The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B4. Beijing 2008 
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—Sukhothai 
■-*— Phrae 
Uttaradit 
Phitsanulok 
—*■ ■ Phichit 
Nakhon Sawan 
—=_... Uthai Thani 
/ ^ Z' / / / 
Figure 7. Major rice harvested areas for each province in the 
Northern part of Central Plain of Thailand (by FAOSTAT) 
2.3.2. Geomorphological survey map (Ohkura,1989) and 
satellite data 
The entire Chao Phraya river basin between Nakhon Sawan and 
Bangkok metropolis often suffer from flood at the end period of 
every rainy season. The rainy season usually begins in about 
May and it will end in about October. Figure 8. shows such 
kind PALSAR image and the result of mathematical 
morphology applied to the left image. 
Figure 8. PALSAR image in the entire Chao Phraya river on 
October 12 th , 2006 (left) and the result of morphological 
analysis (right, white color) 
The author superimposed the result of morphological analysis 
as the flood possibility areas over the geo-morphological 
survey map (Figure 9). Though the surface land use is changed 
by farm land consolidation, the possibility flood areas agree 
with back marsh and delta category avoiding natural levees. 
The geo-morphological survey map represents the 
micro-topography and it reflects the process of formation of 
geographical features. As the flood time is the sediment 
procedure, the flood inundated areas should coincide with the 
geo-morphological survey map, even if the surface land use 
was changed. Therefore this kind of micro-topography map can 
be used for the flood hazard map. 
Figure 9. Geomorphological survey map (right) and the 
superimposed flood possible areas calculated by mathematical 
morphology operation from PALSAR image (left; red color) 
3. HOW TO MAKE “FDMS” 
It is very important that the results of flood extent estimation 
are handed to the people concerning to disaster aid or reduction. 
Therefore many kinds of global platform for disaster risk 
reduction on the Internet are proposed. The author converted 
the result of this Thailand flood analysis into KML format files 
and superimposed those files on the “Google earth” (Figure 10, 
11). The KML is similar to the international Geospatial 
Information System standard, GML (Geography markup 
language) of OGC (Open Geospatial Consortium) or IS019136. 
And The GML is a kind of data format for G1S data exchange 
and distribution using the Internet web, what we call, 
“GeoWeb” (Lake, 2004) . If every organization related to the 
disaster reduction adopts GML or KML, such kind of 
international standard data format, those organization’s work in 
close cooperation with publishing its disaster information on 
the line in the near future. Furthermore Semantic Web will 
strengthen such kind “Geospatial Web” (Scharl, 2007). Those 
data standards can apply to the future disaster management 
system (FDMS). 
Figure 10. Google earth browser image and geo-morphological 
survey map on it