Alternative reference evapotranspiration methods for the main climate types of the state of Paraná, Brazil

Abstract

The objective of this work was to define the best alternative methods for estimating the reference evapotranspiration (ETo) in the main climatic types (Cfa and Cfb) of the state of Paraná, Brazil. The methods tested were Budyko, Camargo, Hargreaves-Samani, Linacre, and Thornthwaite, which were compared to the ETo calculated with the Penman-Monteith ASCE (EToPM) method, between 1986 and 2015, in eight meteorological stations. The performance of the alternative methods was obtained from the coefficient of determination (R2), index “d” of agreement, index “c” of performance, and root mean square error (RMSE). The Hargreaves-Samani method has a better performance in estimating the ETo for the main climatic types in the state of Paraná. The Camargo method allows smaller errors between the standard values of ETo, obtained with the Penman-Monteith method, and the estimated values. The methods of Thornthwaite, Linacre, and Budyko are not adequate to estimate the ETo in any climatic type of the state of Paraná, Brazil.

A Comparative Relation of Distinct Reference Crop Evapotranspiration Models for Southern Brazil

“…max (daily maximum temperature, °), T min (daily minimum temperature, °C), T med (daily average temperature, °C), RH max (daily maximum relative humidity, %), RH min (daily minimum relative humidity, %), RH max (daily average relative humidity, %), Td (daily dew point temperature, °C), Ws (wind speed at 2 meters high, m s -1 ), K↓ (incident global radiation, MJ m -2 day -1 ), K0↓ (solar radiation in the absence of the atmosphere, MJ m -2 day -1 ), Q * (R n ) (radiation balance, MJ m -2 day -1 ), es (saturation vapor pressure, hPa), e (partial pressure water vapor, hPa), and es-e (partial pressure saturation deficit, hPa).RH max , RH min , RH med , and Ws parameters expressed a negative linear correlation for the distinct models, showing the minimal influence for ETo determination. The least results were observed for the Linacre (RH med , -0.8866, RH min , -0.8507, and RH max , -0.7034) models.Research conducted in Paraná, which has similar conditions to the application site of this study, established that the Hargreaves & Samani model presented the most satisfactory performance in estimating ETo for the different physiographic regions of the state(GURSKI et al, 2018).Moreover, the Hargreaves & Samani and Camargo methods were the most accurate for Cfa and Cfb climatic conditions. Furthermore, the model provides more accurate readings in warmer regions, where average temperatures have significant values(FERNANDES et al, 2018).…”

Assessment of surface water resource and allocation optimization for diverse demands in Ethiopia's upper Bilate Watershed

“…Making sure that the data are adequate, whole, accurate, homogenous, and devoid of missing values is crucial. Because they induce bias in the results, errors brought on by improper data processing are serious [ [62] , [63] , [64] , [65] , [66] ]. Extreme values that greatly depart from the median range in a given data collection are known as outliers.…”

Determinação da demanda hídrica através do uso de tanques evaporímetros

“…O desenvolvimento de pesquisas de inovação tecnológica destinada à novos projetos na área da irrigação, é de suma importância visto dada a maior vulnerabilidade ao clima nos últimos anos, principalmente à irregularidade de distribuição das chuvas (Gurski et al, 2018). Desse modo, estudos que avaliam a precisão e a eficácia de métodos alternativos da aferição da evapotranspiração e/ou auxiliam o manejo da irrigação, podem proporcionar aos produtores a adotarem critérios técnicos e coesos no manejo da irrigação (Araújo et al, 2019;Peixoto et al, 2016).…”