Impact of land-cover change in the Southern Amazonia climate: a case study for the region of Alta Floresta, Mato Grosso, Brazil

Environ Monit Assess (2012) 184:877891 DOI 10.1007/s10661-011-2006-x

Impact of land-cover change in the Southern Amazonia climate: a case study for the region of Alta Floresta, Mato Grosso, Brazil

Vincent Dubreuil Nathan Debortoli

Beatriz Funatsu Vincent Ndlec Laurent Durieux

Received: 18 September 2010 / Accepted: 14 March 2011 / Published online: 9 April 2011 Springer Science+Business Media B.V. 2011

Abstract The transformation of forest into pastures in the Brazilian Amazon leads to significant consequences to climate at local scale. In the region of Alta Floresta (Mato Grosso, Brazil), deforestation has been intense with over half the forests being cut since 1970. This article first examines the evolution of precipitation observed in this region and shows a significant trend in the decrease in total precipitation especially at the

V. Dubreuil (B) B. Funatsu V. Ndlec

Laboratoire COSTEL, UMR6554 LETG du CNRS, Universit Rennes 2, Place du Recteur Henri le Moal, 35043 Rennes Cedex, Francee-mail: [email protected]

B. Funatsue-mail: [email protected]

V. Ndlece-mail: [email protected]

N. DebortoliCenter for Sustainable Development,Universidade de Brasilia, Campus Universitrio Darcy Ribeiro - Gleba A, Bloco C - Av. L3 Norte,CEP: 70.904-970 Asa Norte - Braslia-DF, Brazil e-mail: [email protected]

L. DurieuxUnit Espace S140, Institut de Recherche pour le Dveloppement, Reprsentation de lIRD au Brsil CP 7091 - Lago Sul, 71619 - 971BRASILIA (DF), Brazile-mail: [email protected]

end of the dry season and at the beginning of the rainy season. The study then compares the temperatures measured in cleared and forested sectors within a reserve in the area of Alta Floresta (Mato Grosso, Brazil) between 2006 and 2007. The cleared sector was always hotter and drier (from 5% to 10%) than the forested area. This difference was not only especially marked during the day when it reached on average 2C

but also seemed to increase during the night with the onset of the dry season (+0.5C). The Urban

Heat Island effect is also evident especially during the night and in the dry season.

Keywords Deforestation Rainfall

Temperatures Amazonia

Introduction

Several studies have highlighted the specificities of the Amazonian climate and the importance of the interactions between the forest and climate system (Nimer 1989; Nobre et al. 1991; Polcher and Laval 1994; Hasler and Avissar 2006). Apart from precipitation, the forest promote the maintenance of strong humidity and a range...