Sensitivity of the reference evapotranspiration to key climatic variables during the growing season in the Ejina oasis northwest China

Abstract

The standardized FAO56 Penman-Monteith model, which has been the most reasonable method in both humid and arid climatic conditions, provides reference evapotranspiration (ETo) estimates for planning and efficient use of agricultural water resources. And sensitivity analysis is important in understanding the relative importance of climatic variables to the variation of reference evapotranspiration. In this study, a non-dimensional relative sensitivity coefficient was employed to predict responses of ETo to perturbations of four climatic variables in the Ejina oasis northwest China. A 20-year historical dataset of daily air temperature, wind speed, relative humidity and daily sunshine duration in the Ejina oasis was used in the analysis. Results have shown that daily sensitivity coefficients exhibited large fluctuations during the growing season, and shortwave radiation was the most sensitive variable in general for the Ejina oasis, followed by air temperature, wind speed and relative humidity. According to this study, the response of ETo can be preferably predicted under perturbation of air temperature, wind speed, relative humidity and shortwave radiation by their sensitivity coefficients.

Evaluation of the Penman-Monteith (FAO 56 PM) Method for Calculating Reference Evapotranspiration Using Limited Data

“…This data demand is the main constraint on its use in locations where climate data are limited (Stö ckle et al 2004; Trajkovic and Kolakovic 2009a;Li et al 2012;Rahimikhoob et al 2012). This is a common problem in developing countries (Droogers and Allen 2002; Exner-Kittridge and Rains 2010; Gocic and Trajkovic 2010;Tabari 2010;Hou et al 2013) and especially for tropical regions (Wohl et al 2012) and high-altitude areas (Kollas et al 2014), as highlighted in Figure 1.…”

The Variability of ASCE Standardized Reference Evapotranspiration: A Rigorous, CONUS-Wide Decomposition and Attribution

“…The Southwest/Southeast pattern generally mimics the distinction between water-and energy-limited hydroclimates across CONUS, an observation also supported by work at an oasis in western China (Hou et al, 2013). In the water-limited region of the Southwest, the strong linkage between the variabilities of U and ET r may result from variations in the availability of water that dominate changes in ET that in turn result in complementary variations in ET r through advective feedbacks at the land surface-atmosphere interface.…”

“…For example, Saxton (1975) examined Penman-like equations at a daily timescale in western Iowa; Piper (1989) estimated the sensitivity of two monthly Penman-based formulations (Penman, 1963;Doorenbos and Pruitt, 1984) to input errors and parameter uncertainty at low-elevation stations, mostly in the tropics; Hupet and Vanclooster (2001) estimated errors in the FAO-56 equation due to sampling frequency in humid Belgium; Goyal et al (2004) studied weekly driven PM estimates in an arid region in India; and Hou et al (2013) examined the sensitivity of daily FAO-56 estimates in a desert oasis in western China. Perhaps the closest study to this study is that of Irmak et al (2006), who conducted a sensitivity analysis of the daily ASCE05 equation at seven stations across a wide range of hydroclimates and elevations in CONUS.…”

Predicting Biogasification Potential of Urban Wastewater Using Multiparameter Aggregated Index of Influent

“…The trend pattern in the graph shown in Figure is according to pre‐monsoon–monsoon–post‐monsoon seasons . In case of pre‐monsoon, organic loading is comparatively more than that of in Monsoon.…”

“…In this case, the rainfall started from the month of July and continued till November, accordingly readings were noted and interpreted. The trend pattern in the graph shown in Figure 2 is according to pre-monsoon-monsoon-post-monsoon seasons [59][60][61]. In case of pre-monsoon, organic loading is comparatively more than that of in Monsoon.…”