ABSTRACT
Land degradation is a dynamic problem and its negative effect on productivity is increasing. Satellite remote sensing (SRS), geographic information systems (GIS), and global positioning systems(GPS) are useful tools for land degradation studies. SRS data provide timely and reasonably reliable information for large area monitoring when supported by sufficient ground data, which otherwise need considerable amounts of human resources and time if generated through field surveys only. GIS and GPS allow handling of enormous volumes of data, mapping, and delineation of geographical distribution of different types of land degradation. To date, the applications of such technologies have not been fully exploited in the Asian context due to several limitations. Visible/near infrared (V/NIR) SRS has received wider acceptance in land resources studies compared to microwave remote sensing though it is weather independent. Land degradation monitoring is largely concerned with mapping the productivity status of land resources under a given socioeconomic organization, which can be accomplished using SRS to identify, delineate, and monitor such areas with repetitive data collection. GIS helps subsequently to model the relationship between the degradation status and associated factors and actors. Two studies carried out in Thailand illustrate the integration of SRS, GIS, and GPS assess land degradation and develop strategies for land resource management. The first study demonstrates the use of National Oceanic and Atmospheric Administration–Advanced Very High Resolution Radiometer (NOAA–AVHRR) data for crop monitoring in the regional context, while the second study demonstrates the use of Landsat Thematic Mapper (TM) data at the watershed or project level.
