Sustainable economic development can only be obtained by improving the quality of life. Rural water availability and sanitation are therefore priority issues for developing countries experiencing a rapid economic growth, as is the case for Vietnam, and for international aid organisations.
The tropical karst catchment of Suoimuoi, in Northwest Vietnam, is studied in the ‘Vietnamese-Belgian Karst Project – VIBEKAP’. For this region, Le Quoc Hung applied different remote sensing and GIS (Geographic Information System) techniques, with the purpose to deduce geological and hydrological information. Landsat multispectral bands were integrated with the high resolution Landsat ETM7 PAN. Based on this composite image, three applications were implemented :
- the analysis of lineaments and fracture zones for the comprehension of cave development
- the delimitation of groundwater recharge and discharge zones
- the change in land use in the Suoimuoi catchment.
The lineaments identified on the fused image were evaluated by means of aerial photos and existing literature on the area. This resulted in the interpretation of fracture zones, due to tectonic activity. The direction of cave development and distribution were deduced from them. Image classification and transformation techniques were applied for analyzing the groundwater flow system, with the delimitation of groundwater recharge and discharge areas.
Changes in land use were investigated based on Landsat images from 1973, 1993 and 1999, showing an alarming deforestation in the area.
The study shows that important hydrological and land use information can be obtained by means of the application of remote sensing and GIS in karst areas in the tropical rain forest. It thus provides a relevant contribution to a sustainable development of those regions.
report by Prof. Dr. K. Walraevens, Laboratory for Applied Geology and Hydrogeology, Universiteit Gent, Belgium