Figure 3. Experimental Workflow 
4. RESULT AND ANALYSIS 
4.1 Trail Road Landfill 
Figures 4 and 5 show a comparison between the LST and the air 
temperature for specific dates in 2007 and 2008. In 2007, the 
LST for the Trail Road landfill in April and June is higher than 
the air temperature by 10?C. A drop in the temperature 
difference is found in July and August, mainly due to relative 
low sky visibility and haze effects on the remote sensing 
images. The result may be affected even when the atmospheric 
correction is applied. The LST for the landfill site is constantly 
higher than the air temperature by 6?C during September and 
October. 
  
     
     
  
ir Tengrerature 
Temperature °C 
+ 
  
    
-07 May-23 Tun-15 Tui-17 Aug-02 Aug-27 Sept-19 CcD5 
Date 
Apmr-21 M 
Figure 4. Comparison of LST and the Air Temperature for the 
Trail Road Landfill in 2007 
In 2008, the difference between the LST and the air temperature 
varied due to seasonal changes. On April 14, the LST was 7°C 
higher than the air temperature and the difference in the 
temperature was more than 10?C during May to August. The 
temperature difference drops below 7?C after September except 
for the result in October 7th. Based on the results from 2001 to 
2009 as well as the results for 2007 and 2008, one can conclude 
that the LST for the landfill site is always higher than the air 
temperature. 
45 
40 
35 
30 
25 
20 
Temperature °C 
  
Apr-14 May-25 Jul-12 Aug-20 Sept-5  Oct-7  Oct-23 
Date 
Figure 5. Comparison of LST and the Air Temperature for the 
Trail Road Landfill for Year 2008 
The Trail Road landfill site is monitored by a comprehensive 
ground monitoring system, which measures and records the 
amount of landfill gas, the quality of surface and groundwater, 
and soil contamination. A preliminary analysis was conducted 
to determine the correlation between the measurements from 
these monitoring wells and the LST derived from the remote 
sensing images. Such an analysis has not been performed for the 
previous literature which adopted Landsat images for landfill 
monitoring. The measurements of two landfill gas monitoring 
stations (GM-2 and GM-17) are utilized for this preliminary 
analysis. The reasons to select these two stations from the total 
of 28 stations are mainly the availability of the measurements 
recorded in the annual reports and the well distribution of these 
stations among Stages 1 to 4 (see Figure 1). 
These monitoring wells measure the percentage of emitting 
methane (CHy) and the pressure; the records of CH, are taken to 
perform the correlation, as CH, is the main element of landfill 
gas. Also, the measurements from the shallow level of the 
monitoring wells are taken as it is close to the ground level that 
will be close to the land surface for the calculation of LST. Due 
to inconsistency between the date of ground measurement and 
the date of the remote sensing image acquisition, the ground 
data were linearly interpolated so as to align the dates to the 
remote sensing image. Correlation analysis is conducted for 
both 2007 and 2008 by using the regression analysis. 
Figures 6 and 7 show the relationship between the percentages 
of emitting methane recorded in station GM-2 (located at the 
south of Stage 1) and the LST in 2007 and 2008, respectively. 
Figures 8 and 9 show the relationship between the percentages 
of emitting methane recorded in station GM-17 (located at the 
south of Stage 3) and the LST in 2007 and 2008, respectively. 
To remove seasonal effects in the derived LST data, the LST 
value is subtracted from the air temperature, so all the 
measurements are reduced to the same base. Preliminary 
analysis revealed that a mid-correlation was observed for both 
of the ground- monitoring wells in 2008 where R? is 0.573 for 
GM-2 and R? is 0.914 for GM-17. However, both stations had 
low correlation coefficient with the LST measured in 2007 
where R was 0.066 in GM-2 and R? was 0.332 in GM-17). In 
spite of these results, all the fitted regression lines show that the 
amount of emitting methane has direct proportional relationship 
to LST. 
- 0M RA RA 
oO t 4 o « 
  
Percentage of Emitting Methane 
Recorded in the Landfill Gas (%) 
en + OQ 0 
0 2 4 6 8 10 13 14 16 
Temperature Difference (*C) 
Figure 6. Relationship between the Percentage of Emitting ; 
Methane Recorded in GM-2 and the Temperature for 2007 (R 
— 0.066) 
     
       
      
       
    
   
      
     
       
Percentage of Emitting Methane 
Recorded in the Landfill Gas (%) 
es 
ag 
Metha 
Percentage of Emtting Methane 
Recorded in the Landfill Gas 
— 1 
ag 
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Methai 
Percentage of Emitting Methane 
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