Table 2.
Classification accuracies in percent and number of pixels (in parenthesis) for the land use classes present in the four scenes analyzed*
| Landsat ETM+ scene: October 18, 1999 | Landsat ETM+ scene: September 18, 2000 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Overall accuracy = (538/767) = 70.14% | Overall accuracy = (588/691) = 85.09% | ||||||||
| Kappa coefficient = 0.59 | Kappa coefficient = 0.77 | ||||||||
| Late | Early | Garden | Bare soil | Late | Early | Garden | Bare soil | ||
| Late | 74.44 (41) | 18.62 (70) | 4.35 (3) | 0.81 (2) | Late | 89.34 (285) | 7.95 (7) | 0 (0) | 0.81 (2) |
| Early | 23.64 (13) | 65.69 (292) | 5.80 (4) | 4.05 (10) | Early | 7.21 (23) | 87.50 (77) | 10.53 (4) | 2.44 (6) |
| Garden | 1.82 (1) | 2.66 (10) | 84.06 (58) | 20.65 (51) | Garden | 1.88 (6) | 1.14 (1) | 50.00 (19) | 12.6 (31) |
| Bare soil | 0 (0) | 1.06 (4) | 5.80 (4) | 74.49 (194) | Bare soil | 1.57 (5) | 3.41 (3) | 39.47 (15) | 84.15 (207) |
|
| |||||||||
| Landsat ETM+ scene: April 27, 2000 | Landsat ETM+ scene: January 8, 2001 | ||||||||
| Overall accuracy = (227/264) = 85.98% | Overall accuracy = (364/429) = 85.08% | ||||||||
| Kappa coefficient = 0.69 | Kappa coefficient = 0.65 | ||||||||
|
| |||||||||
| Rice | Garden | Bare soil | Rice | Garden | Bare soil | ||||
|
| |||||||||
| Rice | 92.59 (25) | 21.95 (9) | 3.57 (7) | Rice | 91.49 (43) | 29.79 (14) | 5.07 (17) | ||
| Garden | 3.70 (1) | 63.41 (6) | 6.63 (13) | Garden | 6.38 (3) | 61.70 (29) | 7.46 (25) | ||
| Bare soil | 3.70 (1) | 14.63 (41) | 89.8 (176) | Bare soil | 2.13 (1) | 8.51 (4) | 87.46 (293) | ||
*
75% of ground pixels collected were used for the maximum likelihood classification and 25% were used for testing the accuracy of the classification. Late = rice that was still in vegetative stage in September/October; Early = rice that had already reached the reproductive/maturing stage in September/October. In the cold/dry season (January) none of the rice fields had been harvested.