3.2 Surface Instrumentation
3.2.1 Climate Data
Climate data, including precipitation rate, air temperature, and relative humidity,
are collected outside the cave entrance with a tipping bucket rain gauge and an
air temperature/relative humidity sensor. Both instruments are connected to a
microstation for data logging at 10-min intervals. Precipitation data represent the
potential hydrologic input to the epikarst. The air temperature and relative humidity
data are combined with other climate data (wind speed, solar radiation) collected at
nearby Virginia Tech Kentland Farm, to calculate potential evapotranspiration
(using the Penman–Monteith method), a parameter needed to estimate recharge to
the karst system. Although this study was designed to collect climate data at the
site, other studies may be able to fully rely on data collected from nearby weather
stations, thus eliminating the need to install surface equipment.
3.2.2 Precipitation Samples
Precipitation samples were collected near the cave entrance on a monthly basis
from summer 2008 to early 2012 to provide information on chemical and isotopic
inputs to the epikarst. Samples were collected using a closed system precipitation
collector, designed to channel precipitation through a funnel in which a circular
float was placed to minimize evaporation (modeled after [27]) (Fig. 5, top).
Precipitation samples were collected using two different approaches, described
below. From 2008 to 2011, the funnel was attached via plastic tubing to the bottom
Table 2 James Cave instrumentation, including manufacturer and part/model number
Item
Manufacturer
Part/model number
Multiparameter sonde
Hanna Instruments
HI9828
Tipping bucket rain gauge
Onset HOBO
RGB-M002
Microstation data logger
Onset HOBO
H21-002
Level logger
Solinst
3001
Air temperature
Onset HOBO
S-TMB-M002
Temperature/relative humidity
Onset HOBO
S-THB-M002
Barometric pressure logger
Solinst
3001
Water level logger
Onset HOBO
U20-001-01
Barometric pressure logger
Onset HOBO
U20-001-01
Specific conductance logger
Onset HOBO
U24-001
Reed switch
Texas Electronics
120-0018
Terminal block
Texas Electronics
009-0059
Pendant logger
Onset HOBO
UA-003-64
Pulse adaptor
Onset HOBO
S-UCD-M001
Tension lysimeter
Soil Moisture
1900L
Instrumenting Caves to Collect Hydrologic and Geochemical Data: Case Study. . .
213
3.2.1 Climate Data
Climate data, including precipitation rate, air temperature, and relative humidity,
are collected outside the cave entrance with a tipping bucket rain gauge and an
air temperature/relative humidity sensor. Both instruments are connected to a
microstation for data logging at 10-min intervals. Precipitation data represent the
potential hydrologic input to the epikarst. The air temperature and relative humidity
data are combined with other climate data (wind speed, solar radiation) collected at
nearby Virginia Tech Kentland Farm, to calculate potential evapotranspiration
(using the Penman–Monteith method), a parameter needed to estimate recharge to
the karst system. Although this study was designed to collect climate data at the
site, other studies may be able to fully rely on data collected from nearby weather
stations, thus eliminating the need to install surface equipment.
3.2.2 Precipitation Samples
Precipitation samples were collected near the cave entrance on a monthly basis
from summer 2008 to early 2012 to provide information on chemical and isotopic
inputs to the epikarst. Samples were collected using a closed system precipitation
collector, designed to channel precipitation through a funnel in which a circular
float was placed to minimize evaporation (modeled after [27]) (Fig. 5, top).
Precipitation samples were collected using two different approaches, described
below. From 2008 to 2011, the funnel was attached via plastic tubing to the bottom
Table 2 James Cave instrumentation, including manufacturer and part/model number
Item
Manufacturer
Part/model number
Multiparameter sonde
Hanna Instruments
HI9828
Tipping bucket rain gauge
Onset HOBO
RGB-M002
Microstation data logger
Onset HOBO
H21-002
Level logger
Solinst
3001
Air temperature
Onset HOBO
S-TMB-M002
Temperature/relative humidity
Onset HOBO
S-THB-M002
Barometric pressure logger
Solinst
3001
Water level logger
Onset HOBO
U20-001-01
Barometric pressure logger
Onset HOBO
U20-001-01
Specific conductance logger
Onset HOBO
U24-001
Reed switch
Texas Electronics
120-0018
Terminal block
Texas Electronics
009-0059
Pendant logger
Onset HOBO
UA-003-64
Pulse adaptor
Onset HOBO
S-UCD-M001
Tension lysimeter
Soil Moisture
1900L
Instrumenting Caves to Collect Hydrologic and Geochemical Data: Case Study. . .
213