Avaliação do zoneamento agroclimático da expansão da cana-de-açúcar sobre a bacia hidrográfica do rio Paranaíba em um cenário de mudanças climáticas

Abstract

Considering the issue of ethanol growing production projections, which has as consequence the expansion of sugarcane cultivation area and the possibilities of this to impact the environment, the hydric security and the land use were defined strategies to the sugarcane expansion with reduced impacts on environment through agroclimatic zoning, over the Paranaíba river basin. In this thesis, agroclimatic zoning were generated using datasets from Reanalysis 1, historical integrations and climate projections from RegCM4 (CORDEX) forced by the RCP 8.5, and information of sugarcane productivity and water deficit from agricultural system model (DSSAT/CANEGRO). Regarding to the importance of evapotranspiration estimative in agricultural system models, since it impacts the simulations of hydrological deficit and productivity, the main equations of evapotranspiration were evaluated considering the best performance over the basin, and then calibrated and written in the code of (DSSAT/CANEGRO). Therefore, were developed a tool capable of performing better simulations over the studied watershed, providing information with reduced uncertainty to the agroclimatic zoning. The work conclude that modified Priestley-Taylor equation performs better than the equation recommended by FAO (FAO 56-Penman-Monteith). Through the evaluation of agroclimatic zoning, the strategy defined, contemplating the scenario that impacts less the environment, is accomplished by the expansion over the entire (partial) pastureland in the southeast (southwest) region of the basin, with harvest happening on May and August.