文章基本信息

标题：The Spatial Sensitivity Analysis of Evapotranspiration using Penman-Monteith Method at Grid Scale
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作者：Sivarajah Mylevaganam ; Chittaranjan Ray
期刊名称：Journal of Geographic Information System
印刷版ISSN：2151-1950
电子版ISSN：2151-1969
出版年度：2016
卷号：08
期号：01
页码：121-136
DOI：10.4236/jgis.2016.81012
语种：English
出版社：Scientific Research Publishing
摘要：The need to allocate the existing water in a sustainable manner, even with the projected population growth, has made to assess the consumptive use or evapotranspiration (ET), which determines the irrigation demand. As underscored in the literature, Penman-Monteith method which is a combination of aerodynamic and energy balance method is widely used and accepted as the method of estimation of ET. However, the application of Penman-Monteith relies on many climate parameters such as relative humidity, solar radiation, temperature, and wind speed. Therefore, there exists a need to determine the parameters that are most sensitive and correlated with dependent variable (i.e., ET), to strengthen the knowledge base. However, the sensitivity of ET using Penman-Monteith is oftentimes estimated using meteorological data from climate stations. Such estimation of sensitivity may vary spatially and thus there exists a need to estimate sensitivity of ET spatially. Thus, in this paper, based on One-AT-A-Time (OAT) method, a spatial sensitivity tool that can geographically encompass all the best available climate datasets to produce ET and its sensitivity at different spatial scales is developed. The spatial tool is developed as a Python toolbox in ArcGIS using Python, an open source programming language, and the ArcPy site-package of ArcGIS. The developed spatial tool is demonstrated using the meteorological data from Automated Weather Data Network in Nebraska in 2010. To summarize the outcome of the sensitivity analysis using OAT method, sensitivity indices are developed for each raster cell. The demonstration of the tool shows that, among the considered parameters, the computed ET using Penman-Monteith is highly sensitive to solar radiation followed by temperature for the state of Nebraska, as depicted by the sensitivity index. The computed sensitivity index of wind speed and the relative humidity are not that significant compared to the sensitivity index of solar radiation and temperature.
关键词：Evapotranspiration;Penman-Monteith Method;Aerodynamic Method;Energy Balance Method;Python;ArcPy;ArcGIS;Spatial Scale;Geoprocessing;Python Toolbox;Sensitivity Analysis;One-AT-A-Time;Sensitivity Index