ASSESSMENT OF SPOT SATELLITE DATA FOR TROPICAL VEGETATION INVENTORY AND MONITORING IN SUMATRA

Following  a  previous  vegetation  mapping  in  Sumatra  island  (Indonesia),  an  assessment  of  SPOT satellite capability to handle specific problems related to vegetation identification and monitoring from  remote sensing data has been undertaken. Results of visual interpretation and multispectral analysis have shown the usefulness of SPOT data  for the appraisal  of  tropical  vegetation  at medium  scale. This was  particularly  striking  for  the  swampy  vegetation types  including mangroves  and  for  the  secondary vegetation,  for which  significant  improvements have been brought by multispectral classifications. A 20 m ground resolution is neither sufficient  to provide information on  primary  forest  patterns,  nor  to  identify  properly  logged  over  areas.  Never theless,  several  degrees  of depletion  of  the  forest  and  all  the  serial  stages  have  been  identified,  which  is  a  considerable  progress compared with previous remote sensing means. SPOT is a very good alternative to medium scale aerial photographs for the production of medium  scale (1 : 100 000 to 1 : 250 000) vegetation and land-use maps.