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Flooding Monitoring in Bangladesh

### Bangladesh Overview

The Bangladesh, a country of 144,000 square km and 120 millions inhabitants, is permanently subject to severe floods and cyclones. This results in a permanet evolution of river courses and coastal lines.

### Flood Action Plan Project

After the disastrous floods in 1987 and 1988, the French Government applied to United Nation Organizations for funding to undertake a survey of flood in order to design adequate solutions. A long term (15 to 20 years) plan was then decided under the coordination of the World Bank. The phase 0 of this plan for a 5-year monitoring was started up by a group of French companies (BCEOM, Coyne Belier, EDF, SOGREAH, etc.) with French and European Union fundings.

Map of the SPOT image coverage |

### Mapping Module

To support the action of the French companies, there was an urgent need to update the maps as the existing maps were mostly obsolete. The French government decided to use SPOT data for the creation of a new cartography coverage and the monitoring of river flow changes. The SPOT solution was selected as the best way to get a quick and accurate mapping and an efficient tool for monitoring the subsequent evolution.

In a first step, 193 SPOTView Level 2B (refer to cartography presentation) at the scale of 1/50 000 was produced between 1989 and 1990. To produce this first set, the satellite was specifically programmed for the acquisition of Multispectral (colour) images.

From December 1989 to December 1994, new sets of SPOT images were acquired twice a year (March, December) allowing the production of two of 33 SPOTView every year. This imagemaps were regularly used to monitor the course of the main rivers.

In 1995, a new coverage of the full area was performed through 193 SPOTView.

### Further actions

The imagemaps were used first as a substitute to obsolete maps to support field operations. The main aim was to implement the survey of main rivers' flow and to help the modelling of the flood phenomenon. The information extracted from these SPOTView images were also very valuable for thematic studies and generation of land cover maps and soil potential maps.

#### These two images of the same area were acquired one year apart.

© CNES 1993 . Multispectral SPOT Image . 1993 | © CNES 1994 . Multispectral SPOT image . 1994