Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-10-26T11:38:14Z No. of bitstreams: 2 Dissertação - Sérgio Soares da Silva - 2017.pdf: 3227191 bytes, checksum: 2e563811d31bc63d3907c69c9b5b4c4c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-10-26T11:39:11Z (GMT) No. of bitstreams: 2 Dissertação - Sérgio Soares da Silva - 2017.pdf: 3227191 bytes, checksum: 2e563811d31bc63d3907c69c9b5b4c4c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-10-26T11:39:11Z (GMT). No. of bitstreams: 2 Dissertação - Sérgio Soares da Silva - 2017.pdf: 3227191 bytes, checksum: 2e563811d31bc63d3907c69c9b5b4c4c (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-09-29 / The reference evapotranspiration is a fundamental parameter in the calculation of the water balance of watersheds or region as well as in determining the actual evapotranspiration of a crop or vegetation. This climatic parameter also serves as a basis for the determination of the volume and moment of irrigation of a crop. The objective of this research was on daily and monthly basis to evaluate the performance and perform the calibration methods of Hargreaves-Samani, Blaney-Criddle and Thornthwaite original and modified. The verification of performance of the models, both in their original and calibrated forms, was by comparison to the Penman-Monteith FAO 56 method. To evaluate the performance of the methods were used the correlation coefficient (r), the index of agreement (d), the confidence index (c), the mean absolute error (MAE), the mean square error (MSE), the mean square root error (RMSE), the maximum error (ME) and the coefficient of determination (R2). For this research, a series of data of ten years has been used from January 2007 to December 2016, and the first five years were used to evaluate and calibrate the methods and the last five years used to validate the adjusted methods. The meteorological data used come from a conventional station belonging to the National Institute of Meteorology (INMET), located in the southwest of the state of Goiás, more precisely in the city of Jataí-GO. The validation of calibration was performed only by the Hargreaves-Samani and Blaney-Criddle models, because they had the best adjustments over the standard Penman-Monteith FAO-56 method. / A evapotranspiração de referência é parâmetro fundamental no cômputo do balanço hídrico de bacias hidrográficas ou região, bem como na determinação da evapotranspiração real de uma cultura ou vegetação. Este parâmetro climatológico, serve de base também para a determinação do volume e momento de irrigar uma cultura. O objetivo dessa pesquisa foi, em escala diária e mensal, avaliar o desempenho e realizar a calibração dos métodos Hargreaves- Samani, Blaney-Criddle e Thornthwaite original e modificado. A verificação do desempenho desses modelos, tanto em suas formas originais quanto calibradas, foi por meio da comparação ao método de Penman-Monteith FAO 56. Para avaliar o desempenho dos métodos foram utilizados o coeficiente de correlação (r), o índice de concordância (d), o índice de confiança (c), o erro absoluto médio (EAM), o erro quadrático médio (EQM), a raiz do erro quadrado médio (REQM), o erro máximo (EM) e o coeficiente de determinação (R2). Para estapesquisa foi utilizada uma série de dados de dez anos, de janeiro de 2007 a dezembro de 2016, sendo que os cinco primeiros anos foram utilizados para avaliar e calibrar os métodos e os últimos cinco anos utilizados para validar os métodos ajustados. Os dados meteorológicos utilizados são provenientes de uma estação convencional, pertencente ao Instituto Nacional de Meteorologia (INMET), localizada no sudoeste do estado de Goiás, mais precisamente na cidade de Jataí-GO. A validação da calibração foi realizada apenas pelos modelos de Hargreaves-Samani e Blaney-Criddle, pois estes tiveram os melhores ajustes em relação ao método padrão Penman-Monteith FAO-56.

Relevant methods for estimating reference crop evaporation and crop evaporation for selected, pertinent crops growing in the semiarid environments of Arizona and New Mexico are investigated. Daily evaporation estimates over the period 2000-2010 are calculated using standard meteorological data from 35 weather stations. Compared to the FAO-56 Penman-Monteith reference evapotranspiration estimate, the Hargreaves and Priestley-Taylor equations overestimate by 5-15% while the temperature-based Blaney-Criddle method currently used in New Mexico underestimates by 8-13%, on average, the discrepancy being most severe in highly advective regions. Crop evaporation estimates are compared to the one-step Matt-Shuttleworth approach. The Blaney-Criddle method systematically underestimates crop evaporation by 7-30%, while underestimation using the climatically adjusted FAO-56 crop coefficient approach is 1-8% for short crops but ~20% for tall pecan and citrus orchards grown at atmospherically arid locations. Crop surface resistances derived using the Matt-Shuttleworth approach at Fabian Garcia in southern New Mexico compare favorably to literature values.