Desenvolvimento e avaliação de uma estação meteorológica automática para manejo de irrigação

• Autor(a) principal: Finholdt, Gustavo
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3538
• topic: Estação meteorológica automática; Manejo de irrigação; Desenvolvimento tecnológico; Automatic meteorological station; Irrigation management; Technological development; CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA::ENGENHARIA DE AGUA E SOLO

Due to the increasing world population growth, irrigated agriculture is an important strategy to increase food, fiber and agro-energy production. Because of its operationality, irrigation levels determination by means of culture evapotranspiration studies (ETc) has been a widely disseminated and applied technology. Thus, it is necessary to determine a reference evapotranspiration (ETo), which is obtained through data supplied by the Automatic Meteorological Stations (AMS), based on the FAO Penman- Monteith equation, which has a great potential of reducing water consumption and electric energy in irrigation, in addition to reducing potential environmental degradation and labor use. However, the automatic stations are normally imported technologies, with high cost and maintenance, also presenting difficulties in access to maintenance, which is deficient and scarce. Thus, an Automatic Meteorological Station was developed using national technology, designed with five basic sensors (wind velocity, rainfall, air relative humidity, solar irradiance and ambient temperature) to calculate water balance, based on two main parameters: rainfall and ETo. The equipment developed allows data visualization in the equipment itself or in a microcomputer. After the equipment was developed, the sensors were calibrated reaching correlation coefficients (r) of 1,000; 0,998; 0,999; 0,995; and 1,000 for the wind, rainfall, air relative humidity, radiation and temperature sensors, respectively. The equipment was evaluated from 05/17/2008 to 06/12/ 2008 at the meteorological station of the National Instituteof Meteorology (INMET) installed on the Universidade Federal de Viçosa campus. The data were compared taking as reference the INMET s EMA data, model MAWS301 (manufacturer, Vaisala), installed close to the equipment developed. The correlation coefficient estimates (r), mean bias error (MBE) and Root Mean Square Error (RMSE) were used to evaluate the equipment at work. Comparing the equipment data, the following correlation coefficients were obtained: 0.911; 0.999; 0.993; 0.998; and 0.987 of the sensors anemometer, pluviometer, hygrometer, pyranometer and thermometer, respectively. It was concluded that the sensors developed provided adequate results and that the automatic meteorological station developed presented reliable meteorological data measuring and storing conditions.