Potential evapotranspiration change and its attribution in the Qinling Mountains and surrounding area, China, during 1960–2012

Abstract

Based on the observational data of 47 meteorological stations in the northern and southern regions of the Qinling Mountains (NSQ) during 1960–2012, this paper estimated the potential evapotranspiration (ET0) by using the Penman–Monteith method. Further, a quantitative study was conducted of the ET0 spatial distribution pattern, temporal variation rules, influencing factors and attributions. The conclusions were as follows. (1) The spatial distribution of annual ET0 in NSQ decreased from northeast to southwest. The seasonal distribution was summer > spring > autumn > winter. (2) Further, 1979 and 1993 were the turning points of the ET0 trend, at which the value began to decrease or increase over the whole region and sub-regions. At the seasonal scale, in the period of 1960–1979, ET0 in spring, summer, and winter presented a decreasing trend; however, it increased slightly in autumn. During 1980–1993, ET0 in most seasons showed a downward trend except for autumn; in the period of 1994–2012, ET0 declined in summer and autumn, however it increased slightly in spring and winter. (3) The diurnal temperature range during 1960–1979 contributed most to ET0. The decrease of wind speed and solar radiation were the main cause of the ET0 decrease during 1980–2012, which offset the effect of the increase in temperature.

Effect of ecological restoration and climate change on ecosystems: a case study in the Three-Rivers Headwater Region, China

“…The Food and Agriculture Organization (FAO) Penman-Monteith method is the most reliable and universally accepted method to estimate ET 0 for different climatic conditions (calculations described by Jiang et al (2016b)). The humidity index is defined as the ratio of rainfall to ET 0 , which is a comprehensive indicator to reflect climate conditions.…”

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“…The potential evapotranspiration (ET 0 ) was calculated based on the FAO (Food and Agriculture Organization of the United Nations) Penman-Monteith equation (Allen et al, 1998;Jiang et al, 2016d), and several parameters are calibrated using the observed data for each station. The details of FAO Penman-Monteith equation refer to Allen et al (1998).…”

Temporal changes of streamflow and its causes in the Liao River Basin over the period of 1953–2011, northeastern China

“…(15)) (Allen et al, 1998;Jiang et al, 2016cJiang et al, , 2016d to estimate daily E 0 (mm d −1 ). Several parameters have to be calibrated using the observational data for each station in the different regions before the estimation of the net radiation.…”