Processo erosivo laminar no entorno do reservatório da Usina Hidrelétrica Luiz Gonzaga - PE.

Abstract

The environmental degradation, generated on the banks of the reservoirs through erosion, affect the availability and supply of water and the generation of electricity, constituting serious hydraulic and economic consequences, as well as jeopardizing the performance of electricity generation, water supply, navigation, water eutrophication and the reduction of life of the blades of the propellers of the routers. This study aimed to measure the laminar erosion surrounding the Hydroelectric Plant Luiz Gonzaga / PE Thus, there was a study in sixteen areas, from June 2013 to September 2015, surrounding the Hydroelectric Plant Luiz Gonzaga which is located between the states of Pernambuco and Bahia, in the physiographic division called Lower Basin of San Francisco, 25 km downstream from the city of Petrolândia / PE. It conducted the survey pedological and physicochemical characterization of soils and physical characterization of soils marginal desbarrancamento and sediments of the plant's reservoir. It was used the technique of erosion pins to measure the surface lowering the soil layer during the period of two years, thereby allowing the determination of soil losses through the laminar erosion and loss of soil through the marginal desbarrancamento then the erosion rating was performed. The soil survey revealed according to the previous soil maps, a variation in taxonomic classes such that: Eutrophic Regolithic Neosol (RRe) in the area 1; Udorthent Eutrophic (RLe) in the areas 2, 3, 4, 12 and 13; Entisol (RQo) in areas 4, 6, 7, 8, 9, 10, 11 and 16; Luvisol Chromic Orthic (TCo) in the area 5; and Planosol Haplic eutrophic (SXe) in area 15. The physicochemical characterization of the soils studied showed susceptibility of soils to laminar erosion. The loss of soil with laminar erosion in the studied areas ranged from 85.00 to 205.20 kg.ha-1.year-1, being close to the literature tolerance limits. The loss of the marginal desbarrancamento soil around the reservoir ranged from very low (<6 t.ha-1.year-1) to severe (> 33 t ha-1.year-1), printing susceptibility to silting of long term reservoir. However, it is necessary to the proper management and conservation with the use of conservation and soil practices in order to increase soil cover and riparian vegetation using bioengineering techniques to extend the life of the plant's reservoir.