chapter 4: temperature inside the landfill

esistance is directly proportional to the value of the moisture content (Gawande et al, 2003). The
approach, in the case of resistance can be expressed as:
If
and
then there is a resistance drop event.
_
_
R t+ Y < Rt−Y
_
_
t >
Ln( R − Y ) − Ln(
Rt
+ Y )
Z
(4-5)
(4-6)
Where R t+
Y is the mean of the resistance readings over Y days before time t, R − is the
temperature averaged over Y days after time t and Z is the difference between the natural
logarithm of the two averages. Values of Y and Z for analysis of resistance readings were taken
as 20 days and 0.3. Again the different values of Z were tried to find the one which gives the
most reasonable results.
_ _
4.5 Hypothesis Testing
After the temperature events were identified at the injection and monitoring locations, the
next step was to relate these temperature and resistance drop events with the injection events to
refute or support the hypothesis for the study. The hypothesis in the study asserts that
temperature sensors can be used to track moisture arrival in landfilled waste.
Seven different scenarios of injection events and subsequent responses at temperature and
resistance sensors were considered, as defined in Table 4-1. The basic concept in conceiving
these scenarios was whether an injection event is reflected in temperature and/or moisture
47
t Y