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2.3 Input data
The input mainly determines the results of the model. A proper approach for the gathering,
filtering and verification of the information is required.
In this research the required input information is inventoried. This paragraph describes the
source of the input. The input data is divided in the following topics:
- Flood characteristics.
- Land use data.
- Constructions.
- Damage mechanisms.
- Maintenance strategy.
- Costs.

2.3.1 Flood characteristics
Since no detailed hydrologic data was available, floodplain delineation for this project was
performed using actual flood records provided by the Dartmouth Flood Observatory
(University of Colorado, 2012). Although the observatory maintains global flood records from
1985-present, detailed GIS data showing the flood extent for the Tabasco region is available
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since June 28 2011. Using the LANCE_MODIS (NASA, 2012) rapid response processor in
combination with a noise cancelling water pixel identification algorithm (Brakenridge, 2011),
daily flood records are available at a spatial resolution of about 250m. Note that the data only
provides the observed flood extent; the geographic distribution of the associated inundation
depths was not available. GIS data on street networks have been derived from the Open
Streetmap Project (Open StreetMap, 2012) in combination with manual tracking based on
Google Maps imagery.

The identification of flooded roads consisted of the following steps:
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1. Flood extent delineation. Union of 314 daily flood extents over the period June 28
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2011 – May 7 2012;
2. Soil type identification. Preparation of base maps identifying the different top layer soil
types with the region;
3. Road segment identification. Preparation of a road map using a classification of 5
individual road types;
4. Road segment intersection. Intersecting the street network with the delineated flood
extent and soil types to obtain base statistics about length of inundated road
segments;
5. Applying administrative boundaries. Clipping the GIS-data by applying the
administrative boundaries of the Tabasco province.
6. Preparation of Base statistics. Calculation of inundated road segments per soil type
and road type.

Apart from providing the observed flood extent over a longer period, the daily flood records
also provide information about the inundation frequency of individual areas (i.e. the aggregate
amount of days an individual area is flooded).

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