The Jenolan environmental monitoring program

2019·8.8 MB·English

by  Andrew C Baker

The Jenolan Environmental Monitoring Program
Andrew Baker
C.
Karst and Geodiversity Unit
National Parks and Wildlife Service
Office ofEnvironment and Heritage
NSW
Level 2, 203-209 Russell Street, Bathurst, 2795
Published on 30 May 2014 at http://escholarship.library.usyd.edu.au/journals/index.php/LIN
Baker, A.W. (2014). The Jenolan environmental monitoring program. Proceedings ofthe Linnean Society
ofNew South Wales 136 19-34.
,
The Jenolan Environmental Monitoring Program reports on the condition of atmospheric and water
parameters in and around the show caves at Jenolan. This paper summarises the key findings from four
years (2009-2012) ofmonitoring cave atmosphere. The caves were typically characterised by high relative
humidity, moderately stable air temperature (annual variation <2°C) and pronounced seasonal variation in
the concentration ofC0 A major exception was the Temple ofBaal, where C0 was moderately elevated
2. 2
(-2,000 ppm) year round, with no apparent seasonal variation. The concentrations ofC0 inthe caves were
2
generally well below the exposure limit and pose minimal risk to human health.
Abrupt increases in air temperature of up to 0.9°C in <12 minutes occurred in several of the caves, in
particular the Imperial. These increases were characteristic of, and generally corresponded to, commercial
tours, and rapidly stabilised back to the pre-tour temperature after the tour had passed. Similarly, increases
in C0 associated with visitation were generally short lived, except in the Temple of Baal, where peak
2
visitation elevated the CO, for extended periods oftime. The merits and shortfalls of various options for
managing the accumulation ofCO, in the Temple ofBaal are discussed.
Manuscript received 5 December 2013, accepted for publication 16 April 2014.
KEYWORDS:
carbon dioxide, cave atmosphere; Jenolan Caves, temperature, tourist cave.
INTRODUCTION was allocated to the development of an air and
water quality monitoring program. Sites for air and
Themaintenance ofnatural processeswithinkarst water monitoring and equipment were selected in
environments is highly dependant on the interactions 2006 in consultation with the Jenolan Scientific and
between the soil, water and air (Watson et al. 1997). EnvironmentalAdvisory Committee, withmonitoring
In recognition of these interactions, karst managers equipment purchased in 2007 and progressively
around the world are increasingly utilising air and installed in 2008-2009.
water monitoring programs to examine the impacts of The Jenolan Environmental Monitoring Program
humans in show caves (e.g. Pulido-Bosch et al. 1997; (JEMP) measures air and water quality parameters
Russell and MacLean 2008; Lario and Soler 2010). that are of relevance to karst conservation, the
Indeed Cigna(2004) recommends thatthe atmosphere maintenance ofbiological diversity and visitor safety.
in all show caves should be monitored to determine The measurement and reporting of such parameters
whether cave operations are having adverse impacts enables an objective evaluation ofthe environmental
on these unique and delicate environments. performance ofJCRT (or any future successor), with
Jenolan Caves are arguably Australia’s best regards to air and water quality in the show caves.
known show caves, attracting more than 200,000 Specifically, the JEMP aims to achieve this by
visitors each year (Jenolan Caves Reserve Trust establishing and reporting trends in air quality and the
2012). In 2004 the Jenolan Caves Reserve Trust relationship between these trends and anthropogenic
(JCRT) received $4.2 million to undertake capital activity (in particular commercial cave tours) and
works within Jenolan Karst Conservation Reserve trends in water quality at a number of sites with the
(JKCR). Of this funding, approximately $200,000 catchment of the tourist caves. This paper presents
ENVIRONMENTAL MONITORING AT JENOLAN CAVES
the key findings from four years (2009-2012) of
monitoring cave atmosphere in the show caves at
Jenolan.
METHODS
Sites
The Jenolan Karst Conservation Reserve
km
(JKCR), is located approximately 180 southwest
of Sydney (33°49’S, 150° 02’E) and one of eight
reserves that comprise the Greater Blue Mountains
World Heritage Area (DECC 2009). Monitoring of
cave atmosphere was conducted at seven sites within
the show caves and one external reference site. Three
monitoring sites were situated in the Northern Show
Caves (Chifley, Diamond and Imperial) and four
sites in the Southern Show Caves (Mafeking Branch
of Lucas, Orient, River and Temple of Baal (Fig. 1,
Table
1).
