Monday, 12 November 2012

Recent Water Research Outings

It's about time I posted an update on my reservoir project; although there has been a lengthy pause on here since my visits to the Miaoli reservoirs (occassioned by other, more urgent distractions), I've been especially busy over the last couple of weeks down here in the south. First, I have managed to get my hands on much more information - technical and historical information - pertaining to four of the southern reservoirs, Agongdian, Baihe, Nanhua and Tseng-wen. However, some of this information cannot be published yet. Second, I've made some contacts in the Water Resources Agency who may be able to help me further down the line and found out a little about their future projects (including new plans for river management and plans for new reservoirs) for the south Taiwan area. Finally, I've been doing some more photography, so I'll stick some of these recent efforts up here whilst the work goes on...

This is the second of three pressure control stations for the pipeline by which Nanhua reservoir in Tainan county feeds water into Kaohsiung city; the pipe proceeds downhill from Nanhua reservoir for some 58km before reaching Kaohsiung city. This one is sited in the Neimen district of Kaohsiung county at an altitude of 114m above sea level and 66m below Nanhua reservoir. Some short distance behind this station lies a water control gate, which (a) diverts water underground to Agongdian reservoir in Gangshan and (b) appears to mark the approximate beginning of the Erjhen river which forms the natural boundary between Kaohsiung and Tainan. According to the map that I have, one of the new reservoirs will be located upstream on that river, which almost certainly means it will be just to the rear of this control station at what is now "wild boar lake".

One of eight concrete shoulders of the Kaoping river weir, which diverts water into a massive, thirteen-gate entrapment pen from whence it then passes through an initial filtration process and is then pumped out toward the Pingding treatment plant in nearby Dashu district. Just underground parallel to the Kaoping river runs the pipeline from Nanhua reservoir; the two pipelines - one from Nanhua and the other from the Kaoping river - converge to become one before feeding their water into the treatment plant.

A head-on view downstream toward the pump-house from a bridge across the entrapment gates. The three pumps on the right deliver water into the pumping house where a series of twelve pumps pressurize the water and send it uphill on its way to the Pingding treatment plant in Dashu. Below the pumping house there is a digger floating on the intake reservoir; it's job is to shift sediment toward the mouth of a vaccum pump which sucks it out at high pressure - notice the two black pipes snaking over the wall to the left.

The Kaoping river weir intake complex also includes a sluice channel that returns water to the river; a proportion of the intake water is filtered out in order to wash debris (e.g. broken tree branches and such) back out into the river and prevent it from clogging up the pumping system. Even so, plenty of silt still enters the intake reservoir (hence the aforementioned digger and pump system) and is thrown out at high pressure via the two pipes poking out of the wall to the right.

This is the back end of Wushantou reservoir at approximately 7am; my old friend the farmer (or one of his crew) is out paddling on the raft to catch a few fish. The water level is down by what seems to be a meter or so since I was last there earlier this year. Of all of the reservoirs in Taiwan, Wushantou is probably my favourite.

This wreck of an old boat is still tied up to its mooring stick at the back of Baihe reservoir, indicating that what is now essentially marshland was once, perhaps forty or thirty years ago, a shallow harbour for the local farmers/fishermen.

From the south-east rear of Baihe reservoir looking north-east; much of the reservoir has now become marshland but there is still some water especially toward the rear as is just visible through a gap in the trees in the distance (see below). I like the lines in this picture for some reason I can't quite put my finger on yet.

Here is that gap between the trees through which the remaining water can pass from the north-east of the reservoir toward the dam at the south-west. There are, apparently, several small tributaries for Baihe reservoir out at the back there - in addition to the two major rivers to the south-east. Due to their extreme proximity to the mountains, these two rivers have flooded Baihe reservoir with sediment in the five decades since it was first constructed. Although it is now very close to the end of its life-span, amazingly Baihe reservoir is still pumping out water for irrigation and residential use in the two districts of Baihe and Dongshan even today.

At the back of the pressure control station in Neimen district, lies this water control gate where the diversion channel for Agongdian reservoir forms a brief confluence close to the source of the Erhjen river. Out of sight to the left of this image is the narrow, far upstream section of the Erhjen river flowing westwards; straight ahead out of sight behind the gate and beneath the canopy lies the diversion channel from the Yueh Mei weir; the water channel in the forefront of this image is heading down underground toward Agongdian reservoir...

... with the exit point for that diversion channel being here, some 14km south-westwards from the water gate featured in the previous image, at one of the reservoir's two major tributary rivers. The channel flushes out here into the smaller of the two tributary rivers for Agongdian reservoir (the larger one being problematic in that it is full of volcanic mud), it's purpose is to supply the reservoir with fresh, comparatively uncontaminated water.

Agongdian reservoir itself, seen from the north. This is one of many recent pictures I have taken of it from neighbouring Xiaoganshan mountain; this one is from right at the top with me standing on an old concrete bunker from a long-since abandoned military base (which was shifted across to the top of Dagangshan mountain a short distance away to the north-east). The two source rivers for the reservoir are just about visible in the distance at the reservoir's southern end.


For some reason that last picture of Agongdian reservoir has much of its' colour washed out; the actual photograph I am using is a bit darker with stronger colours. I don't know why this is happening.
Changing to an underexposed picture (an F-stop too high) and messing with the saturation seems to have balanced the "wash-out" effect.

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