scholarly journals Regionalization of Precipitation Regimes in Iran Using Principal Component Analysis and Hierarchical Clustering Analysis

2014 ◽  
Vol 1 (4) ◽  
pp. 517-532 ◽  
Author(s):  
Mohammad Darand ◽  
Mohammad Reza Mansouri Daneshvar
Keyword(s):  
Principal Component Analysis ◽  
Hierarchical Clustering ◽  
Clustering Analysis ◽  
Principal Component ◽  
Component Analysis ◽  
Hierarchical Clustering Analysis ◽  
Precipitation Regimes

Improving Hierarchical Clustering of Genotypic Data via Principal Component Analysis

Crop Science ◽  
2013 ◽  
Vol 53 (4) ◽  
pp. 1546-1554 ◽  
Author(s):  
T. L. Odong ◽  
J. van Heerwaarden ◽  
T. J. L. van Hintum ◽  
F. A. van Eeuwijk ◽  
J. Jansen
Keyword(s):  
Principal Component Analysis ◽  
Hierarchical Clustering ◽  
Principal Component ◽  
Component Analysis

scholarly journals Spatial and temporal variability of precipitation and drought in Portugal

2012 ◽  
Vol 12 (5) ◽  
pp. 1493-1501 ◽  
Author(s):  
D. S. Martins ◽  
T. Raziei ◽  
A. A. Paulo ◽  
L. S. Pereira
Keyword(s):  
Principal Component Analysis ◽  
Standardized Precipitation Index ◽  
Principal Component ◽  
Component Analysis ◽  
Maximum Temperature ◽  
Drought Indices ◽  
Drought Severity ◽  
Spatial And Temporal Variability ◽  
Monthly Precipitation ◽  
Precipitation Regimes

Abstract. The spatial variability of precipitation and drought are investigated for Portugal using monthly precipitation from 74 stations and minimum and maximum temperature from 27 stations, covering the common period of 1941–2006. Seasonal precipitation and the corresponding percentages in the year, as well as the precipitation concentration index (PCI), was computed for all 74 stations and then used as an input matrix for an R-mode principal component analysis to identify the precipitation patterns. The standardized precipitation index at 3 and 12 month time scales were computed for all stations, whereas the Palmer Drought Severity Index (PDSI) and the modified PDSI for Mediterranean conditions (MedPDSI) were computed for the stations with temperature data. The spatial patterns of drought over Portugal were identified by applying the S-mode principal component analysis coupled with varimax rotation to the drought indices matrices. The result revealed two distinct sub-regions in the country relative to both precipitation regimes and drought variability. The analysis of time variability of the PC scores of all drought indices allowed verifying that there is no linear trend indicating drought aggravation or decrease. In addition, the analysis shows that results for SPI-3, SPI-12, PDSI and MedPDSI are coherent among them.

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