Equipment
Commercially available instruments manu-
factured by Vaisala were utilised to measure
air temperature (Vaisala ‘HMT 100’, ± 0.2°C),
relative humidity (Vaisala ‘HMT 100’, ±2.5% RH),
barometric pressure (Vaisala ‘PTB 110’ ±0.3 hPa) and
the concentration of carbon dioxide (C0 (Vaisala
% 2)
‘GM220’ ±1.5% of range ± 2 of reading) at each
monitoring site. Monitoring equipment was housed
within a sealed case at each site and connected to
the cave power supply. A data logger (ACR Systems
Inc. ‘SmartReader Plus 7’) recorded each of the
parameters every 6 minutes. This interval was chosen
following preliminary trials in 2008, which found
6 minute intervals were a sufficient frequency to
capture the influence of passing tour groups, whilst
providing sufficient storage time (2 months 12 days)
before the loggerbeganto rewrite overthe oldest data.
Data were downloaded every 2 months for analysis
and inclusion in bi-monthly Condition Reports that
are provided to the JCRT by the OEH Karst and
Geodiversity Unit.
Data analysis
Data were filtered using the ‘macro’ and ‘IF’
functions in Microsoft Excel to remove data that Jubilee Grand Arch
exceeded a maximum permissible temperature range Imperial/Diamonci Lucas/Lurline
Elder River/Pool ofCerberus
between the temperature probe and the data logger Chifley Temple of Baal
(<8°C) or maximum permissible change between H Nettle Orient
Devils Coach House Ribbon
two consecutive time internals (<2°C change in
six minutes). These values were determined from Map
Figure 1. of the tourist cave system at Jeno-
the results of preliminary trails in 2008, which lan. Monitoring sites are numbered as per the de-
ascertained the largest genuine difference between
scription in Table 1. Image courtesy ofthe Jenolan
the temperature probe and the data logger (i.e. the Survey Project.
20 Proc. Linn. Soc. N.S.W., 136, 2014
BAKER
A.
Table 1. Air monitoring sites
Name Site number Site description
Northern Show Caves
In Katie’s Bower, on the tourist platform above the mains power
Chifley Cave
1
distribution
m
Diamond Cave 2 Approximately 5 beyond the end ofthe public viewing area.
Imperial Cave 3 Nellie’s Grotto
Southern Show Caves
In the Mafeking branch approximately ten steps below the
Lucas Cave 4
highest point ofelevation
Orient Cave 5 In Lower Indian Chamber
Under the bridge approximately 15m before the Pool of
River Cave 6
Reflections
Temple ofBaal 7 At the middlejunction next to the switchboard
External site
School House 8 On the south facing wall.
temperature in the sealed case), and largest change RESULTS
between consecutive temperature readings. Filtering
the data was necessary to remove false values that Overview of cave atmosphere
occurred as a result of power outages and surges. The average air temperature in the caves ranged
Where temperature values at a site were false, it from 11.7°C in the Diamond Cave to 15.5°C in the
was assumed that all other parameters at that point Temple of Baal (Table 2, Fig. 2a). In comparison to
in time were also false. The final step offiltering the the external site, where the average air temperature
data involved manually checking the graphed data for was 12°C and ranged from -4°C in winter to >
anomalies. For example, it was common for several 30°C summer, the air temperature within the caves
sites to simultaneously experience an abrupt decrease was highly stable. The Temple of Baal had the least
of all parameters and such values were regarded as variation, with a temperature range of 0.6°C, while
false and removed from the dataset. the Chifley experienced the largest range (3.2°C,
Bimonthlydatasheetswerecombined into asingle Fig. 2a). Similarly for relative humidity (RH), while
spread sheet to determine the average, maximum and the external site experienced a highly degree of
%
minimum values for each of the parameters for the variability (6.9 - 99.6 RH), the cave atmosphere
four year period. The daily average air temperature, was characterised by very high (98.8 - 99.9 %) and
relative humidity and C0 were calculated for each stable RH (Table 2, Fig. 2b). As with air temperature,
2
day from January 1, 2009 to December 31, 2012 and the Chifley experienced the largest range in RH
RH
graphed to examine any variation in cave atmosphere (9.7 %). However given the low variability of
between seasons from one year to the next. Lastly, compared to the precision of the probes (± 2.5%),
to ascertain the influence of commercial cave tours detailed analysis was not possible.
on the cave atmosphere, air temperature, relative Whereas the caves experienced considerably less
humidity and CO, data, one week ofcontinuous data variation in air temperature and RH than the external
(i.e. readings taken every six minutes) for April 5-11 site, this was not the case for C0 with the cave
2,
2012 was graphed at a larger scale. This period was atmosphere recording a much larger range in CO,
chosen as it included Easter (April 6-8), typically one than the external atmosphere (Fig 2c). In comparison
ofthe busiest periods ofvisitation during the year. to the external atmosphere (-380 ppm) the average
concentration of CO, at the monitoring sites within
Proc. Linn. Soc. N.S.W., 136, 2014 21
ENVIRONMENTAL MONITORING AT JENOLAN CAVES
C0
Table 2. Average data (2009-2012) for air temperature, relative humidity and the concentration of
2
at each ofthe monitoring sites.
