Contribution of SPOT images to the comprehension of the dynamics of the delta environment of the Red River (Vietnam)
The Red River delta in Viêt-Nam is a complex deltaic system with a very high population density (under 1000 inhabitants per square km) and with a long history of human interventions on the environment, such as dykes, dams, irrigation and drainage canals. It features a complex landuse system with small fields, overlapping crop calenders and 2 or 3 yearly rice harvests. The delta is subject to fast economic growth related to trade liberalization and land privatization. However, it experiences an increasing frequency of catastrophic events such as typhoons, floods, accelerated soil erosion on the foothills and rapid changes of the coastline. SPOT data have been used as an information layer in an integrated environmental information system developed by VTGEO with funding from IDRC (Canada) to monitor the ongoing changes and to help understanding the complex deltaic dynamics in three areas: soil erosion in the foothills, floods in the centre of the delta and land use changes in the coastal area. SPOT data have been useful to extract crop surfaces at the district level, to map the irrigation and drainage canal network and to monitor the changes in coastlines and forest boundaries. Their major short falls have been a time coverage limited by cloud cover, making flood and crop growth monitoring almost impossible, and a unsufficient number of spectral bands to separate bare soil from dry vegetation or to apply spectral unmixing techniques for up and down scaling of land use maps. But SPOT data are a good complement to other data sources, their major advantage being the good spatial resolution and continuity in time series.
Bibliographic Reference: Paper presented: SPOT - d'une décennie de réalisations à une décennie de promesses, Paris (FR) April 15-19, 1996
Availability: Available from (1) as Paper EN 39687 ORA
Record Number: 199611120 / Last updated on: 1996-10-28
Original language: fr
Available languages: en,fr