Report on Flux-AWS installation
by
Shenggong Li
1) Underground sensors placement at the forest site
We dug a 1.0 m hole near the tower base at the
Mongonmorit mountain forest site for placing underground sensors. We could not dig
it as deep as 1.5 m as planned just because we met rocks. Thus, we slightly
adjusted the sensor array depths as follows:
(a) TDR
sensor of 150 cm was placed at a depth of 10 cm, thus we have two TDR sensors
at 10 cm deep;
(b) two SHPs
were placed respectively at 5 and 10 cm depth;
(c) We only
found 5 Pt sensors in the suitcase and they were put into soil at the depths of
5, 10, 20, 30, and 50 cm, respectively, which have corresponding tag marks of
2, 3, 5, 7 and 8;
(d) One
suction tube was at the depth of 40 cm rather than 50 cm;
(e) No sensor
was buried beneath 100 cm so that the tension meter of 120 cm was not placed;
(f) The
sensor placement area was about 2 m away from one corner of the tower base, and
(g) The arrangement
of the underground sensors see attached digiphotos.
2) The tower at the Mongonmorit forest site
As we went the site, we found the concrete tower base
was completed, but the scaffolding tower has not yet been constructed as
planned. We were supposed to have met the workers, who were responsible for the
construction, but during our field work period, they did not show up. In this
case, we are worrying about the bad influence possibly imposed on the placed
sensors by both fence building and tower erecting. With this concern, we talked
to Dr. Dawaa. He said he would try to contact the construction company and
inform them our concern and tell them to pay close attention to the sensor area
during the construction of the tower and fence.
3) Start of the measurements at KBU site
The work at the Kerlenbayan-Ulaan Grassland was not
as smooth as we had expected. When we went the site, we found the power line
was extended to the site. One technician from the power company said we could
not use electricity without a permit issued by the local government. Processing
the application for the permit might take one to two weeks and be available by
mid November. With our insistence, they agreed to offer two to three hour power
for our temporary use. We connected the cable attached to the logger box at the
site to the power line after checking the voltage (ca. 217 V), then switched on
the switch at the other end (the power substation). However, the fuse was
burned even we tried several times. We suspected that the voltage transformer
inside the logger box (upper box) might have dew water accumulated, leading to
burning of the fuse. Therefore, we gave up both testing the data logger and
starting the measurements. This would avoid damage possibly caused by sudden switching
on of the power by the power company person without our presence. There should
be a power supply box on the power pole near the site, but Dr. Dawaa said the
box was still in Ondorhaan and would be sent to the KBU site recently. We
suggest that we should have a power socket with switch inside the box to both
control power supply and extend power for other use, e.g. data downloading by
computer. A concern in mind is that extreme coldness aroused in deep winter may
bring about an influence on the measurements.
4) Measurements of earth resistance at KBU and forest
sites
We measured the earth resistance both at the forest
and KBU sites, but reading panel always showed outflow data, implying that the earth
resistance might be too large. But the major reason is potentially due to low
temperature, which exceeded the application temperature range of the resistance
meter (0-40 oC), or due to snow cover, which might also affect the
measurements. We should do this measurement next year when soil temperature is
higher (above 0 oC).