Temple of
Chifley Diamond Imperial Lucas Orient River External
Baal
Temperature (°C)
Mean 12.98 12.65 13.04 14.24 14.94 13.36 15.49 12.01
SD
0.33 0.09 0.11 0.06 0.11 0.20 0.05 7.13
Range 3.22 1.02 1.57 2.03 0.94 1.66 0.63 -
Relative humidity (%)
Mean 98.75 99.74 99.85 99.69 99.12 99.61 99.47 72.63
SD
0.59 0.17 0.10 0.01 0.31 0.31 0.06 18.61
Range 9.72 4.37 3.91 2.73 3.79 4.48 1.89 92.74
C0
(ppm)
2
Mean 1,013.4 848.0 857.2 1,098.8 759.2 718.6 2,142.1 381.4
SD
853.1 275.6 413.5 461.3 347.1 333.4 425.3 35.2
Range 4,847.9 1,596.6 2,333.3 2,022.2 2,292.3 1,668.4 2,690.6 352.1
a)
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Chifley Diamond Imperial Lucas Orient River Temple of
Baal
Site
C0
Figure 2. Average a) air temperature, b) relative humidity (RH) and c) concentration at each ofthe
2
monitoring sites from January 1 2009 to December 31 2012. The high-low lines show the range (maxi-
mum and minimum values). Temperature and RH data for the external site are not shown due to the
high degree ofvariability, [b) and c) on following page].
22 Proc. Linn. Soc. N.S.W., 136, 2014
BAKER
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Figure 2 continued
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the caves ranged from 848 ppm in the Diamond to River caves, with the difference in the average air
2,142 ppm in the Temple of Baal. While the average temperature between summer and winter of0.8-1 ,2°C
C0
concentration of was markedly higher in Temple in the Chifley and 0.6-0.7°C in the River Cave (Fig.
2
of Baal compared with the other caves, the highest 3). In the River Cave, the minimum air temperature
C0
concentration of occurred in the Chifley (5,232 typically did not occur until the end of winter (mid-
2
ppm). With the exception of the Chifley and Temple lateAugust), whereas in the Chifley, the minimum air
ofBaal (maximum C0 = 3,662 ppm), the maximum temperature occurred much earlier inwinter. Seasonal
2
C0
concentration of that occurred at any ofthe other variation in the Imperial was inconsistent, with the
2
sites within the caves was < 3,000 ppm (Fig. 2c). difference between summer and winter average air
temperature ranging from ~0.4°C in 2009 to ~0.1°C
Trends in cave atmosphere through time 2012 (Fig. 3). Unfortunately the temperature-relative
Seasonal variation in the average daily air temp- humidity unit in the Temple of Baal and data logger
erature was most pronounced in the Chifley and in the Orient required repair on several occasions.
Proc. Linn. Soc. N.S.W., 136, 2014 23
ENVIRONMENTAL MONITORING AT JENOLAN CAVES
caves.
the
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Proc. Linn. Soc. N.S.W., 136, 2014
BAKER
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Consequently there are substantial gaps in the data visitation over the Easter period had a pronounced
for both these caves, although the data suggest these influence on the concentration of CO, (Fig. 5c). On
sites are characterised by generally highly stable air Thursday 5th April, most of the caves recorded only
temperatures. small increases in CO,, in keeping with relatively low
With the exception of the Temple of Baal, the ratesofvisitation. ConverselyoverEaster, significantly
concentration of CO, in the caves varied between increases in visitation led to higher concentrations of
seasons. CO, peaked during the summer months CO, for periods of time. For example in the Lucas
(December-January), decreased during autumn, Cave, an increase in visitation of between 500-1,000
was at a minimum during winter (June-August) people/day during April 6-8 resulted in substantially
and increased again in spring and summer (Fig. 4). larger increases in CO, than April 5 (Fig. 5c), when
During summer, the maximum average concentration only 140 people visited the cave.
of CO, in the caves was approximately 4-10 times Different caves experienced different trends in
that ofthe external site, whereas in winter, the CO, in the accumulation of CO,. As with air temperature,
the caves (excluding the Temple of Baal) was often abrupt spikes in CO, occurred in the Imperial, Lucas
only slightly elevated above the external atmosphere, and the Orient (Fig. 5c). These abrupt increases were
with a maximum concentration 1.5-2 times that of usually relatively short-lived, however when tours
the external atmosphere. CO, in the Temple of Baal were frequent, the concentration of CO, did not
showed no relationship with season, with major decrease to the pre-tour level before the next tour.
