Applying Hybrid Heuristic Approach to Identify Contaminant Source Information in Transient Groundwater Flow Systems
Table 7
Results of the larger suspicious areas with six release periods and concentrations.
(a)
Initial guess source location
Sifted results
Real source location (m)
Rank
Sifted location (m)
Current objective function value (×10−4)
(150, 310, −21)
1
(110, 270, −9)
0.371
(110, 270, −9)
2
(90, 270, −9)
3.277
3
(130, 270, −9)
4.650
4
(90, 270, −3)
10.61
5
(90, 250, −9)
12.77
(b)
Final result
Estimated source location
First release period (day)
Second release period (day)
Third release period (day)
Fourth release period (day)
Fifth release period (day)
Sixth release period (day)
Optimal objective function value (×10−7)
Computer time
(110, 270, −9)
60.012
56.509
66.845
55.070
61.556
60.587
First release concentration (ppm)
Second release concentration (ppm)
Third release concentration (ppm)
Fourth release concentration (ppm)
Fifth release concentration (ppm)
Sixth release concentration (ppm)
105.53
194.59
147.29
56.852
97.929
70.829
8.191
12 hours
Note that the real release concentration is 100 ppm over the first 60 days, 200 ppm over the second 60 days, 150 ppm over the third 60 days, 50 ppm over the fourth 60 days, 100 ppm over the fifth 60 days, and 70 ppm over the sixth 60 days.
