Publication Date:
2015-05-16
Description:
Evapotranspiration is an important component of the hydrological cycle, which integrates atmospheric demands and surface conditions. Research on spatial and temporal variations of reference evapotranspiration (ET o ) enable understanding of climate change and its effects on hydrological processes and water resources. In this study, ET o was estimated by the FAO-56 Penman–Monteith method in the Jing River Basin in China, based on daily data from 37 meteorological stations from 1960 to 2005. ET o trends were detected by the Mann–Kendall test in annual, seasonal and monthly timescales. Sensitivity coefficients were used to examine the contribution of important meteorological variables to ET o . The influence of agricultural activities, especially irrigation on ET o was also analyzed. We found that ET o showed a decreasing trend in most of the basin in all seasons, except for autumn, which showed an increasing trend. Mean maximum temperature was generally the most sensitive parameter for ET o , followed by relative humidity, solar radiation, mean minimum temperature, and wind speed. Wind speed was the most dominant factor for the declining trend in ET o . The more significant decrease in ET o for agricultural and irrigation stations was mainly due to the more significant decrease in wind speed and sunshine hours, a mitigation in climate warming, and more significant increase in relative humidity compared with natural stations and non-irrigation stations. Changes in ET o and the sensitivity coefficient of meteorological variables in relation to ET o were also affected by topography. Better understanding of ET o response to climate change will enable efficient use of agricultural production and water resources, which could improve the ecological environment in Jing River Basin. This article is protected by copyright. All rights reserved.
Print ISSN:
0885-6087
Electronic ISSN:
1099-1085
Topics:
Architecture, Civil Engineering, Surveying
,
Geography
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