increases typically occurring during periods of peak This frequently resulted in elevated levels of CO,
visitation, as discussed in the following section. until there was a substantial gap between tours or
after the last tour for the day. In the River Cave, CO,
Influence ofvisitors on cave atmosphere accumulation was more gradual, increasing mid-late
Abrupt increases or “spikes” in air temperature morning and decreasing each evening (Fig. 5c).
occurred in several caves and were most pronounced Interestingly, the Temple of Baal exhibited very
in the Imperial, Lucas and Orient (Fig. 5a). Ofthese different trends in CO, compared to the other caves.
caves, the Imperial experienced the largest spikes in During periods of increased visitation such as Easter
airtemperature, with increases ofup to 0.59°C in < 12 2012, the level ofCO, in the Temple ofBaal gradually
minutes during Easter2012 (Fig. 5a). Increases of0.5- increased with visitation during the day, plateaued or
0.7°C frequently occurred in the Imperial throughout marginally decreased during the evening and until the
the fouryears ofmonitoring(asnoted intheBimonthly commencement of tours the following day (Fig. 5c).
reports prepared for JCRT), and this cave consistently Conversely on days when there were fewer visitors,
recorded the largest spikes in air temperature. The such as April 5, 2012, there was a slight decrease in
largest single spike in air temperature, an increase of the average concentration of CO,. Indeed throughout
0.9°C, occurred on the 10th March 2012. Spikes of 2009-2012, periods of high visitation consistently
between 0.2-0.5°C were typical in the Lucas Cave, resulted in peak levels ofCO, (Fig. 6).
as was evident during Easter 2012. Although spikes To examine the relationship between visitation,
in the Orient were often smaller than those in the air temperature and CO, concentrations, these
Imperial and Lucas (typically ~0.2°C), they generally parameters were graphed side by side for the Orient
occurred on a more frequent and regular basis (Fig. Cave (Fig. 7). Simultaneous spikes in air temperature
5a). It is important to note that tours in the Imperial and CO, corresponded with each and every one ofthe
and Lucas frequently did not longer enter the sections tours through the cave. As could be expected, the size
of the caves containing monitoring sites, whereas of each tour influenced the magnitude of the spikes
every tour that entered the Orient entered the chamber in air temperature and CO,. For example on April
where monitoring was conducted. 5, four similar sized tours during the day resulted in
With the exception of the Chifley Cave, the four comparable spikes in air temperature and CO„
RH pm
in the other caves remained virtually constant while a smaller 8 “extended Orient” tour resulted
throughout the week, irrespective ofcommercial tours in much smaller spikes in temperature and CO,.
(Fig 5b). Inthe Chifley Cave, RH, like airtemperature During the Easter long weekend (April 6-9 2012), the
was highly variable and typically increased when air frequency of tours was such that after a tour, the air
temperature within the cave decreased, and decreased temperature and CO, to did not decrease to the pre-
when air temperature increased. tour level before the next tour, resulting in a period
The concentration of CO, in cave atmosphere where temperature and CO, were elevated (Fig. 7).
generally increased midmorning each day, coinciding
with the commencement of cave tours. Increased
Proc. Linn. Soc. N.S.W., 136, 2014 25
ENVIRONMENTAL MONITORING AT JENOLAN CAVES
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26 Proc. Linn. Soc. N.S.W., 136, 2014
222
BAKER
A.
a)
16.0
-Chifley
Diamond
Imperial
•Lucas
Orient
River
•Temple ofBaal
£ 13.5
13.0
12.5
12.0
05-Apr-12 06-Apr-12 07-Apr-12 08-Apr-12 09-Apr-12 10-Apr-12 11-Apr-1
b)
100.0
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Chifley
Diamond
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g
Lucas
| 98.5 Orient
River
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1
£
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97.5
97.0 -I 1 1 i i 1 1
05-Apr-12 06-Apr-12 07-Apr-12 08-Apr-12 09-Apr-12 10-Apr-12 11-Apr-1
C)
4000
3500
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3000
Diamond
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2500 Lucas
Orient
2000 — River
Temple ofBaal
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1500 External
1000
500
0 -I 1 1 1 1 1 1
05-Apr-12 06-Apr-12 07-Apr-12 08-Apr-12 09-Apr-12 10-Apr-12 11-Apr-1
Date
C0
Figure 5. Daily variation in a) air temperature, b) relative humidity (RH) and c) concentration at
2
each ofthe monitoring sites from April 5 to 11 2012. Each parameter was recorded at 6 minutes inter-
vals.
Proc. Linn. Soc. N.S.W., 136, 2014 27
ENVIRONMENTAL MONITORING AT JENOLAN CAVES
Number
of visitors
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the
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Note:
28 Proc. Linn. Soc. N.S.W., 136, 2014