CARTOGRAPHIC APPROACH USING GIS TO IDENTIFY APPROPRIATE SITES FOR SMALL HYDROPOWER SYSTEMS INSTALLATION: APPLICATION TO PRETO RIVER BASIN, CENTRAL BRAZIL

O.A. Carvalho Junior¹, R.F. Guimaraes¹, L.F. Freitas¹, R.A.T. Gomes¹, D. Gomes-Loebmann¹, E.S. Martins², A.P.F. Carvalho³

1 - Brasilia University, Geography Department, Brasilia, Brazil

2 - EMBRAPA, Soil Department, Brasilia, Brazil

3 - INCRA, Remote Sensing Division, Brasilia, Brazil

osmarjr@unb.br

Energy is a vital input for social and economic development of any nation. Economic development of the rural economy and society required an increased energy supply and also a proper energy structure. The Brazilian energetic is characterized by centralized planning and priority to bigger power plants, in order to serve the larger consumption centers. Nowadays, a new model with decentralized energy technologies has been sought, in order to supply energy to isolated municipalities, minimizing transmission and distribution costs of extending grid electricity to dispersed homesteads and under the precondition of clean energy production. One of the options to supply energy for rural electrification, to places far from the interconnected system, in less developed countries is the installation of Small Hydropower System (SHS). The present paper aims mainly to develop an automated methodology to identify appropriate sites for SHSs installation, using Geographical Information System (GIS). The study area is situated in the Rio Preto Basin (Central Brazil). The determination of the physical potential for the SHS construction should consider the conjunction of two main parameters: (a) an outflow estimate based on computed contribution area, and (b) the local slope along the river, which defines the topographical difference across potential dam sites. To simulate the firm outflow data along the river, we used the logarithm regression of the stations data present in basin and the contribution area image. The potential to exploit a river's hydraulic potential for SHS’s can be made considering topographical unevenness: (a) along the profile of the river; and (b) in relation to the flow edges-exploitation of the areas with high gradients in the river banks based on a derivation of water flow by means of a hydraulic structure. The crossing of this information allows the identification of the best places for the SHS construction. The established model enables to identify locating hydropower resources, what represents indispensable information for decision-making in order to build a sustainable energy system. Thus, the new metodology brings a substancial contribution to cartography development of the hydro-energy resource.