LAND COVER AND SOIL LOSS MULTITEMPORAL ANALYSIS: AN APPLICATION OF GEOINDICATORS IN THE PANTANAL WETLANDS (BRAZIL)

摘要

The study area underwent wide land cover transformations from 1966 to 1985: wide extent of natural and semi-natural lands (forest and cerrado), underwent clearing to be replaced by agricultural and zoo-technical areas. From 1966 to 1985 about 32,000km~2 of natural areas were cleared in the whole study area, and 23,000km~2 were deforested in the Planaltos physiographic province alone. This province experienced the widest land cover changes of the study area. After 1985, deforestation continued even though Landsat images and fieldwork allowed to recognize, in the planaltos, natural vegetation within several previously deforested areas. The USLE showed that in the Upper Coxim River watershed the detected land cover changes, related to the period 1966-1985, induced a meaningful growth of the estimated soil loss. These data are in agreement with: a) large gully erosion phenomena (vocorocas) observed during the fieldwork; b) increase of solid discharge detected in the Taquari and Coxim rivers from 1977 to 1997 (Padovani et al., 1998).