Construction of Vegetation Cover Map in Metro Manila for Urban Environmental Evaluation
(b) The leaf area ratio on a tree crown: The binary image (Fig. 1 (b)) is extracted from the photograph
Fig. 1 (a)) taken vertically on the ground. Finally, the ratio of leaf on the tree crown is obtained using binary image.
| Plant name on tree form
| Leaf cover ratio |
| Mean | S. D. |
| Narra | 0.87 | 0.12 |
| Acacia | 0.34 | 0.14 |
| Tangile | 0.62 | 0.28 |
| Molave | 0.71 | 0.14 |
| Bakawan | 0.71 | 0.28 |
| Palm | 0.50 | 0.28 |
| Lawn (dense) | 0.70 | 0.30 |
| Lawn (sparce) | 0.50 | 0.30 |
| Tall tree | 0.61 | 0.19 |
| Middle tree | 0.71 | 0.14 |
| Law tree | 0.62 | 0.28 |
Table. 1 Leaf cover ration on tree crown
Fig. 1. Photograph and binary image of tree crown looked upward on the ground looked upward on the ground in case of Acacia.
Fig. 2. Relationship between VCRP in Satellite data and that in field survey. (Parts of 0% and 100% in field survey are extended in order to prevent the confusion in multi-pointing.)
(4) Comparison of Vegetation Cover Ratio in each Block
Relationship between VCRB in verification block and VCRB is obtained by remote sensing data as shown in figure 2. In this figure, vegetation cover ratio extracted from two types is nearly same. In addition, we can see that VCRB obtained by field survey has been underestimated, because inside residential district or rooftop vegetation had not been observed.
Construction of Vegetation map with VCRP
Figure 3 shows the vegetation map with VCRP constructed using LANDSAT/TM and SPOT/HRV, respectively. Two distribution maps are similar overall, which has been confirmed that the different image shows about 80 percent concordance within 10 percent or less different. We can see that the small scale vegetation are extracted as approximately from 10 to 50 percent in south side of Rizal park where is covered building, pavement, and small vegetation.
Figure 3. Vegetation cover maps with VCRP in Metro Manila Using remote sensing data
Conclusion
The vegetation map with VCRP was constructed by adapting the vegetation mapping algorithm to LANDSAT/TM and SPOT/HRV in Metro Manila. To the purpose of comparing the VCRP map, field survey was also carried out in the same reason. It was clarified the adaptability for the algorithm by comparing the VCRB calculated from remote sensing data and from field survey.
Acknowledgments
This study is supported by "Impact analysis of metropolitan policies for development and environmental conservation in the Philippines" (1997~) as a research project on "research for the future program", JSPS (Japan Society for the Promotion of Science).
Reference
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Donkyu Yun, Akira Hoyano, Naoki SHIRAI and Masahiro SETOJIMA : A study on putting to practical use of urban vegetation mapping with vegetation cover ratio in a pixel Part 1, A method for quantification of vegetation cover ratio in a pixel, Proc. of the 25th Japanese Conference on Remote Sensing, Nov. 1998, Kyoto, Japan. (Japanese)
