Land Use and Land Cover Change in Amazonia Frontier, Ji-Paraná Basin - Rondônia
Lais
Carvalho
Hanada, CENA/USP, lchanada@esalq.usp.br
(Presenting)
Maria Victória
Ramos
Ballester, CENA/USP, vicky@cena.usp.br
Reynaldo
Luiz
Victória, CENA/USP, Reyna@cena.usp.br
Jeffrey
E.
Richey, School of Oceanography - University of Washington, jrichey@u.washington.edu
Massive land-use change has occurred in the Amazon basin in the last 3 decades, resulting from a complex product of economic and social factors, infrastructure development, soil characteristics and cultural factors that reflect in the deforestation process. The Ji-Paraná basin is located in Rondônia State and comprises an area of 75,400 km2, corresponding to 31% of the State area. Intensive migration to this region started in the beginning of 70’s, resulting from governmental settlement projects. Today, more than 60% of the state population lives in this basin. The main objective of this study is to better understand the land use and cover changes in Ji-Paraná basin in the last 15 years and analyze some drivers of tropical deforestation. Deforestation maps were derived from the supervised classification (maximum likelihood rule) of Landsat5-TM and Landsat7- ETM+ images, for the years 1986, 1992, 1996 and 2001. To account for the influence of landscape characteristics we performed a cross tabulation between slope, soil fertility, distance to a main road and land use. Our preliminary results show that the basin lost 20% (15,700 km2) of the original forest cover (without the savanna class). Until 2001 the forest class represented 40,800 km2 (55%) of the basin area. The larger forest patches are located in flat, low fertility (base saturation lower than 50%) and scarce roads areas, corresponding to 23,750 km2, with 7,250 km2 located in conservation units. The forest patches on rich soils are located in the central part of Ji-Paraná basin (5,500 km2) and in areas with scarce roads and near conservation units (10,000 km2).