Mapping Flood using Open Data and Open Source Software

Abstract

This research presents a method of data processing from open data with open-source software for extracting flood boundary areas in Ubon Ratchathani Province. We can use flooding area data as a flood hazard data layer to test “Landscan” data processing, which is highly detailed population distribution data. We verify the accuracy with the population data of the Department of Provincial Administration in finding the population that is affected by the floods. Searching for the area that has received the most significant damage from flooding, we apply the Sentinel-1 satellite from the European Union.  We can easily download the data for analysis as quickly as data available without any charge and use open-source software such as SNAP and QGIS programs for integrating use, enabling processing at every step without hindrances in terms of software and hardware. As by the results, the highest flooding area in Ubon Ratchathani province is on 11 September 2019, with a total flooding area of around ​​346.70 square kilometers or approximately 216,688.13 rai. The analysis result of
29 September 2019, compared with the flood area data analyzed by the Geo-Informatics and Space Technology Development Agency, have a different area of ​​approximately 20.40 square kilometers or 12,750 rai. Subsequently, when analyzing the population data in Ubon Ratchathani province that is processed using “Landscan” data, the total population is 1,615,388 people. When analyzed, the people affected by the flooded area is 37.14 percent of the whole province population with deviations from compared with the data of the Bureau of Registration Administration, Department of Local Administration, at 13 percent. Besides, we can apply the results from the research to find the trend of flooding areas exposure to prepare for prevention timely surveillance of population evacuation to reduce the occurrence of the wide effect. However, the use of data from open sources must be done carefully and checked before using it as the assessment of the situation is at an acceptable level.