scholarly journals Assessment of spatiotemporal variability and trend analysis of reference crop evapotranspiration for the southern region of Peninsular India

2021 ◽  
Author(s):  
Jayashree Tenkila Ramachandra ◽  
Subba Reddy Nandanavana Veerappa ◽  
Dinesh Acharya Udupi
Keyword(s):  
Trend Analysis ◽  
Southern Region ◽  
Spatiotemporal Variability ◽  
Crop Evapotranspiration ◽  
Peninsular India ◽  
Reference Crop Evapotranspiration ◽  
Reference Crop

scholarly journals Terrain Segmentation of Greece Using the Spatial and Seasonal Variation of Reference Crop Evapotranspiration

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Vassilis Aschonitis ◽  
George Miliaresis ◽  
Kleoniki Demertzi ◽  
Dimitris Papamichail
Keyword(s):  
Principal Components ◽  
Cross Correlation ◽  
Linear Models ◽  
Spatiotemporal Variability ◽  
General Linear ◽  
Integrated Analysis ◽  
Crop Evapotranspiration ◽  
Reference Crop Evapotranspiration ◽  
General Linear Models ◽  
Reference Crop

The study presents a combination of techniques for integrated analysis of reference crop evapotranspiration (ETo) in GIS environment. The analysis is performed for Greece and includes the use of (a) ASCE-standardized Penman-Monteith method for the estimation of 50-year mean monthlyETo, (b) cross-correlation and principal components analysis for the analysis of the spatiotemporal variability ofETo, (c)K-means clustering for terrain segmentation to regions with similar temporal variability ofETo, and (d) general linear models for the description ofETobased on clusters attributes. Cross-correlation revealed a negative correlation ofETowith both elevation and latitude and a week positive correlation with longitude. The correlation betweenEToand elevation was maximized during the warm season, while the correlation with latitude was maximized during winter. The first two principal components accounted for the 97.9% of total variance of mean monthlyETo.K-means segmented Greece to 11 regions/clusters. The categorical factor of cluster number together with the parameters of elevation, latitude, and longitude described satisfactorily theETothrough general linear models verifying the robustness of the cluster analysis. This research effort can contribute to hydroclimatic studies and to environmental decision support in relation to water resources management in agriculture.

scholarly journals Impacts of Climatic Change on Reference Crop Evapotranspiration across Different Climatic Zones of Ningxia at Multi-Time Scales from 1957 to 2018

2020 ◽  
Vol 2020 ◽  
pp. 1-23
Author(s):  
Ziyang Zhao ◽  
Hongrui Wang ◽  
Cheng Wang ◽  
Wangcheng Li ◽  
Hao Chen ◽  
...  
Keyword(s):  
Water Management ◽  
Time Scales ◽  
Air Temperature ◽  
Climatic Factors ◽  
Crop Evapotranspiration ◽  
Climatic Zones ◽  
Reference Crop Evapotranspiration ◽  
Short Period ◽  
The Impact ◽  
Reference Crop

The impact of global climate change on agroecosystems is growing, affecting reference crop evapotranspiration (ET0) and subsequent agricultural water management. In this study, the climate factors temporal trends, the spatiotemporal variation, and the climate driving factors of ET0 at different time scales were evaluated across the Northern Yellow River Irrigation Area (NYR), Central Arid Zone (CAZ), and Southern Mountain Area (SMA) of Ningxia based on 20 climatic stations’ daily data from 1957 to 2018. The results showed that the Tmean (daily mean air temperature), Tmax (daily maximum air temperature), and Tmin (daily minimum air temperature) all had increased significantly over the past 62 years, whilst RH (relative humidity), U2 (wind speed at 2 m height), and SD (sunshine duration) had significantly decreasing trends across all climatic zones. At monthly scale, the ET0 was mainly concentrated from April to September. And at annual and seasonal scales, the overall increasing trends were more pronounced in NX, NYR, and SMA, while CAZ was the opposite. For the spatial distribution, ET0 presented a trend of rising first and then falling at all time scales. The abrupt change point for climatic factors and ET0 series was obtained at approximately 1990 across all climatic zones, and the ET0 had a long period of 25a and a short period of 10a at annual scale, while it was 15a and 5a at seasonal scale. RH and Tmax were the most sensitive climatic factors at the annual and seasonal scales, while the largest contribution rates were Tmax and SD. This study not only is important for the understanding of ET0 changes but also provides the preliminary and elementary reference for agriculture water management in Ningxia.

Study on Regional Analysis of Reference Crop Evapotranspiration Based on SPSS

2015 ◽  
Vol 733 ◽  
pp. 415-418
Author(s):  
Li Ying Cao ◽  
He Long Yu ◽  
Gui Fen Chen ◽  
Peng Sun
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Linear Correlation ◽  
Meteorological Data ◽  
Linear Regression Analysis ◽  
Regional Analysis ◽  
Crop Evapotranspiration ◽  
Reference Crop Evapotranspiration ◽  
Reference Crop ◽  
Monteith Equation

Based on the meteorological data collected from 3 stations in recent 10 years in Fushun region, the reference crop evapotranspiration was calculated with the Penman-Monteith equation recommended by FAO in 1990. The evapotranspiration of the region was analyzed using linear regression analysis based on software of SPSS. The results showed that the linear correlation was evident between the evapotranspiration data of stations, but it is not significant for the linear correlation between the stations, neither between the stations. The result will be helpful to analysis of the space distributions of the reference crop evapotranspiration in the region.

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