on the front porch
We stooped under the raised sliding gate and began walking, following Dr Ting who had the flashlight. The walk was made more difficult by the uneven bottom, but the rocks were not sharp and pointy and there was no algae or slime to make them slippery. At this point I gave up on keeping my pants dry, as when I walked the water splashed to nearly my hips. I was happy to be short, as I could walk in the tunnel without bending over, while everyone else was slumped over. After walking about 150 ft, the tunnel we were in was joined by a second tunnel. Dr Ting explained that this second tunnel was the conduit from the ground water weir, a fact that became obvious when we walked past it and realized that the water coming from the ground water weir was about 20 degrees colder than the water coming from the river bed weir. Another few steps and we were standing beneath the subsurface river weir, a series of granite slabs stacked at a 45 degree angle to the the downstream flow of the river above. I'm not sure why I expected a torrent of water, but the weir was collecting a subtle flow of no more than a trickle of water over a very large area, which when accumulated together amounted to quite a bit of water. Dr Ting thinks this design is ingenious despite the fact that it is nearly 100 years old, and I have to agree with him.
The walk back to the ladder seemed like it took a lot less time, and I found it more difficult to keep my footing with a current pushing me forward. Once at the ladder, I climbed back up to the sub floor, and muscled my way up to the gage house floor.
view down the sea wall
Once outside, I explained what we did to Melinda and Shuying, retrieved my stuff, and put my shoes on, while everyone else made their way back to the surface.Next stop was the exit side of the tunnel Ted and I just wandered around in. The water emerges a mile or so down the road, where it is channeled in several different directions. There are many grey pipes that are piled in the water channel, and I am told that they are supply pipes to people's houses. There is not local water supply and treatment system, so people divert water using pipes in the channel for their own uses. This is a common practice in Taiwan, and it explains the grey pipes I have seen in ditches along roadways in the mountain areas.
Next stop is a large cistern like vat with 5 different sluice gates to control water distribution to irrigate the fields. Dr Ting tells us that the unused water eventually returns back to the Linpien River after making several more stops along the way.
Further down the flow path of the weir water is our last stop, one of Dr Ting's pilot study sites. This site is an infiltration basin, to transfer water from the land surface back to the aquifer system, in the hopes of staving off land surbsidence problems. Dr Ting would like to apply this process on a much larger scale than the 10mx10m basin they are using now. Several students have gotten dissertations off of this site, so it has been very useful.
We said good bye to Dr Ting and his companions and set off to return to Tainan City.
looking across the Linpien River
We stopped about a 1/2 hour into our trip for what Dr Wu described as an "icy dessert". Of course we Americans were expecting ice cream. Not quite. Dr Wu's idea of an "icy dessert" is a bowl filled with a baseball sized lump of sugared taro root, wet peanuts, cold green beans, small marshmellow like globs of rice dough (called sticky rice), and a larger blob of sticky rice with some sort of soft fruit (maybe a date?) in the center, all covered with snow cone shavings. The ice shavings are then flavored with a squirt of a brown syrup made from brown sugar dissolved in hot water. There are only a few things I have eaten here that I really disliked. This "icy dessert" was one of them. My limited experience with Asian deserts is that they are not sweet, but this was very sweet to the point of being over powering. Shuying absolutely loved it. She ate all of her taro, most of mine, then had Dr Wu order extra. Ted, Melinda, and I all felt about the same, slightly queasy.
Back in the car, we head for Tainan City via the interstate system. Most everyone took advantage of the down time to catch up on some much needed rest. Dr Wu is a master of sleeping anytime, anywhere. He would have to be, because by his own admittance, he doesn't sleep much at night. He is a very driven man. So, I couldn't resist having Shuying snap a photo of Dr Wu power napping in the front seat on our way home.
We arrived outside our hotel about 6pm. None of us were hungry for one of Dr Wu's big meals, so we asked if he would mind if we just spent the evening in the hotel getting ready for the next day. A gracious host to the end, he seemed concerned that we didn't eat dinner, and left us only when we agreed that if we got hungry we would call him and he would take us to dinner. Of course, that didn't happen.
The only person I saw the remainder of the evening was Shuying, who I bumped into as I was walking down the stairs to go to 7-11 for some chips. Otherwise, I enjoyed just having an evening to relax and take it easy in the hotel.
